Unusual neutral oligosaccharides in mature Sindbis virus glycoproteins are synthesized from truncated precursor oligosaccharides in Chinese hamster ovary cells.
We have previously demonstrated the presence of unusual small asparaginyl-oligosaccharides [(Man)3GlcNAc2-ASN] in the mature glycoproteins of Sindbis virus released from both wild-type and lectin-resistant Chinese hamster ovary cells, but the mechanism of synthesis of these structures was not determined. Gel filtration and endo-beta-N-acetylglucosaminidase analyses of Pronase-digested glycopeptides from [3H]mannose-labelled Sindbis virus released at different times after infection of a phytohaemagglutinin-resistant line of Chinese hamster ovary cells demonstrated that these small asparaginyl-oligosaccharides were present in similar relative amounts in virus released throughout the virus infection, rather than arising primarily at late times when cytopathic effects were maximal. Similar analyses of pulse-labelled, cell-associated viral glycopeptides suggested that these small oligosaccharides on mature virus glycoprotein resulted from the normal alpha 1,2-mannosidase processing of truncated precursor oligosaccharides (containing five rather than nine mannoses), rather than from aberrant processing or degradation of the full-size precursor oligosaccharides or normal intermediates.
D000818:Animals; D002478:Cells, Cultured; D002850:Chromatography, Gel; D006224:Cricetinae; D003412:Cricetulus; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006023:Glycoproteins / Q000096:biosynthesis*; D009844:Oligosaccharides / Q000378:metabolism*; D010053:Ovary; D011498:Protein Precursors / Q000032:analysis*; D012845:Sindbis Virus / Q000378:metabolism*; D014721:Vesicular stomatitis Indiana virus / Q000378:metabolism; D014764:Viral Proteins / Q000096:biosynthesis*
D006023:Glycoproteins; D009844:Oligosaccharides; D011498:Protein Precursors; D014764:Viral Proteins