Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0038362 (stomatitis)
 8,852 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The association of vesicular stomatitis virus proteins with intracellular and plasma membranes was examined by pulse and pulse-chase labeling of virus-infected HeLa cells with [35S]methionine and separation of cell homogenates into three major membrane fractions in discontinuous sucrose gradients. The glycoprotein G was primarily associated with rough endoplasmic reticulum-like membranes after short radioactive pulses (2 to 4 min) but accumulated in the plasma membrane-enriched fraction and the smooth internal membrane fraction with longer pulse or chase periods. The nucleocapsid protein N and the matrix protein M accumulated in the rough endoplasmic reticulum and plasma membrane-like fractions but not in the smooth internal membrane fraction. Only a fraction (35 to 40%) of the viral protein synthesized during a short pulse in the mid-cycle of infection was apparently utilized in released virus. The newly synthesized virus proteins first appeared in released virus in the order: M, N and L, and G.
 ...
PMID:Association of vesicular stomatitis virus proteins with HeLa cell membranes and released virus. 18 39

Glycosylation of the envelope glycoprotein of vesicular stomatitis virus was examined using virus-infected HeLa cells that were pulse-labeled with radioactive sugar precursors. The intracellular sites of glycosylation and the stepwise elongation of the carbohydrate side chains of the G protein were monitored by membrane fractionation and gel filtration of Pronase-digested glycopeptides. The results with short pulses of sugar label (5 to 10 mtein linkage (glucosamine and mannose) are added to G which was associated with the rough endoplasmic reticulum-enriched membrane fraction, whereas the more distal sugars (galactose, sialic acid, fucose, and possibly more glucosamine) are added in the light-density internal membrane fraction. Accumulation of mature G was observed in the plasma membrane-enriched fraction. The gel filtration studies indicated that the initial glycosylation event may be the en bloc addition of a mannose and glucosamine oligomer, followed by the stepwise addition of the more distal sugars.
 ...
PMID:Glycosylation of vesicular stomatitis virus glycoprotein in virus-infected HeLa cells. 18 40

Maturation of viral proteins in cells infected with mutants of vesicular stomatitis virus was studied by surface iodination and cell fractionation. The movement of G, M, and N proteins to the virion bud appeared to be interdependent. Mutations thought to be in G protein prevented its migration to the cell surface, allowed neither M nor N protein to become membrane bound, and blocked formation of viral particles. Mutant G protein appeared not to leave the endoplasmic reticulum at the nonpermissive temperature, but this defect was partially reversible. In cells infected with mutants that caused N protein to be degraded rapidly or prevented its assembly into nucleocapsids, M protein did not bind to membranes and G protein matured to the cell surface, but never entered structures with the density of virions. Mutations causing M protein to be degraded prevented virion formation, and G protein behaved as in cells infected by mutants in N protein. These results are consistent with a model of virion formation involving coalescence of soluble nucleocapsid and soluble M protein with G protein already in the plasma membrane.
 ...
PMID:Maturation of viral proteins in cells infected with temperature-sensitive mutants of vesicular stomatitis virus. 19 42

Previous studies showed that the glycoprotein (G) of vesicular stomatitis virus is synthesized in association with the endoplasmic reticulum (ER) membrane and that all G mRNA co-fractionates with ER membrane. Here, we show that treatment of infected cells with puromycin results in dissociation of G mRNA, and presumably the associated ribosomes, from the ER membrane. Even it extracts from treated cells are kept at low ionic strength (0.01 M KCl), over 80% of G mRNA is found unattached to membranes. There is no evidence for direct interaction of GmRNA with membranes; rather, the linkage apparently is mediated by the nascent G polypeptide.
 ...
PMID:Binding of viral glycoprotein mRNA to endoplasmic reticulum membranes is disrupted by puromycin. 19 64

Membrane assembly was observed to proceed in cell-free extracts. Specifically, the membrane glycoprotein of vesicular stomatitis virus was synthesized in crude extracts of wheat germ in the presence of membrane vesicles derived from pancreatic endoplasmic reticulum. The resulting glycoprotein spans the lipid bilayer asymmetrically, is glycosylated, and is indistinguishable in these respects from the form of the glycoprotein found in the rough endoplasmic reticulum of virus-infected cells. Both glycosylation and asymmetric transmembrane insertion of the glycoprotein into membranes in vitro require protein synthesis in the presence of membranes. The carboxyl-terminal 5% of the polypeptide chain is located on the external surface of vesicles, corresponding to the cytoplasmic surface of the endoplasmic reticulum in cells. Most, or all, of the amino-terminal portion of the glycoprotein, as well as the protein-bound carbohydrate, appears to be located within the lumen of the membrane vesicles. These findings demonstrate that insertion of this membrane protein occurs during or immediately after protein synthesis. The results are consistent with the concepts that the growing membrane protein is extruded across the endoplasmic reticulum membrane amino terminus first and that glycosylation is restricted to the lumenal surface of the membrane. The cell-free system reported here should prove valuable for studying these processes.
 ...
PMID:Membrane assembly in vitro: synthesis, glycosylation, and asymmetric insertion of a transmembrane protein. 19 78

Electron microscope studies showed a high production of melanosomes and viral particles budding into the cisternae of the endoplasmic reticulum in cells derived from a subcutaneous metastasis. The history of this subline (HM6B-A) has been summarized elsewhere. An amelanotic subline (provided by the same patient) did not show similar virus particles. When infected with a vesicular stomatitis virus (VSV) thermolabile mutant (tl), these cells produced a VSV pseudotype in which a thermosensitive antigen was modified. Modification of surface VSV antigens was also detected by neutralisation tests. Using these tests, the VSV-pseudotype particles could be used as a tool to detect one or more antigens to a "putative" human melanomavirus, which might be only partially expressed.
 ...
PMID:[Formation of pseudotypes of VSV after culture in a human melanoma]. 20 12

The glycoprotein (G) of vesicular stomatitis virus (VSV) is synthesized on membrane-bound polyribosomes. Approximately 30 min after its synthesis, it reaches the surface plasma membrane where it is incorporated into budding virus. The first part of this paper focuses on the 2 intracellular, membrane-bound, glycosylated forms of the glycoprotein which are intermediates in its biogenesis. All glycosylation and processing is completed in the smooth microsome fraction before the protein reaches the surface. Next, we turn to the mechanism by which G is synthesized on membrane-bound polyribosomes. All of the G mRNA is bound to membranes, and studies with puromycin suggest that this attachment of G mRNA is mediated by the nascent glycoprotein chain. After its synthesis G is a transmembrane protein with about 30 amino acids at the carboxyl terminus remaining on the cytoplasmic side of the endoplasmic reticulum. Since 95% of the glycoprotein, containing the carbohydrate residues, is resistant to attack by external proteases, it appears to be within the lumen of the endoplasmic reticulum or embedded within the lipid bilayer. Finally, we show that synthesis, glycosylation, and proper asymmetric insertion of G into the ER can be achieved in cell-free extracts. Both glycosylation of G and proper insertion into the ER membrane in this cell-free system require concomitant protein synthesis.
 ...
PMID:Membrane assembly: synthesis and intracellular processing of the vesicular stomatitis viral glycoprotein. 21 48

The role of glycosylation in the maturation of the vesicular stomatitis virus (VSV) glycoprotein was studied by use of the antibiotic tunicamycin. Tunicamycin-treated VSV-infected cells synthesize an unglycosylated form of the VSV glycoprotein (R. Leavitt, S. Schlesinger, and S. Kornfeld, J. Virol. 21:375--385, 1977). We have found that tunicamycin has no effect on the attachment of the glycoprotein to intracellular membranes or on the transport of protein to the lumen of the endoplasmic reticulum. However, tunicamycin prevented the migration of the glycoprotein from the rough endoplasmic reticulum to smooth intracellular membranes.
 ...
PMID:Assembly of viral membranes: maturation of the vesicular stomatitis virus glycoprotein in the presence of tunicamycin. 21 8

The intracellular vesicular stomatitis virus glycoprotein (G) is inserted into membranes such that a small portion of one end of the molecule is exposed on the cytoplasmic surface of the endoplasmic reticulum and is susceptible to proteolytic digestion (T.G. Morrison, C.O. McQuain, and D. Simpson, J. Virol. 28:368-374). We have determined that this region of the G protein contains two methionyl tryptic peptides. The methionyl tryptic peptides of the G protein have been ordered by the use of the antibiotic pactamycin, and the two methionyl tryptic peptides removed by proteolytic digestion of intracellular G protein have been shown to be derived from the carboxyl terminal end of the protein. In addition, we have found that the unglycosylated G protein synthesized in a reticulocyte cell-free reaction migrates on polyacrylamide gels slightly slower than the unglycosylated G protein synthesized in tunicamycin-treated infected cells. We have also compared these G proteins derived from different sources by partial proteolysis (D.W. Cleveland, S.G. Fischer, M.W. Kirschner, and V.K. Laemmli, J. Biol. Chem. 252:1102-1106) and by chymotryptic peptide analysis. We have found minor differences between the two proteins consistent with the removal of 10 to 15 amino acids from the amino terminus of the intracellular G protein.
 ...
PMID:Vesicular stomatitis virus glycoprotein is anchored to intracellular membranes near its carboxyl end and is proteolytically cleaved at its amino terminus. 22 83

Previous work has shown that the mRNA encoding the vesicular stomatitis virus (VSV) glycoprotein (G) is bound to the rough endoplasmic reticulum (RER) and that newly made G protein is localized to the RER. In this paper, we have investigated the topology and processing of the newly synthesized G protein in microsomal vesicles. G was labeled with [35S]methionine ([35S]met), either by pulse-labeling infected cells or by allowing membrane-bound polysomes containing nascent G polipeptides to complete G synthesis in vitro. In either case, digestion of microsomal vesicles with any of several proteases removes approximately 5% (30 amino acids) from each G molecule. These proteases will digest the entire G protein if detergents are present during digestion. Using the method of Dintzis (1961, Proc. Natl. Acad. Sci. U. S. A. 47:247--261) to order tryptic peptides (8), we show that peptides lost from G protein by protease treatment of closed vesicles are derived from the carboxyterminus of the molecule. The newly made VSV G in microsomal membranes is glycosylated. If carbohydrate is removed by glycosidases, the resultant peptide migrates more rapidly on polyacrylamide gels than the unglycosylated, G0, form synthesized in cell-free systems in the absence of membranes. We infer that some proteolytic cleavage of the polypeptide backbone is associated with membrane insertion of G. Further, our findings demonstrate that, soon after synthesis, G is found in a transmembrane, asymmetric orientation in microsomal membranes, with its carboxyterminus exposed to the extracisternal, or cytoplasmic, face of the vesicles, and with most or all of its amino-terminal peptides and its carbohydrate sequestered within the bilayer and lumen of the microsomes.
 ...
PMID:Transmembrane biogenesis of the vesicular stomatitis virus glycoprotein. 22 71


1 2 3 4 5 6 7 8 9 10 Next >>