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Catalytic fragment of protein kinase C exhibits altered substrate specificity toward smooth muscle myosin light chain
Author(s) -
Nakabayashi Hiroki,
Sellers James R.,
Huang Kuo-Ping
Publication year - 1991
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(91)81362-c
Subject(s) - myosin light chain kinase , myosin , immunoglobulin light chain , chemistry , substrate (aquarium) , biophysics , fragment (logic) , microbiology and biotechnology , biochemistry , biology , genetics , antibody , ecology , computer science , programming language
Smooth muscle myosin light chain (LC) can be phosphorylated by myosin light chain kinase (MLCK) at Ser 19 and Thr 18 and by protein kinase C (PKC) at Thr 9 and Ser 1 or Ser 2 under the in vitro assay conditions. Conversion of PKC to the spontaneously active protein kinase M (PKM) by proteolysis resulted in a change in the substrate specificity of the kinase. PKM phosphorylated both sets of sites in LC recognized by MLCK and PKC as analyzed by peptide mapping analysis. The PKM‐catalyzed phosphorylation of these sites was not greatly affected by a MLCK inhibitor, ML‐9, nor by the activators of MLCK, Ca 2+ and calmodulin.