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)

Hamster sarcoma virus (HSV) transformation of Nil-8 fibroblasts is associated with an increase in the average size of N-acetyllactosamine (complex) type N-linked glycans due to an increase in both the average number of branches/chain and in the fraction of N-linked glycans containing poly(GlcNAc(beta 1,3) Gal-(beta 1,4)) (polylactosaminylglycan) chains. Analysis of glycopeptides from the envelope glycoproteins of Sindbis virus and vesicular stomatitis virus (VSV) grown in Nil-8 and Nil/HSV cells indicated that the transformation-associated shift to larger N-linked oligosaccharides selectively affects some glycosylation sites far more than others. Glycosylation of the Sindbis virus glycoproteins and of Asn-179 of VSV G was similar in Nil-8 and Nil/HSV cells; oligosaccharide processing generally did not proceed beyond the biantennary complex stage. In contrast, Asn-336 of VSV G carried primarily biantennary complex glycans in Nil-8-grown virus (ratio, triantennary, and larger to biantennary complex glycans (tri+/bi) = 0.5) but more highly branched structures in Nil/HSV-grown virus (tri+/bi = 8.1). All of the triantennary or larger oligosaccharides from Asn-336 of Nil/HSV-grown VSV G bound to leukoagglutinating phytohemagglutinin-agarose, indicating the presence of a branch attached to the Man3GlcNAc2 core via a beta 1,6-linked GlcNAc residue and suggesting that increased UDP-GlcNAc:alpha-D-mannoside beta 1,6-N-acetylglucosaminyl transferase V (GlcNAc transferase V) activity accompanied transformation. At least 20% of these leukoagglutinating phytohemagglutinin-binding oligosaccharides were sensitive to an enzyme specific for polylactosaminylglycan chains, Escherichia freundii endo-beta-galactosidase.
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PMID:Differential effects of oncogenic transformation on N-linked oligosaccharide processing at individual glycosylation sites of viral glycoproteins. 282 91

The biochemical and kinetic properties of UDP-GlcNAc:alpha-D-mannoside (GlcNAc to Man alpha 1,3) beta 1,2-N-acetylglucosaminyltransferase I (GlcNAc-TI) have been investigated in the Chinese hamster ovary glycosylation mutant Lec1A. Previous studies showed that, whereas Lec1A cells synthesize complex carbohydrates at levels consistent with partial GlcNAc-TI action, no GlcNAc-TI activity was detected in Lec1A cell-free extracts (Stanley, P., and Chaney, W. (1985) Mol. Cell. Biol. 5, 1204-1211). It is now reported that, under altered reaction conditions, GlcNAc-TI activity can be measured in Lec1A cell extracts. The GlcNAc-TI enzyme in Lec1A.2C has a pH optimum of 7.5 (compared with 6.25 for the parental enzyme) and apparent Km values for Man5GlcNAc2Asn and UDP-GlcNAc that are, respectively, 21- and 44-fold higher than the apparent Km values of GlcNAc-TI from parental Chinese hamster ovary cells. Two independent Lec1A mutants possess GlcNAc-TI activities with similarly altered biochemical and kinetic properties. In fact, under optimal assay conditions for each cell line, the level of GlcNAc-TI in Lec1A extracts is equal to that of parental Chinese hamster ovary cell extracts. Interestingly, the two glycosylation sites of the G glycoprotein of vesicular stomatitis virus are processed quite differently in Lec1A cells. The glycopeptide nearest the carboxyl-terminal appears to be a preferred substrate for the Lec1A GlcNAc-TI activity. The combined data suggest that the Lec1A mutation affects the gene that codes for GlcNAc-TI, giving rise to a structurally altered glycosyltransferase with different biochemical properties.
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PMID:Lec1A Chinese hamster ovary cell mutants appear to arise from a structural alteration in N-acetylglucosaminyltransferase I. 294 43

F2A8, a glycosylation mutant of Chinese hamster ovary cells, was isolated without prior enrichment or selective procedures by screening colonies for reduced [3H]mannose incorporation into macromolecules. F2A8 cells incubated with [3H]mannose synthesized 70% the amount of labeled GDP-mannose found in parental cells, and the same oligosaccharides attached to lipid and protein as did parental cells, but in reduced amounts. Incorporation of radioactivity from labeled mannose into saccharide-lipids and into total glycopeptides of F2A8 was reduced 7-fold compared to parental cells. In addition, glycosylation of the vesicular stomatitis virus glycoprotein was reduced in F2A8 cells as assessed by a mobility intermediate between normally glycosylated and unglycosylated protein during sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In vitro assays using membrane preparations showed that F2A8 had parental levels of glucosylphosphoryldolichol synthase and of UDP-GlcNAc:dolichyl phosphate:GlcNAc-phosphotransferase when the enzymatic determinations were done in the presence of exogenous dolichyl phosphate. However, 5-fold less glucosylphosphoryldolichol synthase activity was detected in membranes of F2A8 compared to membranes of parental cells in assays relying on endogenous lipid substrate. F2A8 appears to have reduced amounts of dolichyl phosphate available for its glycosylation reactions.
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PMID:A mutant of Chinese hamster ovary cells with a reduction in levels of dolichyl phosphate available for glycosylation. 339 41

A biochemical basis for the LEC10 mutant phenotype of Chinese hamster ovary cells has been identified. Independent LEC10 mutants, originally selected for resistance to the toxicity of ricin, have been shown to exhibit reduced binding of 125I-ricin at the cell surface. Although this is indicative of structural changes in cell-surface carbohydrates, labeling of plasma membranes with galactose oxidase/[3H]borohydride revealed no significant differences between mutant and parental cells. Alterations in the carbohydrates synthesized by LEC10 cells were, however, resolved by lectin-affinity chromatography of glycopeptides from the G glycoprotein of vesicular stomatitis virus (VSV) grown in LEC10. LEC10/VSV glycopeptides contain a fraction which is not bound to concanavalin A-Sepharose but is strongly retarded on E-PHA (erythroagglutinin from Proteus vulgaris)-agarose. In contrast, CHO/VSV glycopeptides or those from a LEC 10 revertant (R.LEC 10/VSV) do not contain carbohydrates with these properties. High-field 1H NMR spectroscopy of the novel LEC10/VSV carbohydrates showed that they are complex, biantennary structures containing N-acetylglucosamine in beta(1,4)-linkage to the beta-linked core mannose residue. The presence of these structures correlates with the expression of the enzyme responsible for the addition of this "bisecting" GlcNAc residue, UDP-GlcNAc:glycopeptide beta-4-N-acetylglucosaminyltransferase III (GlcNAc-TIII). Parental Chinese hamster ovary cells and the LEC10 revertant possess no detectable GlcNAc-TIII activity. The combined evidence suggests that the LEC10 mutation induces the expression of the GlcNAc-TIII enzyme in Chinese hamster ovary cells.
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PMID:A dominant mutation to ricin resistance in Chinese hamster ovary cells induces UDP-GlcNAc:glycopeptide beta-4-N-acetylglucosaminyltransferase III activity. 623 35

We describe a cell-free system in which the membrane glycoprotein of vesicular stomatitis virus is rapidly and efficiently transported to membranes of the Golgi complex by a process resembling intracellular protein transport. Transport in vitro is energy-dependent and is accompanied by terminal glycosylation of the membrane glycoprotein (dependent upon UDP-GlcNAc and resulting in resistance to endo-beta-N-acetylglucosaminidase H).
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PMID:Transport of vesicular stomatitis virus glycoprotein in a cell-free extract. 625 96

In a previous communication we reported that the newly synthesized membrane glycoprotein of vesicular stomatitis virus could be transported in crude extracts of CHO cells from endoplasmic reticulum-derived membranes to membranes of the Golgi complex. This conclusion was an indirect one, based on the terminal glycosylation of this glycoprotein, a reaction that was dependent upon a Golgi-specific enzyme, UDP-GlcNAc transferase I. We show here that the Golgi fraction of rat liver will substitute for members of CHO cells as a source of transferase I in this reaction. The use of highly purified fractions of liver Golgi membranes, coupled with the ability to recover these membranes from incubations, has now permitted a direct demonstration of net transport of G protein to these heterologous Golgi membranes. This transport reaction is specific, in that the smooth endoplasmic reticulum fraction will not substitute for the Golgi fraction, is quantitatively significant, involving at least 30% of the viral glycoprotein, and is sustained only in the presence of both ATP and a soluble, cytosol fraction of liver cells.
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PMID:Transport of newly synthesized vesicular stomatitis viral glycoprotein to purified Golgi membranes. 626 30