Smooth muscle specific expression of calponin

Publisher Website
Google Scholar
Abstract
Calponin is an actin‐, calmodulin‐. and tropomyosin‐binding protein that has been isolated from smooth muscle tissue. Using a monoclonal antibody specific for avian calponin, we demonstrate a differentiation‐linked increase in calponin expression in embryonic chick gizzard. Cultivation of gizzard smooth muscle cells in vitro resulted in a down‐regulation of calponin expression after the first 48 h that was paralleled by a loss of synthesis of metavinculin and the high molecular weight isoform of caldesmon. In early cultures of smooth muscle cells calponin was localised in the actin‐containing stress fibres but labelling was restricted to the central parts of the actin cytoskeleton. Calponin expression is suggested as a potentially useful index of smooth muscle differentiation.