title: Inactivation and reactivation of the multifunctional calmodulin-dependent protein kinase from brain by autophosphorylation and dephosphorylation: involvement of protein phosphatases from brain.
abstract: The multifunctional calmodulin-dependent protein kinase (calmodulin-kinase) from rat brain was autophosphorylated in a Ca2+- and calmodulin-dependent manner. The activity of the autophosphorylated enzyme was independent of Ca2+ and calmodulin. Calmodulin-kinase was dephosphorylated by protein phosphatase C from bovine brain, which is the catalytic subunits of protein phosphatases 1 and 2A. The holoenzyme of protein phosphatase 2A was also involved in the dephosphorylation of the enzyme. The autophosphorylated sites of calmodulin-kinase were universally dephosphorylated by protein phosphatase C. Calmodulin-kinase was inactivated and reactivated by autophosphorylation and dephosphorylation, respectively. Furthermore, the regulation of calmodulin-kinase by autophosphorylation and dephosphorylation was observed using calmodulin-kinase from canine heart. These results suggest that the activity of calmodulin-kinase is regulated by autophosphorylation and dephosphorylation, and that the regulation is the universal phenomenon for many other calmodulin-kinases in various tissues.
mesh_terms: D000818:Animals; D001921:Brain / Q000201:enzymology*; D002118:Calcium / Q000494:pharmacology; D002147:Calmodulin / Q000494:pharmacology; D002413:Cations, Divalent; D002417:Cattle; D004285:Dogs; D004789:Enzyme Activation; D004793:Enzyme Reactivators; D007700:Kinetics; D009206:Myocardium / Q000201:enzymology; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases / Q000378:metabolism*; D054648:Protein Phosphatase 2; D051381:Rats; D012969:Sodium Fluoride / Q000494:pharmacology
chemical_list: D002147:Calmodulin; D002413:Cations, Divalent; D004793:Enzyme Reactivators; D047428:Protein Kinase Inhibitors; D012969:Sodium Fluoride; D011494:Protein Kinases; D010749:Phosphoprotein Phosphatases; D054648:Protein Phosphatase 2; D002118:Calcium