APStracts 2:0011P, 1995.

Ion Channel Regulation by G Proteins. Wickman, Kevin, and David E. Clapham. Dept. of Pharmacology, Mayo Foundation, Rochester, Minnesota.

APStracts 2:0011P, 1995.

ABSTRACT
Ion channels are poised uniquely to initiate, mediate, or regulate such distinct cellular activities as action potential propagation, secretion, and gene transcription. In retrospect, it is not surprising that studies of ion channels have revealed considerable diversities in their primary structures, regulation, and expression. From a functional standpoint, the various mechanisms coopted by cells to regulate channel activity are particularly fascinating. Extracellular ligands, membrane potential, phosphorylation, ions themselves, and diffusible second messengers are all well-established regulators of ion channel activity. Heterotrimeric GTP-binding proteins (G proteins) mediate many of these types of ion channel regulation by stimulating or inhibiting phosphorylation pathways, initiating intracellular cascades leading to elevation of cytosolic Ca[sup]2+[r] or adenosine 3[prime],5[prime]- cyclic monophosphate levels, or by generating various lipid-derived compounds. By the process of elimination, it would also seem that activated G protein subunits can interact directly with ion channels to elicit regulation. Although there is currently little direct biochemical evidence to support such a mechanism, it is the working hypothesis for the most-studied G protein- regulated ion channels.

APS Manuscript Number P-13-5.
Article publication scheduled October 1995 Physiological Reviews.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 23 September 1995.