title: Asparagine-linked oligosaccharides of Semliki Forest virus grown in mosquito cells.
abstract: The structure of the N-linked oligosaccharides of Semliki Forest viral glycoproteins produced in infected mosquito cells (C6/36) was investigated by biosynthetic labeling, enzymic deglycosylation using endo-beta-N-acetylglucosaminidases H, D, F/glycopeptidase F, exoglycosidase and analysis of the sugars on Concanavalin A-Sepharose columns and by gel filtration chromatography. The results demonstrated that the glycoproteins decorating the virus shed from infected cells have N-linked glycans with a trimannosyl core similar to the core glycans produced by vertebrate and yeast cells. However, the E1 glycoprotein produced by infected C6/36 cells exhibited both a trimannosyl core and a modified trimannosyl core most probably with terminal N-acetylglucosamine. The carbohydrate side chains of Semliki Forest envelope proteins displayed two types of structural heterogeneities existing either at different N-glycosylation sites as in the case of E2, or at the same N-glycosylation site as in the case of E1. In the presence of 1-deoxymannojirimycin, no structural heterogeneities in the glycan chains were found. This strongly suggests that the glycosylation events that lead to the observed sugar heterogeneities occur in the Golgi membranes.
authors.affiliation: Institute for Medical Microbiology, University of Berne, Switzerland.
authors.forename: H Y
authors.initials: HY
authors.lastname: Naim
authors.forename: H
authors.initials: H
authors.lastname: Koblet
mesh_terms: D000330:Aedes; D000818:Animals; D001216:Asparagine / Q000737:chemistry*; D002240:Carbohydrate Sequence; D002478:Cells, Cultured; D002850:Chromatography, Gel; D006023:Glycoproteins / Q000737:chemistry / Q000378:metabolism*; D006026:Glycoside Hydrolases; D006056:Golgi Apparatus / Q000378:metabolism; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry* / Q000378:metabolism; D012672:Semliki forest virus / Q000737:chemistry*; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D006023:Glycoproteins; D009844:Oligosaccharides; D014759:Viral Envelope Proteins; D001216:Asparagine; D006026:Glycoside Hydrolases