title: Phosphorylation of diacylglycerol kinase in vitro by protein kinase C.
abstract: We investigated the effects of enzyme phosphorylation in vitro on the properties of diacylglycerol kinase. Diacylglycerol kinase and protein kinase C, both present as Mr-80,000 proteins, were highly purified from pig thymus cytosol. Protein kinase C phosphorylated diacylglycerol kinase (up to 1 mol of 32P/mol of enzyme) much more actively than did cyclic AMP-dependent protein kinase. Phosphorylated and non-phosphorylated diacylglycerol kinase showed a similar pI, approx. 6.8. Diacylglycerol kinase phosphorylated by either protein kinase C or cyclic AMP-dependent protein kinase was almost exclusively associated with phosphatidylserine membranes. In contrast, soluble kinase consisted of the non-phosphorylated form. The catalytic properties of the lipid kinase were not much affected by phosphorylation, although phosphorylation-linked binding with phosphatidylserine vesicles resulted in stabilization of the enzyme activity.
authors.affiliation: Department of Biochemistry, Sapporo Medical College, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Kanoh
authors.forename: K
authors.initials: K
authors.lastname: Yamada
authors.forename: F
authors.initials: F
authors.lastname: Sakane
authors.forename: T
authors.initials: T
authors.lastname: Imaizumi
mesh_terms: D000818:Animals; D001665:Binding Sites; D019852:Diacylglycerol Kinase; D008566:Membranes / Q000378:metabolism; D010718:Phosphatidylserines / Q000378:metabolism; D010766:Phosphorylation; D010770:Phosphotransferases / Q000378:metabolism*; D011493:Protein Kinase C / Q000302:isolation & purification / Q000378:metabolism*; D011494:Protein Kinases / Q000378:metabolism; D013552:Swine
chemical_list: D010718:Phosphatidylserines; D010770:Phosphotransferases; D011494:Protein Kinases; D019852:Diacylglycerol Kinase; D011493:Protein Kinase C