The yeast spt14 gene is homologous to the human PIG-A gene and is required for GPI anchor synthesis.
The protein encoded by the yeast gene SPT14 shows high sequence similarity to the human protein, PIG-A, whose loss of activity is at the origin of the disease paroxysmal nocturnal hemoglobinuria. The symptoms of this disease are apparently due to a loss of cell surface, glycosylphosphatidylinositol (GPI)-anchored proteins. Like PIG-A mutant cells, spt14 mutant cells are defective in GPI anchoring due to a defect in the synthesis of GlcNAc-PI, the first step of GPI synthesis. The spt14 mutant causes several other abnormalities including transcriptional defects and a downregulation of inositolphosphoceramide synthesis. We suggest that these defects are indirect results of the loss of GPI anchoring.
Schönbächler
M
M
Biozentrum, University of Basel, Switzerland.
Horvath
A
A
Fassler
J
J
Riezman
H
H
D000117:Acetylglucosamine / Q000031:analogs & derivatives / Q000096:biosynthesis; D000217:Acyltransferases / Q000032:analysis; D000595:Amino Acid Sequence; D005656:Fungal Proteins / Q000235:genetics*; D005800:Genes, Fungal / Q000235:genetics*; D006028:Glycosphingolipids / Q000096:biosynthesis; D017261:Glycosylphosphatidylinositols / Q000096:biosynthesis*; D016695:Glycosyltransferases; D006457:Hemoglobinuria, Paroxysmal / Q000209:etiology; D006801:Humans; D007294:Inositol / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics*; D008566:Membranes / Q000378:metabolism; D008969:Molecular Sequence Data; D010716:Phosphatidylinositols / Q000096:biosynthesis; D012440:Saccharomyces / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D012694:Serine / Q000378:metabolism; D051102:Serine C-Palmitoyltransferase; D015534:Trans-Activators; D014158:Transcription, Genetic
D005656:Fungal Proteins; D006028:Glycosphingolipids; D017261:Glycosylphosphatidylinositols; D008565:Membrane Proteins; C081027:N-acetylglucosaminylphosphatidylinositol; D010716:Phosphatidylinositols; C071958:SPT14 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators; C025524:inositolphosphoceramides; C080086:phosphatidylinositol glycan-class A protein; D012694:Serine; D007294:Inositol; D000217:Acyltransferases; D051102:Serine C-Palmitoyltransferase; D016695:Glycosyltransferases; D000117:Acetylglucosamine