Phosphorylation and activation of Ca2+/calmodulin‐dependent protein kinase phosphatase by Ca2+/calmodulin‐dependent protein kinase II

FEBS Letters

Fujisawa, Hitoshi¹  Kameshita, Isamu¹  Ishida, Atsuhiko¹ 

[1] Department of Biochemistry, Asahikawa Medical College, Asahikawa 078-8510, Japan

关键词: Calmodulin-dependent protein kinase II;    Enzyme activation;    Protein phosphatase;    Protein phosphorylation;    Polylysine;    CaMK;    Ca2+/calmodulin-dependent protein kinase;    30 kDa CaMKII;    30 kDa fragment of Ca2+/calmodulin-dependent protein kinase II;    CaMKPase;    Ca2+/calmodulin-dependent protein kinase phosphatase;    poly(Lys);    poly-l-lysine;    poly(Lys)9.6K;    poly(Lys)23K and poly(Lys)87K;    poly-l-lysine with average molecular weights of 9600;    23 000 and 87 000;    respectively;    (Lys)5;    (Lys)10 and (Lys)20;    oligopeptides composed of 5;    10 and 20 lysines;    respectively;   

DOI  :  10.1016/S0014-5793(99)00958-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Ca²⁺/calmodulin-dependent protein kinase phosphatase (CaMKPase) is a protein phosphatase which dephosphorylates autophosphorylated Ca²⁺/calmodulin-dependent protein kinase II (CaMKII) and deactivates the enzyme (Ishida, A., Kameshita, I. and Fujisawa, H. (1998) J. Biol. Chem. 273, 1904–1910). In this study, a phosphorylation-dephosphorylation relationship between CaMKII and CaMKPase was examined. CaMKPase was not significantly phosphorylated by CaMKII under the standard phosphorylation conditions but was phosphorylated in the presence of poly-l-lysine, which is a potent activator of CaMKPase. The maximal extent of the phosphorylation was about 1 mol of phosphate per mol of the enzyme and the phosphorylation resulted in an about 2-fold increase in the enzyme activity. Thus, the activity of CaMKPase appears to be regulated through phosphorylation by its target enzyme, CaMKII.

【 授权许可】

Unknown