Saccharomyces cerevisiae GPI10, the functional homologue of human PIG-B, is required for glycosylphosphatidylinositol-anchor synthesis

• Published in: Biochemical journal Vol. 332 ( Pt 1); no. 1; pp. 153 - 159
• Main Authors: Sütterlin, C, Escribano, M V, Gerold, P, Maeda, Y, Mazon, M J, Kinoshita, T, Schwarz, R T, Riezman, H
• Format: Journal Article
• Language: English
• Published: England 15-05-1998
• Subjects: Amino Acid Sequence; Carbohydrate Conformation; Cell Division - genetics; Cloning, Molecular; Fungal Proteins - chemistry; Glycolipids - chemistry; Glycosylphosphatidylinositols - biosynthesis; Humans; Lactones - pharmacology; Mannose - metabolism; Mannosyltransferases - chemistry; Membrane Proteins - chemistry; Molecular Sequence Data; Saccharomyces cerevisiae - enzymology; Saccharomyces cerevisiae Proteins; Sequence Alignment; Sequence Analysis; Sequence Deletion - genetics; Terpenes - pharmacology
• ISSN: 0264-6021; 1470-8728
• DOI: 10.1042/bj3320153

An increasing number of plasma membrane proteins have been shown to be attached to the membrane via a glycosylphosphatidylinositol (GPI) moiety. All eukaryotes share a highly conserved GPI-core structure EthN-P-Man3-GlcN-PI, where EthN is ethanolamine. We have identified a protein encoded by the yeast open reading frame YGL142C that shares 33% identity with the human Pig-B protein. Deletion of this essential gene leads to a block in GPI anchor biosynthesis. We therefore named the gene GPI10. Gpi10p and Pig-B are functional homologues and the lethal deletion of GPI10 can be rescued by expression of the PIG-B cDNA. As found for PIG-B mutant cells, gpi10 deletant cells cannot attach the third mannose in an alpha-1,2 linkage to the GPI core-structure intermediate. Overexpression of GPI10 gives partial resistance to the GPI-synthesis inhibitor YW3548, suggesting that this gene product may affect the target of the inhibitor.