title: Role of phospholipase D in the activation of protein kinase D by lysophosphatidic acid.
abstract: Protein kinase D was auto-phosphorylated at Ser916 and trans-phosphorylated at Ser744/Ser748 in Rat-2 fibroblasts treated with lysophosphatidic acid. Both phosphorylations were inhibited by 1-butanol, which blocks phosphatidic acid formation by phospholipase D. The phosphorylations were also reduced in Rat-2 clones with decreased phospholipase D activity. Platelet-derived growth factor-induced protein kinase D phosphorylation showed a similar requirement for phospholipase D, but that induced by 4beta-phorbol 12 myristate 13-acetate did not. Propranolol an inhibitor of diacylglycerol formation from phosphatidic acid blocked the phosphorylation of protein kinase D, whereas dioctanoylglycerol induced it. The temporal pattern of auto-phosphorylation of protein kinase D closely resembled that of phospholipase D activation and preceded the trans-phosphorylation by protein kinase C. These results suggest that protein kinase D is activated by lysophosphatidic acid through sequential phosphorylation and that diacylglycerol produced by PLD via phosphatidic acid is required for the autophosphorylation that occurs prior to protein kinase C-mediated phosphorylation.
authors.affiliation: Department of Molecular Physiology and Biophysics, Howard Hughes Medical Institute, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
authors.forename: Yoonseok
authors.initials: Y
authors.lastname: Kam
authors.forename: John H
authors.initials: JH
authors.lastname: Exton
mesh_terms: D020001:1-Butanol / Q000494:pharmacology; D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D002999:Clone Cells; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D008246:Lysophospholipids / Q000494:pharmacology*; D010712:Phosphatidic Acids / Q000096:biosynthesis; D010739:Phospholipase D / Q000378:metabolism*; D010766:Phosphorylation; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051381:Rats; D012694:Serine / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D008246:Lysophospholipids; D010712:Phosphatidic Acids; D010982:Platelet-Derived Growth Factor; D012694:Serine; D020001:1-Butanol; C089212:protein kinase D; D011493:Protein Kinase C; D010739:Phospholipase D; D013755:Tetradecanoylphorbol Acetate