Gimona M, Herzog M, Vandekerckhove J, Small J V
Institute of Molecular Biology, Austrian Academy of Sciences, Salzburg.
FEBS Lett. 1990 Nov 12;274(1-2):159-62. doi: 10.1016/0014-5793(90)81353-p.
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.
