Maria Carla Parrini
Curie Institute
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Publication
Featured researches published by Maria Carla Parrini.
Molecular Cell | 2011
Maria Carla Parrini; Amel Sadou-Dubourgnoux; Kazuhiro Aoki; Katsuyuki Kunida; Marco Biondini; Anastassia Hatzoglou; Patrick Poullet; Etienne Formstecher; Charles Yeaman; Michiyuki Matsuda; Carine Rossé; Jacques Camonis
The coordination of the several pathways involved in cell motility is poorly understood. Here, we identify SH3BP1, belonging to the RhoGAP family, as a partner of the exocyst complex and establish a physical and functional link between two motility-driving pathways, the Ral/exocyst and Rac signaling pathways. We show that SH3BP1 localizes together with the exocyst to the leading edge of motile cells and that SH3BP1 regulates cell migration via its GAP activity upon Rac1. SH3BP1 loss of function induces abnormally high Rac1 activity at the front, as visualized by in vivo biosensors, and disorganized and instable protrusions, as revealed by cell morphodynamics analysis. Consistently, constitutively active Rac1 mimics the phenotype of SH3BP1 depletion: slow migration and aberrant cell morphodynamics. Our finding that SH3BP1 downregulates Rac1 at the motile-cell front indicates that Rac1 inactivation in this location, as well as its activation by GEF proteins, is a fundamental requirement for cell motility.
Nature Methods | 2012
Maxime Deforet; Maria Carla Parrini; Laurence Petitjean; Marco Biondini; Axel Buguin; Jacques Camonis; Pascal Silberzan
Characterizing the migration of a population of cells remains laborious and somewhat subjective. Advances in genetics and robotics allow researchers to perform many experiments in parallel, but analyzing the large sets of data remains a bottleneck. Here we describe a rapid, fully automated correlation-based method for cell migration analysis, compatible with standard video microscopy. This method allows for the computation of quantitative migration parameters via an extensive dynamic mapping of cell displacements.
Biochemical Society Transactions | 2005
Maria Carla Parrini; Michiyuki Matsuda; J. de Gunzburg
Pak1 (p21-activated kinase 1) is a key regulator of the actin cytoskeleton, adhesion and cell motility. Such biological roles require a tight spatial and kinetic control of its localization and activity. We summarize here the current knowledge on Pak1 dynamics in vivo. Inactive dimeric Pak1 is mainly cytosolic. Localized interaction with the activators Cdc42-GTP and Rac1-GTP stimulates the kinase at the sites of cellular protrusions. Moreover, Pak1 is dynamically engaged into multiprotein complexes forming adhesions to the extracellular matrix. Cutting edge microscopy technologies on living cells are finally shedding light on the intricate spatiotemporal mechanisms regulating Pak1.
Journal of Biological Chemistry | 2009
Maria Carla Parrini; Jacques Camonis; Michiyuki Matsuda; Jean de Gunzburg
The p21-activated kinase (PAK) 1 kinase, an effector of the Cdc42 and Rac1 GTPases, regulates cell protrusions and motility by controlling actin and adhesion dynamics. Its deregulation has been linked to human cancer. We show here that activation of PAK1 is necessary for protrusive activity during cell spreading. To investigate PAK1 activation dynamics at live protrusions, we developed a conformational biosensor, based on fluorescence resonance energy transfer. This novel PAK1 biosensor allowed the spatiotemporal visualization of PAK1 activation during spreading of COS-7 cells and during motility of normal rat kidney cells. By using this imaging approach in COS-7 cells, the following new insights on PAK1 regulation were unveiled. First, PAK1 acquires an intermediate semi-open conformational state upon recruitment to the plasma membrane. This semi-open PAK1 species is selectively autophosphorylated on serines in the N-terminal regulatory region but not on the critical threonine 423 in the catalytic site. Second, this intermediate PAK1 state is hypersensitive to stimulation by Cdc42 and Rac1. Third, interaction with PIX proteins contributes to PAK1 stimulation at membrane protrusions, in a GTPase-independent way. Finally, trans-phosphorylation events occur between PAK1 molecules at the membrane possibly playing a relevant role for its activation. This study leads to a model for the complex and accurate regulation of PAK1 kinase in vivo at cell protrusions.
Scientific Reports | 2015
Marco Biondini; Guillaume Duclos; Nathalie Meyer-Schaller; Pascal Silberzan; Jacques Camonis; Maria Carla Parrini
RalA and RalB proteins are key mediators of oncogenic Ras signaling in human oncogenesis. Herein we investigated the mechanistic contribution of Ral proteins to invasion of lung cancer A549 cells after induction of epithelial-mesenchymal transition (EMT) with TGFβ. We show that TGFβ-induced EMT promotes dissemination of A549 cells in a 2/3D assay, independently of proteolysis, by activating the Rho/ROCK pathway which generates actomyosin-dependent contractility forces that actively remodel the extracellular matrix, as assessed by Traction Force microscopy. RalB, but not RalA, is required for matrix deformation and cell dissemination acting via the RhoGEF GEF-H1, which associates with the Exocyst complex, a major Ral effector. Indeed, uncoupling of the Exocyst subunit Sec5 from GEF-H1 impairs RhoA activation, generation of traction forces and cell dissemination. These results provide a novel molecular mechanism underlying the control of cell invasion by RalB via a cross-talk with the Rho pathway.
Cell Reports | 2017
Amanda Remorino; Simon de Beco; Fanny Cayrac; Fahima Di Federico; Gaetan Cornilleau; Alexis Gautreau; Maria Carla Parrini; Jean-Baptiste Masson; Maxime Dahan; Mathieu Coppey
Rac1 is a small RhoGTPase switch that orchestrates actin branching in space and time and protrusion/retraction cycles of the lamellipodia at the cell front during mesenchymal migration. Biosensor imaging has revealed a graded concentration of active GTP-loaded Rac1 in protruding regions of the cell. Here, using single-molecule imaging and super-resolution microscopy, we show an additional supramolecular organization of Rac1. We find that Rac1 partitions and is immobilized into nanoclusters of 50-100 molecules each. These nanoclusters assemble because of the interaction of the polybasic tail of Rac1 with the phosphoinositide lipids PIP2 and PIP3. The additional interactions with GEFs and possibly GAPs, downstream effectors, and other partners are responsible for an enrichment of Rac1 nanoclusters in protruding regions of the cell. Our results show that subcellular patterns of Rac1 activity are supported by gradients of signaling nanodomains of heterogeneous molecular composition, which presumably act as discrete signaling platforms.
Cellular logistics | 2012
Maria Carla Parrini
PAK1 kinase is a crucial regulator of a variety of cellular processes, such as motility, cell division, gene transcription and apoptosis. Its deregulation is involved in several pathologies, including cancer, viral infection and neurodegenerative diseases. Due to this strong implication in human health, the complex network of signaling pathways centered on PAK1 is a subject of intensive investigations. This review summarizes the present knowledge on the multiple PAK1 intracellular localizations and on its shuttling between different compartments. The dynamics of PAK1 localization and activation are finely tuned by the cell and it is this tight control that underlies the capacity of PAK1 to participate in the regulation of many fundamental cell functions. Recently, PAK1 biosensors have been developed to visualize PAK1 activation in live cells. These new imaging tools should be of great help to better understand PAK1 biology and to conceive strategies for efficient and specific PAK1 inhibitors.
Journal of Cell Science | 2016
Marco Biondini; Amel Sadou-Dubourgnoux; Perrine Paul-Gilloteaux; Giulia Zago; Melis D Arslanhan; François Waharte; Etienne Formstecher; Maud Hertzog; Jinchao Yu; Raphaël Guerois; Alexis Gautreau; Giorgio Scita; Jacques Camonis; Maria Carla Parrini
ABSTRACT Coordination between membrane trafficking and actin polymerization is fundamental in cell migration, but a dynamic view of the underlying molecular mechanisms is still missing. The Rac1 GTPase controls actin polymerization at protrusions by interacting with its effector, the Wave regulatory complex (WRC). The exocyst complex, which functions in polarized exocytosis, has been involved in the regulation of cell motility. Here, we show a physical and functional connection between exocyst and WRC. Purified components of exocyst and WRC directly associate in vitro, and interactions interfaces are identified. The exocyst–WRC interaction is confirmed in cells by co-immunoprecipitation and is shown to occur independently of the Arp2/3 complex. Disruption of the exocyst–WRC interaction leads to impaired migration. By using time-lapse microscopy coupled to image correlation analysis, we visualized the trafficking of the WRC towards the front of the cell in nascent protrusions. The exocyst is necessary for WRC recruitment at the leading edge and for resulting cell edge movements. This direct link between the exocyst and WRC provides a new mechanistic insight into the spatio-temporal regulation of cell migration. Highlighted Article: A direct link between exocyst and Wave complexes is revealed, providing new mechanistic insight into the spatio-temporal coordination between membrane trafficking and actin polymerization.
PLOS ONE | 2016
Adriana O. Santos; Maria Carla Parrini; Jacques Camonis
The human genome contains six genes coding for proteins validated in vitro as specific activators of the small GTPases “Ras-related protein Ral-A” and “Ras-related protein Ral-B”, generically named Ral-guanine nucleotide exchange factors (RalGEF). Ral proteins are important contributors to Ras oncogenic signaling, and RAS oncogenes are important in human Non-Small Cell Lung Carcinoma (NSCLC). Therefore in this work, RalGEF contribution to oncogenic and non-oncogenic features of human NSCLC cell lines, as anchorage-dependent and independent growth, cell survival, and proliferation, was investigated. Among all human RalGEF, silencing of RGL1 and RALGPS1 had no detectable effect. However, silencing of either RGL2, RGL3, RALGDS or, to a larger extent, RALGPS2 inhibited cell population growth in anchorage dependent and independent conditions (up to 90 and 80%, respectively). RALGPS2 silencing also caused an increase in the number of apoptotic cells, up to 45% of the cell population in transformed bronchial BZR cells. In H1299 and A549, two NSCLC cell lines, RALGPS2 silencing caused an arrest of cells in the G0/G1-phase of cell cycle. Furthermore, it was associated with the modulation of important cell cycle regulators: the E3 Ubiquitin Protein Ligase S-phase kinase-associated protein 2 (Skp2) was strongly down-regulated (both at mRNA and protein levels), and its targets, the cell cycle inhibitors p27 and p21, were up-regulated. These molecular effects were not mimicked by silencing RALA, RALB, or both. However, RALB silencing caused a modest inhibition of cell cycle progression, which in H1299 cells was associated with Cyclin D1 regulation. In conclusion, RALGPS2 is implicated in the control of cell cycle progression and survival in the in vitro growth of NSCLC cell lines. This function is largely independent of Ral GTPases and associated with modulation of Skp2, p27 and p21 cell cycle regulators.
Communicative & Integrative Biology | 2011
Maria Carla Parrini; Jacques Camonis
The Ras proto-oncogenic proteins, prototypes of the small GTPases, work as molecular switches: they are active when bound to GTP and inactive when bound to GDP. A variety of evidence suggested that the Ras paradigm is not fully valid for the Rho-family of small GTPases. Indeed, permanent activation is not sufficient but it is rather the continuous oscillation between the GDP-bound and GTP-bound conformations (namely the GDP/GTP cycling or GTPase flux), that is required for Rho-GTPases to perform their biological functions and properly coordinate actin cytoskeleton reorganization. In our recent study, we show that Rac1 needs to cycle between the GDP and GTP states in order to efficiently control cell motility. Similarly, it was previously reported that GDP/GTP cycling is required by RhoA for cytokinesis and by Cdc42 for cell polarization. The future challenge is to understand why the GTPase flux is so important for the biological actions of Rho GTPases.