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Phosphorylation of caldesmon
Author(s) -
Abougou J.-C.,
Hagiwara M.,
Hachiya T.,
Terasawa M.,
Hidaka H.,
Hartshorne D.J.
Publication year - 1989
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 - 10.1016/0014-5793(89)81583-2
Subject(s) - caldesmon , calmodulin , protein kinase a , chemistry , kinase , phosphorylation , biochemistry , mitogen activated protein kinase kinase , microbiology and biotechnology , biology , enzyme
The phosphorylation of caldesmon was studied to determine if kinase activity reflected either an endogenous kinase or caldesmon itself. Titration of kinase activity with calmodulin yielded maximum activity at substoichiometric ratios of calmodulin/caldesmon. The sites of phosphorylation on caldesmon for calcium/calmodulin‐dependent protein kinase II and endogenous kinase were the same, but distinct from protein kinase C sites. Phosphorylation in the presence of Ca 2+ and calmodulin resulted in a subsequent increase of endogenous kinase activity in the absence of Ca 2+ . These results suggest that caldesmon is not a protein kinase and that kinase activity in caldesmon preparations is due to calcium/calmodulindependent protein kinase II.