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Phosphorylation and activation of Ca 2+ /calmodulin‐dependent protein kinase phosphatase by Ca 2+ /calmodulin‐dependent protein kinase II
Author(s) -
Kameshita Isamu,
Ishida Atsuhiko,
Fujisawa Hitoshi
Publication year - 1999
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(99)00958-8
Subject(s) - calmodulin , dephosphorylation , phosphorylation , phosphatase , protein kinase a , chemistry , protein phosphorylation , biochemistry , kinase , enzyme , activator (genetics) , microbiology and biotechnology , biology , gene
Ca 2+ /calmodulin‐dependent protein kinase phosphatase (CaMKPase) is a protein phosphatase which dephosphorylates autophosphorylated Ca 2+ /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.