Specific in vitro O-glycosylation of human granulocyte-macrophage colony-stimulating-factor-derived peptides by O-glycosyltransferases of yeast and rat liver cells.
Human granulocyte-macrophage colony-stimulating factor (hGM-CSF) is O-glycosylated at residues Ser9 and Thr10 during secretion by yeast and COS-1 cells [Ernst, J.F., Mermod, J.-J. and Richman, L.I. (1992) Eur. J. Biochem. 203, 663-667]. Two types of octapeptides encompassing residues 4-11 (peptide 4-11) and variants thereof, or residues 8-15 (peptide 8-15) of hGM-CSF were tested as substrates for in vitro O-glycosylation using dolichyl-phosphate- D-mannose: protein O-D-mannosyltransferase (Man-transferase) of the yeast Saccharomyces cerevisiae, or UDP-N-acetyl-alpha-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase (GalNAc-transferase) of rat liver cells. Peptide 8-15 was found to be O-glycosylated at residues Ser9 and Thr10 by GalNAc-transferase and, with reduced efficiency, also by Man-transferase. Peptide 4-11 was a good substrate for yeast Man-transferase, leading to mannosylation of only Thr10, whereas it was very poorly O-glycosylated at positions Ser5 and Ser7 by GalNAc-transferase. The observed differences in peptide-acceptor activities indicate that the site of O-glycosylation depends on similar, but not identical protein structural features in yeast and mammalian cells.
Lorenz
C
C
Institut für Mikrobiologie, Heinrich-Heine-Universität Düsseldorf, Federal Republic of Germany.
Strahl-Bolsinger
S
S
Ernst
J F
JF
D000595:Amino Acid Sequence; D000818:Animals; D006031:Glycosylation; D016695:Glycosyltransferases / Q000378:metabolism*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000378:metabolism*; D006801:Humans; D008099:Liver / Q000201:enzymology*; D008297:Male; D008364:Mannosyltransferases / Q000378:metabolism; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012441:Saccharomyces cerevisiae / Q000201:enzymology*
D009842:Oligopeptides; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D016695:Glycosyltransferases; D008364:Mannosyltransferases