Membrane Trafficking of Integral Cell Junction Proteins and its Functional Consequences
MMembrane Trafficking of Integral Cell Junction Proteins ∗ Arie Horowitz † Faculty of Medicine, Normandy University, France
Though membrane trafficking of cell junction proteins has been studied extensively for more than two decades, theaccumulated knowledge remains fragmentary. The goal of this review is to synthesize studies published mostly in thelast 25 years on the membrane trafficking of the five major junction transmembrane proteins: claudins, occludin, andjunction adhesion molecules (JAMs) in tight junctions; cadherins and nectins in adherens junctions, to comprehendthe current state of the art, to highlight differences and similarities among the trafficking pathways, and to identifytopics that are not fully understood. Clathrin-mediated endocytosis appears to be the main, but not exclusive mode,of internalization. Caveolin-mediated endocytosis and macropinocytosis are employed less frequently. PDZ-domainbinding is the predominant mode of interaction between junction protein cytoplasmic tails and scaffold proteins. It isshared by claudins, the largest family of junction integral proteins, by junction adhesion molecules A, B, and C, andby the three nectins. All eight proteins are destined to either recycling via Rab4/Rab11 GTPases or to degradation.The sorting mechanisms that underlie the specificity of their endocytic pathways and determine their fates are notfully known. New data is presented to introduce an emerging role of junction-associated scaffold proteins in claudinmembrane trafficking.
1. INTRODUCTION Despite being no more than a single-cell thick, the en-dothelial and epithelial cell layers that form the lumi-nal surface of blood and lymph vessels and of numeroustubular organs (e.g., the tracheal, digestive, and uretericsystems), respectively, are the only barriers that pre-vent breaching of the walls of each system and, con-comitantly, its dysfunction. The cytoplasmic faces ofadherens [287] and tight [296] junctions that maintainmonolayer integrity harbor protein complexes which pro-vide structural support and continuity from the junctiontransmembrane proteins to the cytoskeleton. These intri-cate molecular assemblies recycle constantly even in qui-escent cells [57, 64, 232] and undergo extensive remod-eling in response to agonists such as vascular endothe-lial growth factor (VEGF), transforming growth factor(TGF)- β , sphingosine-1-phosphate (S1P), and platelet-derived growth factor (PDGF) [74, 76, 129, 175]. Themolecular mechanisms that determine their membranetrafficking from and to the cell junctions are not fullyknown.Survey of studies reported mostly during the last twodecades reveal that despite the attention given to thesubject of intercellular junction remodeling, the graspof this process is fragmentary. Conceptual progress oncell junction dynamics is hampered by their structuraland functional complexities. While there are only twoor three species of junction transmembrane proteins inadherens [160] and in tight junctions [296], respectively,some of them consist of protein families of multiple mem-bers. Moreover, they bind cytoplasmic protein complexesof varying compositions and sizes that mediate numer-ous signaling pathways and which interface with the cy- ∗ Has not been submitted for publication † Correspondence: Faculty of Medicine, 22 Boulevard Gambetta,76183 Rouen Cedex, Normandy, France; [email protected] Nomenclature: names of the proteins mentioned in the reviewfollow current nomenclature rather than names used in the reviewedstudies to increase clarity and uniformity (e.g., catenin p120 isnamed δ -catenin). toskeleton. A further layer of complexity is conferred bythe diversity of membrane trafficking routes and endo-somes encountered by different junction transmembraneproteins.Much of the data on cell junction dynamics reportedto date was derived from epithelial cells and the organsthey populate. Though it cannot be assumed by defaultthat all the molecular mechanisms that control cell junc-tion dynamics in epithelial cells are identical to the anal-ogous mechanisms in endothelial cells (ECs), their ob-served similarities suggest that they are shared to a largeextent. In a few cases, the review considers data obtainedfrom fibroblasts used to express epithelial or EC junctionproteins free of the confounding effects of the endogenousproteins. The review does not address desmosomes, whichform in epithelial cells but not in ECs, or gap junctions,which have been studied primarily as electrophysiologicalinterfaces.Intercellular junction proteins redistribute from theplasma membrane (PM) to the cytoplasm constitutivelyor in response to agonists such as VEGF in ECs [76],or epithelial growth factor (EGF) in epithelial cells [25].Once internalized, they have one of two possible fates:recycling back to the PM [167, 196], or proteolysis inlysosomes or proteosomes [45, 278]. Membrane traffickingof the integral cell junction proteins confers the plastic-ity that cell junctions require to remodel in response tophysiological and pathological stimuli.For reasons that are related in part to the multiplefunctions of the catenins that bind their cytoplasmic do-mains [157], the membrane trafficking of cadherins is bet-ter known than that of all other intercellular junctiontransmembrane proteins, whereas that of nectins, the sec-ond adherens junction transmembrane protein species, isknown the least.The objective of this review is not to cover exhaustivelyall studies that have a bearing on membrane traffickingof junction proteins, but, to the extent possible, extractpatterns and derive organizational principles. Because ofthe volume of the data and to maintain focus, the review1 a r X i v : . [ q - b i o . S C ] F e b ddresses only the five major integral proteins of tightand adherens cell junctions, i.e., claudins, occludin, andJAMs, and cadherins and nectins, respectively. The cellsystems, agonists, and experimental methods are speci-fied in order to facilitate evaluation of the relevance andvalidity of the conclusions of the reviewed studies.The accompanying schemes in figures 1-5 represent syn-theses of the reviewed studies on each of the five tight andadherens junction transmembrane proteins. They are in-tended to provide an ‘at a glance’ overall view of thesepathways while maintaining the connection with the textby associating each component with one or more rele-vant studies. Figure 6 presents new data which indicatesthat the large junction-associated scaffold protein multi-ple PDZ domain protein (MPDZ) is involved in claudinmembrane trafficking.
2. CLAUDINS
Encoded by 27 known human genes, claudins are thesecond largest family of intercellular junction transmem-brane proteins [86, 139] after the cadherins. Claudins area major tight junction structural component. Their vari-ety may reflect tissue-specific expression of their genes,and/or differences in the extent of sealing they conferon tight junctions. Claudins are 210-305 amino-acid-longtetraspan proteins with cytoplasmic amino- and carboy-termini (Fig. 1). The majority of claudins harbor a post-synaptic density-95/Discs large/Zonula occludens (PDZ)-binding motif at their carboxy termini [86], implying thattheir recruitment to tight junctions or to trafficking path-ways is mediated by proteins that harbor PDZ domains.Whereas most members of the claudin family genes are ex-pressed in epithelial cells, their subsets vary among hostorgans. A smaller number of claudin genes are expressedin ECs. In mouse brain capillaries, the expression levels ofCldn5 and Cldn11 are predominant, but multiple sourcesindicate that Cldn1, 3, 10, 12 and 20 are also expressedat significant levels in these cells [188]. Claudins seal thetight junctions by forming elongated peripheral strandson the cell’s surface [72, 168]. In endothelial [239, 280], orepithelial [145, 231] cells, claudin removal by endocytosisfrom the tight junctions invariably increased monolayerpermeability. Claudin strands on abutting cells can formheterophilic interactions, though only a small number ofcombinations had been reported [73]. Claudin-1, a pro-totypical member of the family, underwent constitutiverecycling in several epithelial cell types [57] . Furtherobservations recounted bellow suggested this behavior isshared by numerous claudins in epithelial and endothelialcells.
The predominant endocytic pathway of the claudins isclathrin-mediated. Calcium depletion of human colon car-cinoma epithelial cells resulted in claudin-1 and claudin-4collocation with the clathrin heavy chain and with theclathrin adaptor protein α -adaptin (AP2A1) [22, 110].Their removal from the cell junctions was blocked bycytosolic acidification, sucrose-induced hypertonic stress,and phenylarsine oxide, all of which block clathrin-mediated endocytosis [94, 170, 219]. The endocytosed claudins were recruited to early endosomes [144]. Becauseclaudins 1 and 4 collocated in that compartment withsyntaxin-4, a t -SNARE that mediates docking of trans-port vesicles to the PM [16], it appears they were readiedfor reincorporation in the PM once intercellular junctionswere restored [110]. In contrast to the effect of hypertonicstress, the induction of hypotonic stress by halving the os-molarity of the medium induced endocytosis of claudin-1and -2 in Madin-Darby canine kidney (MDCK) cells. Itsblockage by pharmacological inhibition of dynamin, a GT-Pase required for the scission of clathrin-coated vesicles[42], or of clathrin polymerization, indicated that claudin-1 and -2 underwent clathrin-mediated endocytosis [67].The homologous carboxy-terminus PDZ-binding mo-tif shared by 20 members of the claudin family under-lies the similarity of their membrane trafficking path-ways. A missense mutation that replaced threonine inthe -2 position of the motif to an arginine (T233R) waslinked to familial hypomagnesaemia with hypercalciuriaand nephrocalcinosis (FHHNC) [172], an inherited kid-ney disorder. Unlike native claudin-16, the mutant didnot bind zona occludens (ZO)-1 when expressed in MDCKcells. When triggered to undergo constitutive endocyto-sis by temperature elevation from 4 ◦ C to 37 ◦ C, claudin-16appeared in lysosomes instead of intercellular junctions.Though junction recruitment appeared to require thePDZ-binding motif, endocytosis evidently occurred in itsabsence because a claudin-16 with a missense L203X mu-tation, which truncates most of its intercellular carboxy-terminus domain including the PDZ-binding motif, wasretained at the cell junctions when constitutive clathrin-mediated endocytosis was inhibited [119, 172]. However,the abundance of the L203X mutant at the cell junctionswas substantially lower than the wild-type (WT) variantand, unlike the latter, was present throughout the cyto-plasm (ibid.).Clathrin-mediated endocytosis of claudins was inducedby several physiological and pharmacological agonists.EGF induced claudin-2 binding to the clathrin heavychain and α -adaptin in MDCK epithelial cells [105]. Theendocytosed claudin-2 traversed early endosomes andcollocated with lysosome-associated membrane protein(LAMP)-1 [33], but not with the Golgi apparatus, sug-gesting it was destined to lysosomal degradation ratherthan recycling. Cevimeline, a specific agonist of the M1and M3 muscarinic acetylcholine (Ach) receptors [9], aswell as carbachol, a non-selective Ach receptor agonistanalog, induced claudin-4 binding to clathrin and to theendocytic sorting protein arrestin- β β β trans -binding2 DZ-binding motifClaudinsInteracting proteinKinaseAgonist ClathrinReferene numberCaveolin junctions T191S195S208K199 S217
Ub-CLDN5syntaxin-8 early endosome endocytosis arrestin- β endocytosisLysjunctionsPKA CLDN16
LNX1
LNX2PDZRN3
CLDN5CLDN16CLDN2 p38MAPK1/3
CLDN4CLDN1 ? CLDN2syntaxin-4 RE cPLA2 α CHMP3
PIKfyve LAMP2
24 25
Lys
LAMP1 RAB7
RAB4 TGNGolgi
MICALL2 RAB13
17 26 EE RAB11 CLDN3,4,5 transcytosis
CLDN1,2,4,5,16EGFACh TGF β CLDN1,4,5,11,16,19 ER RAB11 LIMP2
10 4 5 69 16 201210 116 LE CLDN16CLDN16CLDN1,2,3,4,5 CLDN1,5CLDN3
Nucleus arrestin- β α -adaptin CLDN5 CLDN1,4CLDN1,4
Figure 1: Claudin membrane trafficking pathways.
Relevant studies are amalgamated rand coupled to the illus-trated events by the circled numbers. Claudins were internalized via either clathrin caveolin or mediated endocytosis, or viamacropinocytosis. It was partially retrieved to the PM via Rab4, Rab11 and Rab13-mediated recycling or diverted to lysosomaldegradation. The claudin isoforms addressed in the reviewed studies are indicated. The inset presents phosphorylation sitesthat regulate claudin membrane trafficking, its carboxy-terminus PDZ-binding motif, and the ubiquitin ligases that bind it.EGF and CCL2-induced claudin endocytosis increased tight junction permeability (red arrows). The two adjoining plasmamembranes in this figure and in figures 2-5 represent two abutting cells. Dashed lines indicate speculative features. EE, earlyendosome; LE, late endosome; Lys, lysosome; RE, recycling endosome. Numbers correspond to the following references: (1)[40], (2) ([57], (3) [58], (4) [67], (5) [77], (6) [104], (7) [105], (8) [106], (9) [110], (10) [140], (11) [141], (12) [145], (13) [151], (14)[153], (15) [155], (16) [173], (17) [184], (18) [210], (19) [223], (20) [239], (21) [241], (22) [249], (23) [253], (24) [264], (25) [265],(26) [282], (27) [288]. claudins located on adjoining Caco-2 and human embry-onic kidney (HEK)-293 epithelial cells by peptidomimet-ics of the first extracellular loop of claudin-1 inducedclathrin-mediated endocytosis of endogenous claudin-1and -5 [239]. Because the endocytosis was a direct re-sult of the release of the mechanical coupling betweenclaudins rather than the downstream effect of specific ag-onists or cell culture conditions, this result is arguably themost generic indication that the default internalizationmechanism of claudins is clathrin-mediated endocytosis.Uniquely among all the junction transmembrane proteinsdiscussed in this review, claudin-3 redistributed from thetight junctions of primary human bronchial epithelial cellsto their nuclei in response to TGF β trans -binding [201], reduced transcytosis frequency. Remark-ably, transcytosis was inhibited by either chlorpromazine,an inhibitor of adaptor protein (AP)-2 complex bind-ing to clathrin [270], or by filipin, which interferes withcaveolae assembly by removal of cholesterol from the PM[225]. Paradoxically, the dynamin-specific pharmacologi-cal inhibitor dynasore [148] appeared to have no effect ontranscytosis, in conflict with the effective chlorpromazine-induced inhibition. Collocation with the microtubule-associated protein 1A/1B-light chain 3 (MAP1LC3B) andwith autophagy related protein 16L (ATG16L) indicatedthe transcytosed claudins were targeted to autophago-somes. Accumulation in the cytoplasm upon administra-tion of the lysosome inhibitor chloroquine [273] suggestedthat they were destined to lysosomal degradation, similarto the observation of Matsuda et al. [155].While there is abundant evidence for the dependenceof monolayer barrier function on claudin phosphorylation[8, 51, 52, 66, 281], the specific effect of phosphorylationon membrane trafficking is less documented. In quiescentMDCK cells, claudin-16 was phosphorylated constitu-tively [104] by cyclic adenosine monophosphate (cAMP)-dependent protein kinase (PK)-A, as the phosphoryla-tion was blocked by several PKA and adenylyl cyclaseinhibitors and restored by cAMP. Single site mutationsof potentially phosphorylatable serines pinpointed thePKA-phosphorylation to S217 in the claudin-16 carboxy-terminal cytoplasmic domain. Dephosphorylated claudin-16 did not associate with ZO1 and was located predom-inantly in the cytoplasm or in lysosomes. Claudin-16phosphorylated on S217 was recruited to the cell junc-tions and bound the soluble N-ethylmaleimide-sensitivefactor attachment protein receptor (SNARE) syntaxin-8[203], which mediates endocytosis of cell membrane pro-teins and fusion of endocytic vesicles to early endosomes[212]. The phosphorylation of claudins-3 and -5 was alsoattributed to PKA [51, 237]. S208 in the cytoplasmic do-main of claudin-2 was phosphorylated in quiescent MDCKcells maintained in serum-supplemented medium [264].A phosphomimetic S208E mutant was detected at thecell edges, suggesting that S208 phosphorylation inducedclaudin-2 recruitment to cell junctions. Concordantly, themajority of the S208A dephosphomimetic mutant popula-tion was in the cytoplasm and collocated with the lysoso-mal marker protein LAMP2 [33]. Mutations that reducedthe recruitment of claudin-2 to the cell junctions, such asthe removal of the carboxy-terminus PDZ-binding motif,were accompanied by a lower phosphorylation level, sug-gesting that the unidentified kinase that phosphorylatedS208 was located on the cytoplasmic leaflet of the PM.Binding of claudin-4 to arrestin- β β
2, which, in turn, recruited clathrin.Hence, the phosphorylation was required for the clathrin-mediated endocytosis of claudin-4. Hypotonic stress-induced phosphorylation and endocytosis of claudin-1 and-2 in MDCK cells [67] was attributed to MAPK p38(MAPK14) because it was blocked by SB202190, its spe-cific pharmacological inhibitor [62]. Based on previousstudies [2, 235, 264], the phosphorylated residues wereassumed to be T191 in claudin-1 and S208 in claudin-2.This premise was supported by the resistance of the phos-phomimetic claudin-1 and -2 mutants T191E and S208E,respectively, to their removal from the cell junctions byhypotonic stress. Conversely, the dephosphomimetic mu-tants T191A and S208A were segregated to the cytosoland collocated with the late endosome marker Rab7 andthe lysosomal marker LAMP1.Claudin-5 underwent caveolin/lipid raft-mediated en-docytosis in mouse brain primary ECs in response tothe monocyte chemoattractant [3] chemokine C-C ligand(CCL)-2 [241] based on the collocation of claudin-5 withcholera toxin, a marker of caveolin-mediated endocytosisand on the inhibition of claudin-5 endocytosis by choles-terol depletion. Collocation with either caveolin or a lipidraft marker was not shown.
The recruitment of claudins from the Golgi apparatusto intercellular junctions required the activity of cytosolicphospholipase A2 (cPLA2)- α , an arachidonic acid gen-erating enzyme involved in the formation of cytoplasmictubular membranes [224]. In subconfluent human um-bilical cord ECs (HUVECs) cPLA2 α and claudin-5 werelocated in separate cytoplasmic punctae [210]. There wasa reciprocal relationship between the cellular locations ofcPLA2 α and claudin-5: when the cells reached conflu-ence, inactive cPLA2 α was present in the Golgi apparatus[93], whereas claudin-5 was located at intercellular junc-tions. Depletion of cPLA2 α by knockdown of its gene, PLA2G4A , or by pyrrolidine-mediated pharmacologicalinhibition [227], was accompanied by removal of claudin-5 from the cell junctions and its accumulation in the Golgiapparatus, suggesting that cPLA2 α activity was requiredfor claudin-5 trafficking from the Golgi to the junctions.Rab13 plays a major role in the recruitment of tightjunction transmembrane proteins to cell junctions [154].The recycling of claudin-1 to the PM after recovery ofMDCK cells from calcium depletion was slowed downby siRNA-mediated knockdown of Rab13, or by expres-sion of the GTP hydrolysis-defective mutant Rab13Q67L[282]. The recycling required Rab13 binding to its effectormolecule interacting with CasL-like 2 (MICALL2) [253], afilamentous (f)-actin and α -actinin-4 binding protein thatdrives f-actin crosslinking during intercellular junction as-sembly [180, 217]. The trafficking pattern of Rab13 sug-gested that claudin-1 translocated from the trans-Golginetwork (TGN) to recycling endosomes, and from themto the PM [184].4laudins employ several trafficking pathways and mul-tiple Rab GTPases that are determined in part by theconditions the cells are subjected to. Claudin-5 endocy-tosed in mouse brain microvascular ECs in response toCCL2 [272], and collocated with Rab4 [241], a ‘fast’ traf-ficking GTPase [44]. It did not collocate with the lyso-somal marker LAMP2, indicating it was recycled to thePM rather than degraded. In agreement, the recyclinginhibitor bafilomycin-A1 [204] prevented the removal ofclaudin-5 from Rab4-containing vesicles. Claudin-16 re-cycling in quiescent MDCK cells was regulated by Rab11[106], a ‘slow’ recycling GTPase [259]. Inhibition of Rab11activity by either a dominant-negative Rab11S25N mu-tant, or by primaquine, a pharmacological inhibitor ofvesicle trafficking [238] decreased claudin-16 presence atthe cell junctions in favor of collocation with the early en-dosome antigen (EEA) 1 and the lysosome marker lyso-some membrane protein (LIMP)-2 [14]. The recycling ofclaudin-2 from the cytoplasm to the junctions of MDCKcells switched from incubation on ice to 37 ◦ C required theactivity or Rab14 [145], a GTPase involved in traffickingfrom the TGN to early endosome [205]. Knockdown ofRab14 by short hairpin (sh) RNA resulted in claudin-2targeting to lysosomes. Rab7, a late endosome marker[236], mediated the trafficking of transcytosed claudin-3and -4 to the lysosome in MDCK cells [155].Similar to around a third of all translated proteins ineukaryotic cells [43], the translocation of claudin-1 fromthe endoplasmic reticulum (ER) to the Golgi apparatusoccurs via membrane trafficking in coat protein complex(COP)-2 vesicles. The binding of claudin-1 to the Sec24Csubunit of COP2 [240] was shared by claudins 4, 5, 11,16, and 19 [288], all of which have a tyrosine and valineat their carboxy-termini that functions as an ER exportsignal. These residues were required but not sufficientfor Sec24c binding, which probably involves the wholeclaudin cytoplasmic domain. Expectedly, knockdown ofSec24c reduced the abundance of claudin-1 at the cell sur-face.The endosomal sorting complex required for trans-port (ESCRT), a multi-protein assemblage that mediatesmembrane budding and scission in several cellular con-texts [266] and the sorting of ubiquitinated cargo [117]was required for the constitutive recycling of claudin-1in quiescent confluent MDCK cells [57]. Expression oftruncated CHMP3, an ESCRT3 component (Raiborg andStenmark, 2009), blocked membrane budding [56], result-ing in the mutant’s accumulation in abnormally large vac-uolar structures that contained both early and late endo-somal markers. Dominant- negative CHMP3 collocatedwith claudin-1 and -2 and with ubiquitin. Because surfacebiotinylation indicated a reduction of cell surface claudin-1, it was concluded that dominant-negative CHMP3 im-paired claudin-1 recycling. However, the ESCRT complexis thought to mediate primarily the budding of multivesic-ular body (MVB) intraluminal vesicules [117], the mainsource of lysosome-targeted cargo, rather than recyclingtubules. Since the cell-surface biotin fraction was not sep-arated from the rest of the cell lysate, it is conceivablethat the abundance of recycled claudin-1 was overesti- mated. The interaction of CHMP3 with phosphatidyli-nositol (3,5) phosphate (PtdIns(3,5)P2), an endomem-brane phospholipid, is essential for MVB genesis [275].PtdIns(3,5)P2) and its precursor, PtdIns 5-P, are synthe-sized by phosphatidylinositol 3-phosphate 5-kinase (PIK-fyve) [221]. Concordantly, perturbation of PIKfyve activ-ity by the pharmacological inhibitor YM201636 demon-strated that constitutive recycling of claudin-1 in MDCKcells depends on PIKfyve [58], similar to its dependence onESCRT [114]. Approximately 35 percent of total cell sur-face claudin-1 was endocytosed and recycled in its major-ity back to the PM in untreated MDCK cells. In contrast,administration of YM201636 resulted in the accumula-tion of all the claudin-1 population in large cytoplasmicclusters. Whereas claudin-2 responded to YM201636 likeclaudin-1, the trafficking of claudin-4 was unaffected, sug-gesting that its rate of endocytosis is significantly lowerthan those of claudin-1 and -2. The inhibition of claudin-1 and -2 endocytosis prevented restoration of the bar-rier function of MDCK cell monolayers [58]. Collectively,these results indicate that endocytic trafficking pathwaysdiffer not only among tight junction protein species butalso within the claudin family.Though most of the data on claudin membrane traf-ficking addressed individual claudin species, their dynam-ics are interdependent. This is not surprising given thelarge number of claudin species and the abundance ofseveral species in the same cell. Claudin-4 trafficking inquiescent HEK-293 cells depended on claudin-8, but notvice-versa [98]. Normally the two claudins traveled to-gether in endocytic vesicles and bound the scaffold pro-tein multi (M)PDZ [113, 130]. However, when claudin-8was knocked down by siRNA, claudin-4 was sequesteredto the ER and the Golgi apparatus. The intracellulardynamics and cell junction recruitment of claudins-2 and-4 in and MDCK cells differed from each other [265]. Inconfluent cells, both claudins were located mainly at thecell junctions and to a lesser extent in cytoplasmic vesi-cles. Both newly synthesized claudins originated in theGolgi apparatus, but claudin-4 preceded claudin-2 at thecell junctions. Conjugation of fluorophores that emittedat either 549 or 505 nm to ‘old’ or to newly synthesizedclaudins, respectively, revealed that ‘old’ claudins were re-moved from the cell junctions to endocytic vesicles. Partof these vesicles were destined to lysosomal digestion,as they collocated with LAMP2. Surprisingly, removalof the carboxy-terminus PDZ-binding motif of claudin-4,which is required for binding to the PDZ domains of ZO1and ZO2 [109], slowed the rate but not the steady-stateabundance of claudin-2 at the cell junctions. Apparently,the PDZ-binding motif facilitates but is not categoricallyrequired for claudin recruitment to cell junctions. Thetruncated claudin-4 half-life was longer than that of WTclaudin-4, likely because it was unable to bind the E3uniquitin ligase ligand of numb-protein X (LNX)1. Theremoval of the PDZ-binding motif of claudin-2 probablydid not abolish its binding to ZO1 or ZO2 because, un-like claudin-1 and 4, it harbors a tyrosine at position -6that is required for the formation of a second ZO bindingsite [185]. This tyrosine, which is present in other eight5laudins, may account for the overabundance of claudin-2over claudins 1, 3, 4, and 7 at the cell junctions of MDCKcells [265].
Endocytosed claudins, either constitutively or in re-sponse to external stimuli, undergo either lysosomal di-gestion or proteosomal degradation. Claudin-1 and -2 en-docytosed in MDCK cells subjected to hypotonic stressand treated by the lysosome inhibitor chloroquine accu-mulated in LAMP1-associated endosomes [67]. The in-hibition of this accumulation by SB202190 indicated itdepended on p38-dependent trafficking, though the spe-cific role of p38 in this process was not reported. Depri-vation of oxygen and glucose from-immortalized bEND3mouse brain ECs, was followed by claudin-5 lysosomaldegradation rather than recycling [140, 141]. In quiescentHenrietta Lax (HeLa) cervical carcinoma cells, claudin-5 was polyubiquitinated on K199, K214, and K215 inthe carboxy-terminus cytoplasmic domain, though ubiq-uitination of K199 was sufficient for proteolysis of morethan half of the cellular claudin-5 population [151]. Sev-eral claudins were ubiquitinated by LNX1, a proteinthat harbors 4 PDZ domains. The first PDZ domain ofLNX1 bound the claudin-1 PDZ-binding motif in quies-cent MDCK cells [249]. Overexpression of EGFP-fusedLNX1 resulted in the removal of claudins 1, 2, and 4from the cell junctions. EGFP-LNX1collocated in partat the cell junctions with ZO1, occludin, and E-cadherin,whereas it collocated with claudin-2 in the cytoplasm, in-cluding in late endosomes and lysosomes. Apparently,LNX1 ubiquitinated only claudins at the cell junctions.Since ubiquitination serves as both an endocytic signaland for targeting to the interior of MVBs [171], LNX1 mayhave designated cell junction claudins for removal fromthe cell junctions by endocytosis, followed by lysosomaldigestion. LNX2, which has the same domain structureas LNX1 and is close to fifty percent identical, bound thecarboxy-terminus of claudin-1 [288] and was likely, there-fore, to have functioned as its E3 ubiquitin ligase. Ratherthan LNX1 or 2, claudin-16 was ubiquitinated by the twoPDZ domain-containing RING finger protein (PDZRN)-3[153]. Similar to LNX1, PDZRN3 bound claudin-16 viaits PDZ-binding motif, induced its endocytosis from thecell junctions, and designated it to lysosomal digestion, asindicated by its collocation with the late endosome markerRab7.
3. OCCLUDIN
Occludin is encoded by a single gene in humans. Itis grouped into a 3-member proteins family named tightjunction–associated MARVEL protein (TAMP), based onsharing a 130-residue MAL and related proteins for vesi-cle trafficking and membrane link (MARVEL) domain[208]. The MARVEL region spans the four transmem-brane domains, corresponding to residues 60-269 of hu-man occludin. Similar to claudins, occludin is a tetraspanprotein, but its size is substantially larger (522 aminoacids,), primarily due to a longer carboxy-terminus do-main that consists of 257 amino acids in humans (Fig. 2).Its cytoplasmic domain binds the Src homology 3 (SH3) and the guanylate kinase (GuK) domains of ZO1 via itscoiled-coil region [136, 174]. Occludin is recruited to thetight junctions by claudin [71] and incorporated into theclaudin strands in a punctate pattern [233].
There is extensive similarity between the endocyticand recycling pathways of claudins and occludin. Likeclaudins, occludin underwent continuous constitutive en-docytosis in malignant MTD-1A mouse mammary epithe-lial cells [167]. In a monolayer of MDCK cells that un-derwent wounding, occludin underwent clathrin-mediatedendocytosis with a half-time of 15 min [64]. A pre-vious study from the same group established that oc-cludin endocytosis was mediated by clathrin [63]. Sim-ilar to claudin-1 and -4, occludin collocated with theclathrin heavy chain and with the clathrin adaptor α -adaptin in human colon carcinoma epithelial cells af-ter calcium depletion [110]. VEGF induced clathrin-dependent endocytosis and phosphorylation of S490 inthe carboxy-terminus cytoplasmic domain of occludin inprimary bovine retinal ECs [175]. The phosphorylationinduced binding of the E3 ligase Itch and prompted oc-cludin poly-ubiquitination, ubiquitination, though the un-derlying mechanism remained speculative because of thelarge distance between S490 and the polyp-proline mo-tif in occludin’s amino-terminus to which the WW do-main of Itch binds [256]. Ubiquitinated occludin boundepsin-1 epidermal growth factor receptor pathway sub-strate (EPS)-15, and hepatocyte growth factor-regulatedtyrosine kinase substrate (HRS). Both proteins harborubiquitin-interacting motifs and facilitate endocytosis ofubiquitinated cell-surface proteins [95]. Endocytosed oc-cludin collocated with each of these proteins in cyto-plasmic punctae. Rab5, an early endosome marker [32],also collocated with occludin in cytoplasmic punctae in amonolayer of wounded MDCK cells [63].TNF α , the prototypic member of the tumor necro-sis factor ligand superfamily, induced caveolin-1-mediatedoccludin endocytosis in mouse jejunal epithelial cellsdownstream of myosin light chain kinase (MLCK) ac-tivation [152] and in Caco-2 and T84 human colonmetastatic epithelial cells [29]. The endocytosis requiredthe carboxy-terminal 107 amino acids of the cytoplas-mic tail of occludin, TNF α induced caveolin-mediatedendocytosis of occludin in Caco-2 and T84 human colonmetastatic epithelial cells. The endocytosis required thecarboxy-terminal 107 amino acids of the cytoplasmic tailof occludin, a region shared with and named after RNApolymerase II elongation factor ELL, a region shared withand named after RNA polymerase II elongation factorELL [233]. The ELL region afforded binding to ZO1and occludin dimerization [136]. In its absence, trun-cated occludin remained at the lateral cell membrane de-spite TNF α treatment, and, inversely, its expression hada dominant-negative effect on the endocytosis of endoge-nous occludin [29]. The ELL positively charged residues,in particular K433, were essential for ZO1 binding to oc-cludin [29].All three major tight junction transmembrane proteins,claudin, occludin, and JAM, underwent macropinocytosis6 E RAB4RAB11 NMM2 RHOAMLCKROCK
Lys TGNGolgiER
MICALL2 EE VEGF
15 16
TNF α CCL2
18 13
MLCK LE IFN γ cPLA2 α tubulindynein transcytosis OCLN RAB5
RAB7
187 115 16 187 12 14 3 7 18 917 314 2015 16
Prot
OccludinInteracting proteinKinaseAgonist ClathrinReferene numberCaveolin
PKC η junctiondisassembly ELL
PKC β
11 5 2 7419 1015 16 nPKC cPKCitchpoly Ub OCLN OCLN RAB13
Nucleus syntaxin-4 OCLN
Permeability
Figure 2: Occludin membrane trafficking pathways.
Occludin was internalized via either clathrin or caveolin-mediatedendocytosis, or via macropinocytosis. It was partially retrieved to the PM via Rab4, Rab11 and Rab13-mediated recycling ordiverted to lysosomal or proteasomal degradation. The inset presents phosphorylation sites that regulate occludin membranetrafficking and binding sites of ZO1 and itch. VEGF, CCL2, TNF α ,, and IFN γ -induced occludin endocytosis increased tightjunction permeability (red arrows). Rab13-mediated occludin recycling restored tight junction integrity (green T). Dashedline indicates speculative feature. EE, early endosome; LE, late endosome; Lys, lysosome; MLCK, myosin light chain kinase,NMM2, non-muscle myosin 2; Prot, proteasome; RE, recycling endosome. Numbers correspond to the following references: (1)[5], (2) [6], (3) [23], (4) [29], (5) [61], (6) [63], (7) [64], (8) [77], (9) [81], (10) [89], (11) ([92], (12) [110], (13) [152], (14) [167],(15) [175], (16) [176], (17) [210], (18) [241], (19) [246], 20) [253], (21) [262]. in T84 cells treated by interferon (IFN)- γ [262], a cytokinethat disrupts the integrity of epithelial cell monolayers[149]. The internalized tight junction transmembrane pro-teins were recruited collectively to subapical actin-coatedvacuoles at a relatively slow rate, 38 hours after IFN γ treatment. IFN γ initiated the formation of vacuoles byactivating non-muscle myosin-2 via RhoA, Rho-associatedkinase, and MLCK. The vacuoles were identified as recy-cling endosomes by collocation with Rab4 and Rab11 [23].Like claudin-5, occludin collocated with cholera toxin, in-dicating it underwent caveolin/lipid raft-mediated endo-cytosis in CCL2-treated mouse brain primary ECs [241].IFN γ -induced endocytosis of occludin reduced the trans-epithelial resistance of monolayers of Caco-2 cells [226].Similar to claudins, occludin is phosphorylated at mul-tiple sites in the carboxy-terminus cytoplasmic domain.The phosphorylation’s effects on occludin endocytosiswere site-specific. The most predominant occludin ki-nases were either ‘conventional’ (c) Ca and diacyl-glycerol (DAG)-dependent, or ‘atypical’ (a) Ca and DAG-independent PKCs. Because DAG induces tightjunction assembly [12], the DAG analogs phorbol 12-myristate 13-acetate and 1,2-dioctanoylglycerol were ad-ministered to MDCK cells to activate cPKCs [6]. Un-der low calcium conditions, the treatment resulted inoccludin’s phosphorylation on S388 (detected by massspectroscopy) and induced its recruitment to tight junc-tions. Conversely, treatment of Ca -replenished MDCKcells with the GF-109203X PKC-specific pharmacologicalinhibitor [255] resulted in occludin’s dephosphorylation.The phosphorylation detected by mass spectroscopy onS388 was attributed to a cPKC because a mixture ofPKC α , β I, β II, and γ phosphorylated in vitro the re-combinant carboxy-terminus cytoplasmic domain of oc-cludin. In contrast, calcium replenishment induced phos-phorylation of T403/404 and promoted the recruitmentof occludin to MDCK cell junctions [246]. Occludinmutated on T403/404 to dephosphorylation-mimickingalanines was removed from the cell junctions upon cal-cium replenishment, whereas phosphorylation-mimicking7403/404D mutants were recruited to the junctions. Mo-tivated by its conspicuous expression in epithelial cells[192], immunoblotting of occludin-precipitated cell lysateconfirmed that PKC η , a ‘novel’ diacylglycerol-dependentPKC, bound the carboxy-terminus cytoplasmic domainof occludin. Its pharmacological inhibition by a pseudosubstrate peptide [187] and by its knockdown resultedin the disruption of the tight junctions of MDCK cells.Intriguingly, a study from the same group concludedthat calcium replenishment-induced phosphorylation ofthe nearby Y398 and Y402 of human occludin expressedin MDCK cells had an opposite effect on occludin: ratherthan recruiting occludin, it prevented its incorporation incell junctions [61]. This effect was attributed to the abol-ishment of occludin binding to ZO1. In vitro experimentssuggested that Src was the likely kinase responsible forthe phosphorylation.The involvement of aPKCs in the maintenance of epi-dermal barrier function [92] instigated investigation intothe role of PKC ζ in the regulation of Caco-2 cell tightjunctions [112]. Treatment of quiescent cell monolayersby a myristoylated PKC ζ pseudosubstrate disrupted thetight junctions and slowed their assembly when the cellswere subjected to a ‘calcium switch’, i.e., incubation ina calcium-chelating medium followed by calcium-enrichedmedium. PKC ζ bound a recombinant 150 residue-longrecombinant carboxy-terminus cytoplasmic domain of oc-cludin in vitro. Threonine scanning of the cytoplasmicdomain attributed the phosphorylation to T424 and T438in the carboxy-terminus cytoplasmic domain.Calcium replenishment-induced phosphorylation ofTyr398 and Tyr402 of human occludin expressed inMDCK cells prevented its recruitment to cell junctionsand its binding to ZO1 [61]. In vitro experiments sug-gested that Src was the likely kinase responsible for thephosphorylation. In contrast to the effects of the abovephosphorylations, calcium replenishment-induced phos-phorylation of the nearby T403/404 sites (determined bymass spectroscopy) induced occludin recruitment to theintercellular junctions of MDCK cells [246]. Occludinmutated on T403/404 to dephosphorylation-mimickingalanines was removed from the MDCK cell junctionsupon calcium replenishment, whereas mutants harbor-ing phosphorylation-mimicking replacements to aspartatewere recruited to the junctions. Motivated by its con-spicuous expression in epithelial cells [192], immunoblot-ting of occludin-precipitated cell lysate confirmed thatPKC η , a ‘novel’ diacylglycerol-dependent PKC, boundthe carboxy-terminus cytoplasmic domain of occludin. Itspharmacological inhibition by a pseudo substrate peptide[187] and knockdown resulted in the disruption of thetight junctions of MDCK cells.The effects of VEGF downstream signaling on inter-cellular junction proteins have been of obvious interestbecause the growth factor induces intercellular junctiondisassembly [215]. Since a phosphorylation cascade typi-cally ensues downstream of tyrosine kinase receptors, nu-merous studies probed the extent of the phosphorylationof intercellular junction transmembrane proteins. Sev-eral early studies detected VEGF-induced phosphoryla- tion of occludin in primary bovine retinal ECs [7] anddetermined that it existed in five to seven phosphory-lated forms, suggesting the presence of multiple phospho-rylation sites that were at least in part the substrates ofPKC β β
1, an ATP-competitive PKC β -specificinhibitor, reversed the VEGF-induced redistribution ofoccludin, suggesting that it was triggered by S490 de-phosphorylation [176]. Like claudin, Rab13 played a major role in the consti-tutive recycling of occludin in quiescent malignant mousemammary epithelial cells, as indicated by the stabiliza-tion of occludin at the cell junctions by expression ofa dominant-negative Rab13Q67L mutant in MTD-1Acells. Both occludin and claudins 1 and 4 collocatedwith the t -SNARE protein syntaxin-4 in T84 epithelialcells [110] and required the Rab13 effector MICALL2 torecycle back to the PM [253]. Deletion of the Rab13-binding domain of MICALL2 disrupted occludin recyclingto the plasma membrane and prevented an increase inthe trans-epithelial resistance, indicating that the perme-ability of the cellular monolayer remained high. WhereasRab13-dependent trafficking bypassed the canonic recy-cling markers Rab4 and Rab11 [167], occludin collocatedwith Rab4 in mouse brain primary ECs treated by CCL2[241] and with both Rab4 and Rab11 in IFN γ -treatedT84 cells [23]. In quiescent serum-starved MDCK cells,a minority of the claudin population returned to the PMvia recycling endosomes in a Rab11-dependent manner[64]. Furthermore, cPLA2 α regulated the trafficking ofoccludin between the Golgi apparatus and HUVEC junc-tions in the same manner as claudin-5: depletion or in-hibition of cPLA2 α was accompanied by the removal ofoccludin from the cell junctions and its accumulation inthe Golgi apparatus [210]. Possibly because of its role inthe maintenance of the Golgi apparatus structure [156],partitioning defective protein 3 (Par-3) was required forthe trafficking of occludin from the TGN to the junc-tions of TNF α -treated Caco-2 cells. In its absence, oc-cludin accumulated in the TGN [292]. Occludin translo-cated from the TGN to the surface of quiescent Caco-2or MDCK cells along microtubules in vesicles propelledby the minus-end-directed molecular motor dynein at anapproximate velocity of 1.6 µ m/s [81]. The first 18 aminoacids of the cytoplasmic domain were sufficient for tar-geting occludin to the cell surface. Among these, residuesI279 and W281 were essential, possibly because they con-stituted a TGN export signal [133]. Unlike claudins, ESCRT did not regulate the recyclingand fate of occludin [57]. Though there is heterogene-ity in the half lives of claudins [263], several studies con-curred that the half-life of occludin is shorter than thoseof claudins by as much as three-fold [209, 256]. Directmeasurements of occludin and claudin-1 dynamics in qui-escent MDCK cells by fluorescence recovery after pho-8obleaching revealed an inverse relation between the twoproteins: whereas 76 percent of the steady-state popula-tion of claudin-1 was attached to cell junctions, the sizeof the unattached cytoplasmic fraction of occludin underthe same conditions was 71 percent [232].The aforementioned ubiquitin ligase Itch bound theamino-terminus cytoplasmic domain of occludin in HEK-293 and LLC-PK pig kidney epithelial cells [256]. Basedon the effect of the proteasome-specific inhibitor MG132[216], occludin was determined to undergo proteasomaldegradation. The VEGF-induced phosphorylation of oc-cludin on S490 in bovine endothelial retinal cells discussedabove was required for Itch binding to occludin, for oc-cludin ubiquitination, and, subsequently, for its proteaso-mal degradation [175]. VEGF augmented an ongoing low-level constitutive proteasomal degradation of occludin. Inserum-starved MDCK cells, close to half of the cellularoccludin population underwent constitutive endocytosisin an approximate half-time of 15 min. The majority ofthe endocytosed occludin population was apparently de-graded, as only 20 percent returned to the cell surface[64]. Based on collocation with neuropeptide-Y, a lyso-somal marker [251], and on the effect of bafilomycin-A1,a lysosomal inhibitor [290], occludin degradation was at-tributed to the lysosome.
4. JUNCTIONAL ADHESION MOLECULE(JAM)
The best-known members of the JAM protein familyare encoded by 3 genes, F11R, JAM2 and JAM3. JAM’sare 298-310 amino acid-long single pass proteins of theimmunoglobulin family (Fig. 3). Their cytoplasmic do-mains range in length from 39 to 48 amino-acids andharbor a PDZ-binding motifs at their carboxy-terminithat binds the scaffold protein ZO1 at intercellular junc-tions [60]. JAM-A forms homophilic trans -dimers [166],whereas JAM-B and JAM-C can form either homo- orheterophilic interactions [127]. The topology of the JAMsas single pass transmembrane proteins contrasts with thefour-pass topology of both claudins and occludin. A sub-stantial part of the relatively limited number of studies,compared to the latter two proteins, was focused on virusentry (e.g., [280]), a phenomenon that is deliberately notaddressed in this review. Consequently, knowledge of themembrane trafficking of the JAM proteins under physio-logical conditions is relatively scarce, particularly of JAM-B and -C. Though multiple residues in the JAM cyto-plasmic domain are phosphorylated by identified kinases[243], their phosphorylation has not been linked to mem-brane trafficking.Several of the studies reviewed above analyzed multi-ple species of tight junction proteins, including the JAMs.Similar to claudins-1 and -4, JAM-A collocated with theclathrin heavy chain and α -adaptin in T84 cells, indicat-ing that they were all endocytosed via clathrin-coatedvesicles [110]. Subsequently, JAM-A was recruited toearly endosomes, followed by segregation into a cyto-plasmic subapical compartment where it collocated withsyntaxin-4, possibly in preparation of reincorporation in the PM upon restoration of intercellular junctions. Col-lectively, these observations imply that JAM-A shares theendocytic pathway of the other prominent tight junctionproteins in response to calcium chelation. The same con-clusion can be drawn in regard to the administration ofIFN γ to T84 cells, whereby both occludin and JAM-A un-derwent macropinocytosis [23, 262]. The internalized pro-teins subsequently collocated with markers of early endo-somes and with Rab4 and -11, markers of ‘fast’ and ‘slow’recycling, respectively [23]. Either calcium chelation orstimulation with TNF α induced endocytosis of JAM-C inHUVECs [123]. Subsequently, it was observed in tubu-lar extensions from membranous structures formed at thecell junctions, but the endocytic pathway was not identi-fied. The recruitment of JAM-C to the cell junctions de-pended on its interaction with junction-proximal scaffoldproteins (likely ZO1 or -2), as indicated by an increase inits presence near the Golgi apparatus at the expense ofthe cell junctions upon deletion of its PDZ-binding motif.JAM-A endocytosis in Sertoli cells, which generate thehemato-testicular barrier, was blocked by knockdown ofthe clathrin heavy chain [277].The induction of macropinocytosis appears to be com-mon to the responses of all tight junction integral proteinsto inflammatory agonists: lipopolysaccharide (LSP) andCCL2 induced the also the micropinocytosis of JAM-A[242], but more recent studies revealed that under theseconditions, JAM-A trafficking differed from claudin andoccludin. The JAM-A population that translocated fromthe cell junctions and relocated to cytoplasmic punctaein immortalized mouse brain bEND.3 ECs was separatefrom internalized occludin and claudin-5, as well as fromvascular endothelial (VE)-cadherin. JAM-A translocatedfrom the cell junctions to the cytoplasm in 10-20 minand recycled back to the PM in 30-60 min, substantiallyfaster than the 24-48-hour dynamics observed by previ-ous studies [23, 262]. Internalized JAM-A collocated withand required the activity of Rab34, a known mediator ofmacropinosome formation [244]. Subsequently, endocy-tosed JAM-A collocated with Rab5 and Rab4, indicat-ing it trafficked to early endosomes and recycled rapidly[242]. JAM-A was not collocated with Rab7, suggest-ing that only a small fraction of its population under-went lysosomal degradation. Similar to the response ofJAM-A to IFN γ , lipopolysaccharide (LPS) and CCL2-induced macropinocytosis required the activities of RhoAand Rho-associated protein kinase (ROCK).The dynamics of JAM-C in quiescent human dermalmicrovascular ECs were dissimilar from JAM-A. In con-trast to the latter, approximately 80 percent of the cel-lular JAM-C was in the cytoplasm [190]. The remain-ing 20 percent were distributed diffusely on the cell sur-face rather than sequestered at the cell junctions. VEGFstimulation increased the cell-surface associated JAM-Cfraction to 60 percent in approximately one hour. Inter-estingly, the translocation was anterograde, opposite tothe VEGF-induced translocation of all other cell junctionintegral proteins, possibly paralleling the apparent pro-motion of intercellular permeability by JAM-C, contraryto JAM-A. A recent study on JAM-C dynamics in quies-9 yntaxin-4 JAM-A RE ROCK RHOA
Lys
TGNGolgiEREE
JAM-CInteracting proteinAgonist ClathrinReferene numberPDZ-binding motif LE RAB34 RAB5 α -adaptin poly-Ub CBL JAM-A
Nucleus
RAB4TGF β α VEGFCCL2 IFN γ Permeability
JAM-AJAM-A JAM-C
Figure 3: JAM membrane trafficking pathways.
JAMs were internalized via clathrin-mediated endocytosis or viamacropinocytosis. They were partially retrieved to the PM via Rab4-mediated recycling or diverted to lysosomal degradation.JAM removal from the plasma membrane increased tight junction permeability. TGF β
3, TNF α , CCL2, and IFN γ -inducedJAM-A/C endocytosis increased tight junction permeability (red arrows). EE, early endosome; LE, late endosome; Lys,lysosome; RE, recycling endosome. Numbers correspond to the following references: (1) [23], (2) [110], (3) [120], (4) [123], (5)[190], (6) [241], (7) [262], (8) [277]. cent HUVECs reported that JAM-C was primarily at thejunctions of confluent cells, and that two thirds of thispopulation was removed from the junctions in two hoursby constitutive recycling [123]. The cytoplasmic JAM-Cpopulation was detected partially in early endosomes andin MVBs, indicating that it was targeted at least in partto lysosomal degradation. In essence, the effect of VEGFon JAM-C dynamics is opposite to its effect on JAM-A.Monolayer permeability increased despite the recruitmentof JAM-C to the cell junctions. The mechanism that con-fers this intriguing effect is unknown. Mutation of allfour lysines located in the JAM-C cytoplasmic domain toarginines, intended to abolish its ubiquitination, resultedin an increase in JAM-C abundance in early endosomes,coupled with its decrease in MVBs. Unlike wild typeJAM-C, which was targeted by ubiquitination to MVBsand, subsequently, to lysosomes, the mutant did not as-sociate with the E3 ligase Casitas B-lineage lymphoma(CBL), supporting CBL’s role in JAM-C recruitment toMVBs.
5. CADHERINS
Cadherin membrane trafficking is better understoodthan that of any other cell junction integral protein.Cadherins are the largest junction transmembrane pro-tein family, consisting of 114 members [38]. They ad- join neighboring cells by homophilic binding interactions.This review focuses on the most abundant (though notthe only) cadherins in epithelial and in ECs: epithelial(E) and VE-cadherin, respectively. It includes relevantstudies on neuronal (N) cadherin, which is expressed alsoin endothelial [182] and epithelial [186] cells. Human E-and VE-cadherin are 882 and 784 amino acid-long single-pass transmembrane proteins. They harbor five modularimmunoglobulin-like extracellular-cadherin domains andcytoplasmic domains of 151 and 163 amino acids, respec-tively (Fig. 4). Unlike claudins, JAMs, and nectins,cadherins do not harbor a PDZ-binding motif and donot interact directly with PDZ domain-containing scaf-fold proteins. The canonical binding partners of their cy-toplasmic domains are three members of the catenin pro-tein family, α -, β -, and α -catenin (p120) [195]. β -cateninbinds the carboxy-terminus region of the E-cadherin cyto-plasmic domain (residues 811-882 of human E-cadherin)and to α -catenin [100], whereas α -catenin binds the jux-tamembrane region of the E-cadherin cytoplasmic domain(residues 758-769) [285]. α -catenin crosslinks E-cadherinto f-actin under stretch [26]. VE-cadherin interacts withthe three catenins in a similar manner [128]. There is am-ple evidence that VE-cadherin endocytosis in response toVEGF reduces endothelial barrier integrity and increasesits permeability [76, 129].10 E-cadherin S840-S846,S847L741-L742 β -catenin E-cadherin
Numb21 LAMTOR1
VAPA/BWDR44 ARHGAP10MICAL1RAB8aRAB10 FIP2PI345P3
RAB11RAB4 f-actin TIAM1CDC42RACIQGAP1 ARP2/3
LysLE cadherinRAB7 β -catenin HRS ubiquitinhakai SRC ERTGNGolgiEE transcytosis cadherin KinaseCadherinInteracting proteinAgonist Referene number ClathrinPhosphatidyl-inositolEEA1
RasRin2pacsin-2 RACRALACDC42 Exoc2,3,6 MPP5 Prot cadherin
41 1
SNX1
52 73114 27 4116PIPKI γ AP1B1
PI45P2 golgin-A1 DYN2
28 29
ARF6HGF NME1GTP KIF3 β -catenin tubulin cadherin cadherin
34 243014 cadherin RAB5 cadherin cadherin Nucleus cadherin β -catenin α -catenincadherin
37 1
EGF cadherinGDPGRDN BradHGFVEGF Figure 4: E- and VE-cadherin trafficking pathways
E- and VE-cadherin were internalized via clathrin-mediated endo-cytosis or via macropinocytosis. They were partially retrieved to the PM via Rab8a, Rab10, and Rab11-mediated recycling ordiverted to lysosomal or proteasomal degradation. VEGF-induced endocytosis increased adherens junction permeability (redarrow); HGF-induced endocytosis increased adherens junction disassembly. Rab11a-mediated VE-cadherin recycling restoredadherens junction integrity (green T). Inset shows phosphorylation sites and binding proteins to the cytoplasmic domain ofeach cadherin. Brad, bradykinin; CCP, clathrin-coated pit; EE, early endosome; GRDN, girdin; E, late endosome; Lys, lyso-some; Prot, proteasome; RE, recycling endosome. Numbers correspond to the following references: (1) [25], (2) [35], (3) [36],(4) [31], (5) [50], (6) [68], (7) [76], (8) [79], (9) [83], (10) [96], (11) [111], (12) [121], (13) [131], (14) [134], (15) [137], (16) [138],(17) [142], (18) [143], (19) [146], (20) [158], (21) [161], (22) [163], (23) [164], (24) [177], (25) [181], (26) [191], (27) [194], (28)[196], (29) [197], (30) [198], (31) [199], (32) [202], (33) [218], (34) [220], (35) [229], (36) [252], (37) [267], (38) [269], (39) [274],(40) [274], (41) [279], (42) [283].
Similar to tight junction transmembrane proteins, E-cadherin was construed to undergo constitutive endocy-tosis, induced by transferring either MDCK cells [134], orMCF-7 epithelial breast cancer cells [199] from 18 ◦ C to37 ◦ C. This conclusion was based on the inhibitory effec-tiveness of K + depletion [132] and of the pharmacologicalinhibitor bafilomycin A1 [116]. The presence of a YDSLLmotif at position 827 of human E-cadherin cytoplasmicdomain, known to recruit the host protein to clathrin-coated pits [257], further supported this premise [134].In contrast, the E-cadherin constitutive endocytosis inMCF-7 cells was found to be clathrin-independent. Nev-ertheless, E-cadherin was detected in clathrin-coated pitsby transmitted electron microscopy (EM), and, as the au-thors admitted, clathrin-dependent endocytosis may haveoccurred before the earliest sampled time point of 5 minpost the 118 ◦ C to 37 ◦ C switch [199]. Constitutive en- docytosis of VE-cadherin in human dermal microvascularECs was not positively identified, but its attributes wereconsistent with clathrin-dependent endocytosis [278].VE-cadherin in VEGF-treated HUVECs appeared incytoplasmic vesicles as soon as 2 min after VEGF ad-ministration, where it collocated with clathrin, dynamin-2, and the early endosome markers Rab5 and EEA1[76]. The cytoplasmic domain VE-cadherin harbors a con-served region close to the δ -catenin binding site that wasphosphorylated by p21-activated kinase (PAK)-1 on S665in a Src-dependent manner. The phosphorylation of thissite was required and sufficient for VE-cadherin endocy-tosis. In contrast, a non-phosphorylatable S665V mutantremained at the cell junctions, whereas a S665D phospho-mimetic mutant was endocytosed constitutively in the ab-sence of VEGF [76]. The phosphorylation of S665 likelyrecruited the clathrin-binding endocytic adapter arrestin- β
1, which bound to and collocated with endocytosed VE-11adherin. Src is constitutively active in vein ECs, induc-ing the phosphorylation of Y658 and Y685 in the cyto-plasmic domain of VE-cadherin in HUVECs [191]. Thephosphorylation sensitized VE-cadherin to bradykinin, aninflammatory cytokine that increases vessel permeability[101]. Bradykinin induced VE-cadherin ubiquitinationand clathrin-mediated endocytosis, without dissociating δ -catenin. Apparently, the promotion of endocytosis byubiquitination overcame the inhibitory effect of δ -cateninbinding to VE-cadherin.A recent study reported that the proteoglycansyndecan-4 collocated with VE-cadherin along HUVECjunctions and interacted with it independently of theformer’s glycosaminoglycan chains [47]. VEGF admin-istration induced Src-mediated phosphorylation of Y180in the syndecan-4 cytoplasmic domain, followed by co-endocytosis with VE-cadherin. VEGF-induced endocy-tosis of VE-cadherin in ECs devoid of syndecan-4 wasapproximately 3-fold lower and the increase in their per-meability was around half than in syndecan-4-expressingECs. The manner by which syndecan-4 facilitated VE-cadherin endocytosis was not identified.An insight into the relation between the homophilic trans interaction of cadherin ectoplasmic domains andcadherin endocytosis into its host cell was provided bycoculturing A-431 human epidermal carcinoma epithelialcells that expressed E-cadherin with either a W213C orT227C mutation [258]. The positions of the cysteinespermitted only the crosslinking of W213C-T227C trans -interacting dimers E-cadherins after inducing dimeriza-tion by elevating Ca concentration to 1 mM and re-ducing the respective sulfhydryl groups of each mutant[228] with the cysteine-specific crosslinker DPDPB [293].The relation between E-cadherin binding in trans and itsendocytosis was detected by tracking the abundance ofcrosslinked heterodimers by immunoprecipitation. ATPdepletion by sodium azide or hypertonic shock producedby medium supplementation with sucrose, conditionsknown to inhibit endocytosis [94, 230] prevented inter-cellular junction disruption by calcium chelation or bytrypsin treatment. These results suggested that endo-cytosis was the main mechanism of adhesive E-cadherindissociation [258]. In contrast, f-actin disruption by cy-tochalasin D or by latrunculin A, or reduction of myosin-generated tension by the ROCK inhibitor Y-27632 or theMLCK inhibitor ML-7, had minor effects on the abun-dance of E-cadherin dimers or on their formation rate.EM analysis showed that E-cadherin was internalizedin endocytic vesicles emanating from adherens junctions(ibid.).Observations made by two-photon fluorescence recov-ery after photobleaching (FRAP) and fast 3D fluorescencemicroscopy determined less than 10 percent of the totalcell-surface E-cadherin in MDCK cells was free to dif-fuse laterally [46]. The majority of the population re-cycled between binding in trans at the cell surface andthe cytoplasm by endocytosis, with a surface residencetime of 4 min. Close to half of the cytoplasmic E-cadherin translocated from the PM by endocytosis withinless than 3 min. In support of endocytosis as an exchange mechanism between the trans-interacting and cytoplas-mic E-cadherin populations, both dynasore and myristyltrimethyl ammonium bromide (MiTMAB), a noncompet-itive inhibitor of the GTPase activity of dynamin [206],suppressed E-cadherin exchange between the cytoplasmand the PM. The endocytosis rate and its inhibitor sen-sitivity suggested that it was clathrin-mediated. Subse-quent studies measured the turnover of E-cadherin in qui-escent A-431 cells by fusing its cytoplasmic domain tothe green-to-red photoconvertible protein Dendra2 [96].This technique distinguished between newly recruitedE-cadherins fluorescing in green and red-fluorescing E-cadherins that dissociated from cell junctions after photo-conversion. Junction-residing E-cadherins were replacedcontinuously with a half-time of approximately 2.5 min.E-cadherin turnover at the cell junctions was apparentlyenergy-dependent, because ATP depletion slowed it sub-stantially.The activity of the ADP-ribosylation factor (Arf)-6, a GTPase that regulates membrane trafficking be-tween the PM and recycling endosomes [53], was essen-tial for E-cadherin endocytosis. Expression of an Arf6dominant-negative mutant blocked hepatocyte growthfactor (HGF)-induced internalization of E-cadherin down-stream of Src [196]. A subsequent study determined thatArf6 was required for dynamin activation [197]. Yeast-two-hybrid screen of Arf6-binding proteins identified nu-cleoside diphosphate kinase A (NME1), which synthesizesthe GTP that drives dynamin activity [261]. E-cadherinendocytosis in MDCK cells entailed the recruitment ofNME1 to GTP-Arf6 [197] and sequestration of the Rac1guanine exchange factor (GEF) TIAM1 [194]. The ensu-ing reduction of Rac1 activity at the cell junctions pre-sumably facilitated the inward translocation of endocy-tosed vesicles. The expression of dominant-negative dy-namin 2-K44A hindered E-cadherin endocytosis. BecauseE-cadherin did not collocate with caveolin, its endocytosiswas apparently clathrin-dependent. Induction of vesiclebudding in an adherens junction-enriched fraction of ratliver cells followed by β -catenin vesicle immunoisolation,revealed that E-cadherin co-sedimented with the clathrinheavy chain, epsin-1, and the clathrin-coated vesicle com-ponent α -adaptin (AP2B1) (Brodsky [22, 111]. Furtherestablishing the dependence of E-cadherin endocytosis onclathrin, expression of the epsin N-terminal homology(ENTH) domain, which inhibits clathrin-dependent en-docytosis of the EGF and insulin receptors [179], blockedeither HGF or low calcium-induced E-cadherin endocy-tosis in MDCK cells [111]. A chimera consisting of theE-cadherin ectoplasmic domain and the Fc region of hu-man IgG expressed in mouse fibroblasts was endocytosedat 2 µ M but not at 2 mM calcium, indicating that onlynon- trans -interacting E-cadherin on the surface of ad-joining cells was endocytosed, in agreement with Troy-anovksy et al. [258].
Trans -bound E-cadherin inducedthe activation of the Rho GTPases Rac and Cdc42 [111].In turn, active Rac and Cdc42 inhibited E-cadherin en-docytosis, presumably by the f-actin cross linking activ-ity of their effector, ras GTPase-activating-like proteinIQGAP1 [15, 126]. In agreement, f-actin depolymeriza-12ion by latrunculin-A augmented E-cadherin endocyto-sis. The scission of E-cadherin-endocytic vesicles in HeLacells by dynamin-2 required the GAP activity of girdin,an actin and α -adaptin-binding protein, which interactsspecifically with GTP-bound dynamin-2 and catalyzes itshydrolysis [274]. The E-cadherin sorting mechanism togirdin-associated coated pits was not reported. The in-teraction of E-cadherin with α -adaptin, and, indirectly,with clathrin [91] was regulated in MCF-7 epithelial cellsby Numb, via its binding to the carboxy-terminus of δ -catenin [220]. The E-cadherin interaction with Numb wasrequired for its endocytosis and targeting to the cell’s ba-solateral region. The phosphorylation of Numb by PKC ζ inhibited its binding to E-cadherin and α -adaptin, butthe manner by which PKC ζ activity was regulated wasnot specified.E-cadherin endocytosis was linked to another adherensjunction transmembrane protein, nectin. The endocyto-sis of non-cross-interacting E-cadherin expressed in theaforementioned mouse fibroblasts [111] was reduced sig-nificantly when these cells were transfected by full-lengthnectin-1, but not by nectin-1 devoid of the four amino-acid PDZ-binding domain at the carboxy terminus of itscytoplasmic domain [97], presumably because the latterwas unable to bind afadin. While the expression of full-length afadin in fibroblasts expressing E-cadherin andnectin-1 did not inhibit E-cadherin endocytosis, the ex-pression of afadin lacking the amino-terminus domain re-duced endocytosis, apparently because that domain se-questers Rap1[97]. The role of Rap1 in E-cadherin endo-cytosis was deduced to be the stabilization of E-cadherinbinding to δ -catenin, because co-expression of constitu-tively active Rap1 with E-cadherin and nectin-1 increasedthe abundance of E-cadherin-coimmunoprecipitated δ -catenin compared to cells that expressed nectin-1 devoidof the PDZ-binding motif. The Rap1-mediated stabiliza-tion mechanism was not specified.The incorporation of epithelial cell surface proteinsthat harbor a dileucine motif, including E-cadherin,into clathrin-coated vesicles requires interaction with theAP1 complex subunit β γ phos-phatidylinositol phosphate kinase (PIPKI γ ) synthesizesphosphatidylinositol (4,5) phosphate (PtdIns(4,5)P ), aphosphoinositol that facilitates the assembly of coat pro-tein complexes [39]. PIPKI γ associated preferentiallywith dimeric E-cadherin in MDCK cells, as well as withVE-cadherin in HUVECs and with N-cadherin in HEK-293 cells [138]. The E-cadherin binding region was nar-rowed down to amino-acids 837-847 in its cytoplasmicdomain, a motif conserved in VE- and N-cadherin. In-terference with PIPKI γ activity by either knockdown orexpression of a kinase-dead mutant resulted in depletionof E-cadherin from the cell junctions and its accumulationin cytoplasmic vesicles. In addition to its enzymatic activ-ity, PIPKI γ recruited E-cadherin to endocytic vesicles bybinding to subunit β ◦ C to 37 ◦ C [163]. Whereas knockdown of δ -catenin increased the endocytosis of wildtype E-cadherin, it had no such effect on the leucine toalanine mutant. Apparently, both δ -catenin dissociationand the presence of the dileucine motif are required forE-cadherin endocytosis.The role of both the conserved dileucine motif and apresumably ubiquitinated K738 by in the endocytic sort-ing of cadherin was confirmed by their mutation to valine-alanine and to arginine, respectively [96]. Consequently,the constitutive endocytosis of the E-cadherin mutant inquiescent A-431 cells was practically blocked. Surpris-ingly, the mutation had no effect on E-cadherin turnoverat the cell junctions, indicating that endocytosis cannotfully account for it. The turnover mechanism was notidentified. Further analysis revealed that the binding of δ -catenin to the cytoplasmic domain of E-cadherin andthe interaction of the dileucine motif with clathrin adap-tor complexes were not entirely independent of each other[108]. δ -catenin binding involved two regions in the cy-toplasmic domain, a ‘static’ motif spanning residues 747-781, and a ‘dynamic’ site that encompasses the dileucineendocytosis motif. The latter site was permissive to bind-ing competition between δ -catenin and clathrin adap-tor complexes such as AP2, whose binding would initi-ate E-cadherin endocytosis. δ -catenin-d binding to E-cadherin was regulated by phosphorylation: MAPK1/3(ERK)-mediated phosphorylation of T310 of δ -catenin inMCF10A cells undergoing wound closure abolished itsbinding to E-cadherin and released the latter from thecell surface [124]. Glycogen synthase kinase-3 (GSK3)-mediated phosphorylation of the same residue dissociated δ -catenin from N-cadherin in astrocyte cells [200].The association of E- or VE-cadherin with the endo-cytic machinery was mediated by their cytoplasmic do-mains. An internalized chimera consisting of the ecto-plasmic and transmembrane domains of the interleukin(IL) 2 receptor (IL2R) and the cytoplasmic domain ofVE-cadherin collocated extensively with endogenous VE-cadherin in early endosomes when constitutive endocyto-sis was induced by transferring human dermal microvas-cular cells from 4 ◦ C to 37 ◦ C [278]. Cytosol acidifi-cation and K + depletion, approaches shown to inhibitclathrin endocytosis [94, 132], inhibited the endocytosisof the IL2R-VE-cadherin chimera. The chimera inter-nalized in 5 min after transference to 37 º C and collo-cated with endocytosed transferrin, a marker of clathrin-dependent endocytosis [88]. Overexpression of δ -cateninblocked internalization of IL2R-VE-cadherin, whereas re-placing the EMD binding motif at position 652 of hu-man VE-cadherin [254] to alanines abolished δ -cateninbinding. Chimeric VE-cadherin collocated with clathrinand appeared in cytoplasmic punctae [279]. These re-sults indicated that the clathrin-mediated endocytosis ofVE-cadherin requires dissociation of δ -catenin from itscytoplasmic domain. Once endocytosed, both δ - and β -catenin dissociated from VE-cadherin. Subsequent stud-ies determined that δ -catenin blocked VE-cadherin endo-cytosis by sequestering it away from membrane domainsthat were presumably populated by the clathrin-adaptorcomplex AP2 via an unknown mechanism [35]. In contrast13o Xiao et al. [279], replacement of the EMD motif to ala-nines resulted only in a small reduction of the mutant’sendocytosis in A-431 cells [181]. Rather, replacement ofthe GGG motif at position 649 in the δ -catenin-bindingregion of human VE-cadherin abolished the binding of δ -catenin almost completely. The δ -catenin binding regionin human and mouse VE-cadherin spanned residues K627– N664, out of which the K627 – S634 sub-region corre-sponds to the aforementioned E-cadherin ‘dynamic’ bind-ing site [108], and the remaining V635 – N664 sub-regioncorresponds to the ‘static’ binding site. δ -catenin bind-ing to VE-cadherin inhibited its endocytosis by maskingthe DEE motif at position 646 and prevented the bindingof Kaposi sarcoma virus ubiquitin ligase K5 to K626 andK633. A subsequent study from the same group revealedthat the 646DEE motif was sufficient for VE-cadherin en-docytosis, whereas the abolishment of δ -catenin bindingalone by mutating 649GGG to AAA was not [84]. Therole of the DEE motif in VE-cadherin endocytosis was notspecified.E-cadherin endocytosis required the activity of RhoGTPases and their effects on the actin cytoskeleton [49].Expression of a Cdc42 loss-of-function (LOF) mutant inthe epithelial cells of the Drosophila dorsal thorax re-sulted in a drastic reduction in the number of E-cadherinvesicular structures in the cytoplasm [79], and in the ap-pearance of tubular endocytic vesicles associated with ad-herens junctions [135]. A LOF mutation in actin-relatedprotein (Arp)-3, a subunit of the Arp2/3 complex anda Cdc42 effector [147], resulted in similar blockage of E-cadherin endocytosis [79]. LOF mutations of Par6 or ofp21-activated kinase (Pak)-1, both of which are Cdc42effectors [19, 75], phenocopied the effect of Cdc42 LOFmutation on E-cadherin endocytosis [135].In vitro experiments in HUVECs and in vivo experi-ments in zebrafish revealed that homophilic VE-cadherin trans dimers on adjacent cells underwent transcytosiswhile remaining bound to δ -catenin [218]. The transcy-tosis required myosin-driven traction transmitted via f-actin, and Rac1 activity. The endocytic pathway wasnot specified, but none of the known pathways appearedto be involved. A contrasting phenomenon was observedin motile HUVECs when they formed transient focal ad-herenes junctions that anchored force-bearing stress-fibers[103]. VE-cadherin located in these junctions was sub-jected to imbalanced tenstile forces that generates asym-metric junction geometry. Despite the asymmetry, only9 percent of the VE-cadherin cellular population under-went transcytosis, whereas the majority was endocytosedinto its host cell [50]. The endocytosis was apparently bal-anced out by recruitment of the bin, amphiphysin, and rvs(BAR) domain protein pacsin-2 to the curved PM aroundfocal adherens junctions. Endocytosed VE-cadherin wasdetected in Rab5 and Rab4-labeled vesicles, indicatingthat it recycled rapidly to the PM. Similar to tight junc-tion transmembrane proteins, E-cadherin was internalizedby macropinocytosis. The application of EGF to MCF-7 epithelial breast cancer cells resulted in the collocationof E-cadherin with δ and β -catenin in EEA1-associated2-2.25 µ m macropinosomes, followed by translocation to the juxtanuclear region [25]. Part of this population wasin late endosomes and lysosomes, but its majority wasrecycled back to the cell surface (see below).E-cadherin endocytosis was associated with severaltypes of posttranlational modifications. Viral Src ex-pressed in MDCK cells phopshorylaetd Tyr755 and 758in the cytoplasmic domain of E-cadherin [68]. The phos-phorylation enabled binding of the E3 ligase hakai andubiquitination of E-cadherin, increasing the endocyto-sis of the latter in response to HGF. More recent stud-ies [83] addressed the Src-mediated phosphorylation ofTyr658 of VE-cadherin in human lung microvascular ECs,a modification known to dissociate δ -catenin from VE-cadherin and facilitate its endocytosis [202], was trig-gered by trimeric G α
13 GTPase. G α
13 binds both Srcand residues 752-762 of the VE-cadherin cytoplasmic do-main [83]. E-cadherin expressed in A-431 cells was con-stitutively phosphorylated on serines 840, 846 and 847in the β -catenin binding motif [83]. The phosphoryla-tion facilitated β -catenin binding and favored the recruit-ment of E-cadherin to the PM. The kinase was not iden-tified but was presumed to reside in the Golgi apparatus.Contrary to the latter study, Src-mediated phosphoryla-tion of VE-cadherin on Tyr731 in HUVECs prevented β -catenin binding, and, consequently, would have favoredVE-cadherin endocytosis and lysosomal targeting [202].Endocytosed E-cadherin in MDCK and MCF-7 cellsand endocytosed VE-cadherin in human dermal microvas-cular ECs underwent Rab5-mediated trafficking to earlyendosomes [121, 198]. In response to HGF, Rab5 wasactivated by the GEF Ras and Rab interactor (RIN)-2downstream of Ras [121]. N-cadherin expressed in im-mortalized rat fibroblasts collocated with δ -catenin in cy-toplasmic vesicles that translocated retrogradely at 0.5-1.0 µ m/s upon adherens junction disassembly induced bycalcium chelation [34]. Vesicle movement was disruptedby nocodazole, indicating they translocated along micro-tubules. The movement was driven by kinesin, recruitedto the vesicular N-cadherin via δ -catenin, which binds thekinesin heavy chain [284]. Multiple studies identified the Golgi apparatus and theTGN as major destinations or departure points of cad-herin during either constitutive recycling [134, 199], oras a result of the expression of dominant-negative Rac1[268]. Newly synthesized N-cadherin precursor expressedin HeLa cells was present in the ER and the Golgi appara-tus prior to the cleavage of its signal peptide (residues 1-25) and propeptide (residues 26-159) [267]. The carboxy-terminus of the N-cadherin precursor was phosphorylatedand bound to δ -catenin, followed by the biding of α and β catenins as a dimer. The stoichiometric ratios of N-cadherin to the three catenins were close to unity, sug-gesting that most of the precursor N-cadherin was boundto catenins before it translocated from the ER and Golgi.Contrary to Wahl et al. [267], Miranda et al. ruled outsystematically the presence of δ -catenin in the ER andthe Golgi apparatus of MDCK cells [161]. The disagree-ment was attributed to unspecified phenotypic differencesbetween HeLa and MDCK cells. The transport of N-14adherin from the Golgi apparatus to the periphery ofmouse neural progenitor cells was driven by kinesin KIF3[252], a microtubule plus end-directed anterograde molec-ular motor that associates with N-cadherin via β -catenin[91]. Mutation of the dileucine motif at residues 741-742of human E-cadherin expressed in MDCK cells interferedwith its routing to the basolateral membrane, showingthat the association with δ -catenin was required for itscorrect targeting [161]. This conclusion was challengedby a subsequent study, which found that E-cadherin mu-tants that lacked the whole cytoplasmic domain, or whoseleucines were substituted by alanines, were detected ex-clusively on the PM of MDCK cells [163]. Instead of thebasolateral membrane, the latter study concluded thatthe dileucine motif targeted E-cadherin to lysosomes [164](see below). No explanation was provided to reconcilethe disagreement between the conclusions of Miranda etal. and Miyashita and Ozawa in regard to the role of thedileucine motif in E-cadherin basolateral targeting.Newly synthesized wild type E-cadherin, or a truncatedmutant devoid of the dileucine motif expressed in theHeLa cells, translocated constitutively from the TGN viatubular or spherical endosomes that moved at an approx-imate rate of 3 µ m/s [143]. In a minority of cases, thevesicles reached the cell periphery in 40 s. After remain-ing stationary for 10 s, the vesicles disappeared, possiblyafter fusion with the PM. The initial membrane traffickingof E-cadherin away from the Golgi apparatus was sharedwith occludin and claudin-5 [224]. The exit from the TGNwas mediated by golgin-A1, a protein that binds directlyto the TGN membrane [143]. Golgin-A1 was requiredup to but not after the budding of E-cadherin-associatedvesicle from the TGN. The recruitment of E-cadherin tothe PM in MDCK cells required the activities of Rac1and Cdc42 [268]. Expression of dominant-negative mu-tants of the two GTPases resulted in the accumulationof E-cadherin in large perinuclear vesicles that collocatedpoorly with Golgi and TGN markers. The GTPase RalAthat is a component of the exocyst and is required forits structural stability [169], enhanced the delivery of E-cadherin-containing vesicles from the TGN to the PM[269]. Ubiquinated E-cadherin that would be normallydestined to lysosomal degradation [118] was diverted insubcobfluent T84 epithelial cells to recycling togetherwith β -catenin by the deubiquitinase fat facets in mam-mals (FAM) [177]. FAM collocated with both proteins inthe Golgi apparatus and in cytoplasmic vesicles that werepossibly headed to the PM. Because FAM interacted withE-cadherin and β -catenin only in subconfluent cells, thismechanism is apparently inactive once cell junctions arestabilized.Observations on epithelial proximal tubule cells fromindividuals carrying autosomal dominant polycystic kid-ney disease caused by LOF mutations in PKD1 and PKD2revealed that E-cadherin was sequestered in perinuclearvesicles and was absent from the cell junctions [31]. Themutant genes encode polycystins 1 and 2, large 11-passtrasmembrane proteins that are present in adherens junc-tions [222] and bind E-cadherin [21]. The nature of thevesicles and the manner by which polycistins facilitate the recruitment of E-cadherin to cell junctions are un-known. Another mechanism that favored E-cadherin re-cycling over degrdation was attributed to late endoso-mal/lysosomal adaptor and MAPK and MTOR activa-tor (LAMTOR)-1 (named alternatively lipid raft adap-tor protein p18), a protein that binds endosomal outermembranes and suppresses trafficking to lysosomes [178].When rat lung microvascular ECs were challenged byLPS, overexpression of LAMTOR1 suppressed the re-moval of VE-cadherin from the cell junctions and de-creased its abundance in late endosomes in favor of earlyendosomes [36]. These effects required LAMTOR1 bind-ing to endosomes, and may have been exerted by the sup-pression of Rab7 and enhancement of Rab11 activities.The involvement of Rab GTPases in cadherin mem-brane trafficking is known in more detail than for anyother junction transmembrane protein. E-cadherin thatunderwent constitutive endocytosis in MCF-7 cells col-located with Rab11 and relocated back to the cell sur-face in 15-30 min [199]. The majority of the above-mentioned vesicular E-cadherin expressed in HeLa cells[143] trafficked in Rab11-associated recycling endosomesfrom which they moved to and fused with the PM. The ex-pression of a dominant negative Rab11 mutant in MDCKcells resulted in mistargeting of E-cadherin which translo-cated to the apical instead of to the basolateral region [48].The recycling of VE-cadherin in human lung microvascu-lar ECs required specifically the activity of Rab11a [283].VE-cadherin endocytosed in response to calcium chela-tion collocated with Rab11a in cytoplasmic vesicles. De-pletion of Rab11a blocked VE-cadherin recycling back tothe PM, resulting in its accumulation in lysosomes. VE-cadherin and Rab11a associated with each other by form-ing a ternary complex with Rab11 family-interacting pro-tein (FIP)-2, a Rab11 effector that binds PtdIns(3,4,5)P and targets recycling vesicles to the PM [137]. Knock-down of Rab11a impaired VE-cadherin recycling to thecell junctions and increased the vascular leakage in LPS-treated mice [283]. Similar to its endocytosis from thePM, trafficking of E-cadherin from the TGN to recy-cling endosome required PIPKI γ activity [138]. The in-hibition of brefeldin A-inhibited GEF (BIG)-2, an ArfGEF citepRN487, blocked the trafficking of E-cadherinand β -catenin from the TGN to the adherens junctions ofMDCK cells [229]. The role of Arf GTPases in this leg ofE-cadherin trafficking could be the targeting of recyclingvesicles to the PM [53].The trafficking of E-cadherin from recycling endo-somes to the PM of MDCK cells depended on Rab8and MICALL2 [282], a Rab8 and Rab13 effector in-volved in the recycling of tight junction transmem-brane proteins [167]. MICALL2 mediates membranetrafficking by regulating the assembly state of f-actin[217]. A recent study found that GTP-bound Rab8a andRab10 were recruited to elongated E-cadherin-containingtubular vesicles in the perinuclear region of HeLa cells[146], followed by the recruitment of MICAL1, an actinfilament-severing protein [102] and a likely Rab8 effec-tor [207]. In turn, MICAL1 recruited the Rho GTPase-activating protein 10 (ARHGAP10), a BAR domain con-15aining protein, which extends and stabilizes tubular vesi-cles. ARHGAP10 recruited tryptophan-aspartate (WD)repeat-containing protein 44 (WDR44), a scaffold pro-tein that bridges elongating tubules with the endoplas-mic reticulum (ER) by binding to vesicle-associated mem-brane protein-associated proteins A and B (VAPA/B)[13]. This mode of exocytosis suggests that E-cadherinsegregated from other cargo proteins prior to exiting theER [146].The trafficking of E-cadherin in Drosophila epithelialcells from recycling endosomes to adherens junctions wasmediated by the exocyst octameric complex. LOF ofthe genes encoding the Exoc2, Exoc3, and Exoc6 sub-units, which are required for vesicle tethering to the PM[276], resulted in the accumulation of VE-cadherin, andof α and of β -catenin in enlarged Rab11-marked recy-cling endosomes [131]. E-cadherin shares with claudinsthe syntaxin-4-dependent mechanism of docking to thePM described above [110]. E-cadherin delivery to the PMin MDCK cells required an apicobasal complex protein,protein associated associated with lin seven (PALS1)-1(named alternatively MPP5). In its absence, E-cadherinaccumulated in cytoplasmic punctae adjacent to the cellperiphery that did not collocate with early or recyclingendosomes, or with Golgi markers [271]. The accumula-tion was caused probably by mislocation of the exocyst,as was indicated by the absence of Exoc4 from the celljunctions. The recycling of E-cadherin that underwentmacropinocytosis into MCF-7 cells was mediated by sort-ing nexin (Snx)-1 [25], an adaptor protein that mediatescargo selection by the retromer complex and retrogradetrafficking to the TGN [27]. Given its involvement inearly endosome to Golgi retrieval of proteins destined fordegradation [82], association with Snx1 was expected todivert E-cadherin from degradation to recycling [25]. Inagreement, Snx1 knockdown reduced substantially the re-cycling of E-cadherin to the cell surface. Inhibition of the proteasome by MG132 blocked VE-cadherin constitutive endocytosis in dermal microvascu-lar ECs altogether, whereas inhibition of lysosome activ-ity by chloroquine resulted in the accumulation of VE-cadherin in cytoplasmic punctae [278]. These results sug-gested that both degradative pathways were involved inthe processing of VE-cadherin, albeit at different stages ofendocytosis. The manner by which catalytic inhibition ofproteasome activity by MG132 [122] blocks VE-cadherinendocytosis is unknown.Temperature-dependent overexpression of constitu-tively active Src in MDCK cells increased substantiallythe preexisting basal abundance of E-cadherin lysosomaldigestion products at the permissive temperature [198].E-cadherin was shown to be a Src substrate, suggest-ing that its tyrosine phosphorylation induced ubiquitina-tion, possibly by the hakai ligase [68], followed by tar-geting to lysosomes. The lysosomal sorting was medi-ated by the endocytic scaffold protein HRS, which col-located with E-cadherin in cytoplasmic vesicles and inLAMP1-associated endosomes. The switch to permissivetemperature enhanced Rab7 activity, whereas the expres- sion of dominant-negative Rab7 blocked E-cadherin lyso-somal degradation, in agreement with the established roleof Rab7 in trafficking to lysosomes [30]. The dependenceof E-cadherin targeting to the lysosome on Rab7 wasshared by VE-cadherin undergoing constitutive endocy-tosis in HUVECs [218].Aside from its role in regulating cadherin endocyto-sis, the dileucine motif was implicated in the target-ing of cadherin to the lysosome (Miyashita and Ozawa,2007a). This conclusion stemmed from observations thatreplacement of the leucines with alanines resulted in therecruitment of E-cadherin to the basolateral membraneof MDCK cells and its absence from the lysosome, un-like wild-type E-cadherin. Dileucine motif sorting of E-cadherin required β -catenin binding to the cadherin cy-toplasmic domain [164], though the binding region of thelatter is close to 70 amino acids downstream of the mo-tif. E-cadherin mutants that lost the ability to bind β -catenin translocated through the biosynthetic pathwayand reached early endosomes, but instead of undergoingexocytosis to the PM, they were diverted to lysosomes[164]. It was hypothesized that β -catenin binding to thenatively folded E-cadherin cytoplasmic domain blockedthe dileucine motif, thus preventing E-cadherin recruit-ment to lysosomes.
6. NECTINS
The nectin family consists of four single pass junctiontransmembrane proteins ranging in size from 510 to 549amino acids [150] (Fig. 5). Nectins 1-3 are expressed ubiq-uitously, whereas nectin-4 is specific to the placenta [213].Nectins form cis-homodimers and either homophilic orheterophilic trans dimers via their extracellular domains,which contain three IgG-like loops [165]. The nectin cy-toplasmic domains, which vary between 41 to 140 aminoacids, harbor a carboxy-terminus PDZ-binding motif thatconforms to the E/A-X-Y-V (X – any amino acid) con-sensus sequence. All nectins bind the PDZ domain of theadaptor protein Afadin, which cross links them to f-actin[248]. Nectin is the first junction transmembrane proteinrecruited to the PM during the formation of intercellularjunctions [11]. Nectin-bound afadin recruits α -catenin,followed by cadherin [247]. Nectin initiates the formationof tight junctions through the binding of ZO1 to the PDZdomain of afadin [59], which crosslinks nectins by dimer-ization [162]. Afadin’s role in bridging adherens and tightjunctions is addressed in section 7 below.The trafficking pathway of nectin is the least knownamong junction transmembrane proteins. Nectin was ini-tially identified as a poliovirus receptor [159] and means ofentry [80] into epithelial human cells. Studies on nectin-mediated virus entry indicated that clustered nectins un-derwent phagocytosis [37] or lipid raft-mediated endo-cytosis [80]. Because these mechanisms differ from theclathrin-dependent endocytosis of nectin observed duringthe remodeling of the junctions among mouse embryo NIH3T3 fibroblasts [69], they will not be addressed. Nectinis present in Sertoli cells and was shown to play an im-portant role in spermatogenesis [20]. Though it does notfunction in these cells solely as an intercellular junction16 adherin Lys nectin LE transcytosis EE RE MPP3 MPP5 RAB11a ER VPS35VPS26VPS29 afadindrebrinf-actin PDZD11PLEKHA7 α -catenin Prot nectin δ -cateninnectin Interacting protein ClathrinReferene number
NectinCadherin
PDZ-binding motif
53 45 2
TGNGolgi retromer
Nucleus nectinnectin
Permeability
Figure 5: Nectin trafficking pathways.
Nectin was internalized via clathrin-mediated endocytosis It was partially retrievedto the PM via Rab11a-mediated recycling or diverted to lysosomal or proteasomal degradation. EE, early endosome; LE, lateendosome; Lys, lysosome; Prot, proteasome; RE, recycling endosome. Numbers correspond to the following references: (1)[54], (2) [69], (3) [78], (4) [85], (5) [125], (6) [211], (7) [291]. protein, it may employ the same endocytic pathway as inepithelial or endothelial cells. The endocytosis of nectin-2 in Sertoli cells was characterized as clathrin-dependentbecause its degradation was blocked by shRNA-mediatedclathrin knockdown [294]. Nectin-4 bound in trans tonectin-1 on the surface of adjoining A-431 cells under-went transcytosis into the nectin-1-expressing host cell[78]. The dominance of nectin-1 in the pulling contestwith nectin-4 was attributed to its stronger anchoring tothe cytoskeleton relative to nectin-4. The endocytosednectin-1-nectin-4 dimer apparently escaped degradationas it was not collocated with LAMP-1. Instead, the dimercollocated with vacuolar protein sorting-associated pro-tein (VPS) 35 subunit of the retromer, a trimeric com-plex that mediates tubulation and sorts cargo proteinsfor delivery either to the PM or the TGN [28].Similar to its endocytosis, nectin recycling is poorlyknown. The recruitment of nectin-1 to the junctionsof transformed monkey kidney fibroblasts (COS-7) de-pended on its binding to MAGUK p55 protein (MPP)-3 [54], a scaffold protein that binds nectin-1 and -3 viaits single PDZ domain. The exclusion of nectin-2 indi-cates that this interaction is highly specific: the last fourcarboxy-terminus amino-acids of both human and mousenectin-1 and -3 are identical, but they share only the last two amino-acids with nectin-2. Consequently, MPP3 wasnot required for cell junction recruitment of nectin-2. Incontrast, MPP5, which has a similar domain structureto MPP3, including a single PDZ domain, recruited allthree nectins, albeit with lower efficacy for nectin-1 [54].It is unknown how binding to the afadin PDZ domain,the canonical nectin scaffold protein at the cell junctions[248], is reconciled with MPP3 and MPP5 binding to thenectin carboxy-terminus. Studies on Sertoli cells observedcolocation of nectin-2 with Rab5a and Rab11a, indicatingit reached early endosome and underwent ‘slow’ recyclingto the cells’ adhesive junctions [291].An additional layer of complexity is added to the re-cruitment of nectin to cell junctions by the actin [10] andafadin-binding [211] scaffold protein drebrin. Knockdownof drebrin reduced the abundance of nectin-2 and -3 atthe junctions of HUVECs [211]. The binding of drebrin toafadin, mediated by their respective poly-proline regions,was required for nectin stabilization at the junctions. Thiswas indicated by the increased abundance of nectin-2 inearly endosomes and in lysosomes upon drebrin knock-down. The stabilization of nectin-2 at the cell junc-tions required the formation of a nectin-afadin-drebrincomplex. Afadin is the component of another trimericcomplex consisting of PDZ domain-containing protein17PDZD)-11, a small single PDZ domain protein, andpleckstrin homology domain-containing family A member(PLEKHA)-7 which binds afadin and δ -catenin directly[125]. The interactions of PDZZ11 with the PDZ-bindingmotif of nectins 1 and 3 and with PLEKHA7 stabilizeadherens junctions by crosslinking nectin to cadherin viaPLEKHA7 [85]. Similar to drebrin, either PDZD11 orPLEKHA7 knockdown caused partial loss of nectin-1 and-3 from MDCK cell junctions. The loss was prevented byadministration of MG132, implying that nectin was de-graded by the proteasome, in addition to the lysosome.PLEKHA7 recruited PDZD11 to cell junctions via thebinding of its first WW domain to a site located amongthe first 44 amino-terminal amino-acids of PDZD11. ThePDZ domain of PDZD11 bound directly to the carboxy-terminus of nectin-1 and -3 [85], thus stabilizing their at-tachment to cell junctions.The studies reviewed above highlight the exceptionallylarge number of PDZ domain-containing proteins thatnectins bind. In addition to afadin, all nectins bindPKC α -binding protein (PICK)1 [214], MPDZ, and pals1-associated tight junction protein (PATJ) [1]. Nectin-1and -3 bind also MPP3, MPP5, PDZD11, and PAR3[250]. Though the functional specificity associated witheach nectin binding-partner is unclear, their relativelylarge number and variety suggest that nectin has versatilecontext-dependent roles in the regulation of intercellularjunctions and in other cellular functions.
7. DISCUSSION7.1
Specificity versus mutuality among endocytic path-ways.
Occludin and E-cadherin contain putative sort-ing motifs in their carboxy-terminus cytoplasmic domains[110] that conform to known consensus sequences [99], buttheir function has not been confirmed. The co-endocytosisof GFP-claudin-3 and endogenous claudin-4 reported byMatsuda et al. [155] agrees with the high homologyor identity of the putative sorting motif in their 2nd(AF/LGVLL) and 4th (YVGW) transmembrane domain,respectively, proposed by Ivanov et al. Similarly, the sort-ing motifs in the 4th transmembrane domains of claudins1, 2, and 7, which were reported to be co-endocytosed byGehne et al. [77] are also either identical (claudins 1 and2; YLGI) or homologous (claudin-7; FIGW).A tight versus adherens junction specificity is conferredby the mediation of their recycling by different Rab GT-Pases. Rab8 GTPases mediate the recycling of adherensjunction integral proteins, whereas Rab13 performs thesame function in tight junctions [282]. Their mutual ef-fector, MICALL2, is shared, however, by both types ofcell junction. It is unknown how the junction-type speci-ficity is conferred on Rab8a and Rab13.Possibly the most prominent and best understood linkbetween adherens and tight junction proteins is mediatedby the adaptor protein afadin. Once bound to nectin,which is the first transmembrane protein recruited tocell junctions, it recruits ZO1 [289] via the binding ofits proline-rich motifs to the SH3 domain of ZO1 [189].Afadin-bound ZO1 recruits JAM-A [70] and claudins, initiating their polymerization into strands [260]. Con-versely, ZO1/2 facilitate adherens junction assembly [193]by participating in the generation of a structurally sup-portive circumferential f-actin bundle along the cell junc-tions [107].Within adherens junctions, the endocytosis of E-cadherin is regulated by nectin. Nectin-bound afadinrecruits the GTPase Rap1 [18], inducing the binding of δ -catenin to afadin, and, concomitantly, recruiting E-cadherin. When bound in trans to nectin on adjoiningcells, nectin blocked E-cadherin endocytosis in its hostcell [97]. Fate decision.
Despite having been published morethan ten years ago [24, 286], the insightful discussionsof potential fate ‘decision’ mechanisms of integral celljunction proteins are largely relevant today because therehas been relatively little progress in understanding thesemechanisms. The earliest fate-determining step of cad-herin appears to be Src-mediated phosphorylation, fol-lowed by ubiquitination, sorting by HRS, and Rab7-dependent trafficking to lysosomes, as described above[198]. The endosome outer membrane-binding proteinand Rag GTPase GEF LAMTOR1 promoted E-cadherinrecycling from early endosomes to the plasma membrane,while preventing its trafficking to late endosomes [36]. Itwas not specified, however whether it achieved this effectby activating Rag, or via another mechanism. A differentearly endosome-associated sorting activity was attributedto the retromer adaptor proteins Snx1, which diverted E-cadherin from degradation to recycling to the PM [25].Other studies observed diversion of E-cadherin from lyso-somal degradation to recycling and recruitment to celljunctions following its deubiquitination in the Golgi ap-paratus by FAM [177] or activation of Arf in the TGN bythe GEF BIG2 [229], resulting in E-cadherin recyling tothe plasma membrane [53].
Implications of liquid-liquid phase separation.
Re-cent studies demonstrated that the scaffold protein ZO1drives the generation of tight junctions while forming cy-toplasmic condensates in live MDCK cells [17]. The for-mation of such condensates by ZO1 and potentially byother junction-associated scaffold proteins, e.g., MPDZand PATJ [90], is a novel aspect of intercellular junctiondynamics that provides new insight into their assemblymechanisms. The PM, ER, and endosomes provide plat-forms for the formation of liquid-liquid phase-separatedcondensates [295]. The emerging mechanism of tight junc-tion initiation consists of ZO1 transition into PM-boundcondensates, the partitioning of claudin, occludin, and ofthe scaffold proteins afadin and cinglulin into the conden-sates, and the triggering of claudin polymerization [17].Do claudin and occludin that translocate from the TGNto the plasma membrane by membrane trafficking disso-ciate from the vesicles that carry them and partition intoZO1 condensates, or do they partition into the ZO1 con-densate while remaining inserted into the vesicles’ mem-branes until the vesicles fuse with the PM?
Functional specificity of scaffold proteins.
As elab-orated above, the ZO protein family plays a major rolein the recruitment of tight junction proteins as well as in18
Cherry-SiTmCherry-Rab11aMPDZ MergedMergedMPDZ Claudin-5MPDZ Merged
ABC
Figure 6: MPDZ collocates with vesicular Rab11 and the TGN, and with claudin-5.
Subconfluent human dermalmicrovascular primary ECs were transduced by lentivirus expressing either Rab11a (A) or sialyltransferase (SiT) (B), a TGNmarker [41] fused to mCherry, permeabilized by Triton X100, fixed by formaldehyde, and immunolabelled by antibody toMPDZ. Arrows point to cytoplasmic punctae of collocated MPDZ and Rab11 in A, or of collocated MPDZ and TGN markerin panel B. Note that MPDZ and Rab11a collocate also in the TGN. C. ECs permeabilized and fixed as above after 30 min ofVEGF treatment were immunolabeled by antibodies to MPDZ and claudin-5. Arrows point to collocated MPDZ and claudin-5along the cell junctions and in cytoplasmic punctae. Bars, 10 µ m. the structural support of tight junctions, whereas afadinplays a similar role in adherens junction assembly. ZO1/2bind numerous claudins via their PDZ domains, whereasafadin nectins in the same manner. These, however, arenot the only binding partners of the PDZ-binding motifsof claudins, JAMs, and nectins. The homologous largescaffold proteins PATJ and MPDZ bind essentially thesame junction transmembrane proteins and have been lo-calized to the cell junctions, similar to ZO1/2 and afadin[183, 234]. How then are the interactions of claudinsand nectins with ZO1/2 and afadin, respectively, recon-ciled with their interactions with PATJ/MPDZ? What arethe specific functions of PATJ/MPDZ? Are those func-tions linked to intercellular junction homeostasis similarto ZO1/2 and afadin? While these questions cannot beanswered in full at this time, preliminary data from theauthor’s lab show that MPDZ collocates with Rab11a incytoplasmic punctae (Fig. 6A) and is present in the TGN of subconfluent human dermal primary microvascular ECs(Fig. 6B), suggesting that MPDZ undergoes membranetrafficking from the TGN to cell junctions. In parallel,MPDZ collocates with claudin-5, a prominent claudin inECs [168], along EC junctions and in cytoplasmic punc-tae (Fig. 6C), suggesting that MPDZ, and possibly PATJ,are involved in junction protein dynamics rather than intheir stabilization at the cell junctions. Acknowledgement:
I attempted to review all thestudies I considered relevant to the review’s subject.Studies that were superseded by more recent ones werenot included. Readers are encouraged to inform me ofmissed studies. I will consider all suggestions and includethem if they add new information.
Conflict of interest:
None.19 eferences [1] M. Adachi, Y. Hamazaki, Y. Kobayashi, M. Itoh, S. Tsukita,M. Furuse, and S. Tsukita. Similar and distinct propertiesof mupp1 and patj, two homologous pdz domain-containingtight-junction proteins.
Mol Cell Biol , 29(9):2372–89, 2009.ISSN 1098-5549 (Electronic) 0270-7306 (Linking). doi: 10.1128/MCB.01505-08. URL .[2] W. Ahmad, K. Shabbiri, B. Ijaz, S. Asad, M. T. Sarwar,S. Gull, H. Kausar, K. Fouzia, I. Shahid, and S. Hassan.Claudin-1 required for hcv virus entry has high potentialfor phosphorylation and o-glycosylation.
Virol J , 8:229,2011. ISSN 1743-422X (Electronic) 1743-422X (Linking). doi:10.1186/1743-422X-8-229. URL .[3] M. N. Ajuebor, C. M. Hogaboam, T. Le, and M. G. Swain.C-c chemokine ligand 2/monocyte chemoattractant protein-1 directly inhibits nkt cell il-4 production and is hepato-protective in t cell-mediated hepatitis in the mouse.
J Im-munol , 170(10):5252–9, 2003. ISSN 0022-1767 (Print) 0022-1767 (Linking). doi: 10.4049/jimmunol.170.10.5252. URL .[4] D. R. Alessi, A. Cuenda, P. Cohen, D. T. Dudley, and A. R.Saltiel. Pd 098059 is a specific inhibitor of the activation ofmitogen-activated protein kinase kinase in vitro and in vivo.
JBiol Chem , 270(46):27489–94, 1995. ISSN 0021-9258 (Print)0021-9258 (Linking). doi: 10.1074/jbc.270.46.27489. URL .[5] M. M. Alfajaro, E. H. Cho, D. S. Kim, J. Y. Kim, J. G.Park, M. Soliman, Y. B. Baek, C. H. Park, M. I. Kang,S. I. Park, and K. O. Cho. Early porcine sapovirus infec-tion disrupts tight junctions and uses occludin as a core-ceptor.
J Virol , 93(4), 2019. ISSN 1098-5514 (Electronic)0022-538X (Linking). doi: 10.1128/JVI.01773-18. URL .[6] A. Y. Andreeva, E. Krause, E. C. Muller, I. E. Blasig, andD. I. Utepbergenov. Protein kinase c regulates the phos-phorylation and cellular localization of occludin.
J BiolChem , 276(42):38480–6, 2001. ISSN 0021-9258 (Print) 0021-9258 (Linking). doi: 10.1074/jbc.M104923200. URL .[7] D. A. Antonetti, A. J. Barber, L. A. Hollinger, E. B. Wolpert,and T. W. Gardner. Vascular endothelial growth factor in-duces rapid phosphorylation of tight junction proteins oc-cludin and zonula occluden 1. a potential mechanism for vas-cular permeability in diabetic retinopathy and tumors.
JBiol Chem , 274(33):23463–7, 1999. ISSN 0021-9258 (Print)0021-9258 (Linking). doi: 10.1074/jbc.274.33.23463. URL .[8] S. Aono and Y. Hirai. Phosphorylation of claudin-4 is re-quired for tight junction formation in a human keratinocytecell line.
Exp Cell Res , 314(18):3326–39, 2008. ISSN 1090-2422 (Electronic) 0014-4827 (Linking). doi: 10.1016/j.yexcr.2008.08.012. URL .[9] H. Arisawa, E. Imai, N. Fujise, K. Fukui, and H. Masunaga.General pharmacological profile of the novel muscarinic re-ceptor agonist sni-2011, a drug for xerostomia in sjogren’ssyndrome. 1st communication: effects on general behaviorand central nervous system.
Arzneimittelforschung , 52(1):14–20, 2002. ISSN 0004-4172 (Print) 0004-4172 (Linking).doi: 10.1055/s-0031-1299850. URL .[10] H. Asada, K. Uyemura, and T. Shirao. Actin-binding protein,drebrin, accumulates in submembranous regions in parallelwith neuronal differentiation.
J Neurosci Res , 38(2):149–59,1994. ISSN 0360-4012 (Print) 0360-4012 (Linking). doi: 10.1002/jnr.490380205. URL . [11] T. Asakura, H. Nakanishi, T. Sakisaka, K. Takahashi,K. Mandai, M. Nishimura, T. Sasaki, and Y. Takai. Sim-ilar and differential behaviour between the nectin-afadin-ponsin and cadherin-catenin systems during the formationand disruption of the polarized junctional alignment in ep-ithelial cells.
Genes Cells , 4(10):573–81, 1999. ISSN 1356-9597 (Print) 1356-9597 (Linking). doi: 10.1046/j.1365-2443.1999.00283.x. URL .[12] M. S. Balda, L. Gonzalez-Mariscal, K. Matter, M. Cerei-jido, and J. M. Anderson. Assembly of the tight junction:the role of diacylglycerol.
J Cell Biol , 123(2):293–302, 1993.ISSN 0021-9525 (Print) 0021-9525 (Linking). doi: 10.1083/jcb.123.2.293. URL .[13] Y. Baron, P. G. Pedrioli, K. Tyagi, C. Johnson, N. T.Wood, D. Fountaine, M. Wightman, and G. Alexandru.Vapb/als8 interacts with ffat-like proteins including the p97cofactor faf1 and the asna1 atpase.
BMC Biol , 12:39,2014. ISSN 1741-7007 (Electronic) 1741-7007 (Linking). doi:10.1186/1741-7007-12-39. URL .[14] J. G. Barriocanal, J. S. Bonifacino, L. Yuan, and I. V. San-doval. Biosynthesis, glycosylation, movement through thegolgi system, and transport to lysosomes by an n-linkedcarbohydrate-independent mechanism of three lysosomal in-tegral membrane proteins.
J Biol Chem , 261(35):16755–63,1986. ISSN 0021-9258 (Print) 0021-9258 (Linking). URL .[15] A. M. Bashour, A. T. Fullerton, M. J. Hart, and G. S.Bloom. Iqgap1, a rac- and cdc42-binding protein, directlybinds and cross-links microfilaments.
J Cell Biol , 137(7):1555–66, 1997. ISSN 0021-9525 (Print) 0021-9525 (Linking).doi: 10.1083/jcb.137.7.1555. URL .[16] M. K. Bennett, J. E. Garcia-Arraras, L. A. Elferink, K. Pe-terson, A. M. Fleming, C. D. Hazuka, and R. H. Scheller.The syntaxin family of vesicular transport receptors.
Cell ,74(5):863–73, 1993. ISSN 0092-8674 (Print) 0092-8674 (Link-ing). doi: 10.1016/0092-8674(93)90466-4. URL .[17] O. Beutel, R. Maraspini, K. Pombo-Garcia, C. Martin-Lemaitre, and A. Honigmann. Phase separation of zonulaoccludens proteins drives formation of tight junctions.
Cell ,179(4):923–936 e11, 2019. ISSN 1097-4172 (Electronic) 0092-8674 (Linking). doi: 10.1016/j.cell.2019.10.011. URL .[18] B. Boettner, E. E. Govek, J. Cross, and L. Van Aelst. Thejunctional multidomain protein af-6 is a binding partner ofthe rap1a gtpase and associates with the actin cytoskeletalregulator profilin.
Proc Natl Acad Sci U S A , 97(16):9064–9, 2000. ISSN 0027-8424 (Print) 0027-8424 (Linking). doi:10.1073/pnas.97.16.9064. URL .[19] G. M. Bokoch. Biology of the p21-activated kinases.
Annu RevBiochem , 72:743–81, 2003. ISSN 0066-4154 (Print) 0066-4154(Linking). doi: 10.1146/annurev.biochem.72.121801.161742.URL .[20] M. J. Bouchard, Y. Dong, J. McDermott, B. M., D. H.Lam, K. R. Brown, M. Shelanski, A. R. Bellve, and V. R.Racaniello. Defects in nuclear and cytoskeletal morphologyand mitochondrial localization in spermatozoa of mice lack-ing nectin-2, a component of cell-cell adherens junctions.
MolCell Biol , 20(8):2865–73, 2000. ISSN 0270-7306 (Print) 0270-7306 (Linking). doi: 10.1128/mcb.20.8.2865-2873.2000. URL .
21] C. A. Boucher, H. H. Ward, R. L. Case, K. S. Thurston,X. Li, A. Needham, E. Romero, D. Hyink, S. Qamar, T. Roit-bak, S. Powell, C. Ward, P. D. Wilson, A. Wandinger-Ness,and R. N. Sandford. Receptor protein tyrosine phosphatasesare novel components of a polycystin complex.
Biochim Bio-phys Acta , 1812(10):1225–38, 2011. ISSN 0006-3002 (Print)0006-3002 (Linking). doi: 10.1016/j.bbadis.2010.11.006. URL .[22] F. M. Brodsky, C. Y. Chen, C. Knuehl, M. C. Towler, andD. E. Wakeham. Biological basket weaving: formation andfunction of clathrin-coated vesicles.
Annu Rev Cell Dev Biol ,17:517–68, 2001. ISSN 1081-0706 (Print) 1081-0706 (Link-ing). doi: 10.1146/annurev.cellbio.17.1.517. URL .[23] M. Bruewer, M. Utech, A. I. Ivanov, A. M. Hopkins,C. A. Parkos, and A. Nusrat. Interferon-gamma inducesinternalization of epithelial tight junction proteins via amacropinocytosis-like process.
FASEB J , 19(8):923–33, 2005.ISSN 1530-6860 (Electronic) 0892-6638 (Linking). doi: 10.1096/fj.04-3260com. URL .[24] D. M. Bryant and J. L. Stow. The ins and outs of e-cadherintrafficking.
Trends Cell Biol , 14(8):427–34, 2004. ISSN0962-8924 (Print) 0962-8924 (Linking). doi: 10.1016/j.tcb.2004.07.007. URL .[25] D. M. Bryant, M. C. Kerr, L. A. Hammond, S. R. Joseph,K. E. Mostov, R. D. Teasdale, and J. L. Stow. Egf in-duces macropinocytosis and snx1-modulated recycling of e-cadherin.
J Cell Sci , 120(Pt 10):1818–28, 2007. ISSN 0021-9533 (Print) 0021-9533 (Linking). doi: 10.1242/jcs.000653.URL .[26] C. D. Buckley, J. Tan, K. L. Anderson, D. Hanein, N. Volk-mann, W. I. Weis, W. J. Nelson, and A. R. Dunn. Celladhesion. the minimal cadherin-catenin complex binds toactin filaments under force.
Science , 346(6209):1254211,2014. ISSN 1095-9203 (Electronic) 0036-8075 (Linking). doi:10.1126/science.1254211. URL .[27] M. V. Bujny, V. Popoff, L. Johannes, and P. J. Cullen. Theretromer component sorting nexin-1 is required for efficientretrograde transport of shiga toxin from early endosome tothe trans golgi network.
J Cell Sci , 120(Pt 12):2010–21,2007. ISSN 0021-9533 (Print) 0021-9533 (Linking). doi:10.1242/jcs.003111. URL .[28] C. Burd and P. J. Cullen. Retromer: a master conductorof endosome sorting.
Cold Spring Harb Perspect Biol , 6(2),2014. ISSN 1943-0264 (Electronic) 1943-0264 (Linking). doi:10.1101/cshperspect.a016774. URL .[29] M. M. Buschmann, L. Shen, H. Rajapakse, D. R. Raleigh,Y. Wang, Y. Wang, A. Lingaraju, J. Zha, E. Abbott, E. M.McAuley, L. A. Breskin, L. Wu, K. Anderson, J. R. Turner,and C. R. Weber. Occludin ocel-domain interactions arerequired for maintenance and regulation of the tight junc-tion barrier to macromolecular flux.
Mol Biol Cell , 24(19):3056–68, 2013. ISSN 1939-4586 (Electronic) 1059-1524 (Link-ing). doi: 10.1091/mbc.E12-09-0688. URL .[30] B. P. Ceresa and S. J. Bahr. rab7 activity affects epidermalgrowth factor:epidermal growth factor receptor degradationby regulating endocytic trafficking from the late endosome.
JBiol Chem , 281(2):1099–106, 2006. ISSN 0021-9258 (Print)0021-9258 (Linking). doi: 10.1074/jbc.M504175200. URL . [31] A. J. Charron, S. Nakamura, R. Bacallao, and A. Wandinger-Ness. Compromised cytoarchitecture and polarized traffickingin autosomal dominant polycystic kidney disease cells.
J CellBiol , 149(1):111–24, 2000. ISSN 0021-9525 (Print) 0021-9525(Linking). doi: 10.1083/jcb.149.1.111. URL .[32] P. Chavrier, R. G. Parton, H. P. Hauri, K. Simons, andM. Zerial. Localization of low molecular weight gtp bind-ing proteins to exocytic and endocytic compartments.
Cell ,62(2):317–29, 1990. ISSN 0092-8674 (Print) 0092-8674 (Link-ing). doi: 10.1016/0092-8674(90)90369-p. URL .[33] J. W. Chen, T. L. Murphy, M. C. Willingham, I. Pastan,and J. T. August. Identification of two lysosomal membraneglycoproteins.
J Cell Biol , 101(1):85–95, 1985. ISSN 0021-9525 (Print) 0021-9525 (Linking). doi: 10.1083/jcb.101.1.85.URL .[34] X. Chen, S. Kojima, G. G. Borisy, and K. J. Green. p120catenin associates with kinesin and facilitates the transportof cadherin-catenin complexes to intercellular junctions.
JCell Biol , 163(3):547–57, 2003. ISSN 0021-9525 (Print) 0021-9525 (Linking). doi: 10.1083/jcb.200305137. URL .[35] C. M. Chiasson, K. B. Wittich, P. A. Vincent, V. Faun-dez, and A. P. Kowalczyk. p120-catenin inhibits ve-cadherininternalization through a rho-independent mechanism.
MolBiol Cell , 20(7):1970–80, 2009. ISSN 1939-4586 (Electronic)1059-1524 (Linking). doi: 10.1091/mbc.E08-07-0735. URL .[36] H. Chichger, H. Duong, J. Braza, and E. O. Harrington.p18, a novel adaptor protein, regulates pulmonary endothe-lial barrier function via enhanced endocytic recycling of ve-cadherin.
FASEB J , 29(3):868–81, 2015. ISSN 1530-6860(Electronic) 0892-6638 (Linking). doi: 10.1096/fj.14-257212.URL .[37] C. Clement, V. Tiwari, P. M. Scanlan, T. Valyi-Nagy, B. Y.Yue, and D. Shukla. A novel role for phagocytosis-like uptakein herpes simplex virus entry.
J Cell Biol , 174(7):1009–21,2006. ISSN 0021-9525 (Print) 0021-9525 (Linking). doi: 10.1083/jcb.200509155. URL .[38] N. Colas-Algora and J. Millan. How many cadherins do hu-man endothelial cells express?
Cell Mol Life Sci , 76(7):1299–1317, 2019. ISSN 1420-9071 (Electronic) 1420-682X(Linking). doi: 10.1007/s00018-018-2991-9. URL .[39] B. M. Collins, A. J. McCoy, H. M. Kent, P. R. Evans, andD. J. Owen. Molecular architecture and functional modelof the endocytic ap2 complex.
Cell , 109(4):523–35, 2002.ISSN 0092-8674 (Print) 0092-8674 (Linking). doi: 10.1016/s0092-8674(02)00735-3. URL .[40] X. Cong, Y. Zhang, J. Li, M. Mei, C. Ding, R. L. Xiang,L. W. Zhang, Y. Wang, L. L. Wu, and G. Y. Yu. Claudin-4 is required for modulation of paracellular permeability bymuscarinic acetylcholine receptor in epithelial cells.
J Cell Sci ,128(12):2271–86, 2015. ISSN 1477-9137 (Electronic) 0021-9533 (Linking). doi: 10.1242/jcs.165878. URL .[41] R. Y. Dahdal and K. J. Colley. Specific sequences in the sig-nal anchor of the beta-galactoside alpha-2,6-sialyltransferaseare not essential for golgi localization. membrane flanking se-quences may specify golgi retention.
J Biol Chem , 268(35):26310–9, 1993. ISSN 0021-9258 (Print) 0021-9258 (Linking).URL .
42] H. Damke, T. Baba, D. E. Warnock, and S. L. Schmid.Induction of mutant dynamin specifically blocks endocyticcoated vesicle formation.
J Cell Biol , 127(4):915–34, 1994.ISSN 0021-9525 (Print) 0021-9525 (Linking). doi: 10.1083/jcb.127.4.915. URL .[43] J. Dancourt and C. Barlowe. Protein sorting receptors inthe early secretory pathway.
Annu Rev Biochem , 79:777–802, 2010. ISSN 1545-4509 (Electronic) 0066-4154 (Linking).doi: 10.1146/annurev-biochem-061608-091319. URL .[44] E. Daro, P. van der Sluijs, T. Galli, and I. Mellman. Rab4 andcellubrevin define different early endosome populations on thepathway of transferrin receptor recycling.
Proc Natl Acad SciU S A , 93(18):9559–64, 1996. ISSN 0027-8424 (Print) 0027-8424 (Linking). doi: 10.1073/pnas.93.18.9559. URL .[45] M. A. Davis, R. C. Ireton, and A. B. Reynolds. A core func-tion for p120-catenin in cadherin turnover.
J Cell Biol , 163(3):525–34, 2003. ISSN 0021-9525 (Print) 0021-9525 (Link-ing). doi: 10.1083/jcb.200307111. URL .[46] S. de Beco, C. Gueudry, F. Amblard, and S. Coscoy. En-docytosis is required for e-cadherin redistribution at matureadherens junctions.
Proc Natl Acad Sci U S A , 106(17):7010–5, 2009. ISSN 1091-6490 (Electronic) 0027-8424 (Linking).doi: 10.1073/pnas.0811253106. URL .[47] G. De Rossi, M. Vahatupa, E. Cristante, S. Arokiasamy,S. E. Liyanage, U. May, L. Pellinen, H. Uusitalo-Jarvinen,J. W. Bainbridge, T. A. H. Jarvinen, and J. R. White-ford. Pathological angiogenesis requires syndecan-4 for effi-cient vegfa (vascular endothelial growth factor a)-induced ve-cadherin internalization.
Arterioscler Thromb Vasc Biol , pageATVBAHA121315941, 2021. ISSN 1524-4636 (Electronic)1079-5642 (Linking). doi: 10.1161/ATVBAHA.121.315941.URL .[48] M. Desclozeaux, J. Venturato, F. G. Wylie, J. G. Kay, S. R.Joseph, H. T. Le, and J. L. Stow. Active rab11 and func-tional recycling endosome are required for e-cadherin traffick-ing and lumen formation during epithelial morphogenesis.
AmJ Physiol Cell Physiol , 295(2):C545–56, 2008. ISSN 0363-6143(Print) 0363-6143 (Linking). doi: 10.1152/ajpcell.00097.2008.URL .[49] G. J. Doherty and H. T. McMahon. Mechanisms of en-docytosis.
Annu Rev Biochem , 78:857–902, 2009. ISSN1545-4509 (Electronic) 0066-4154 (Linking). doi: 10.1146/annurev.biochem.78.081307.110540. URL .[50] Y. L. Dorland, T. S. Malinova, A. M. van Stalborch, A. G.Grieve, D. van Geemen, N. S. Jansen, B. J. de Kreuk,K. Nawaz, J. Kole, D. Geerts, R. J. Musters, J. de Rooij,P. L. Hordijk, and S. Huveneers. The f-bar protein pac-sin2 inhibits asymmetric ve-cadherin internalization fromtensile adherens junctions.
Nat Commun , 7:12210, 2016.ISSN 2041-1723 (Electronic) 2041-1723 (Linking). doi: 10.1038/ncomms12210. URL .[51] T. D’Souza, R. Agarwal, and P. J. Morin. Phosphorylationof claudin-3 at threonine 192 by camp-dependent protein ki-nase regulates tight junction barrier function in ovarian cancercells.
J Biol Chem , 280(28):26233–40, 2005. ISSN 0021-9258(Print) 0021-9258 (Linking). doi: 10.1074/jbc.M502003200.URL .[52] T. D’Souza, F. E. Indig, and P. J. Morin. Phosphoryla-tion of claudin-4 by pkcepsilon regulates tight junction bar-rier function in ovarian cancer cells.
Exp Cell Res , 313(15):3364–75, 2007. ISSN 0014-4827 (Print) 0014-4827 (Linking). doi: 10.1016/j.yexcr.2007.06.026. URL .[53] C. D’Souza-Schorey, E. van Donselaar, V. W. Hsu, C. Yang,P. D. Stahl, and P. J. Peters. Arf6 targets recycling vesiclesto the plasma membrane: insights from an ultrastructuralinvestigation.
J Cell Biol , 140(3):603–16, 1998. ISSN 0021-9525 (Print) 0021-9525 (Linking). doi: 10.1083/jcb.140.3.603.URL .[54] A. Dudak, J. Kim, B. Cheong, H. J. Federoff, and S. T.Lim. Membrane palmitoylated proteins regulate traffick-ing and processing of nectins.
Eur J Cell Biol , 90(5):365–75, 2011. ISSN 1618-1298 (Electronic) 0171-9335 (Linking).doi: 10.1016/j.ejcb.2011.01.004. URL .[55] D. T. Dudley, L. Pang, S. J. Decker, A. J. Bridges, and A. R.Saltiel. A synthetic inhibitor of the mitogen-activated pro-tein kinase cascade.
Proc Natl Acad Sci U S A , 92(17):7686–9, 1995. ISSN 0027-8424 (Print) 0027-8424 (Linking). doi:10.1073/pnas.92.17.7686. URL .[56] J. D. Dukes, J. D. Richardson, R. Simmons, and P. Whitley.A dominant-negative escrt-iii protein perturbs cytokinesis andtrafficking to lysosomes.
Biochem J , 411(2):233–9, 2008. ISSN1470-8728 (Electronic) 0264-6021 (Linking). doi: 10.1042/BJ20071296. URL .[57] J. D. Dukes, L. Fish, J. D. Richardson, E. Blaikley, S. Burns,C. J. Caunt, A. D. Chalmers, and P. Whitley. Functional escrtmachinery is required for constitutive recycling of claudin-1 and maintenance of polarity in vertebrate epithelial cells.
Mol Biol Cell , 22(17):3192–205, 2011. ISSN 1939-4586 (Elec-tronic) 1059-1524 (Linking). doi: 10.1091/mbc.E11-04-0343.URL .[58] J. D. Dukes, P. Whitley, and A. D. Chalmers. The pikfyve in-hibitor ym201636 blocks the continuous recycling of the tightjunction proteins claudin-1 and claudin-2 in mdck cells.
PLoSOne , 7(3):e28659, 2012. ISSN 1932-6203 (Electronic) 1932-6203 (Linking). doi: 10.1371/journal.pone.0028659. URL .[59] K. Ebnet, C. U. Schulz, M. K. Meyer Zu Brickwedde, G. G.Pendl, and D. Vestweber. Junctional adhesion molecule inter-acts with the pdz domain-containing proteins af-6 and zo-1.
JBiol Chem , 275(36):27979–88, 2000. ISSN 0021-9258 (Print)0021-9258 (Linking). doi: 10.1074/jbc.M002363200. URL .[60] K. Ebnet, M. Aurrand-Lions, A. Kuhn, F. Kiefer, S. Butz,K. Zander, M. K. Meyer zu Brickwedde, A. Suzuki, B. A.Imhof, and D. Vestweber. The junctional adhesion molecule(jam) family members jam-2 and jam-3 associate with the cellpolarity protein par-3: a possible role for jams in endothelialcell polarity.
J Cell Sci , 116(Pt 19):3879–91, 2003. ISSN 0021-9533 (Print) 0021-9533 (Linking). doi: 10.1242/jcs.00704.URL .[61] B. C. Elias, T. Suzuki, A. Seth, F. Giorgianni, G. Kale,L. Shen, J. R. Turner, A. Naren, D. M. Desiderio, andR. Rao. Phosphorylation of tyr-398 and tyr-402 in occludinprevents its interaction with zo-1 and destabilizes its assem-bly at the tight junctions.
J Biol Chem , 284(3):1559–69,2009. ISSN 0021-9258 (Print) 0021-9258 (Linking). doi:10.1074/jbc.M804783200. URL .[62] P. A. Eyers, M. Craxton, N. Morrice, P. Cohen, andM. Goedert. Conversion of sb 203580-insensitive map ki-nase family members to drug-sensitive forms by a sin-gle amino-acid substitution.
Chem Biol , 5(6):321–8, 1998.ISSN 1074-5521 (Print) 1074-5521 (Linking). doi: 10.1016/s1074-5521(98)90170-3. URL .
63] S. J. Fletcher, N. S. Poulter, E. J. Haining, and J. Z.Rappoport. Clathrin-mediated endocytosis regulates oc-cludin, and not focal adhesion, distribution during epithelialwound healing.
Biol Cell , 104(4):238–56, 2012. ISSN 1768-322X (Electronic) 0248-4900 (Linking). doi: 10.1111/boc.201100004. URL .[64] S. J. Fletcher, M. Iqbal, S. Jabbari, D. Stekel, and J. Z. Rap-poport. Analysis of occludin trafficking, demonstrating con-tinuous endocytosis, degradation, recycling and biosyntheticsecretory trafficking.
PLoS One , 9(11):e111176, 2014. ISSN1932-6203 (Electronic) 1932-6203 (Linking). doi: 10.1371/journal.pone.0111176. URL .[65] H. Folsch, M. Pypaert, S. Maday, L. Pelletier, and I. Mell-man. The ap-1a and ap-1b clathrin adaptor complexes de-fine biochemically and functionally distinct membrane do-mains.
J Cell Biol , 163(2):351–62, 2003. ISSN 0021-9525(Print) 0021-9525 (Linking). doi: 10.1083/jcb.200309020.URL .[66] M. Fujibe, H. Chiba, T. Kojima, T. Soma, T. Wada, T. Ya-mashita, and N. Sawada. Thr203 of claudin-1, a putativephosphorylation site for map kinase, is required to promotethe barrier function of tight junctions.
Exp Cell Res , 295(1):36–47, 2004. ISSN 0014-4827 (Print) 0014-4827 (Linking).doi: 10.1016/j.yexcr.2003.12.014. URL .[67] N. Fujii, Y. Matsuo, T. Matsunaga, S. Endo, H. Sakai, M. Ya-maguchi, Y. Yamazaki, J. Sugatani, and A. Ikari. Hypo-tonic stress-induced down-regulation of claudin-1 and -2 me-diated by dephosphorylation and clathrin-dependent endo-cytosis in renal tubular epithelial cells.
J Biol Chem , 291(47):24787–24799, 2016. ISSN 1083-351X (Electronic) 0021-9258 (Linking). doi: 10.1074/jbc.M116.728196. URL .[68] Y. Fujita, G. Krause, M. Scheffner, D. Zechner, H. E. Leddy,J. Behrens, T. Sommer, and W. Birchmeier. Hakai, a c-cbl-like protein, ubiquitinates and induces endocytosis of the e-cadherin complex.
Nat Cell Biol , 4(3):222–31, 2002. ISSN1465-7392 (Print) 1465-7392 (Linking). doi: 10.1038/ncb758.URL .[69] T. Fujito, W. Ikeda, S. Kakunaga, Y. Minami, M. Kajita,Y. Sakamoto, M. Monden, and Y. Takai. Inhibition of cellmovement and proliferation by cell-cell contact-induced in-teraction of necl-5 with nectin-3.
J Cell Biol , 171(1):165–73, 2005. ISSN 0021-9525 (Print) 0021-9525 (Linking). doi:10.1083/jcb.200501090. URL .[70] A. Fukuhara, K. Irie, H. Nakanishi, K. Takekuni,T. Kawakatsu, W. Ikeda, A. Yamada, T. Katata, T. Honda,T. Sato, K. Shimizu, H. Ozaki, H. Horiuchi, T. Kita, andY. Takai. Involvement of nectin in the localization of junc-tional adhesion molecule at tight junctions.
Oncogene , 21(50):7642–55, 2002. ISSN 0950-9232 (Print) 0950-9232 (Linking).doi: 10.1038/sj.onc.1205875. URL .[71] M. Furuse, K. Fujita, T. Hiiragi, K. Fujimoto, and S. Tsukita.Claudin-1 and -2: novel integral membrane proteins localizingat tight junctions with no sequence similarity to occludin.
JCell Biol , 141(7):1539–50, 1998. ISSN 0021-9525 (Print) 0021-9525 (Linking). doi: 10.1083/jcb.141.7.1539. URL .[72] M. Furuse, H. Sasaki, K. Fujimoto, and S. Tsukita. A sin-gle gene product, claudin-1 or -2, reconstitutes tight junc-tion strands and recruits occludin in fibroblasts.
J CellBiol , 143(2):391–401, 1998. ISSN 0021-9525 (Print) 0021-9525 (Linking). doi: 10.1083/jcb.143.2.391. URL . [73] M. Furuse, H. Sasaki, and S. Tsukita. Manner of interaction ofheterogeneous claudin species within and between tight junc-tion strands.
J Cell Biol , 147(4):891–903, 1999. ISSN 0021-9525 (Print) 0021-9525 (Linking). doi: 10.1083/jcb.147.4.891.URL .[74] Y. Gao and W. Y. Lui. Transforming growth factor-beta1(tgf-beta1) regulates cell junction restructuring via smad-mediated repression and clathrin-mediated endocytosis ofnectin-like molecule 2 (necl-2).
PLoS One , 8(5):e64316,2013. ISSN 1932-6203 (Electronic) 1932-6203 (Linking). doi:10.1371/journal.pone.0064316. URL .[75] S. M. Garrard, C. T. Capaldo, L. Gao, M. K. Rosen, I. G.Macara, and D. R. Tomchick. Structure of cdc42 in a com-plex with the gtpase-binding domain of the cell polarity pro-tein, par6.
EMBO J , 22(5):1125–33, 2003. ISSN 0261-4189(Print) 0261-4189 (Linking). doi: 10.1093/emboj/cdg110.URL .[76] J. Gavard and J. S. Gutkind. Vegf controls endothelial-cell permeability by promoting the beta-arrestin-dependentendocytosis of ve-cadherin.
Nat Cell Biol , 8(11):1223–34,2006. ISSN 1465-7392 (Print) 1465-7392 (Linking). doi: 10.1038/ncb1486. URL .[77] N. Gehne, A. Lamik, M. Lehmann, R. F. Haseloff, A. V. And-jelkovic, and I. E. Blasig. Cross-over endocytosis of claudinsis mediated by interactions via their extracellular loops.
PLoSOne , 12(8):e0182106, 2017. ISSN 1932-6203 (Electronic) 1932-6203 (Linking). doi: 10.1371/journal.pone.0182106. URL .[78] A. R. Generous, O. J. Harrison, R. B. Troyanovsky, M. Ma-teo, C. K. Navaratnarajah, R. C. Donohue, C. K. Pfaller,O. Alekhina, A. P. Sergeeva, I. Indra, T. Thornburg, I. Ko-chetkova, D. D. Billadeau, M. P. Taylor, S. M. Troyanovsky,B. Honig, L. Shapiro, and R. Cattaneo. Trans-endocytosiselicited by nectins transfers cytoplasmic cargo, includinginfectious material, between cells.
J Cell Sci , 132(16),2019. ISSN 1477-9137 (Electronic) 0021-9533 (Linking). doi:10.1242/jcs.235507. URL .[79] M. Georgiou, E. Marinari, J. Burden, and B. Baum. Cdc42,par6, and apkc regulate arp2/3-mediated endocytosis to con-trol local adherens junction stability.
Curr Biol , 18(21):1631–8, 2008. ISSN 0960-9822 (Print) 0960-9822 (Linking). doi:10.1016/j.cub.2008.09.029. URL .[80] R. J. Geraghty, C. Krummenacher, G. H. Cohen, R. J. Eisen-berg, and P. G. Spear. Entry of alphaherpesviruses medi-ated by poliovirus receptor-related protein 1 and poliovirusreceptor.
Science , 280(5369):1618–20, 1998. ISSN 0036-8075 (Print) 0036-8075 (Linking). doi: 10.1126/science.280.5369.1618. URL .[81] L. G. Glotfelty, A. Zahs, C. Iancu, L. Shen, and G. A. Hecht.Microtubules are required for efficient epithelial tight junctionhomeostasis and restoration.
Am J Physiol Cell Physiol , 307(3):C245–54, 2014. ISSN 1522-1563 (Electronic) 0363-6143(Linking). doi: 10.1152/ajpcell.00336.2013. URL .[82] S. Gokool, D. Tattersall, and M. N. Seaman. Ehd1 in-teracts with retromer to stabilize snx1 tubules and facili-tate endosome-to-golgi retrieval.
Traffic , 8(12):1873–86, 2007.ISSN 1398-9219 (Print) 1398-9219 (Linking). doi: 10.1111/j.1600-0854.2007.00652.x. URL .[83] H. Gong, X. Gao, S. Feng, M. R. Siddiqui, A. Garcia, M. G.Bonini, Y. Komarova, S. M. Vogel, D. Mehta, and A. B. Malik.Evidence of a common mechanism of disassembly of adherens unctions through galpha13 targeting of ve-cadherin. J ExpMed , 211(3):579–91, 2014. ISSN 1540-9538 (Electronic) 0022-1007 (Linking). doi: 10.1084/jem.20131190. URL .[84] C. M. Grimsley-Myers, R. H. Isaacson, C. M. Cadwell,J. Campos, M. S. Hernandes, K. R. Myers, T. Seo, W. Gi-ang, K. K. Griendling, and A. P. Kowalczyk. Ve-cadherinendocytosis controls vascular integrity and patterning duringdevelopment.
J Cell Biol , 219(5), 2020. ISSN 1540-8140 (Elec-tronic) 0021-9525 (Linking). doi: 10.1083/jcb.201909081.URL .[85] D. Guerrera, J. Shah, E. Vasileva, S. Sluysmans, I. Mean,L. Jond, I. Poser, M. Mann, A. A. Hyman, and S. Citi.Plekha7 recruits pdzd11 to adherens junctions to stabilizenectins.
J Biol Chem , 291(21):11016–29, 2016. ISSN 1083-351X (Electronic) 0021-9258 (Linking). doi: 10.1074/jbc.M115.712935. URL .[86] D. Gunzel. Claudins: vital partners in transcellular andparacellular transport coupling.
Pflugers Arch , 469(1):35–44, 2017. ISSN 1432-2013 (Electronic) 0031-6768 (Linking).doi: 10.1007/s00424-016-1909-3. URL .[87] S. J. Hagen. Non-canonical functions of claudin proteins:Beyond the regulation of cell-cell adhesions.
Tissue Barri-ers , 5(2):e1327839, 2017. ISSN 2168-8370 (Electronic) 2168-8362 (Linking). doi: 10.1080/21688370.2017.1327839. URL .[88] J. A. Hanover, M. C. Willingham, and I. Pastan. Ki-netics of transit of transferrin and epidermal growth fac-tor through clathrin-coated membranes.
Cell , 39(2 Pt 1):283–93, 1984. ISSN 0092-8674 (Print) 0092-8674 (Link-ing). doi: 10.1016/0092-8674(84)90006-0. URL .[89] N. S. Harhaj, E. A. Felinski, E. B. Wolpert, J. M. Sund-strom, T. W. Gardner, and D. A. Antonetti. Vegf acti-vation of protein kinase c stimulates occludin phosphory-lation and contributes to endothelial permeability.
InvestOphthalmol Vis Sci , 47(11):5106–15, 2006. ISSN 0146-0404(Print) 0146-0404 (Linking). doi: 10.1167/iovs.06-0322. URL .[90] T. S. Harmon, A. S. Holehouse, M. K. Rosen, and R. V.Pappu. Intrinsically disordered linkers determine the inter-play between phase separation and gelation in multivalentproteins.
Elife , 6, 2017. ISSN 2050-084X (Electronic) 2050-084X (Linking). doi: 10.7554/eLife.30294. URL .[91] M. Y. Hein, N. C. Hubner, I. Poser, J. Cox, N. Nagaraj,Y. Toyoda, I. A. Gak, I. Weisswange, J. Mansfeld, F. Buch-holz, A. A. Hyman, and M. Mann. A human interactomein three quantitative dimensions organized by stoichiometriesand abundances.
Cell , 163(3):712–23, 2015. ISSN 1097-4172 (Electronic) 0092-8674 (Linking). doi: 10.1016/j.cell.2015.09.053. URL .[92] I. Helfrich, A. Schmitz, P. Zigrino, C. Michels, I. Haase,A. le Bivic, M. Leitges, and C. M. Niessen. Role of apkcisoforms and their binding partners par3 and par6 in epi-dermal barrier formation.
J Invest Dermatol , 127(4):782–91, 2007. ISSN 1523-1747 (Electronic) 0022-202X (Linking).doi: 10.1038/sj.jid.5700621. URL .[93] S. P. Herbert, S. Ponnambalam, and J. H. Walker. Cytosolicphospholipase a2-alpha mediates endothelial cell proliferationand is inactivated by association with the golgi apparatus.
Mol Biol Cell , 16(8):3800–9, 2005. ISSN 1059-1524 (Print)1059-1524 (Linking). doi: 10.1091/mbc.e05-02-0164. URL . [94] J. Heuser. Effects of cytoplasmic acidification on clathrin lat-tice morphology.
J Cell Biol , 108(2):401–11, 1989. ISSN 0021-9525 (Print) 0021-9525 (Linking). doi: 10.1083/jcb.108.2.401.URL .[95] K. Hofmann and L. Falquet. A ubiquitin-interacting mo-tif conserved in components of the proteasomal and lysoso-mal protein degradation systems.
Trends Biochem Sci , 26(6):347–50, 2001. ISSN 0968-0004 (Print) 0968-0004 (Link-ing). doi: 10.1016/s0968-0004(01)01835-7. URL .[96] S. Hong, R. B. Troyanovsky, and S. M. Troyanovsky. Sponta-neous assembly and active disassembly balance adherens junc-tion homeostasis.
Proc Natl Acad Sci U S A , 107(8):3528–33,2010. ISSN 1091-6490 (Electronic) 0027-8424 (Linking). doi:10.1073/pnas.0911027107. URL .[97] T. Hoshino, T. Sakisaka, T. Baba, T. Yamada, T. Kimura,and Y. Takai. Regulation of e-cadherin endocytosis by nectinthrough afadin, rap1, and p120ctn.
J Biol Chem , 280(25):24095–103, 2005. ISSN 0021-9258 (Print) 0021-9258 (Link-ing). doi: 10.1074/jbc.M414447200. URL .[98] J. Hou, A. Renigunta, J. Yang, and S. Waldegger. Claudin-4forms paracellular chloride channel in the kidney and requiresclaudin-8 for tight junction localization.
Proc Natl Acad SciU S A , 107(42):18010–5, 2010. ISSN 1091-6490 (Electronic)0027-8424 (Linking). doi: 10.1073/pnas.1009399107. URL .[99] V. W. Hsu, M. Bai, and J. Li. Getting active: protein sort-ing in endocytic recycling.
Nat Rev Mol Cell Biol , 13(5):323–8, 2012. ISSN 1471-0080 (Electronic) 1471-0072 (Link-ing). doi: 10.1038/nrm3332. URL .[100] A. H. Huber and W. I. Weis. The structure of the beta-catenin/e-cadherin complex and the molecular basis of di-verse ligand recognition by beta-catenin.
Cell , 105(3):391–402, 2001. ISSN 0092-8674 (Print) 0092-8674 (Linking).doi: 10.1016/s0092-8674(01)00330-0. URL .[101] D. Hulstrom and E. Svensjo. Intravital and electron mi-croscopic study of bradykinin-induced vascular permeabilitychanges using fitc-dextran as a tracer.
J Pathol , 129(3):125–33, 1979. ISSN 0022-3417 (Print) 0022-3417 (Linking). doi:10.1002/path.1711290304. URL .[102] R. J. Hung, C. W. Pak, and J. R. Terman. Direct redoxregulation of f-actin assembly and disassembly by mical.
Sci-ence , 334(6063):1710–3, 2011. ISSN 1095-9203 (Electronic)0036-8075 (Linking). doi: 10.1126/science.1211956. URL .[103] S. Huveneers, J. Oldenburg, E. Spanjaard, G. van der Krogt,I. Grigoriev, A. Akhmanova, H. Rehmann, and J. de Rooij.Vinculin associates with endothelial ve-cadherin junctions tocontrol force-dependent remodeling.
J Cell Biol , 196(5):641–52, 2012. ISSN 1540-8140 (Electronic) 0021-9525 (Linking).doi: 10.1083/jcb.201108120. URL .[104] A. Ikari, S. Matsumoto, H. Harada, K. Takagi, H. Hayashi,Y. Suzuki, M. Degawa, and M. Miwa. Phosphorylationof paracellin-1 at ser217 by protein kinase a is essentialfor localization in tight junctions.
J Cell Sci , 119(Pt 9):1781–9, 2006. ISSN 0021-9533 (Print) 0021-9533 (Linking).doi: 10.1242/jcs.02901. URL .[105] A. Ikari, A. Takiguchi, K. Atomi, and J. Sugatani. Epi-dermal growth factor increases clathrin-dependent endocyto-sis and degradation of claudin-2 protein in mdck ii cells. J ell Physiol , 226(9):2448–56, 2011. ISSN 1097-4652 (Elec-tronic) 0021-9541 (Linking). doi: 10.1002/jcp.22590. URL .[106] A. Ikari, C. Tonegawa, A. Sanada, T. Kimura, H. Sakai,H. Hayashi, H. Hasegawa, M. Yamaguchi, Y. Yamazaki,S. Endo, T. Matsunaga, and J. Sugatani. Tight junctionallocalization of claudin-16 is regulated by syntaxin 8 in re-nal tubular epithelial cells. J Biol Chem , 289(19):13112–23,2014. ISSN 1083-351X (Electronic) 0021-9258 (Linking). doi:10.1074/jbc.M113.541193. URL .[107] J. Ikenouchi, K. Umeda, S. Tsukita, M. Furuse, andS. Tsukita. Requirement of zo-1 for the formation of belt-like adherens junctions during epithelial cell polarization.
JCell Biol , 176(6):779–86, 2007. ISSN 0021-9525 (Print) 0021-9525 (Linking). doi: 10.1083/jcb.200612080. URL .[108] N. Ishiyama, S. H. Lee, S. Liu, G. Y. Li, M. J. Smith, L. F.Reichardt, and M. Ikura. Dynamic and static interactionsbetween p120 catenin and e-cadherin regulate the stabilityof cell-cell adhesion.
Cell , 141(1):117–28, 2010. ISSN 1097-4172 (Electronic) 0092-8674 (Linking). doi: 10.1016/j.cell.2010.01.017. URL .[109] M. Itoh, M. Furuse, K. Morita, K. Kubota, M. Saitou, andS. Tsukita. Direct binding of three tight junction-associatedmaguks, zo-1, zo-2, and zo-3, with the cooh termini ofclaudins.
J Cell Biol , 147(6):1351–63, 1999. ISSN 0021-9525(Print) 0021-9525 (Linking). doi: 10.1083/jcb.147.6.1351.URL .[110] A. I. Ivanov, A. Nusrat, and C. A. Parkos. Endocytosis ofepithelial apical junctional proteins by a clathrin-mediatedpathway into a unique storage compartment.
Mol BiolCell , 15(1):176–88, 2004. ISSN 1059-1524 (Print) 1059-1524 (Linking). doi: 10.1091/mbc.e03-05-0319. URL .[111] G. Izumi, T. Sakisaka, T. Baba, S. Tanaka, K. Morimoto,and Y. Takai. Endocytosis of e-cadherin regulated by rac andcdc42 small g proteins through iqgap1 and actin filaments.
JCell Biol , 166(2):237–48, 2004. ISSN 0021-9525 (Print) 0021-9525 (Linking). doi: 10.1083/jcb.200401078. URL .[112] S. Jain, T. Suzuki, A. Seth, G. Samak, and R. Rao. Proteinkinase czeta phosphorylates occludin and promotes assem-bly of epithelial tight junctions.
Biochem J , 437(2):289–99,2011. ISSN 1470-8728 (Electronic) 0264-6021 (Linking). doi:10.1042/BJ20110587. URL .[113] B. Jeansonne, Q. Lu, D. A. Goodenough, and Y. H. Chen.Claudin-8 interacts with multi-pdz domain protein 1 (mupp1)and reduces paracellular conductance in epithelial cells.
CellMol Biol (Noisy-le-grand) , 49(1):13–21, 2003. ISSN 0145-5680 (Print) 0145-5680 (Linking). URL .[114] H. B. Jefferies, F. T. Cooke, P. Jat, C. Boucheron, T. Koizumi,M. Hayakawa, H. Kaizawa, T. Ohishi, P. Workman, M. D.Waterfield, and P. J. Parker. A selective pikfyve inhibitorblocks ptdins(3,5)p(2) production and disrupts endomem-brane transport and retroviral budding.
EMBO Rep , 9(2):164–70, 2008. ISSN 1469-221X (Print) 1469-221X (Link-ing). doi: 10.1038/sj.embor.7401155. URL .[115] Y. Jiang, Y. R. Li, H. Tian, M. Ma, and H. Matsunami. Mus-carinic acetylcholine receptor m3 modulates odorant recep-tor activity via inhibition of beta-arrestin-2 recruitment.
Nat Commun , 6:6448, 2015. ISSN 2041-1723 (Electronic) 2041-1723 (Linking). doi: 10.1038/ncomms7448. URL .[116] L. S. Johnson, K. W. Dunn, B. Pytowski, and T. E. McGraw.Endosome acidification and receptor trafficking: bafilomycina1 slows receptor externalization by a mechanism involvingthe receptor’s internalization motif.
Mol Biol Cell , 4(12):1251–66, 1993. ISSN 1059-1524 (Print) 1059-1524 (Linking).doi: 10.1091/mbc.4.12.1251. URL .[117] D. J. Katzmann, M. Babst, and S. D. Emr. Ubiquitin-dependent sorting into the multivesicular body pathway re-quires the function of a conserved endosomal protein sort-ing complex, escrt-i.
Cell , 106(2):145–55, 2001. ISSN0092-8674 (Print) 0092-8674 (Linking). doi: 10.1016/s0092-8674(01)00434-2. URL .[118] D. J. Katzmann, G. Odorizzi, and S. D. Emr. Receptordownregulation and multivesicular-body sorting.
Nat RevMol Cell Biol , 3(12):893–905, 2002. ISSN 1471-0072 (Print)1471-0072 (Linking). doi: 10.1038/nrm973. URL .[119] P. J. Kausalya, S. Amasheh, D. Gunzel, H. Wurps, D. Muller,M. Fromm, and W. Hunziker. Disease-associated muta-tions affect intracellular traffic and paracellular mg2+ trans-port function of claudin-16.
J Clin Invest , 116(4):878–91,2006. ISSN 0021-9738 (Print) 0021-9738 (Linking). doi:10.1172/JCI26323. URL .[120] U. Kern, V. Wischnewski, M. L. Biniossek, O. Schilling,and T. Reinheckel. Lysosomal protein turnover contributesto the acquisition of tgfbeta-1 induced invasive propertiesof mammary cancer cells.
Mol Cancer , 14:39, 2015. ISSN1476-4598 (Electronic) 1476-4598 (Linking). doi: 10.1186/s12943-015-0313-5. URL .[121] T. Kimura, T. Sakisaka, T. Baba, T. Yamada, and Y. Takai.Involvement of the ras-ras-activated rab5 guanine nucleotideexchange factor rin2-rab5 pathway in the hepatocyte growthfactor-induced endocytosis of e-cadherin.
J Biol Chem , 281(15):10598–609, 2006. ISSN 0021-9258 (Print) 0021-9258(Linking). doi: 10.1074/jbc.M510531200. URL .[122] A. F. Kisselev and A. L. Goldberg. Proteasome inhibitors:from research tools to drug candidates.
Chem Biol , 8(8):739–58, 2001. ISSN 1074-5521 (Print) 1074-5521 (Link-ing). doi: 10.1016/s1074-5521(01)00056-4. URL .[123] K. B. Kostelnik, A. Barker, C. Schultz, T. P. Mitchell, V. Ra-jeeve, I. J. White, M. Aurrand-Lions, S. Nourshargh, P. Cutil-las, and T. D. Nightingale. Dynamic trafficking and turnoverof jam-c is essential for endothelial cell migration.
PLoS Biol ,17(12):e3000554, 2019. ISSN 1545-7885 (Electronic) 1544-9173 (Linking). doi: 10.1371/journal.pbio.3000554. URL .[124] P. Kota, E. M. Terrell, D. A. Ritt, C. Insinna, C. J. West-lake, and D. K. Morrison. M-ras/shoc2 signaling modulatese-cadherin turnover and cell-cell adhesion during collectivecell migration.
Proc Natl Acad Sci U S A , 116(9):3536–3545,2019. ISSN 1091-6490 (Electronic) 0027-8424 (Linking). doi:10.1073/pnas.1805919116. URL .[125] S. Kurita, T. Yamada, E. Rikitsu, W. Ikeda, and Y. Takai.Binding between the junctional proteins afadin and plekha7and implication in the formation of adherens junction inepithelial cells.
J Biol Chem , 288(41):29356–68, 2013.ISSN 1083-351X (Electronic) 0021-9258 (Linking). doi: 10.1074/jbc.M113.453464. URL . JBiol Chem , 271(38):23363–7, 1996. ISSN 0021-9258 (Print)0021-9258 (Linking). doi: 10.1074/jbc.271.38.23363. URL .[127] C. Lamagna, P. Meda, G. Mandicourt, J. Brown, R. J.Gilbert, E. Y. Jones, F. Kiefer, P. Ruga, B. A. Imhof, andM. Aurrand-Lions. Dual interaction of jam-c with jam-band alpha(m)beta2 integrin: function in junctional complexesand leukocyte adhesion.
Mol Biol Cell , 16(10):4992–5003,2005. ISSN 1059-1524 (Print) 1059-1524 (Linking). doi:10.1091/mbc.e05-04-0310. URL .[128] M. G. Lampugnani, M. Corada, L. Caveda, F. Breviario,O. Ayalon, B. Geiger, and E. Dejana. The molecular orga-nization of endothelial cell to cell junctions: differential asso-ciation of plakoglobin, beta-catenin, and alpha-catenin withvascular endothelial cadherin (ve-cadherin).
J Cell Biol , 129(1):203–17, 1995. ISSN 0021-9525 (Print) 0021-9525 (Link-ing). doi: 10.1083/jcb.129.1.203. URL .[129] M. G. Lampugnani, F. Orsenigo, M. C. Gagliani, C. Tac-chetti, and E. Dejana. Vascular endothelial cadherin controlsvegfr-2 internalization and signaling from intracellular com-partments.
J Cell Biol , 174(4):593–604, 2006. ISSN 0021-9525(Print) 0021-9525 (Linking). doi: 10.1083/jcb.200602080.URL .[130] M. A. Lanaspa, A. Andres-Hernando, C. J. Rivard, Y. Dai,and T. Berl. Hypertonic stress increases claudin-4 expres-sion and tight junction integrity in association with mupp1 inimcd3 cells.
Proc Natl Acad Sci U S A , 105(41):15797–802,2008. ISSN 1091-6490 (Electronic) 0027-8424 (Linking). doi:10.1073/pnas.0805761105. URL .[131] J. Langevin, M. J. Morgan, J. B. Sibarita, S. Aresta,M. Murthy, T. Schwarz, J. Camonis, and Y. Bellaiche.Drosophila exocyst components sec5, sec6, and sec15 regu-late de-cadherin trafficking from recycling endosomes to theplasma membrane.
Dev Cell , 9(3):365–76, 2005. ISSN 1534-5807 (Print) 1534-5807 (Linking). doi: 10.1016/j.devcel.2005.07.013. URL .[132] J. M. Larkin, M. S. Brown, J. L. Goldstein, and R. G. An-derson. Depletion of intracellular potassium arrests coatedpit formation and receptor-mediated endocytosis in fibrob-lasts.
Cell , 33(1):273–85, 1983. ISSN 0092-8674 (Print) 0092-8674 (Linking). doi: 10.1016/0092-8674(83)90356-2. URL .[133] M. Lavie, L. Linna, R. I. Moustafa, S. Belouzard, M. Fuka-sawa, and J. Dubuisson. Role of the cytosolic domain of oc-cludin in trafficking and hepatitis c virus infection.
Traffic ,20(10):753–773, 2019. ISSN 1600-0854 (Electronic) 1398-9219(Linking). doi: 10.1111/tra.12680. URL .[134] T. L. Le, A. S. Yap, and J. L. Stow. Recycling of e-cadherin: a potential mechanism for regulating cadherin dy-namics.
J Cell Biol , 146(1):219–32, 1999. ISSN 0021-9525(Print) 0021-9525 (Linking). URL .[135] A. Leibfried, R. Fricke, M. J. Morgan, S. Bogdan, and Y. Bel-laiche. Drosophila cip4 and wasp define a branch of thecdc42-par6-apkc pathway regulating e-cadherin endocytosis.
Curr Biol , 18(21):1639–48, 2008. ISSN 0960-9822 (Print)0960-9822 (Linking). doi: 10.1016/j.cub.2008.09.063. URL . [136] Y. Li, A. S. Fanning, J. M. Anderson, and A. Lavie. Struc-ture of the conserved cytoplasmic c-terminal domain of oc-cludin: identification of the zo-1 binding surface.
J MolBiol , 352(1):151–64, 2005. ISSN 0022-2836 (Print) 0022-2836 (Linking). doi: 10.1016/j.jmb.2005.07.017. URL .[137] A. J. Lindsay and M. W. McCaffrey. The c2 domains ofthe class i rab11 family of interacting proteins target recy-cling vesicles to the plasma membrane.
J Cell Sci , 117(Pt19):4365–75, 2004. ISSN 0021-9533 (Print) 0021-9533 (Link-ing). doi: 10.1242/jcs.01280. URL .[138] K. Ling, S. F. Bairstow, C. Carbonara, D. A. Turbin, D. G.Huntsman, and R. A. Anderson. Type i gamma phos-phatidylinositol phosphate kinase modulates adherens junc-tion and e-cadherin trafficking via a direct interaction with mu1b adaptin.
J Cell Biol , 176(3):343–53, 2007. ISSN 0021-9525(Print) 0021-9525 (Linking). doi: 10.1083/jcb.200606023.URL .[139] F. Liu, M. Koval, S. Ranganathan, S. Fanayan, W. S. Han-cock, E. K. Lundberg, R. C. Beavis, L. Lane, P. Duek, L. Mc-Quade, N. L. Kelleher, and M. S. Baker. Systems proteomicsview of the endogenous human claudin protein family.
J Pro-teome Res , 15(2):339–59, 2016. ISSN 1535-3907 (Electronic)1535-3893 (Linking). doi: 10.1021/acs.jproteome.5b00769.URL .[140] J. Liu, X. Jin, K. J. Liu, and W. Liu. Ma-trix metalloproteinase-2-mediated occludin degradation andcaveolin-1-mediated claudin-5 redistribution contribute toblood-brain barrier damage in early ischemic stroke stage.
J Neurosci , 32(9):3044–57, 2012. ISSN 1529-2401 (Elec-tronic) 0270-6474 (Linking). doi: 10.1523/JNEUROSCI.6409-11.2012. URL .[141] J. Liu, J. Weaver, X. Jin, Y. Zhang, J. Xu, K. J. Liu, W. Li,and W. Liu. Nitric oxide interacts with caveolin-1 to fa-cilitate autophagy-lysosome-mediated claudin-5 degradationin oxygen-glucose deprivation-treated endothelial cells.
MolNeurobiol , 53(9):5935–5947, 2016. ISSN 1559-1182 (Elec-tronic) 0893-7648 (Linking). doi: 10.1007/s12035-015-9504-8.URL .[142] J. G. Lock and J. L. Stow. Rab11 in recycling endosomesregulates the sorting and basolateral transport of e-cadherin.
Mol Biol Cell , 16(4):1744–55, 2005. ISSN 1059-1524 (Print)1059-1524 (Linking). doi: 10.1091/mbc.e04-10-0867. URL .[143] J. G. Lock, L. A. Hammond, F. Houghton, P. A. Gleeson, andJ. L. Stow. E-cadherin transport from the trans-golgi networkin tubulovesicular carriers is selectively regulated by golgin-97.
Traffic , 6(12):1142–56, 2005. ISSN 1398-9219 (Print)1398-9219 (Linking). doi: 10.1111/j.1600-0854.2005.00349.x.URL .[144] S. H. Low, M. Miura, P. A. Roche, A. C. Valdez, K. E.Mostov, and T. Weimbs. Intracellular redirection of plasmamembrane trafficking after loss of epithelial cell polarity.
MolBiol Cell , 11(9):3045–60, 2000. ISSN 1059-1524 (Print) 1059-1524 (Linking). doi: 10.1091/mbc.11.9.3045. URL .[145] R. Lu, D. L. Johnson, L. Stewart, K. Waite, D. Elliott, andJ. M. Wilson. Rab14 regulation of claudin-2 trafficking mod-ulates epithelial permeability and lumen morphogenesis.
MolBiol Cell , 25(11):1744–54, 2014. ISSN 1939-4586 (Electronic)1059-1524 (Linking). doi: 10.1091/mbc.E13-12-0724. URL .[146] S. Lucken-Ardjomande Hasler, Y. Vallis, M. Pasche, and H. T.McMahon. Graf2, wdr44, and mical1 mediate rab8/10/11-dependent export of e-cadherin, mmp14, and cftr deltaf508. Cell Biol , 219(5), 2020. ISSN 1540-8140 (Electronic) 0021-9525 (Linking). doi: 10.1083/jcb.201811014. URL .[147] L. Ma, R. Rohatgi, and M. W. Kirschner. The arp2/3 com-plex mediates actin polymerization induced by the small gtp-binding protein cdc42.
Proc Natl Acad Sci U S A , 95(26):15362–7, 1998. ISSN 0027-8424 (Print) 0027-8424 (Linking).doi: 10.1073/pnas.95.26.15362. URL .[148] E. Macia, M. Ehrlich, R. Massol, E. Boucrot, C. Brunner, andT. Kirchhausen. Dynasore, a cell-permeable inhibitor of dy-namin.
Dev Cell , 10(6):839–50, 2006. ISSN 1534-5807 (Print)1534-5807 (Linking). doi: 10.1016/j.devcel.2006.04.002. URL .[149] J. L. Madara and J. Stafford. Interferon-gamma directly af-fects barrier function of cultured intestinal epithelial mono-layers.
J Clin Invest , 83(2):724–7, 1989. ISSN 0021-9738(Print) 0021-9738 (Linking). doi: 10.1172/JCI113938. URL .[150] K. Mandai, Y. Rikitake, M. Mori, and Y. Takai. Nectins andnectin-like molecules in development and disease.
Curr TopDev Biol , 112:197–231, 2015. ISSN 1557-8933 (Electronic)0070-2153 (Linking). doi: 10.1016/bs.ctdb.2014.11.019. URL .[151] I. Mandel, T. Paperna, A. Volkowich, M. Merhav, L. Glass-Marmor, and A. Miller. The ubiquitin-proteasome pathwayregulates claudin 5 degradation.
J Cell Biochem , 113(7):2415–23, 2012. ISSN 1097-4644 (Electronic) 0730-2312 (Linking).doi: 10.1002/jcb.24118. URL .[152] A. M. Marchiando, L. Shen, W. V. Graham, C. R. Weber,B. T. Schwarz, n. Austin, J. R., D. R. Raleigh, Y. Guan,A. J. Watson, M. H. Montrose, and J. R. Turner. Caveolin-1-dependent occludin endocytosis is required for tnf-inducedtight junction regulation in vivo.
J Cell Biol , 189(1):111–26, 2010. ISSN 1540-8140 (Electronic) 0021-9525 (Linking).doi: 10.1083/jcb.200902153. URL .[153] K. Marunaka, C. Furukawa, N. Fujii, T. Kimura, T. Furuta,T. Matsunaga, S. Endo, H. Hasegawa, N. Anzai, Y. Yamazaki,M. Yamaguchi, and A. Ikari. The ring finger- and pdz domain-containing protein pdzrn3 controls localization of the mg(2+)regulator claudin-16 in renal tube epithelial cells.
J BiolChem , 292(31):13034–13044, 2017. ISSN 1083-351X (Elec-tronic) 0021-9258 (Linking). doi: 10.1074/jbc.M117.779405.URL .[154] A. M. Marzesco, I. Dunia, R. Pandjaitan, M. Recouvreur,D. Dauzonne, E. L. Benedetti, D. Louvard, and A. Zahraoui.The small gtpase rab13 regulates assembly of functional tightjunctions in epithelial cells.
Mol Biol Cell , 13(6):1819–31,2002. ISSN 1059-1524 (Print) 1059-1524 (Linking). doi:10.1091/mbc.02-02-0029. URL .[155] M. Matsuda, A. Kubo, M. Furuse, and S. Tsukita. A pe-culiar internalization of claudins, tight junction-specific adhe-sion molecules, during the intercellular movement of epithelialcells.
J Cell Sci , 117(Pt 7):1247–57, 2004. ISSN 0021-9533(Print) 0021-9533 (Linking). doi: 10.1242/jcs.00972. URL .[156] T. Matsui, T. Watanabe, K. Matsuzawa, M. Kakeno, N. Oku-mura, I. Sugiyama, N. Itoh, and K. Kaibuchi. Par3 andapkc regulate golgi organization through clasp2 phosphory-lation to generate cell polarity.
Mol Biol Cell , 26(4):751–61, 2015. ISSN 1939-4586 (Electronic) 1059-1524 (Linking).doi: 10.1091/mbc.E14-09-1382. URL . [157] P. D. McCrea and C. J. Gottardi. Beyond beta-catenin:prospects for a larger catenin network in the nucleus.
NatRev Mol Cell Biol , 17(1):55–64, 2016. ISSN 1471-0080 (Elec-tronic) 1471-0072 (Linking). doi: 10.1038/nrm.2015.3. URL .[158] A. E. McEwen, M. T. Maher, R. Mo, and C. J. Gottardi.E-cadherin phosphorylation occurs during its biosynthesis topromote its cell surface stability and adhesion.
Mol Biol Cell ,25(16):2365–74, 2014. ISSN 1939-4586 (Electronic) 1059-1524(Linking). doi: 10.1091/mbc.E14-01-0690. URL .[159] C. L. Mendelsohn, E. Wimmer, and V. R. Racaniello. Cel-lular receptor for poliovirus: molecular cloning, nucleotidesequence, and expression of a new member of the im-munoglobulin superfamily.
Cell , 56(5):855–65, 1989. ISSN0092-8674 (Print) 0092-8674 (Linking). doi: 10.1016/0092-8674(89)90690-9. URL .[160] W. Meng and M. Takeichi. Adherens junction: moleculararchitecture and regulation.
Cold Spring Harb Perspect Biol ,1(6):a002899, 2009. ISSN 1943-0264 (Electronic) 1943-0264(Linking). doi: 10.1101/cshperspect.a002899. URL .[161] K. C. Miranda, S. R. Joseph, A. S. Yap, R. D. Teasdale, andJ. L. Stow. Contextual binding of p120ctn to e-cadherin atthe basolateral plasma membrane in polarized epithelia.
JBiol Chem , 278(44):43480–8, 2003. ISSN 0021-9258 (Print)0021-9258 (Linking). doi: 10.1074/jbc.M305525200. URL .[162] M. Miyahara, H. Nakanishi, K. Takahashi, K. Satoh-Horikawa, K. Tachibana, and Y. Takai. Interaction of nectinwith afadin is necessary for its clustering at cell-cell con-tact sites but not for its cis dimerization or trans interac-tion.
J Biol Chem , 275(1):613–8, 2000. ISSN 0021-9258(Print) 0021-9258 (Linking). doi: 10.1074/jbc.275.1.613. URL .[163] Y. Miyashita and M. Ozawa. Increased internalization ofp120-uncoupled e-cadherin and a requirement for a dileucinemotif in the cytoplasmic domain for endocytosis of the pro-tein.
J Biol Chem , 282(15):11540–8, 2007. ISSN 0021-9258(Print) 0021-9258 (Linking). doi: 10.1074/jbc.M608351200.URL .[164] Y. Miyashita and M. Ozawa. A dileucine motif in its cytoplas-mic domain directs beta-catenin-uncoupled e-cadherin to thelysosome.
J Cell Sci , 120(Pt 24):4395–406, 2007. ISSN 0021-9533 (Print) 0021-9533 (Linking). doi: 10.1242/jcs.03489.URL .[165] Y. Momose, T. Honda, M. Inagaki, K. Shimizu, K. Irie,H. Nakanishi, and Y. Takai. Role of the secondimmunoglobulin-like loop of nectin in cell-cell adhesion.
Biochem Biophys Res Commun , 293(1):45–9, 2002. ISSN0006-291X (Print) 0006-291X (Linking). doi: 10.1016/S0006-291X(02)00183-3. URL .[166] A. C. Monteiro, A. C. Luissint, R. Sumagin, C. Lai, F. Viel-muth, M. F. Wolf, O. Laur, K. Reiss, V. Spindler, T. Stehle,T. S. Dermody, A. Nusrat, and C. A. Parkos. Trans-dimerization of jam-a regulates rap2 and is mediated by adomain that is distinct from the cis-dimerization interface.
Mol Biol Cell , 25(10):1574–85, 2014. ISSN 1939-4586 (Elec-tronic) 1059-1524 (Linking). doi: 10.1091/mbc.E14-01-0018.URL .[167] S. Morimoto, N. Nishimura, T. Terai, S. Manabe, Y. Ya-mamoto, W. Shinahara, H. Miyake, S. Tashiro, M. Shimada,and T. Sasaki. Rab13 mediates the continuous endocytic re-cycling of occludin to the cell surface.
J Biol Chem , 280(3):2220–8, 2005. ISSN 0021-9258 (Print) 0021-9258 (Linking).doi: 10.1074/jbc.M406906200. URL . J Cell Biol , 147(1):185–94, 1999. ISSN 0021-9525 (Print) 0021-9525 (Linking). doi: 10.1083/jcb.147.1.185.URL .[169] S. Moskalenko, D. O. Henry, C. Rosse, G. Mirey, J. H. Ca-monis, and M. A. White. The exocyst is a ral effectorcomplex.
Nat Cell Biol , 4(1):66–72, 2002. ISSN 1465-7392(Print) 1465-7392 (Linking). doi: 10.1038/ncb728. URL .[170] A. L. Moss and W. F. Ward. Multiple pathways for lig-and internalization in rat hepatocytes. i: Effects of anoxia,phenylarsine oxide and monensin.
J Cell Physiol , 149(2):313–8, 1991. ISSN 0021-9541 (Print) 0021-9541 (Linking).doi: 10.1002/jcp.1041490219. URL .[171] D. Mukhopadhyay and H. Riezman. Proteasome-independentfunctions of ubiquitin in endocytosis and signaling.
Science ,315(5809):201–5, 2007. ISSN 1095-9203 (Electronic) 0036-8075 (Linking). doi: 10.1126/science.1127085. URL .[172] D. Muller, P. J. Kausalya, F. Claverie-Martin, I. C. Meij,P. Eggert, V. Garcia-Nieto, and W. Hunziker. A novel claudin16 mutation associated with childhood hypercalciuria abol-ishes binding to zo-1 and results in lysosomal mistargeting.
Am J Hum Genet , 73(6):1293–301, 2003. ISSN 0002-9297(Print) 0002-9297 (Linking). doi: 10.1086/380418. URL .[173] D. Muller, P. J. Kausalya, I. C. Meij, and W. Hunziker. Fa-milial hypomagnesemia with hypercalciuria and nephrocalci-nosis: blocking endocytosis restores surface expression of anovel claudin-16 mutant that lacks the entire c-terminal cy-tosolic tail.
Hum Mol Genet , 15(7):1049–58, 2006. ISSN 0964-6906 (Print) 0964-6906 (Linking). doi: 10.1093/hmg/ddl020.URL .[174] S. L. Muller, M. Portwich, A. Schmidt, D. I. Utepbergenov,O. Huber, I. E. Blasig, and G. Krause. The tight junctionprotein occludin and the adherens junction protein alpha-catenin share a common interaction mechanism with zo-1.
JBiol Chem , 280(5):3747–56, 2005. ISSN 0021-9258 (Print)0021-9258 (Linking). doi: 10.1074/jbc.M411365200. URL .[175] T. Murakami, E. A. Felinski, and D. A. Antonetti. Oc-cludin phosphorylation and ubiquitination regulate tightjunction trafficking and vascular endothelial growth factor-induced permeability.
J Biol Chem , 284(31):21036–46, 2009.ISSN 1083-351X (Electronic) 0021-9258 (Linking). doi: 10.1074/jbc.M109.016766. URL .[176] T. Murakami, T. Frey, C. Lin, and D. A. Antonetti. Proteinkinase cbeta phosphorylates occludin regulating tight junc-tion trafficking in vascular endothelial growth factor-inducedpermeability in vivo.
Diabetes , 61(6):1573–83, 2012. ISSN1939-327X (Electronic) 0012-1797 (Linking). doi: 10.2337/db11-1367. URL .[177] R. Z. Murray, L. A. Jolly, and S. A. Wood. The fam deubiqui-tylating enzyme localizes to multiple points of protein traffick-ing in epithelia, where it associates with e-cadherin and beta-catenin.
Mol Biol Cell , 15(4):1591–9, 2004. ISSN 1059-1524(Print) 1059-1524 (Linking). doi: 10.1091/mbc.e03-08-0630.URL .[178] S. Nada, A. Hondo, A. Kasai, M. Koike, K. Saito,Y. Uchiyama, and M. Okada. The novel lipid raft adap-tor p18 controls endosome dynamics by anchoring the mek-erk pathway to late endosomes.
EMBO J , 28(5):477–89,2009. ISSN 1460-2075 (Electronic) 0261-4189 (Linking). doi:10.1038/emboj.2008.308. URL . [179] S. Nakashima, K. Morinaka, S. Koyama, M. Ikeda,M. Kishida, K. Okawa, A. Iwamatsu, S. Kishida, andA. Kikuchi. Small g protein ral and its downstream moleculesregulate endocytosis of egf and insulin receptors.
EMBOJ , 18(13):3629–42, 1999. ISSN 0261-4189 (Print) 0261-4189(Linking). doi: 10.1093/emboj/18.13.3629. URL .[180] H. Nakatsuji, N. Nishimura, R. Yamamura, H. O. Kanayama,and T. Sasaki. Involvement of actinin-4 in the recruitmentof jrab/mical-l2 to cell-cell junctions and the formation offunctional tight junctions.
Mol Cell Biol , 28(10):3324–35,2008. ISSN 1098-5549 (Electronic) 0270-7306 (Linking). doi:10.1128/MCB.00144-08. URL .[181] B. A. Nanes, C. Chiasson-MacKenzie, A. M. Lowery,N. Ishiyama, V. Faundez, M. Ikura, P. A. Vincent, and A. P.Kowalczyk. p120-catenin binding masks an endocytic sig-nal conserved in classical cadherins.
J Cell Biol , 199(2):365–80, 2012. ISSN 1540-8140 (Electronic) 0021-9525 (Link-ing). doi: 10.1083/jcb.201205029. URL .[182] P. Navarro, L. Ruco, and E. Dejana. Differential localizationof ve- and n-cadherins in human endothelial cells: Ve-cadherincompetes with n-cadherin for junctional localization.
J CellBiol , 140(6):1475–84, 1998. ISSN 0021-9525 (Print) 0021-9525 (Linking). doi: 10.1083/jcb.140.6.1475. URL .[183] S. P. Ngok, R. Geyer, M. Liu, A. Kourtidis, S. Agrawal,C. Wu, H. R. Seerapu, L. J. Lewis-Tuffin, K. L. Moodie,D. Huveldt, R. Marx, J. M. Baraban, P. Storz, A. Horowitz,and P. Z. Anastasiadis. Vegf and angiopoietin-1 exert op-posing effects on cell junctions by regulating the rho gef syx.
J Cell Biol , 199(7):1103–15, 2012. ISSN 1540-8140 (Elec-tronic) 0021-9525 (Linking). doi: 10.1083/jcb.201207009.URL .[184] R. L. Nokes, I. C. Fields, R. N. Collins, and H. Folsch. Rab13regulates membrane trafficking between tgn and recycling en-dosomes in polarized epithelial cells.
J Cell Biol , 182(5):845–53, 2008. ISSN 1540-8140 (Electronic) 0021-9525 (Link-ing). doi: 10.1083/jcb.200802176. URL .[185] J. Nomme, A. Antanasijevic, M. Caffrey, C. M. Van Itallie,J. M. Anderson, A. S. Fanning, and A. Lavie. Structuralbasis of a key factor regulating the affinity between the zonulaoccludens first pdz domain and claudins.
J Biol Chem , 290(27):16595–606, 2015. ISSN 1083-351X (Electronic) 0021-9258(Linking). doi: 10.1074/jbc.M115.646695. URL .[186] J. Nurnberger, R. L. Bacallao, and C. L. Phillips. Inversinforms a complex with catenins and n-cadherin in polarizedepithelial cells.
Mol Biol Cell , 13(9):3096–106, 2002. ISSN1059-1524 (Print) 1059-1524 (Linking). doi: 10.1091/mbc.e02-04-0195. URL .[187] M. Ohba, K. Ishino, M. Kashiwagi, S. Kawabe, K. Chida,N. H. Huh, and T. Kuroki. Induction of differentiation innormal human keratinocytes by adenovirus-mediated intro-duction of the eta and delta isoforms of protein kinase c.
Mol Cell Biol , 18(9):5199–207, 1998. ISSN 0270-7306 (Print)0270-7306 (Linking). doi: 10.1128/mcb.18.9.5199. URL .[188] S. Ohtsuki, H. Yamaguchi, Y. Katsukura, T. Asashima, andT. Terasaki. mrna expression levels of tight junction pro-tein genes in mouse brain capillary endothelial cells highlypurified by magnetic cell sorting.
J Neurochem , 104(1):147–54, 2008. ISSN 1471-4159 (Electronic) 0022-3042 (Link-ing). doi: 10.1111/j.1471-4159.2007.05008.x. URL . J BiolChem , 285(7):5003–12, 2010. ISSN 1083-351X (Electronic)0021-9258 (Linking). doi: 10.1074/jbc.M109.043760. URL .[190] V. V. Orlova, M. Economopoulou, F. Lupu, S. Santoso, andT. Chavakis. Junctional adhesion molecule-c regulates vas-cular endothelial permeability by modulating ve-cadherin-mediated cell-cell contacts.
J Exp Med , 203(12):2703–14,2006. ISSN 0022-1007 (Print) 0022-1007 (Linking). doi: 10.1084/jem.20051730. URL .[191] F. Orsenigo, C. Giampietro, A. Ferrari, M. Corada,A. Galaup, S. Sigismund, G. Ristagno, L. Maddaluno, G. Y.Koh, D. Franco, V. Kurtcuoglu, D. Poulikakos, P. Baluk,D. McDonald, M. Grazia Lampugnani, and E. Dejana. Phos-phorylation of ve-cadherin is modulated by haemodynamicforces and contributes to the regulation of vascular perme-ability in vivo.
Nat Commun , 3:1208, 2012. ISSN 2041-1723(Electronic) 2041-1723 (Linking). doi: 10.1038/ncomms2199.URL .[192] S. Osada, K. Mizuno, T. C. Saido, Y. Akita, K. Suzuki,T. Kuroki, and S. Ohno. A phorbol ester receptor/proteinkinase, npkc eta, a new member of the protein kinase cfamily predominantly expressed in lung and skin.
J BiolChem , 265(36):22434–40, 1990. ISSN 0021-9258 (Print)0021-9258 (Linking). URL .[193] T. Otani, T. P. Nguyen, S. Tokuda, K. Sugihara, T. Sug-awara, K. Furuse, T. Miura, K. Ebnet, and M. Furuse.Claudins and jam-a coordinately regulate tight junction for-mation and epithelial polarity.
J Cell Biol , 218(10):3372–3396, 2019. ISSN 1540-8140 (Electronic) 0021-9525 (Link-ing). doi: 10.1083/jcb.201812157. URL .[194] Y. Otsuki, M. Tanaka, S. Yoshii, N. Kawazoe, K. Nakaya, andH. Sugimura. Tumor metastasis suppressor nm23h1 regulatesrac1 gtpase by interaction with tiam1.
Proc Natl Acad SciU S A , 98(8):4385–90, 2001. ISSN 0027-8424 (Print) 0027-8424 (Linking). doi: 10.1073/pnas.071411598. URL .[195] M. Ozawa, H. Baribault, and R. Kemler. The cytoplasmicdomain of the cell adhesion molecule uvomorulin associateswith three independent proteins structurally related in differ-ent species.
EMBO J , 8(6):1711–7, 1989. ISSN 0261-4189(Print) 0261-4189 (Linking). URL .[196] F. Palacios, L. Price, J. Schweitzer, J. G. Collard, andC. D’Souza-Schorey. An essential role for arf6-regulated mem-brane traffic in adherens junction turnover and epithelial cellmigration.
EMBO J , 20(17):4973–86, 2001. ISSN 0261-4189(Print) 0261-4189 (Linking). doi: 10.1093/emboj/20.17.4973.URL .[197] F. Palacios, J. K. Schweitzer, R. L. Boshans, and C. D’Souza-Schorey. Arf6-gtp recruits nm23-h1 to facilitate dynamin-mediated endocytosis during adherens junctions disassembly.
Nat Cell Biol , 4(12):929–36, 2002. ISSN 1465-7392 (Print)1465-7392 (Linking). doi: 10.1038/ncb881. URL .[198] F. Palacios, J. S. Tushir, Y. Fujita, and C. D’Souza-Schorey.Lysosomal targeting of e-cadherin: a unique mechanism forthe down-regulation of cell-cell adhesion during epithelial tomesenchymal transitions.
Mol Cell Biol , 25(1):389–402, 2005.ISSN 0270-7306 (Print) 0270-7306 (Linking). doi: 10.1128/MCB.25.1.389-402.2005. URL . [199] A. D. Paterson, R. G. Parton, C. Ferguson, J. L. Stow, andA. S. Yap. Characterization of e-cadherin endocytosis inisolated mcf-7 and chinese hamster ovary cells: the initialfate of unbound e-cadherin.
J Biol Chem , 278(23):21050–7, 2003. ISSN 0021-9258 (Print) 0021-9258 (Linking). doi:10.1074/jbc.M300082200. URL .[200] F. Peglion, F. Llense, and S. Etienne-Manneville. Adherensjunction treadmilling during collective migration.
Nat CellBiol , 16(7):639–51, 2014. ISSN 1476-4679 (Electronic) 1465-7392 (Linking). doi: 10.1038/ncb2985. URL .[201] J. Piontek, L. Winkler, H. Wolburg, S. L. Muller, N. Zuleger,C. Piehl, B. Wiesner, G. Krause, and I. E. Blasig. For-mation of tight junction: determinants of homophilic in-teraction between classic claudins.
FASEB J , 22(1):146–58, 2008. ISSN 1530-6860 (Electronic) 0892-6638 (Linking).doi: 10.1096/fj.07-8319com. URL .[202] M. D. Potter, S. Barbero, and D. A. Cheresh. Tyrosinephosphorylation of ve-cadherin prevents binding of p120- andbeta-catenin and maintains the cellular mesenchymal state.
JBiol Chem , 280(36):31906–12, 2005. ISSN 0021-9258 (Print)0021-9258 (Linking). doi: 10.1074/jbc.M505568200. URL .[203] R. Prekeris, B. Yang, V. Oorschot, J. Klumperman, andR. H. Scheller. Differential roles of syntaxin 7 and syntaxin8 in endosomal trafficking.
Mol Biol Cell , 10(11):3891–908,1999. ISSN 1059-1524 (Print) 1059-1524 (Linking). doi:10.1091/mbc.10.11.3891. URL .[204] J. F. Presley, S. Mayor, T. E. McGraw, K. W. Dunn, andF. R. Maxfield. Bafilomycin a1 treatment retards transferrinreceptor recycling more than bulk membrane recycling.
JBiol Chem , 272(21):13929–36, 1997. ISSN 0021-9258 (Print)0021-9258 (Linking). doi: 10.1074/jbc.272.21.13929. URL .[205] T. Proikas-Cezanne, A. Gaugel, T. Frickey, and A. Nord-heim. Rab14 is part of the early endosomal clathrin-coatedtgn microdomain.
FEBS Lett , 580(22):5241–6, 2006. ISSN0014-5793 (Print) 0014-5793 (Linking). doi: 10.1016/j.febslet.2006.08.053. URL .[206] A. Quan, A. B. McGeachie, D. J. Keating, E. M. van Dam,J. Rusak, N. Chau, C. S. Malladi, C. Chen, A. McCluskey,M. A. Cousin, and P. J. Robinson. Myristyl trimethyl am-monium bromide and octadecyl trimethyl ammonium bro-mide are surface-active small molecule dynamin inhibitorsthat block endocytosis mediated by dynamin i or dynamin ii.
Mol Pharmacol , 72(6):1425–39, 2007. ISSN 1521-0111 (Elec-tronic) 0026-895X (Linking). doi: 10.1124/mol.107.034207.URL .[207] A. Rai, A. Oprisko, J. Campos, Y. Fu, T. Friese, A. Itzen,R. S. Goody, E. M. Gazdag, and M. P. Muller. bmerbdomains are bivalent rab8 family effectors evolved by geneduplication.
Elife , 5, 2016. ISSN 2050-084X (Electronic)2050-084X (Linking). doi: 10.7554/eLife.18675. URL .[208] D. R. Raleigh, A. M. Marchiando, Y. Zhang, L. Shen,H. Sasaki, Y. Wang, M. Long, and J. R. Turner. Tightjunction-associated marvel proteins marveld3, tricellulin, andoccludin have distinct but overlapping functions.
Mol BiolCell , 21(7):1200–13, 2010. ISSN 1939-4586 (Electronic) 1059-1524 (Linking). doi: 10.1091/mbc.E09-08-0734. URL . PLoS One , 8(2):e55972,2013. ISSN 1932-6203 (Electronic) 1932-6203 (Linking). doi:10.1371/journal.pone.0055972. URL .[210] E. Regan-Klapisz, V. Krouwer, M. Langelaar-Makkinje,L. Nallan, M. Gelb, H. Gerritsen, A. J. Verkleij, and J. A.Post. Golgi-associated cpla2alpha regulates endothelial cell-cell junction integrity by controlling the trafficking of trans-membrane junction proteins.
Mol Biol Cell , 20(19):4225–34, 2009. ISSN 1939-4586 (Electronic) 1059-1524 (Linking).doi: 10.1091/mbc.E08-02-0210. URL .[211] K. Rehm, L. Panzer, V. van Vliet, E. Genot, and S. Lin-der. Drebrin preserves endothelial integrity by stabilizingnectin at adherens junctions.
J Cell Sci , 126(Pt 16):3756–69, 2013. ISSN 1477-9137 (Electronic) 0021-9533 (Linking).doi: 10.1242/jcs.129437. URL .[212] V. Renigunta, T. Fischer, M. Zuzarte, S. Kling, X. Zou,K. Siebert, M. M. Limberg, S. Rinne, N. Decher,G. Schlichthorl, and J. Daut. Cooperative endocytosis of theendosomal snare protein syntaxin-8 and the potassium chan-nel task-1.
Mol Biol Cell , 25(12):1877–91, 2014. ISSN 1939-4586 (Electronic) 1059-1524 (Linking). doi: 10.1091/mbc.E13-10-0592. URL .[213] N. Reymond, S. Fabre, E. Lecocq, J. Adelaide, P. Dubreuil,and M. Lopez. Nectin4/prr4, a new afadin-associated memberof the nectin family that trans-interacts with nectin1/prr1through v domain interaction.
J Biol Chem , 276(46):43205–15, 2001. ISSN 0021-9258 (Print) 0021-9258 (Linking). doi:10.1074/jbc.M103810200. URL .[214] N. Reymond, S. Garrido-Urbani, J. P. Borg, P. Dubreuil,and M. Lopez. Pick-1: a scaffold protein that interacts withnectins and jams at cell junctions.
FEBS Lett , 579(10):2243–9, 2005. ISSN 0014-5793 (Print) 0014-5793 (Linking). doi:10.1016/j.febslet.2005.03.010. URL .[215] W. G. Roberts and G. E. Palade. Increased microvascularpermeability and endothelial fenestration induced by vascu-lar endothelial growth factor.
J Cell Sci , 108 ( Pt 6):2369–79, 1995. ISSN 0021-9533 (Print) 0021-9533 (Linking). URL .[216] K. L. Rock, C. Gramm, L. Rothstein, K. Clark, R. Stein,L. Dick, D. Hwang, and A. L. Goldberg. Inhibitors of theproteasome block the degradation of most cell proteins andthe generation of peptides presented on mhc class i molecules.
Cell , 78(5):761–71, 1994. ISSN 0092-8674 (Print) 0092-8674(Linking). doi: 10.1016/s0092-8674(94)90462-6. URL .[217] A. Sakane, A. A. Abdallah, K. Nakano, K. Honda, W. Ikeda,Y. Nishikawa, M. Matsumoto, N. Matsushita, T. Kitamura,and T. Sasaki. Rab13 small g protein and junctional rab13-binding protein (jrab) orchestrate actin cytoskeletal orga-nization during epithelial junctional development.
J BiolChem , 287(51):42455–68, 2012. ISSN 1083-351X (Electronic)0021-9258 (Linking). doi: 10.1074/jbc.M112.383653. URL .[218] T. Sakurai, M. J. Woolls, S. W. Jin, M. Murakami, andM. Simons. Inter-cellular exchange of cellular componentsvia ve-cadherin-dependent trans-endocytosis.
PLoS One , 9(6):e90736, 2014. ISSN 1932-6203 (Electronic) 1932-6203(Linking). doi: 10.1371/journal.pone.0090736. URL . [219] K. Sandvig, S. Olsnes, O. W. Petersen, and B. van Deurs.Acidification of the cytosol inhibits endocytosis from coatedpits.
J Cell Biol , 105(2):679–89, 1987. ISSN 0021-9525 (Print)0021-9525 (Linking). doi: 10.1083/jcb.105.2.679. URL .[220] K. Sato, T. Watanabe, S. Wang, M. Kakeno, K. Matsuzawa,T. Matsui, K. Yokoi, K. Murase, I. Sugiyama, M. Ozawa,and K. Kaibuchi. Numb controls e-cadherin endocytosisthrough p120 catenin with apkc.
Mol Biol Cell , 22(17):3103–19, 2011. ISSN 1939-4586 (Electronic) 1059-1524 (Link-ing). doi: 10.1091/mbc.E11-03-0274. URL .[221] D. Sbrissa, O. C. Ikonomov, and A. Shisheva. Pikfyve, amammalian ortholog of yeast fab1p lipid kinase, synthesizes5-phosphoinositides. effect of insulin.
J Biol Chem , 274(31):21589–97, 1999. ISSN 0021-9258 (Print) 0021-9258 (Linking).doi: 10.1074/jbc.274.31.21589. URL .[222] M. S. Scheffers, P. van der Bent, F. Prins, L. Spruit, M. H.Breuning, S. V. Litvinov, E. de Heer, and D. J. Peters.Polycystin-1, the product of the polycystic kidney disease1 gene, co-localizes with desmosomes in mdck cells.
HumMol Genet , 9(18):2743–50, 2000. ISSN 0964-6906 (Print)0964-6906 (Linking). doi: 10.1093/hmg/9.18.2743. URL .[223] C. Schilpp, R. Lochbaum, P. Braubach, D. Jonigk, M. Frick,P. Dietl, and O. H. Wittekindt. Tgf-beta1 increases per-meability of ciliated airway epithelia via redistribution ofclaudin 3 from tight junction into cell nuclei.
Pflugers Arch ,2021. ISSN 1432-2013 (Electronic) 0031-6768 (Linking). doi:10.1007/s00424-020-02501-2. URL .[224] J. A. Schmidt, D. N. Kalkofen, K. W. Donovan, and W. J.Brown. A role for phospholipase a2 activity in membranetubule formation and tgn trafficking.
Traffic , 11(12):1530–6,2010. ISSN 1600-0854 (Electronic) 1398-9219 (Linking). doi:10.1111/j.1600-0854.2010.01115.x. URL .[225] J. E. Schnitzer, P. Oh, E. Pinney, and J. Allard. Filipin-sensitive caveolae-mediated transport in endothelium: re-duced transcytosis, scavenger endocytosis, and capillary per-meability of select macromolecules.
J Cell Biol , 127(5):1217–32, 1994. ISSN 0021-9525 (Print) 0021-9525 (Linking).doi: 10.1083/jcb.127.5.1217. URL .[226] B. T. Schwarz, F. Wang, L. Shen, D. R. Clayburgh, L. Su,Y. Wang, Y. X. Fu, and J. R. Turner. Light signals di-rectly to intestinal epithelia to cause barrier dysfunctionvia cytoskeletal and endocytic mechanisms.
Gastroenterol-ogy , 132(7):2383–94, 2007. ISSN 0016-5085 (Print) 0016-5085 (Linking). doi: 10.1053/j.gastro.2007.02.052. URL .[227] K. Seno, T. Okuno, K. Nishi, Y. Murakami, F. Watanabe,T. Matsuura, M. Wada, Y. Fujii, M. Yamada, T. Ogawa,T. Okada, H. Hashizume, M. Kii, S. Hara, S. Hagishita,S. Nakamoto, K. Yamada, Y. Chikazawa, M. Ueno, I. Teshi-rogi, T. Ono, and M. Ohtani. Pyrrolidine inhibitors of hu-man cytosolic phospholipase a(2).
J Med Chem , 43(6):1041–4, 2000. ISSN 0022-2623 (Print) 0022-2623 (Linking). doi:10.1021/jm9905155. URL .[228] L. Shapiro, A. M. Fannon, P. D. Kwong, A. Thompson,M. S. Lehmann, G. Grubel, J. F. Legrand, J. Als-Nielsen,D. R. Colman, and W. A. Hendrickson. Structural ba-sis of cell-cell adhesion by cadherins.
Nature , 374(6520):327–37, 1995. ISSN 0028-0836 (Print) 0028-0836 (Linking).doi: 10.1038/374327a0. URL . Nat Genet , 36(1):69–76, 2004. ISSN 1061-4036 (Print) 1061-4036 (Linking).doi: 10.1038/ng1276. URL .[230] E. A. Shelden, J. M. Weinberg, D. R. Sorenson, C. A. Ed-wards, and F. M. Pollock. Site-specific alteration of actinassembly visualized in living renal epithelial cells during atpdepletion.
J Am Soc Nephrol , 13(11):2667–80, 2002. ISSN1046-6673 (Print) 1046-6673 (Linking). doi: 10.1097/01.asn.0000033353.21502.31. URL .[231] L. Shen and J. R. Turner. Actin depolymerization disruptstight junctions via caveolae-mediated endocytosis.
Mol BiolCell , 16(9):3919–36, 2005. ISSN 1059-1524 (Print) 1059-1524(Linking). doi: 10.1091/mbc.e04-12-1089. URL .[232] L. Shen, C. R. Weber, and J. R. Turner. The tight junctionprotein complex undergoes rapid and continuous molecularremodeling at steady state.
J Cell Biol , 181(4):683–95, 2008.ISSN 1540-8140 (Electronic) 0021-9525 (Linking). doi: 10.1083/jcb.200711165. URL .[233] A. Shilatifard, W. S. Lane, K. W. Jackson, R. C. Conaway,and J. W. Conaway. An rna polymerase ii elongation factorencoded by the human ell gene.
Science , 271(5257):1873–6, 1996. ISSN 0036-8075 (Print) 0036-8075 (Linking). doi:10.1126/science.271.5257.1873. URL .[234] K. Shin, S. Straight, and B. Margolis. Patj regulates tightjunction formation and polarity in mammalian epithelial cells.
J Cell Biol , 168(5):705–11, 2005. ISSN 0021-9525 (Print)0021-9525 (Linking). doi: 10.1083/jcb.200408064. URL .[235] R. Shiomi, K. Shigetomi, T. Inai, M. Sakai, and J. Ikenouchi.Camkii regulates the strength of the epithelial barrier.
SciRep , 5:13262, 2015. ISSN 2045-2322 (Electronic) 2045-2322(Linking). doi: 10.1038/srep13262. URL .[236] T. Soldati, C. Rancano, H. Geissler, and S. R. Pfeffer. Rab7and rab9 are recruited onto late endosomes by biochemi-cally distinguishable processes.
J Biol Chem , 270(43):25541–8, 1995. ISSN 0021-9258 (Print) 0021-9258 (Linking). doi:10.1074/jbc.270.43.25541. URL .[237] T. Soma, H. Chiba, Y. Kato-Mori, T. Wada, T. Yamashita,T. Kojima, and N. Sawada. Thr(207) of claudin-5 is in-volved in size-selective loosening of the endothelial barrierby cyclic amp.
Exp Cell Res , 300(1):202–12, 2004. ISSN0014-4827 (Print) 0014-4827 (Linking). doi: 10.1016/j.yexcr.2004.07.012. URL .[238] B. Somasundaram, J. C. Norman, and M. P. Mahaut-Smith. Primaquine, an inhibitor of vesicular transport, blocksthe calcium-release-activated current in rat megakaryocytes.
Biochem J , 309 ( Pt 3):725–9, 1995. ISSN 0264-6021 (Print)0264-6021 (Linking). doi: 10.1042/bj3090725. URL .[239] C. Staat, C. Coisne, S. Dabrowski, S. M. Stamatovic, A. V.Andjelkovic, H. Wolburg, B. Engelhardt, and I. E. Blasig.Mode of action of claudin peptidomimetics in the transientopening of cellular tight junction barriers.
Biomaterials , 54:9–20, 2015. ISSN 1878-5905 (Electronic) 0142-9612 (Linking).doi: 10.1016/j.biomaterials.2015.03.007. URL . [240] S. M. Stagg, P. LaPointe, A. Razvi, C. Gurkan, C. S. Pot-ter, B. Carragher, and W. E. Balch. Structural basis forcargo regulation of copii coat assembly.
Cell , 134(3):474–84,2008. ISSN 1097-4172 (Electronic) 0092-8674 (Linking). doi:10.1016/j.cell.2008.06.024. URL .[241] S. M. Stamatovic, R. F. Keep, M. M. Wang, I. Jankovic,and A. V. Andjelkovic. Caveolae-mediated internalization ofoccludin and claudin-5 during ccl2-induced tight junction re-modeling in brain endothelial cells.
J Biol Chem , 284(28):19053–66, 2009. ISSN 0021-9258 (Print) 0021-9258 (Linking).doi: 10.1074/jbc.M109.000521. URL .[242] S. M. Stamatovic, N. Sladojevic, R. F. Keep, and A. V. And-jelkovic. Relocalization of junctional adhesion molecule a dur-ing inflammatory stimulation of brain endothelial cells.
MolCell Biol , 32(17):3414–27, 2012. ISSN 1098-5549 (Electronic)0270-7306 (Linking). doi: 10.1128/MCB.06678-11. URL .[243] T. Steinbacher, D. Kummer, and K. Ebnet. Junctional ad-hesion molecule-a: functional diversity through molecularpromiscuity.
Cell Mol Life Sci , 75(8):1393–1409, 2018. ISSN1420-9071 (Electronic) 1420-682X (Linking). doi: 10.1007/s00018-017-2729-0. URL .[244] P. Sun, H. Yamamoto, S. Suetsugu, H. Miki, T. Take-nawa, and T. Endo. Small gtpase rah/rab34 is associatedwith membrane ruffles and macropinosomes and promotesmacropinosome formation.
J Biol Chem , 278(6):4063–71,2003. ISSN 0021-9258 (Print) 0021-9258 (Linking). doi:10.1074/jbc.M208699200. URL .[245] J. M. Sundstrom, B. R. Tash, T. Murakami, J. M. Flana-gan, M. C. Bewley, B. A. Stanley, K. B. Gonsar, and D. A.Antonetti. Identification and analysis of occludin phospho-sites: a combined mass spectrometry and bioinformatics ap-proach.
J Proteome Res , 8(2):808–17, 2009. ISSN 1535-3893(Print) 1535-3893 (Linking). doi: 10.1021/pr7007913. URL .[246] T. Suzuki, B. C. Elias, A. Seth, L. Shen, J. R. Turner,F. Giorgianni, D. Desiderio, R. Guntaka, and R. Rao. Pkceta regulates occludin phosphorylation and epithelial tightjunction integrity.
Proc Natl Acad Sci U S A , 106(1):61–6,2009. ISSN 1091-6490 (Electronic) 0027-8424 (Linking). doi:10.1073/pnas.0802741106. URL .[247] K. Tachibana, H. Nakanishi, K. Mandai, K. Ozaki, W. Ikeda,Y. Yamamoto, A. Nagafuchi, S. Tsukita, and Y. Takai. Twocell adhesion molecules, nectin and cadherin, interact throughtheir cytoplasmic domain-associated proteins.
J Cell Biol , 150(5):1161–76, 2000. ISSN 0021-9525 (Print) 0021-9525 (Link-ing). doi: 10.1083/jcb.150.5.1161. URL .[248] K. Takahashi, H. Nakanishi, M. Miyahara, K. Mandai,K. Satoh, A. Satoh, H. Nishioka, J. Aoki, A. Nomoto, A. Mi-zoguchi, and Y. Takai. Nectin/prr: an immunoglobulin-like cell adhesion molecule recruited to cadherin-based ad-herens junctions through interaction with afadin, a pdzdomain-containing protein.
J Cell Biol , 145(3):539–49, 1999.ISSN 0021-9525 (Print) 0021-9525 (Linking). doi: 10.1083/jcb.145.3.539. URL .[249] S. Takahashi, N. Iwamoto, H. Sasaki, M. Ohashi, Y. Oda,S. Tsukita, and M. Furuse. The e3 ubiquitin ligase lnx1p80promotes the removal of claudins from tight junctions in mdckcells.
J Cell Sci , 122(Pt 7):985–94, 2009. ISSN 0021-9533(Print) 0021-9533 (Linking). doi: 10.1242/jcs.040055. URL . J Biol Chem , 278(8):5497–500, 2003. ISSN 0021-9258 (Print) 0021-9258 (Linking). doi:10.1074/jbc.C200707200. URL .[251] J. W. Taraska, D. Perrais, M. Ohara-Imaizumi, S. Naga-matsu, and W. Almers. Secretory granules are recapturedlargely intact after stimulated exocytosis in cultured en-docrine cells.
Proc Natl Acad Sci U S A , 100(4):2070–5,2003. ISSN 0027-8424 (Print) 0027-8424 (Linking). doi:10.1073/pnas.0337526100. URL .[252] J. Teng, T. Rai, Y. Tanaka, Y. Takei, T. Nakata, M. Hirasawa,A. B. Kulkarni, and N. Hirokawa. The kif3 motor transportsn-cadherin and organizes the developing neuroepithelium.
NatCell Biol , 7(5):474–82, 2005. ISSN 1465-7392 (Print) 1465-7392 (Linking). doi: 10.1038/ncb1249. URL .[253] T. Terai, N. Nishimura, I. Kanda, N. Yasui, and T. Sasaki.Jrab/mical-l2 is a junctional rab13-binding protein mediatingthe endocytic recycling of occludin.
Mol Biol Cell , 17(5):2465–75, 2006. ISSN 1059-1524 (Print) 1059-1524 (Linking).doi: 10.1091/mbc.e05-09-0826. URL .[254] M. A. Thoreson, P. Z. Anastasiadis, J. M. Daniel, R. C.Ireton, M. J. Wheelock, K. R. Johnson, D. K. Humming-bird, and A. B. Reynolds. Selective uncoupling of p120(ctn)from e-cadherin disrupts strong adhesion.
J Cell Biol , 148(1):189–202, 2000. ISSN 0021-9525 (Print) 0021-9525 (Link-ing). doi: 10.1083/jcb.148.1.189. URL .[255] D. Toullec, P. Pianetti, H. Coste, P. Bellevergue, T. Grand-Perret, M. Ajakane, V. Baudet, P. Boissin, E. Boursier,F. Loriolle, and et al. The bisindolylmaleimide gf 109203xis a potent and selective inhibitor of protein kinase c.
JBiol Chem , 266(24):15771–81, 1991. ISSN 0021-9258 (Print)0021-9258 (Linking). URL .[256] A. Traweger, D. Fang, Y. C. Liu, W. Stelzhammer, I. A.Krizbai, F. Fresser, H. C. Bauer, and H. Bauer. The tightjunction-specific protein occludin is a functional target of thee3 ubiquitin-protein ligase itch.
J Biol Chem , 277(12):10201–8, 2002. ISSN 0021-9258 (Print) 0021-9258 (Linking). doi:10.1074/jbc.M111384200. URL .[257] I. S. Trowbridge, J. F. Collawn, and C. R. Hopkins. Signal-dependent membrane protein trafficking in the endocyticpathway.
Annu Rev Cell Biol , 9:129–61, 1993. ISSN 0743-4634 (Print) 0743-4634 (Linking). doi: 10.1146/annurev.cb.09.110193.001021. URL .[258] R. B. Troyanovsky, E. P. Sokolov, and S. M. Troyanovsky.Endocytosis of cadherin from intracellular junctions is thedriving force for cadherin adhesive dimer disassembly.
MolBiol Cell , 17(8):3484–93, 2006. ISSN 1059-1524 (Print) 1059-1524 (Linking). doi: 10.1091/mbc.e06-03-0190. URL .[259] O. Ullrich, S. Reinsch, S. Urbe, M. Zerial, and R. G. Parton.Rab11 regulates recycling through the pericentriolar recyclingendosome.
J Cell Biol , 135(4):913–24, 1996. ISSN 0021-9525(Print) 0021-9525 (Linking). doi: 10.1083/jcb.135.4.913. URL .[260] K. Umeda, J. Ikenouchi, S. Katahira-Tayama, K. Furuse,H. Sasaki, M. Nakayama, T. Matsui, S. Tsukita, M. Fu-ruse, and S. Tsukita. Zo-1 and zo-2 independently determine where claudins are polymerized in tight-junction strand for-mation.
Cell , 126(4):741–54, 2006. ISSN 0092-8674 (Print)0092-8674 (Linking). doi: 10.1016/j.cell.2006.06.043. URL .[261] T. Urano, S. Fushida, K. Furukawa, and H. Shiku. Hu-man nm23-h1-protein and h2-protein have similar nucleo-side diphosphate kinase-activities.
Int J Oncol , 1(4):425–30, 1992. ISSN 1019-6439 (Print) 1019-6439 (Linking). doi:10.3892/ijo.1.4.425. URL .[262] M. Utech, A. I. Ivanov, S. N. Samarin, M. Bruewer, J. R.Turner, R. J. Mrsny, C. A. Parkos, and A. Nusrat. Mech-anism of ifn-gamma-induced endocytosis of tight junctionproteins: myosin ii-dependent vacuolarization of the apicalplasma membrane.
Mol Biol Cell , 16(10):5040–52, 2005. ISSN1059-1524 (Print) 1059-1524 (Linking). doi: 10.1091/mbc.e05-03-0193. URL .[263] C. M. Van Itallie, O. R. Colegio, and J. M. Anderson.The cytoplasmic tails of claudins can influence tight junc-tion barrier properties through effects on protein stability.
J Membr Biol , 199(1):29–38, 2004. ISSN 0022-2631 (Print)0022-2631 (Linking). doi: 10.1007/s00232-004-0673-z. URL .[264] C. M. Van Itallie, A. J. Tietgens, K. LoGrande, A. Aponte,M. Gucek, and J. M. Anderson. Phosphorylation of claudin-2 on serine 208 promotes membrane retention and reducestrafficking to lysosomes.
J Cell Sci , 125(Pt 20):4902–12,2012. ISSN 1477-9137 (Electronic) 0021-9533 (Linking). doi:10.1242/jcs.111237. URL .[265] C. M. Van Itallie, K. F. Lidman, A. J. Tietgens, and J. M.Anderson. Newly synthesized claudins but not occludin areadded to the basal side of the tight junction.
Mol Biol Cell ,30(12):1406–1424, 2019. ISSN 1939-4586 (Electronic) 1059-1524 (Linking). doi: 10.1091/mbc.E19-01-0008. URL .[266] M. Vietri, M. Radulovic, and H. Stenmark. The many func-tions of escrts.
Nat Rev Mol Cell Biol , 21(1):25–42, 2020.ISSN 1471-0080 (Electronic) 1471-0072 (Linking). doi: 10.1038/s41580-019-0177-4. URL .[267] r. Wahl, J. K., Y. J. Kim, J. M. Cullen, K. R. Johnson, andM. J. Wheelock. N-cadherin-catenin complexes form prior tocleavage of the proregion and transport to the plasma mem-brane.
J Biol Chem , 278(19):17269–76, 2003. ISSN 0021-9258(Print) 0021-9258 (Linking). doi: 10.1074/jbc.M211452200.URL .[268] B. Wang, F. G. Wylie, R. D. Teasdale, and J. L. Stow.Polarized trafficking of e-cadherin is regulated by rac1 andcdc42 in madin-darby canine kidney cells.
Am J PhysiolCell Physiol , 288(6):C1411–9, 2005. ISSN 0363-6143 (Print)0363-6143 (Linking). doi: 10.1152/ajpcell.00533.2004. URL .[269] L. Wang, G. Li, and S. Sugita. Rala-exocyst interaction medi-ates gtp-dependent exocytosis.
J Biol Chem , 279(19):19875–81, 2004. ISSN 0021-9258 (Print) 0021-9258 (Linking). doi:10.1074/jbc.M400522200. URL .[270] L. H. Wang, K. G. Rothberg, and R. G. Anderson. Mis-assembly of clathrin lattices on endosomes reveals a regulatoryswitch for coated pit formation.
J Cell Biol , 123(5):1107–17,1993. ISSN 0021-9525 (Print) 0021-9525 (Linking). doi: 10.1083/jcb.123.5.1107. URL . Mol BiolCell , 18(3):874–85, 2007. ISSN 1059-1524 (Print) 1059-1524(Linking). doi: 10.1091/mbc.e06-07-0651. URL .[272] M. Weber, M. Uguccioni, M. Baggiolini, I. Clark-Lewis, andC. A. Dahinden. Deletion of the nh2-terminal residue convertsmonocyte chemotactic protein 1 from an activator of basophilmediator release to an eosinophil chemoattractant.
J ExpMed , 183(2):681–5, 1996. ISSN 0022-1007 (Print) 0022-1007(Linking). doi: 10.1084/jem.183.2.681. URL .[273] E. Welman and T. J. Peters. Prevention of lysosome dis-ruption in anoxic myocardium by chloroquine and methylprednisolone.
Pharmacol Res Commun , 9(1):29–38, 1977.ISSN 0031-6989 (Print) 0031-6989 (Linking). doi: 10.1016/s0031-6989(77)80051-9. URL .[274] L. Weng, A. Enomoto, H. Miyoshi, K. Takahashi, N. Asai,N. Morone, P. Jiang, J. An, T. Kato, K. Kuroda,T. Watanabe, M. Asai, M. Ishida-Takagishi, Y. Murakumo,H. Nakashima, K. Kaibuchi, and M. Takahashi. Regulationof cargo-selective endocytosis by dynamin 2 gtpase-activatingprotein girdin.
EMBO J , 33(18):2098–112, 2014. ISSN 1460-2075 (Electronic) 0261-4189 (Linking). doi: 10.15252/embj.201488289. URL .[275] P. Whitley, B. J. Reaves, M. Hashimoto, A. M. Riley,B. V. Potter, and G. D. Holman. Identification of mam-malian vps24p as an effector of phosphatidylinositol 3,5-bisphosphate-dependent endosome compartmentalization.
JBiol Chem , 278(40):38786–95, 2003. ISSN 0021-9258 (Print)0021-9258 (Linking). doi: 10.1074/jbc.M306864200. URL .[276] J. R. Whyte and S. Munro. Vesicle tethering complexes inmembrane traffic.
J Cell Sci , 115(Pt 13):2627–37, 2002. ISSN0021-9533 (Print) 0021-9533 (Linking). URL .[277] W. Xia, E. W. Wong, D. D. Mruk, and C. Y. Cheng. Tgf-beta3 and tnfalpha perturb blood-testis barrier (btb) dynam-ics by accelerating the clathrin-mediated endocytosis of in-tegral membrane proteins: a new concept of btb regulationduring spermatogenesis.
Dev Biol , 327(1):48–61, 2009. ISSN1095-564X (Electronic) 0012-1606 (Linking). doi: 10.1016/j.ydbio.2008.11.028. URL .[278] K. Xiao, D. F. Allison, M. D. Kottke, S. Summers, G. P.Sorescu, V. Faundez, and A. P. Kowalczyk. Mechanisms ofve-cadherin processing and degradation in microvascular en-dothelial cells.
J Biol Chem , 278(21):19199–208, 2003. ISSN0021-9258 (Print) 0021-9258 (Linking). doi: 10.1074/jbc.M211746200. URL .[279] K. Xiao, J. Garner, K. M. Buckley, P. A. Vincent, C. M.Chiasson, E. Dejana, V. Faundez, and A. P. Kowalczyk.p120-catenin regulates clathrin-dependent endocytosis of ve-cadherin.
Mol Biol Cell , 16(11):5141–51, 2005. ISSN1059-1524 (Print) 1059-1524 (Linking). doi: 10.1091/mbc.e05-05-0440. URL .[280] Z. Xu, R. Waeckerlin, M. D. Urbanowski, G. van Marle, andT. C. Hobman. West nile virus infection causes endocytosis ofa specific subset of tight junction membrane proteins.
PLoSOne , 7(5):e37886, 2012. ISSN 1932-6203 (Electronic) 1932-6203 (Linking). doi: 10.1371/journal.pone.0037886. URL . [281] M. Yamamoto, S. H. Ramirez, S. Sato, T. Kiyota, R. L. Cerny,K. Kaibuchi, Y. Persidsky, and T. Ikezu. Phosphorylation ofclaudin-5 and occludin by rho kinase in brain endothelial cells.
Am J Pathol , 172(2):521–33, 2008. ISSN 0002-9440 (Print)0002-9440 (Linking). doi: 10.2353/ajpath.2008.070076. URL .[282] R. Yamamura, N. Nishimura, H. Nakatsuji, S. Arase, andT. Sasaki. The interaction of jrab/mical-l2 with rab8and rab13 coordinates the assembly of tight junctions andadherens junctions.
Mol Biol Cell , 19(3):971–83, 2008.ISSN 1939-4586 (Electronic) 1059-1524 (Linking). doi: 10.1091/mbc.e07-06-0551. URL .[283] Z. Yan, Z. G. Wang, N. Segev, S. Hu, R. D. Minshall, R. O.Dull, M. Zhang, A. B. Malik, and G. Hu. Rab11a medi-ates vascular endothelial-cadherin recycling and controls en-dothelial barrier function.
Arterioscler Thromb Vasc Biol ,36(2):339–49, 2016. ISSN 1524-4636 (Electronic) 1079-5642(Linking). doi: 10.1161/ATVBAHA.115.306549. URL .[284] M. Yanagisawa, I. N. Kaverina, A. Wang, Y. Fujita, A. B.Reynolds, and P. Z. Anastasiadis. A novel interaction betweenkinesin and p120 modulates p120 localization and function.
JBiol Chem , 279(10):9512–21, 2004. ISSN 0021-9258 (Print)0021-9258 (Linking). doi: 10.1074/jbc.M310895200. URL .[285] A. S. Yap, C. M. Niessen, and B. M. Gumbiner. The jux-tamembrane region of the cadherin cytoplasmic tail supportslateral clustering, adhesive strengthening, and interactionwith p120ctn.
J Cell Biol , 141(3):779–89, 1998. ISSN 0021-9525 (Print) 0021-9525 (Linking). doi: 10.1083/jcb.141.3.779.URL .[286] A. S. Yap, M. S. Crampton, and J. Hardin. Making andbreaking contacts: the cellular biology of cadherin regulation.
Curr Opin Cell Biol , 19(5):508–14, 2007. ISSN 0955-0674(Print) 0955-0674 (Linking). doi: 10.1016/j.ceb.2007.09.008.URL .[287] A. S. Yap, G. A. Gomez, and R. G. Parton. Adherens junc-tions revisualized: Organizing cadherins as nanoassemblies.
Dev Cell , 35(1):12–20, 2015. ISSN 1878-1551 (Electronic)1534-5807 (Linking). doi: 10.1016/j.devcel.2015.09.012. URL .[288] P. Yin, Y. Li, and L. Zhang. Sec24c-dependent transportof claudin-1 regulates hepatitis c virus entry.
J Virol , 91(18), 2017. ISSN 1098-5514 (Electronic) 0022-538X (Link-ing). doi: 10.1128/JVI.00629-17. URL .[289] S. Yokoyama, K. Tachibana, H. Nakanishi, Y. Yamamoto,K. Irie, K. Mandai, A. Nagafuchi, M. Monden, and Y. Takai.alpha-catenin-independent recruitment of zo-1 to nectin-based cell-cell adhesion sites through afadin.
Mol Biol Cell , 12(6):1595–609, 2001. ISSN 1059-1524 (Print) 1059-1524 (Link-ing). doi: 10.1091/mbc.12.6.1595. URL .[290] T. Yoshimori, A. Yamamoto, Y. Moriyama, M. Futai, andY. Tashiro. Bafilomycin a1, a specific inhibitor of vacuolar-type h(+)-atpase, inhibits acidification and protein degrada-tion in lysosomes of cultured cells.
J Biol Chem , 266(26):17707–12, 1991. ISSN 0021-9258 (Print) 0021-9258 (Linking).URL .[291] J. S. Young, Y. Takai, K. L. Kojic, and A. W. Vogl. In-ternalization of adhesion junction proteins and their associ-ation with recycling endosome marker proteins in rat sem-iniferous epithelium.
Reproduction , 143(3):347–57, 2012.ISSN 1741-7899 (Electronic) 1470-1626 (Linking). doi: 10.1530/REP-11-0317. URL . JGastroenterol , 50(11):1103–13, 2015. ISSN 1435-5922 (Elec-tronic) 0944-1174 (Linking). doi: 10.1007/s00535-015-1066-z.URL .[293] G. N. Zecherle, A. Oleinikov, and R. R. Traut. The proximityof the c-terminal domain of escherichia coli ribosomal proteinl7/l12 to l10 determined by cysteine site-directed mutagenesisand protein-protein cross-linking.
J Biol Chem , 267(9):5889–96, 1992. ISSN 0021-9258 (Print) 0021-9258 (Linking). URL .[294] X. Zhang and W. Y. Lui. Dysregulation of nectin-2 in thetesticular cells: an explanation of cadmium-induced maleinfertility.
Biochim Biophys Acta , 1839(9):873–84, 2014.ISSN 0006-3002 (Print) 0006-3002 (Linking). doi: 10.1016/j.bbagrm.2014.07.012. URL .[295] Y. G. Zhao and H. Zhang. Phase separation in membranebiology: The interplay between membrane-bound organellesand membraneless condensates.
Dev Cell , 55(1):30–44, 2020.ISSN 1878-1551 (Electronic) 1534-5807 (Linking). doi: 10.1016/j.devcel.2020.06.033. URL .[296] C. Zihni, C. Mills, K. Matter, and M. S. Balda. Tight junc-tions: from simple barriers to multifunctional molecular gates.
Nat Rev Mol Cell Biol , 17(9):564–80, 2016. ISSN 1471-0080(Electronic) 1471-0072 (Linking). doi: 10.1038/nrm.2016.80.URL ..