Open AccessSpecific in vitro O ‐glycosylation of human granulocyte‐macrophage colony‐stimulating‐factor‐derived peptides by O ‐glycosyltransferases of yeast and rat liver cells
Author(s) -
LORENZ Claudia,
STRAHLBOLSINGER Sabine,
ERNST Joachim F.
Publication year - 1992
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1992.tb16886.x
Subject(s) - biochemistry , glycosylation , transferase , peptide , yeast , glycosyltransferase , in vitro , saccharomyces cerevisiae , microbiology and biotechnology , biology , chemistry , enzyme
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‐α‐ 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.