RRC ID 6645
Author Warnecke D, Erdmann R, Fahl A, Hube B, Müller F, Zank T, Zähringer U, Heinz E.
Title Cloning and functional expression of UGT genes encoding sterol glucosyltransferases from Saccharomyces cerevisiae, Candida albicans, Pichia pastoris, and Dictyostelium discoideum.
Journal J Biol Chem
Abstract Sterol glucosides, typical membrane-bound lipids of many eukaryotes, are biosynthesized by a UDP-glucose:sterol glucosyltransferase (EC 2. 4.1.173). We cloned genes from three different yeasts and from Dictyostelium discoideum, the deduced amino acid sequences of which all showed similarities with plant sterol glucosyltransferases (Ugt80A1, Ugt80A2). These genes from Saccharomyces cerevisiae (UGT51 = YLR189C), Pichia pastoris (UGT51B1), Candida albicans (UGT51C1), and Dictyostelium discoideum (ugt52) were expressed in Escherichia coli. In vitro enzyme assays with cell-free extracts of the transgenic E. coli strains showed that the genes encode UDP-glucose:sterol glucosyltransferases which can use different sterols such as cholesterol, sitosterol, and ergosterol as sugar acceptors. An S. cerevisiae null mutant of UGT51 had lost its ability to synthesize sterol glucoside but exhibited normal growth under various culture conditions. Expression of either UGT51 or UGT51B1 in this null mutant under the control of a galactose-induced promoter restored sterol glucoside synthesis in vitro. Lipid extracts of these cells contained a novel glycolipid. This lipid was purified and identified as ergosterol-beta-D-glucopyranoside by nuclear magnetic resonance spectroscopy. These data prove that the cloned genes encode sterol-beta-D-glucosyltransferases and that sterol glucoside synthesis is an inherent feature of eukaryotic microorganisms.
Volume 274(19)
Pages 13048-59
Published 1999-5-7
DOI 10.1074/jbc.274.19.13048
PII S0021-9258(18)36845-5
PMID 10224056
MeSH Amino Acid Sequence Animals Base Sequence Cloning, Molecular Conserved Sequence DNA Primers Dictyostelium / enzymology Dictyostelium / genetics* Escherichia coli / genetics Glucosyltransferases / chemistry Glucosyltransferases / genetics* Glucosyltransferases / metabolism Glycolipids / chemistry Glycolipids / isolation & purification Magnetic Resonance Spectroscopy Molecular Sequence Data Pichia / enzymology Pichia / genetics* Saccharomyces cerevisiae / chemistry Saccharomyces cerevisiae / enzymology Saccharomyces cerevisiae / genetics* Sequence Homology, Amino Acid
IF 4.238
Times Cited 93
Cellular slime molds G24062