Hg. Shin et Kt. Murray, Conventional protein kinase C isoforms and cross-activation of protein kinase A regulate cardiac Na+ current, FEBS LETTER, 495(3), 2001, pp. 154-158
We tested the hypothesis that specific isoforms of protein kinase C (PKC) a
re responsible for modulation of Na+ current (I-Na) derived from the human
cardiac Na+ channel using activators and inhibitors selective for specific
PKCs. Experimental results demonstrated that I-Na, suppression was mediated
he activation of conventional PKCs (cPKCs) and possibly resulted from chan
nel internalization. In the presence of cPKC inhibition. phorbol ester appl
ication unexpectedly increased Na+ current. an effect eliminated he inhibit
ion of protein kinase A. These findings demonstrate complex modulation of c
ardiac I-Na hi protein kinases and provide further evidence that PKC isofor
ms have distinct protein targets, (C) 2001 Federation of European Biochemic
al Societies. Published by Elsevier Science B.V. All rights reserved.