title: Protein kinase C phosphorylates the synthetic peptide Arg-Arg-Lys-Ala-Ser-Gly-Pro-Pro-Val in the presence of phospholipid plus either Ca2+ or a phorbol ester tumor promoter.
abstract: The synthetic nonapeptide Arg-Arg-Lys-Ala-Ser-Gly-Pro-Pro-Val is a substrate for in vitro phosphorylation by a partially purified preparation of rat brain protein kinase C, with Kmapp of about 130 microM. The closely related peptide kemptide was a much weaker substrate, bovine serum albumin was not a substrate and the peptide Arg-Arg-Lys-Ala-Ala-Gly-Pro-Pro-Val was a weak inhibitor of the enzyme. Protein kinase C-catalyzed phosphorylation of histone III-S and the nonapeptide are regulated by identical mechanisms since with both substrates the reaction required added phospholipid and either Ca2+ (1mM) or TPA (200 nM TPA). Our findings show that polypeptides containing multiple basic residues followed by the sequence Ala-Ser can be substrates for TPA-stimulated phosphorylation by protein kinase C.
mesh_terms: D000818:Animals; D001921:Brain / Q000201:enzymology*; D002118:Calcium / Q000494:pharmacology*; D004533:Egtazic Acid / Q000494:pharmacology; D007700:Kinetics; D009842:Oligopeptides / Q000378:metabolism*; D010704:Phorbols / Q000494:pharmacology*; D010716:Phosphatidylinositols / Q000494:pharmacology*; D010766:Phosphorylation; D011493:Protein Kinase C; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D013379:Substrate Specificity; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
chemical_list: D009842:Oligopeptides; D010704:Phorbols; D010716:Phosphatidylinositols; D047428:Protein Kinase Inhibitors; D004533:Egtazic Acid; C042848:arginyl-arginyl-lysyl-alanyl-seryl-glycyl-prolyl-prolyl-valine; D011494:Protein Kinases; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium