Structures of glycosylphosphatidylinositol membrane anchors from Saccharomyces cerevisiae

• Published in: The Journal of biological chemistry Vol. 268; no. 35; pp. 26365 - 26374
• Main Authors: Fankhauser, C, Homans, S W, Thomas-Oates, J E, McConville, M J, Desponds, C, Conzelmann, A, Ferguson, M A
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15.12.1993; American Society for Biochemistry and Molecular Biology
• Subjects: carbohidratos; Carbohydrate Conformation; Carbohydrate Sequence; carbohydrates; cell membranes; fosfolipidos; Fungal Proteins - chemistry; Gas Chromatography-Mass Spectrometry; glucide; Glycolipids - chemistry; Glycopeptides - chemistry; Glycosylphosphatidylinositols - chemistry; lipide; lipidos; lipids; Lipids - chemistry; Magnetic Resonance Spectroscopy; membranas celulares; membrane cellulaire; Molecular Sequence Data; phosphatide; phospholipids; purificacion; purification; saccharomyces cerevisiae; Saccharomyces cerevisiae - chemistry; Spectrometry, Mass, Fast Atom Bombardment
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/S0021-9258(19)74324-5

Metabolic labeling studies suggest that Saccharomyces cerevisiae contains many glycoproteins that are anchored in the lipid bilayer by glycosylphosphatidylinositol membrane anchors. Membrane anchors were purified from a crude yeast membrane protein fraction and analyzed by two-dimensional 1H-1H NMR, fast atom bombardment-mass spectrometry, compositional and methylation linkage analyses, as well as chemical and enzymatic modifications. The yeast glycosylphosphatidylinositol anchors consist of the following structures: ethanolamine-PO4-6(R-2)Man alpha 1-2Man alpha 1-6Man alpha 1-4Glc-NH2 alpha 1-6myo-inositol-1-PO4-lipid, where R is mainly Man alpha 1- (80%) with some Man alpha 1-2Man alpha 1- (15%) and Man alpha 1-3Man alpha 1- (5%). The core region of the yeast anchors (ethanolamine-PO4-6Man alpha 1-2Man alpha 1-6Man alpha 1-4GlcNH2 alpha 1-6myo-inositol-1-PO4) is identical to the conserved core region found in glycosylphosphatidylinositol anchors from protozoa and mammals. The lipid moieties of the total yeast glycosylphosphatidylinositol anchors are mainly ceramides, consisting mostly of C18:0 phytosphingosine and C26:0 fatty acid. However, the lipid moiety of the glycosylphosphatidylinositol anchor of the purified ggp125 protein is a lyso- or diacylglycerol, containing C26:0 fatty acids. This suggests that yeast adds different lipid components to the glycosylphosphatidylinositol anchors of different proteins.