IndraLab

"Thus, MLC-kinase has a regulatory phosphorylation site(s) that is phosphorylated by the autophosphorylated form of CaM-kinase II and is blocked by Ca2+/CaM-binding."

"These observations indicate that the purified JTC contain membrane-bound calmodulin-dependent protein kinase that undergoes autophosphorylation and catalyzes phosphorylation of various membrane proteins."

"Dual role of calmodulin in autophosphorylation of multifunctional CaM kinase may underlie decoding of calcium signals."

"The kinetics of autophosphorylation of the cytoskeletal form of the neuronal calmodulin-dependent protein kinase type II were studied as a function of calmodulin binding under the same conditions."

"These results suggest a plausible model in which autophosphorylation of CaM-kinase II leads to a conformational change in the region of 293Phe-Asn-Ala295 which makes these residues accessible for binding to CaM."

"Along with information from the crystal structure of Ca2+/CaM bound to CKII(290-314) (Meador, W. E., Means, A. R., and Quiocho, F. A. (1993) Science 262, 1718-1721), our results suggest a model in which CaM-dependent autophosphorylation of CaM-kinase induces a conformational change in the region of the CaM-binding domain which allows the formation of additional stabilizing interactions with CaM."

"In contrast, dissociation of CaM from either autophosphorylated CaM-kinase or peptide CKII(290-314) was extremely slow with apparent off-rates of about 3-9 x 10(-5) s-1."

"Autophosphorylation of CaM-kinase II produces a form of the enzyme not requiring Ca(2+)/calmodulin for sustained activity. We report that autophosphorylated CaM-kinase II dephosphorylates itself in the presence of ADP (termed autodephosphorylation). The dephosphorylation was unaffected by phosphatase inhibitors and was nucleotide specific, occurring with ADP but not with AMP, GTP, or GDP. (32)P-ATP was produced when ADP was added to (32)P-labeled CaM-kinase II, indicating that the enzyme was undergoing dephosphorylation through a reversal of the autophosphorylation reaction. ATP addition also produced loss of (32)P from the autophosphorylated enzyme while maintaining the kinase in a phosphorylated state."

"We report that autophosphorylated CaM-kinase II dephosphorylates itself in the presence of ADP (termed autodephosphorylation)."