The och1 mutant of Schizosaccharomyces pombe produces galactosylated core structures of N-linked oligosaccharides.
Unlike the budding yeast Saccharomyces cerevisiae, the fission yeast Schizosaccharomyces pombe synthesizes large outer chains on the N-linked oligosaccharides that consist mainly of D-Gal and D-Man residues. The fission yeast och1(+) gene product has alpha1,6-mannosyltransferase activity, and Och1p is the key enzyme in the initiation of outer chain elongation. Although the in vitro substrate specificity of S. pombe Och1p has been reported (Yoko-o et al., FEBS Lett., 489, 75-80 (2001)), the structure of the N-linked oligosaccharides of och1Delta cells has not been investigated. In this study, we report a structural analysis of S. pombe N-linked oligosaccharides. Lectin blot analysis indicated that galactose residues were attached to the cell surface glycoproteins of the och1Delta cells. We conducted a structural analysis of pyridylaminated N-linked oligosaccharides prepared from galactomannoproteins by HPLC and (1)H NMR. These analyses revealed that the N-linked oligosaccharides of the och1Delta cells displayed heterogeneity in the glycan consisting of Hex(11-15)GlcNAc(2). The structural heterogeneity arose mainly from the addition of alpha1,2- and alpha1,3-Gal residues to the Man(9)GlcNAc(2) core structure.
Ohashi
Takao
T
Department of Life Sciences, Faculty of Agriculture, Kagawa University, Japan.
Ikeda
Yuka
Y
Tanaka
Naotaka
N
Nakakita
Shin-ichi
S
Natsuka
Shunji
S
Giga-Hama
Yuko
Y
Takegawa
Kaoru
K
D000586:Amination; D002851:Chromatography, High Pressure Liquid; D004721:Endoplasmic Reticulum / Q000378:metabolism; D005690:Galactose / Q000378:metabolism*; D006834:Hydrazines / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008364:Mannosyltransferases / Q000235:genetics / Q000378:metabolism*; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D009844:Oligosaccharides / Q000096:biosynthesis* / Q000737:chemistry; D011725:Pyridines / Q000737:chemistry; D012568:Schizosaccharomyces / Q000166:cytology / Q000201:enzymology* / Q000235:genetics*; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism*
D006834:Hydrazines; D050505:Mutant Proteins; D009844:Oligosaccharides; D011725:Pyridines; D029702:Schizosaccharomyces pombe Proteins; C029424:hydrazine; D008364:Mannosyltransferases; C539723:Och1 protein, S pombe; C023666:pyridine; D005690:Galactose