title: Coordinate regulation of phospholipid biosynthesis by serine in Saccharomyces cerevisiae.
abstract: The addition of L-serine to inositol-containing growth medium repressed membrane-associated CDPdiacylglycerol synthase (CTP:phosphatidate cytidylyltransferase, EC 2.7.7.41) and phosphatidylserine synthase (CDPdiacylglycerol:L-serine O-phosphatidyltransferase, EC 2.7.8.8) activities and subunit levels in wild-type Saccharomyces cerevisiae. Enzyme activities and subunit levels were not repressed when inositol was absent from the growth medium. The addition of L-serine to the growth medium did not affect the phospholipid composition of wild-type cells. CDPdiacylglycerol synthase and phosphatidylserine synthase were not regulated in the S. cerevisiae inositol biosynthesis ino2, ino4, and opi1 regulatory mutants, suggesting that regulation by inositol plus L-serine is coupled to inositol synthesis. Inositol and L-serine did not affect the activities of purified CDPdiacylglycerol synthase and phosphatidylserine synthase. The addition of compounds structurally related to L-serine to the growth medium of wild-type cells also resulted in a repression of CDPdiacylglycerol synthase and phosphatidylserine synthase but only in the presence of inositol. Phosphatidylinositol synthase (CDPdiacylglycerol:myo-inositol 3-phosphatidyltransferase, EC 2.7.8.11) was not regulated by inositol plus L-serine.
mesh_terms: D051607:CDP-Diacylglycerol-Inositol 3-Phosphatidyltransferase; D010717:CDPdiacylglycerol-Serine O-Phosphatidyltransferase / Q000378:metabolism; D002794:Choline / Q000378:metabolism; D019856:Ethanolamine; D004983:Ethanolamines / Q000378:metabolism; D007294:Inositol / Q000378:metabolism; D009154:Mutation; D009713:Nucleotidyltransferases / Q000378:metabolism; D010743:Phospholipids / Q000096:biosynthesis*; D010770:Phosphotransferases / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000378:metabolism*; D012694:Serine / Q000502:physiology*; D013237:Stereoisomerism; D017855:Transferases (Other Substituted Phosphate Groups)
chemical_list: D004983:Ethanolamines; D010743:Phospholipids; D012694:Serine; D007294:Inositol; D019856:Ethanolamine; D010770:Phosphotransferases; D009713:Nucleotidyltransferases; C022348:phosphatidate cytidylyltransferase; D017855:Transferases (Other Substituted Phosphate Groups); D051607:CDP-Diacylglycerol-Inositol 3-Phosphatidyltransferase; D010717:CDPdiacylglycerol-Serine O-Phosphatidyltransferase; D002794:Choline