Localization of alpha 1----3-linked mannoses in the N-linked oligosaccharides of Saccharomyces cerevisiae mnn mutants.
Neutral and phosphorylated N-linked oligosaccharides were isolated from Saccharomyces cerevisiae mnn9 and mnn9 gls1 mutant mannoproteins and separated into homologues that differed in the number of terminal alpha 1----3-linked mannoses. In each type of oligosaccharide, the addition of such mannose was shown to occur in an ordered rather than a random fashion. The results confirm and extend an earlier report that dealt with the N-linked oligosaccharides from yeast invertase [Trimble, R.B., & Atkinson, P.H. (1986) J. Biol. Chem. 261, 9815-9824], and they suggest that the postulated processing pathway can be generalized to include phosphorylated and glucose-containing N-linked oligomannosides. We conclude that this processing pathway is identical for the analogous oligosaccharides from the mnn9 and wild-type strains of S. cerevisiae. Analysis of the mnn2 mnn10 mannoprotein revealed that a similar modification occurred at the branched terminus of the outer chain as well as in the core in this mutant.
Alvarado
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Department of Biochemistry, University of California, Berkeley 94720.
Ballou
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Hernandez
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LM
Ballou
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CE
D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002851:Chromatography, High Pressure Liquid; D009682:Magnetic Resonance Spectroscopy; D008358:Mannose / Q000032:analysis*; D008562:Membrane Glycoproteins / Q000235:genetics*; D009154:Mutation; D009844:Oligosaccharides / Q000235:genetics* / Q000302:isolation & purification; D010766:Phosphorylation; D012441:Saccharomyces cerevisiae / Q000235:genetics*
D008562:Membrane Glycoproteins; D009844:Oligosaccharides; C025363:mannoproteins; D008358:Mannose