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

To determine the particular intracellular steps in the glycosylation of the vesicular stomatitis virus (VSV) glycoprotein that were altered in several lectin-resistant CHO cell lines, VSV-infected parental and mutant cells were pulse-labeled for 30 and 120 min with [3H]mannose and [3H]glucosamine. Cell-associated viral glycopeptides were analyzed by gel filtration combined with specific glycosidase digestions and compared with the corresponding mature virion oligosaccharides. The intracellular glycosylation of the VSV glycoprotein in a mutant cell line resistant to phytohemagglutinin was identical to that in the normal cells except for a complete block in processing at a specific step in the final trimming of the oligomannosyl core from five to three mannoses. The results demonstrated that a double-mutant cell line selected from the phytohemagglutinin-resistant cells for resistance to concanavalin A had an additional defect in one of the earliest stages of glycosylation, resulting in smaller precursor oligosaccharides linked to protein.
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PMID:Altered synthesis and processing of oligosaccharides of vesicular stomatitis virus glycoprotein in different lectin-resistant Chinese hamster ovary cell lines. 625 77

The fusion of BHK-21-KB cells by vesicular stomatitis virus was not induced in Eagle's minimal essential medium without glucose. In medium containing glucose, the rate of polykaryocyte formation decreased as the concentration of glucose was reduced below 5 mM. However, no reduction in virus production 24 hr after infection was seen under this condition. Addition of pyruvate or mannose to the culture medium caused a reversal of cell fusing activity. Cell fusion and virus growth were significantly suppressed by sodium azide and 2,4-dinitrophenol.
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PMID:Requirement of carbohydrates for cell fusion induced by vesicular stomatitis virus. 626 40

A method is presented for separation of tryptic glycopeptides-containing oligosaccharides of the N-asparagine-linked type. High performance liquid chromatography (HPLC) of glycopeptides on a C18 reverse-phase system eluted with a gradient of 0%-50% acetonitrile in 0.1 M NaPO4 pH 2.2 resolves the two major glycosylation sites from the envelope glycoprotein (G) of vesicular stomatitis virus. Glycopeptides containing N-linked oligosaccharides of the complex type coelute with those containing N-linked oligosaccharides of the neutral, high mannose type, indicating that separation is based upon peptide rather than carbohydrate composition. The contribution of the carbohydrate component to glycopeptide elution, as determined by cleavage of the high mannose oligosaccharides with endo-beta-Nacetylglucosaminidase H, is that of a significant, but minor, decrease in peptide retention time. Comparison of the tryptic glycopeptide profiles of G isolated from both wild type and mutant strains of VSV illustrates the rapid, reproducible, and quantitative nature of the technique. Through HPLC analysis of appropriately treated glycopeptides, it is possible to explore both the nature and extent of glycosylation at individual sites in glycoproteins in a single step.
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PMID:Separation of glycopeptides by high performance liquid chromatography. 627 84

The glycosylation of the G-protein was analyzed in vesicular stomatitis virus-infected baby hamster kidney cells incubated in the absence of glucose. The results indicate that the G-protein in glucose-starved cells is initially glycosylated from a lipid donor with a glucosylated oligosaccharide which is resistant to endo-beta-N-acetylglucosaminidase H and partially susceptible to alpha-mannosidase. With longer times, the protein-bound carbohydrate chain becomes much more sensitive to alpha-mannosidase while remaining endo-beta-N-acetylglucosaminidase H-resistant. Purified virions from glucose-starved baby hamster kidney cells, labeled with [35S]methionine and isolated on a sucrose gradient, contain altered forms of the G-protein, whereas the other viral proteins remain unchanged. These altered forms could also be radiolabeled with [3H]mannose, and upon analysis of labeled glycopeptides by chromatography on concanavalin A-Sepharose and Bio-Gel P-6, it was apparent that modification of the oligosaccharide portion of the G-protein occurs in baby hamster kidney cells, leading to aberrant mature carbohydrate chains.
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PMID:Altered G-protein glycosylation in vesicular stomatitis virus-infected glucose-deprived baby hamster kidney cells. 628 41

The single glycoprotein species of vesicular stomatitis virus exhibits heterogeneity in isoelectric focusing. Short term radioisotopic labeling of infected cells revealed that this heterogeneity is acquired after synthesis and glycosylation of the protein, during the period of oligosaccharide processing from the high mannose to the complex form. In this process, radioactive sulfate is incorporated randomly into different glycoprotein molecules, conferring unequal amounts of negative charge upon them. Since the virus glycoprotein is processed by cellular pathways, it is likely that differential sulfation is responsible for much of the charge heterogeneity displayed by cellular glycoproteins.
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PMID:Contribution of oligosaccharide sulfation to the charge heterogeneity of a viral glycoprotein. 628 54

Based on subcellular fractionation data, the following maturation pathways were proposed for the Newcastle disease virus glycoproteins. During or shortly after synthesis in rough endoplasmic reticulum, hemagglutinin-neuraminidase (HN) and fusion (F0) glycoproteins underwent dolichol pyrophosphate-mediated glycosylation, and HN assumed a partially trypsin-resistant conformation. HN began to associate into disulfide-linked dimers in rough endoplasmic reticulum, and at least one of its oligosaccharide side chains was processed to a complex form en route to the cell surface. During migration in intracellular membranes, F0 was proteolytically cleaved to F1.2. Neither HN nor F1,2 required oligosaccharide side chains for migration to plasma membranes, and cleavage of F0 also occurred without glycosylation. Virion- and plasma membrane-associated HN contained both complex and high-mannose oligosaccharide chains on the same molecule, and F1,2 contained at least high-mannose forms. Several of the properties of HN were notable for a viral glycoprotein. The oligosaccharide side chains of HN were modified very slowly in chick cells, whereas those of the G glycoprotein of vesicular stomatitis virus were rapidly processed to a complex form. Therefore, their different rates of migration and carbohydrate processing were intrinsic properties of these glycoproteins. Consistent with its slow maturation, the HN glycopolypeptide accumulated to high levels in intracellular membranes as well as in plasma membranes. Intracellular HN contained immature oligosaccharide side chains, suggesting that it accumulated in the pre-Golgi/Golgi segment of the maturation pathway. The major site of accumulation of mature HN with neuraminidase activity was the plasma membrane.
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PMID:Maturation of the envelope glycoproteins of Newcastle disease virus on cellular membranes. 628 83

The intracellular migration of G protein in vesicular stomatitis virus-infected cells was visualized by light and electron microscope radioautography after a 2-min pulse with [3H]mannose followed by nonradioactive chase for various intervals. The radioactivity initially (at 5-10 min) appeared predominantly in the endoplasmic reticulum, and the [3H]mannose-labeled G protein produced was sensitive to endoglycosidase H. Silver grains were subsequently (at 30-40 min) observed over the Golgi apparatus, and the [3H]mannose-labeled G protein became resistant to endoglycosidase H digestion. Our data directly demonstrate the intracellular transport of a plasmalemma-destined transmembrane glycoprotein through the Golgi apparatus.
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PMID:Intracellular transport of the transmembrane glycoprotein G of vesicular stomatitis virus through the Golgi apparatus as visualized by electron microscope radioautography. 628 38

Addition of 50 micrograms/ml chloroquine to neuroblastoma cells 1 h before infection with temperature-sensitive mutant ts G31 (III) of vesicular stomatitis virus (VSV) prevented virus-induced cell fusion from occurring. Interestingly, addition of chloroquine after infection still inhibited cell fusion. Based on the number of fusion events required to produce the polykaryocytes observed, cell fusion was inhibited 92% when chloroquine was added 1 h post-infection and 77% when chloroquine was added 2 h post-infection. The inhibition of virus-induced cell fusion could not be accounted for by an inhibition of virus protein synthesis because the virus protein synthesis measured 6 h post-infection was 90% of that in untreated, infected cells with chloroquine added 1 h post-infection, and the same as untreated, infected cells when chloroquine was added 2 h post-infection. No virus proteins were made, however, when chloroquine was added before infection, which is consistent with a chloroquine-mediated inhibition of virus uncoating. The release of infectious virions was completely inhibited when chloroquine was added before infection or 1 or 2 h post-infection, which indicated an inhibition of virus maturation in the later stages of virus assembly. By indirect immunofluorescence the virus glycoprotein (G protein) could not be detected on the surface of chloroquine-treated, infected cells, but the G protein was present inside the treated cells. With 125I-labelled anti-G protein IgG, 16% of the G protein found on the surface of untreated, infected cells was on the cell surface when chloroquine was added 2 h post-infection. When chloroquine was removed from infected cells, the G protein accumulated at the cell surface, and this accumulation could not be prevented by tunicamycin, an inhibitor of glycosylation. Furthermore, galactose was incorporated into the G protein in the presence of chloroquine. Therefore, the VSV G protein was being synthesized and glycosylated in the presence of chloroquine but the drug prevented the expression of the glycoprotein at the cell surface during the final stages of G protein assembly.U
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PMID:Inhibition of vesicular stomatitis virus glycoprotein expression by chloroquine. 629 May 97

A variant line (LV-1) of mouse myeloma MOPC 315 (IgA, lambda 2) has lost the ability to synthesize L chain. It synthesizes an altered H chain (H' chain) that is turned over intracellularly and is not secreted. Rescue of H' chain secretion can be accomplished by fusion of LV-1 to a variant of another myeloma line, MPC 11 (IgG2b, kappa), which only synthesizes a light chain. The hybrid (X-2) secretes the H' chain in a four chain structure (kappa 2 alpha' 2). In wild-type MOPC 315 cells, it was reported previously that inhibition of core sugar addition blocks the secretion of the H chain polypeptide. We have studied glycosylation in MPOC 315 wild-type, LV-1 variant, and X-2 hybrid cell lines. The ability of all three lines to add the core sugars mannose and glucosamine to heavy chain was demonstrated. Due to the instability of the H' chain in LV-1, it is difficult to assess H' chain fucosylation directly. To study fucose addition in LV-1, the enveloped virus vesicular stomatitis (VSV), which can infect the three lines, was utilized. The fucosylation and secretion of VSV glycoprotein G was discernible in all three lines; however, only LV-1 cannot activate free fucose, and instead fucosylates through conversion of the mannose intermediate. Normal fucose addition to H chain in a wild-type cell occurred immediately before secretion. The fact that degradation of H' chain in LV-1 begins before fucosylation suggests that the rescue of H' chain secretion by formation of the X-2 hybrid is due to the acquired presence of a suitable L chain rather than complementation of a sugar defect. These observations indicate that proper assembly of the polypeptide components of some secretory proteins, e.g., Ig molecules, is required for the secretion of the individual chains.
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PMID:Glycosylation and secretion of an altered immunoglobulin heavy chain in mouse myeloma MOPC 315. 629 92

Swainsonine, an inhibitor of glycoprotein processing, inhibits the formation of the normal oligosaccharide chain of the G protein of vesicular stomatitis virus. Thus, when vesicular stomatitis virus was grown in baby hamster kidney cells in the presence of swainsonine (15 to 500 ng/ml) and labeled with [2-(3)H]mannose, the oligosaccharide portion of the G protein was completely susceptible to the action of endoglucosaminidase H. However, the normal viral glycoprotein is not susceptible to this enzyme. Various enzymatic treatments and methylation studies of the mannose-labeled oligosaccharides suggest that swainsonine causes the formation of a hybrid-type oligosaccharide having an oligomannosyl core (Man(5)GlcNAc(2)-Asn) characteristic of neutral oligosaccharides plus the branch structure (NeuNAc-Gal-GlcNAc) characteristic of the complex oligosaccharides. A structure for this hybrid oligosaccharide is proposed. Swainsonine had no effect on the incorporation of [(14)C]leucine into viral proteins, nor did it change the number of PFU produced in these cultures. It did, however, slightly decrease the incorporation of [(3)H]glucosamine and increase the incorporation of [(3)H]mannose. Vesicular stomatitis virus raised in the presence of swainsonine bound much more tightly to columns of concanavalin A-Sepharose than did control virus. Swainsonine had to be added within the first 4 or 5 h of virus infection to be effective. Thus, when 100 ng of the alkaloid per ml was added at any time within the first 3 h of infection, essentially all of the glycoprotein was susceptible to digestion by endoglucosaminidase H. However, when swainsonine was added 4 h after the start of infection, 30% of the glycopeptides became resistant to endoglucosaminidase H; at 5 h, 70% were resistant. The effect of swainsonine was reversible since removal of the alkaloid allowed the cells to form the normal complex glycoproteins. However, the time of removal was critical in terms of oligosaccharide structure.
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PMID:Alterations in the structure of the oligosaccharide of vesicular stomatitis virus G protein by swainsonine. 629 70


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