title: Schizosaccharomyces pombe glycosylation mutant with altered cell surface properties.
abstract: Mutagenesis of Schizosaccharomyces pombe cells yielded a strain that made reduced amounts of invertase. A comparison of the O- and N-linked carbohydrate chains of the wild-type and mutant glycoproteins revealed that a single type of alpha 1-->2-linked mannose was missing in the mutant. Analysis of the wild-type galactomannoprotein showed that it contained a heterogeneous small "core" oligosaccharide fraction linked to asparagine with sugar compositions that ranged from Man9(GlcNAc)2- to Gal4Man10(GlcNAc)2-. The galactose units are in terminal positions of a Man10(GlcNAc)2- unit that is similar to the mannoprotein core of Saccharomyces cerevisiae. Attached to this core in a larger oligosaccharide fraction is an alpha 1-->6-linked polymannose chain that is substituted at position 2 with alpha-linked mannose and galactose. The O-linked sugars consist of mannose, alpha 1-->2-linked mannosylmannose and alpha 1-->2-linked galactosylmannose, along with small amounts of tri- and tetrasaccharides. The glycosylation mutant lacks alpha 1-->2-linked mannose on both the O-linked chains and the outer chain of the large N-linked chains, suggesting that it may be defective in regulation of an alpha 1,2-mannosyltransferase that adds mannose to glycoproteins in the Golgi.
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley 94720.
authors.forename: C E
authors.initials: CE
authors.lastname: Ballou
authors.forename: L
authors.initials: L
authors.lastname: Ballou
authors.forename: G
authors.initials: G
authors.lastname: Ball
mesh_terms: D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D006026:Glycoside Hydrolases / Q000235:genetics / Q000378:metabolism; D006031:Glycosylation; D008364:Mannosyltransferases / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000737:chemistry* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D009005:Monosaccharides / Q000032:analysis; D016296:Mutagenesis; D009844:Oligosaccharides / Q000737:chemistry / Q000302:isolation & purification; D029701:Saccharomyces cerevisiae Proteins; D012568:Schizosaccharomyces / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D043324:beta-Fructofuranosidase
chemical_list: D008562:Membrane Glycoproteins; D009005:Monosaccharides; D009844:Oligosaccharides; D029701:Saccharomyces cerevisiae Proteins; C025363:mannoproteins; C068701:KRE2 protein, S cerevisiae; D008364:Mannosyltransferases; D006026:Glycoside Hydrolases; D043324:beta-Fructofuranosidase