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Calmodulin isoform‐specific activation of a rice calmodulin‐binding kinase conferred by only three amino‐acids of OsCaM61
Author(s) -
Li Dian-Fan,
Li Jing,
Ma Li,
Zhang Lei,
Lu Ying-Tang
Publication year - 2006
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/j.febslet.2006.06.090
Subject(s) - calmodulin , protein kinase a , oryza sativa , biochemistry , kinase , threonine , serine , amino acid , chemistry , biology , enzyme , gene
The kinase activity of a Ca 2+ /calmodulin (CaM)‐binding serine/threonine protein kinase from rice ( Oryza sativa ) (OsCBK) has been reported to be unaffected by OsCaM1 binding. In this study, we examined whether other rice CaMs can stimulate OsCBK. It was observed that OsCaM61 stimulated OsCBK in a Ca 2+ ‐dependent manner. In addition, Ala 111 , Gly 123 and Ser 127 were identified as critical residues for OsCBK activation. Mutational study and fluorescent spectroscopy analysis indicated that CaM‐binding affinity does not correlate with the kinase activity and that these key amino‐acids in OsCaM61 play a vital role in suitable changes of OsCBK conformation for kinase activation.