Noriko Tateishi

Organ-specific difference in the sugar chains of γ-glutamyltranspeptidase

Sugar chains of gamma-glutamyltranspeptidase purified from neonatal mouse liver and adult mouse kidney were quantitatively released as oligosaccharides from the polypeptide backbone by hydrazinolysis. A comparative study of the structures of the oligosaccharides has revealed that the GlcNAc beta 1 leads to 4Man beta 1 leads to group is found in the sugar chains of kidney enzyme but not in those of liver enzyme. This is considered as an organ-specific difference common to mammals because the same phenomenon was found in bovine and rat enzymes.

Induction of a 23 kDa stress protein by oxidative and sulfhydryl-reactive agents in mouse peritoneal macrophages

The synthesis of 23 kDa protein was enhanced when mouse peritoneal macrophages were exposed to oxidative agents such as hydrogen peroxide and menadione, or to sulfhydryl-reactive agents such as diethylmaleate, cadmium chloride and sodium arsenite. After 11 h exposure to these agents the 23 kDa protein was one of the actively synthesized proteins in the macrophages. Under similar conditions the 34 kDa protein previously identified as heme oxygenase, was induced and its synthesis preceded that of the 23 kDa protein. Neither the 23 kDa or the 34 kDa protein was induced by hyperthermia. Conversely, the various oxidative and sulfhydryl-reactive agents employed here did not induce the major heat shock proteins in the macrophages. When the macrophages were activated by bacterial lipopolysaccharide or other stimulants, many proteins are known to be induced, however, the 23 kDa and 34 kDa proteins were not induced. The 34 kDa protein, i.e., heme oxygenase, has been found to be stress-induced in various types of cell, but not the 23 kDa protein. This suggests that the 23 kDa protein is a stress protein predominantly expressed in macrophages.

Decrease of glutathione and induction of γ-glutamyltransferase by dibutyryl-3′,5′-cyclic AMP in rat liver

Abstract Administration of dibutyryl-3′,5′-cyclic AMP to rats caused marked, but temporary, decrease of liver glutathione. This decrease appeared to be catalyzed by γ-glutamyltransferase, because it occured concomitantly with induction of the enzyme and increase of cysteine in the liver. The biological half-life of hepatic γ-glutamyltransferase was estimated to be about 3 hours. It is proposed that the physiological levels of glutathione and γ-glutamyltransferase in the liver are controlled by 3′,5′-cyclic AMP, and that liver glutathione may serve as a reservoir of cysteine, which can be mobilized by the transferase.

The structures of the carbohydrate moieties of mouse kidney γ-glutamyltranspeptidase: Occurrence of X-antigenic determinants and bisecting N-acetylglucosamine residues☆

Paper electrophoresis and Bio-Gel P-4 column chromatography of the oligosaccharides released from mouse kidney gamma-glutamyltranspeptidase by hydrazinolysis gave fractionation patterns quite distinct from those of the bovine and rat kidney enzymes. Structural studies of the fractionated oligosaccharides by sequential exoglycosidase digestion in combination with methylation analysis showed that mouse kidney gamma-glutamyltranspeptidase contains a series of bisected complex-type asparagine-linked sugar chains with the following oligosaccharides as their outer chain moieties: GlcNAc beta 1----, Sia alpha 2----Gal beta 1----4GlcNAc beta 1----, Gal beta 1----4(Fuc alpha 1----3)GlcNAc beta 1----, and sialylated N-acetyllactosamine repeating sugar chains. Some of these sugar chains were found for the first time in glycoproteins.

Ontogeny of neuropeptides in the nucleus ventromedialis hypothalami of the rat: An immunohistochemical analysis

The ontogeny of leucine-enkephalin (ENK)-, cholecystokinin-8 (CCK)-, substance P (SP)- and neurotensin (NT)-like immunoreactive structures were examined in the nucleus ventromedialis hypothalami (vm) of the rat by means of an indirect immunofluorescence method. ENK- (ENKI), SP- (SPI) and CCK-like immunoreactive (CCKI) structures in the vm exhibited very similar ontogenetic developments, though no CCKI cells were detected. ENKI fibers as well as SPI fibers and neurons first appeared at gestational day 21, ENKI neurons at postnatal day 2, and CCKI fibers at postnatal day 1. These structures subsequently increased in number. The maximum content was reached at postnatal day 21 and was observed even in the adult rats (postnatal day 30). On the other hand, NTI fibers first appeared at postnatal day 1; they decreased in number and no or only a few NTI fibers were seen in the adult rats. No NTI cells were seen in the vm.

Comparison of the partial sequences of nucleolar and cytoplasmic RNA's of rat liver

Abstract 1. 1. The partial nucleotide sequences of nucleolar precursor RNA and cytoplasmic RNA were compared. 2. 2. The products of digestion of nucleolar and cytoplasmic RNA by pancreatic ribonuclease were analyzed by a two-step column chromatography procedure, in which oligonucleotides were first separated according to chain length, and then mono-, di- and trinucleotides were rechromatographed separately. 3. 3. In general, the base sequences of both nucleolar and cytoplasmic RNA deviated significantly from a random distribution. 4. 4. The distribution of 32 P in the partial nucleotide sequences of nucleolar 45-S and 28-S RNA and cytoplasmic 28-S RNA differed only in minor details. 28-S rRNA seemed to have different base sequences from those of 18-S RNA. 5. 5. The nucleolar 45-S RNA chain cannot be converted as a whole to rRNA because there is a discrepancy between the frequencies of the partial nucleotide sequences of 45-S RNA and the sum of those of 28-S and 18-S rRNA. These results suggested that there are non-ribosomal sequences in nucleolar 45-S RNA of rat liver, as reported previously for tumor tissues 14,15 .