title: The involvement of mnn4 and mnn6 mutations in mannosylphosphorylation of O-linked oligosaccharide in yeast Saccharomyces cerevisiae.
abstract: The structure of O-linked acidic oligosaccharide from Saccharomyces cerevisiae was analyzed. The chitinase, exclusively O-glycosylated extracelluar protein, was purified from strains mnn1, mnn1 mnn4, mnn1 mnn6 and deltakre2 and the oligosaccharides were hydrolyzed by O-linked sugar chain specific hydrazinolysis. The mannosylphosphorylated mannotriose (M3-P-M) was detected in strain mnn1, but not in the other three strains (mnn1n mnn4, mnn1 mnn6 and deltakre2). alpha-Mannosidase treatment and matrix-assisted laser desorption ionization time-of-flight mass spectrometry of mannosylphosphorylated mannotriose revealed that mannosylphosphate was attached to a middle mannose of alpha-1,2-linked mannotriose. This result indicates that the mnn4 and mnn6 mutations affect the mannosylphosphorylation of O-linked oligosaccharide, together with that of N-linked oligosaccharide. The amount of mannosylphosphorylated mannotriose was 7% of total O-linked oligosaccharides (20% of neutral mannotriose) of chitinase in strain mnn1.
authors.affiliation: Molecular Biology Department, National Institute of Bioscience and Human Technology, Tsukuba, Ibaraki, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nakayama
authors.forename: Y
authors.initials: Y
authors.lastname: Feng
authors.forename: A
authors.initials: A
authors.lastname: Tanaka
authors.forename: Y
authors.initials: Y
authors.lastname: Jigami
mesh_terms: D000469:Alkaline Phosphatase; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002851:Chromatography, High Pressure Liquid; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D005800:Genes, Fungal; D008360:Mannosephosphates / Q000737:chemistry / Q000378:metabolism*; D008361:Mannosidases; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D009844:Oligosaccharides / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D043323:alpha-Mannosidase
chemical_list: D005656:Fungal Proteins; C105147:MNN4 protein, S cerevisiae; D008360:Mannosephosphates; D008565:Membrane Proteins; D009844:Oligosaccharides; D029701:Saccharomyces cerevisiae Proteins; D000469:Alkaline Phosphatase; D008361:Mannosidases; D043323:alpha-Mannosidase