Protein kinase c translocation and protein kinase c-dependent
protein phosphorylation during myocardial ischemia.
Albert, Carolyn J., and David A. Ford.
Department of Biochemistry and Molecular Biology, St. Louis
University Health Sciences Center
APStracts 5:0425H, 1998.
The present study demonstrates that the alpha, epsilon and iota
isozymes of protein kinase C (PKC) are translocated to particulate
fractions from the cytosol during brief intervals of global ischemia
as well as reperfusion of ischemic rat myocardium. In contrast,
phorbol ester treatment of perfused hearts resulted in the
translocation of the alpha, delta and epsilon isozymes of PKC to
particulate fractions. Additionally, the alpha, delta and epsilon
isozymes of PKC are translocated to particulate fractions in phorbol
ester-stimulated, isolated adult rat cardiac myocytes. Concomitant
with the translocation of PKC isozymes to particulate fractions
during myocardial ischemia, increased protein phosphorylation was
observed which was blocked by pretreatment of hearts with the
selective PKC inhibitor, bisindolylmaleimide I (50 nM). In
particular, ischemia resulted in the phosphorylation of 26kD, 20kD
and 17kD particulate-associated proteins. Taken together, the present
findings are the first to demonstrate that specific PKC isozymes are
translocated to particulate fractions in the ischemic and the
reperfused ischemic rat heart resulting in the phosphorylation of
specific particulate-associated proteins.
Received 26 May 1998; accepted in final form 6 October 1998.
APS Manuscript Number H428-8.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1998 The American Physiological Society.
Published in APStracts on 10 November 1998