Qualitative immunoblot analysis of pkc isoforms expressed in airway smooth muscle. Togashi, Hideaki, Carol A. Hirshman, and Charles W. Emala. Departments of Anesthesiology* and Environmental Health Sciences, The Johns Hopkins Medical Institutions, Baltimore, Maryland 21205
APStracts 3:0224L, 1996.
Protein kinase C (PKC) was originally identified as a single serine/threonine protein kinase with calcium- and phospholipid -dependent activity, but more recently PKC has been found to consist of a family of multiple isoenzymes with different biochemical characteristics, substrates, and co-factor requirements. PKC is particularly important in regulating airway smooth muscle (ASM) tone. Although a previous investigation has demonstrated PKC-b, -d, -e, -q and -z in canine trachealis muscle, additional PKC isoforms have not been characterized in ASM. Therefore, immunoblot analysis using 9 isotype-specific antibodies was used to further characterize the expression of PKC isoforms in porcine ASM. In addition to the previously described b, d, e, and z isoforms in ASM, the calcium -dependent [alpha] isoform, and the calcium- and diacylglycerol -independent isoforms i/l and m were identified. This study demonstrates multiple PKC isoforms in porcine ASM that can participate in intracellular signaling pathways in this tissue.

Received 9 February 1996; accepted in final form 31 October 1996.
APS Manuscript Number L44-6.
Article publication pending Am. J. Physiol. (Lung Cell. Mol.
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 31 December 1996