Identification of the multifunctional calmodulin-dependent protein kinase in the cytosol, sarcoplasmic reticulum, and sarcolemma of rabbit skeletal muscle.
A multifunctional calmodulin-dependent protein kinase (calmodulin kinase) was purified from the cytosol of rabbit skeletal muscle as a subunit of 58 kDa. A 58-kDa protein in sarcoplasmic reticulum (SR) and sarcolemma (SL) of rabbit skeletal muscle was endogenously phosphorylated in a calmodulin-dependent manner. The 58-kDa protein in SR and SL was considered to be identical to the subunit of cytosol calmodulin kinase on the basis of immunoreactivity, calmodulin binding, and autophosphorylation studies and on the patterns of protease-treated phosphopeptides. Calmodulin kinase showed broad substrate specificity and phosphorylated troponins I and T.
Sato
H
H
First Department of Internal Medicine, Kumamoto University Medical School, Japan.
Fukunaga
K
K
Araki
S
S
Ohtsuki
I
I
Miyamoto
E
E
D000818:Animals; D001921:Brain / Q000201:enzymology; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D002147:Calmodulin / Q000378:metabolism; D002148:Calmodulin-Binding Proteins / Q000032:analysis; D003600:Cytosol / Q000201:enzymology; D054736:Elongation Factor 2 Kinase; D007700:Kinetics; D008970:Molecular Weight; D009132:Muscles / Q000201:enzymology*; D017830:Octoxynol; D010748:Phosphopeptides / Q000032:analysis; D010766:Phosphorylation; D011092:Polyethylene Glycols / Q000494:pharmacology; D011494:Protein Kinases / Q000302:isolation & purification* / Q000378:metabolism; D011817:Rabbits; D051381:Rats; D012508:Sarcolemma / Q000201:enzymology; D012519:Sarcoplasmic Reticulum / Q000201:enzymology; D013379:Substrate Specificity
D002147:Calmodulin; D002148:Calmodulin-Binding Proteins; D010748:Phosphopeptides; D011092:Polyethylene Glycols; D017830:Octoxynol; D011494:Protein Kinases; C517691:Eef2k protein, rat; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D054736:Elongation Factor 2 Kinase