Ryanodine Receptor Ca[sup]2+[r] Release Channels: Does Diversity in Form
Equal Diversity in Function?.
SUTKO, JOHN L. AND JUDITH A. AIREY.
Department of Pharmacology, University of Nevada School of Medicine, Reno,
Nevada
APStracts 2:0030P, 1996.
ABSTRACT
Investigations of the distributions of each RyR isoform, and of the properties
of SR calcium release in preparations expressing only the RyR1 isoform, as
well as the use of RyR isoform-specific channel modifiers. Complexities in
calcium signaling in eukaryotic cells require diversity in the proteins
involved in generating these signals. In this review, we consider the
ryanodine receptor (RyR) family of intracellular calcium release channels.
This includes species, tissue, and cellular distributions of the RyRs and
mechanisms of activation, deactivation, and inactivation of RyR calcium
release events. In addition, as first observed in nonmammalian vertebrate
skeletal muscles, it is now clear that more than one RyR isoform is frequently
coexpressed within many cell types. How multiple ryanodine receptor release
channels are used to generate intracellular calcium transients is unknown.
Therefore, a primary focus of this review is why more than one RyR is required
for this purpose, particularly in a tissue, such as vertebrate fast-twitch
skeletal muscles, where a relatively simple and straightforward change in
calcium would appear to be required to elicit contraction. Finally, the roles
of the RyR isoforms and the calcium release events they mediate in the
development of embryonic skeletal muscle is considered.
APS Manuscript Number P10-6.
Article publication pending October 1996, Physiological Reviews.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 13 November 1996