The Saccharomyces cerevisiae PLB1 gene encodes a protein required for lysophospholipase and phospholipase B activity.

摘要: Several enzymes with lysophospholipase/phospholipase B activity have been described from the budding yeast Saccharomyces cerevisiae. In vitro, these are capable of hydrolyzing all phospholipids that can be extracted cells. Two forms enzyme isolated plasma membranes and a third culture supernatants periplasmic space, but their biological roles not determined. These highly glycosylated were reported to very similar catalytic properties differed respect apparent molecular weight. We gene S. cerevisiae, encoding protein predicted share 45% amino acid sequence identity phospholipase Penicillium notatum. This gene, designated PLB1, was mapped left arm chromosome VIII. No residual detected upon assay extracts or plb1 delta mutant. Thus, either PLB1 encodes previously isoforms its product is required for expression activation. Deletion did result in any phenotypic defect, suggesting we failed identify growth conditions would betray such defect Plb1p functionally redundant another protein, whose has gone undetected. A mutant released wild-type levels soluble phosphatidylinositol metabolite glycerophosphoinositol into medium greatly reduced corresponding phosphatidylcholine phosphatidylethanolamine metabolites. results indicate principally responsible production deacylation products phosphatidylinositol.