Subcellular distribution and immunocytochemical localization of protein kinase C in myocardium, and phosphorylation of troponin in isolated myocytes stimulated by isoproterenol or phorbol ester.
Protein kinase C (PKC) catalytic activity was found in the cytosol, sarcolemma and sarcoplasmic reticulum, and PKC immunoreactivity was found in the striated regions and sarcolemma of rat hearts. Enhanced phosphorylation of troponin T and, to a lesser extent, troponin I was noted in isolated rat cardiac myocytes incubated with PKC activator phorbol ester, but only the phosphorylation of troponin I was stimulated by isoproterenol. It is suggested that PKC-mediated phosphorylation of troponin might be involved in regulation of myocardial function or in pathophysiology of the heart.
Liu
J D
JD
Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia 30322.
Wood
J G
JG
Raynor
R L
RL
Wang
Y C
YC
Noland
T A
TA
Ansari
A A
AA
Kuo
J F
JF
D000818:Animals; D002451:Cell Compartmentation; D007124:Immunoenzyme Techniques; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology*; D009206:Myocardium / Q000201:enzymology*; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism*; D051381:Rats; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014336:Troponin / Q000378:metabolism*
D010750:Phosphoproteins; D014336:Troponin; D011493:Protein Kinase C; D007545:Isoproterenol; D013755:Tetradecanoylphorbol Acetate