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Updated: Jun 25, 2026

Pull-down of Calmodulin-binding Proteins
Published on: January 23, 2012
Calmodulin isoform-specific activation of a rice calmodulin-binding kinase conferred by only three amino-acids of
1Key Lab of MOE for Plant Developmental Biology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
Abstract:
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.
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