Regulation of phosphatidylinositol 4-kinase from the yeast Saccharomyces cerevisiae by CDP-diacylglycerol

J Biol Chem. 1994 Apr 15;269(15):11018-24.


Regulation of the 45- and 55-kDa forms of Saccharomyces cerevisiae membrane-associated phosphatidylinositol (PI) 4-kinase (ATP:phosphatidylinositol 4-phosphotransferase) by phospholipids was examined using Triton X-100/phospholipid-mixed micelles. CDP-diacylglycerol and phosphatidylglycerol inhibited 45-kDa PI 4-kinase activity in a dose-dependent manner. Kinetic analyses of the 45-kDa PI 4-kinase showed that phosphatidylglycerol was a competitive inhibitor with respect to PI (Ki = 2 mol %), and CDP-diacylglycerol was a mixed type of inhibitor with respect to PI (Ki = 4 mol %) and MgATP (Ki = 5 mol %). 55-kDa PI 4-kinase activity was not significantly affected by phospholipids. The physiological relevance of CDP-diacylglycerol inhibition of 45-kDa PI 4-kinase activity was examined using plasma membranes from inositol auxotrophic (ino1) cells. Immunoblot analysis showed that 45-kDa PI 4-kinase expression in plasma membranes was not affected by inositol starvation of ino1 cells. However, both 45-kDa PI 4-kinase activity and its product PI 4-phosphate were reduced in plasma membranes from inositol-starved ino1 cells. The CDP-diacylglycerol concentration (9.6 mol %) in plasma membranes of inositol-starved ino1 cells was 12-fold higher than its concentration (0.8 mol %) in plasma membranes of inositol-supplemented cells. Plasma membranes of inositol-starved ino1 cells also had increased levels of phosphatidate, phosphatidylserine, phosphatidylethanolamine, and cardiolipin. However, these phospholipids did not affect pure 45-kDa PI 4-kinase activity. The concentration of CDP-diacylglycerol in plasma membranes of inositol-starved ino1 cells was in the range of the inhibitor constants determined for CDP-diacylglycerol by kinetic analyses using pure 45-kDa PI 4-kinase. These results raised the suggestion that 45-kDa PI 4-kinase activity may be regulated in vivo by CDP-diacylglycerol.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • 1-Phosphatidylinositol 4-Kinase
  • Cell Fractionation
  • Cell Membrane / chemistry
  • Cell Membrane / enzymology
  • Cell Membrane / metabolism
  • Cytidine Diphosphate Diglycerides / pharmacology*
  • Diacylglycerol Cholinephosphotransferase / metabolism*
  • Inositol / metabolism
  • Kinetics
  • Membrane Lipids / isolation & purification
  • Membrane Lipids / metabolism
  • Phosphatidylglycerols / pharmacology
  • Phospholipids / isolation & purification
  • Phospholipids / metabolism
  • Phosphotransferases (Alcohol Group Acceptor) / isolation & purification
  • Phosphotransferases (Alcohol Group Acceptor) / metabolism*
  • Saccharomyces cerevisiae / enzymology*
  • Saccharomyces cerevisiae / growth & development
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins*


  • Cytidine Diphosphate Diglycerides
  • Membrane Lipids
  • Phosphatidylglycerols
  • Phospholipids
  • Saccharomyces cerevisiae Proteins
  • Inositol
  • Phosphotransferases (Alcohol Group Acceptor)
  • 1-Phosphatidylinositol 4-Kinase
  • PIK1 protein, S cerevisiae
  • Diacylglycerol Cholinephosphotransferase