Invited Review: Focal adhesion and small heat shock proteins in the regulation of
actin remodeling and contractility in smooth muscle.
Gerthoffer, William T., and Susan J. Gunst.
2Department of Cellular and Integrative Physiology, Indiana University School of
Medicine, Indianapolis, Indiana 46202«hyphen»5120; and 1Department of
Pharmacology, University of Nevada School of Medicine, Reno, Nevada
89557«hyphen»9946
APStracts 8:0259A, 2001.
Smooth muscle cells are able to adapt rapidly to chemical and mechanical signals
impinging on the cell surface. It has been suggested that dynamic changes in the actin
cytoskeleton contribute to the processes of contractile activation and mechanical
adaptation in smooth muscle. In this review, evidence for functionally important changes
in actin polymerization during smooth muscle contraction is summarized. The functions
and regulation of proteins associated with "focal adhesion complexes"
(membrane-associated dense plaques) in differentiated smooth muscle, including
integrins, focal adhesion kinase (FAK), Src, paxillin, and the 27-kDa small heat shock
protein (HSP27) are described. Integrins in smooth muscles are key elements of
mechanotransduction pathways that communicate with and are regulated by focal
adhesion proteins that include FAK, Src, and paxillin as well as proteins known to
mediate cytoskeletal remodeling. Evidence that functions of FAK and Src protein kinases
are closely intertwined is discussed as well as evidence that focal adhesion proteins
mediate key signal transduction events that regulate actin remodeling and contraction.
HSP27 is reviewed as a potentially significant effector protein that may regulate actin
dynamics and cross-bridge function in response to activation of p21-activated kinase and
the p38 mitogen-activated protein kinase signaling pathway by signaling pathways linked
to integrin proteins. These signaling pathways are only part of a large number of yet to be
defined pathways that mediate acute adaptive responses of the cytoskeleton in smooth
muscle to environmental stimuli.
APS Manuscript Number A426-1.
Article publication pending J Appl Physiol
ISSN 1080-4757 Copyright 2001 The American Physiological Society.
Published in APStracts on 18 June 2001