Smooth muscle specific expression of calponin.
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.
Gimona
M
M
Institute of Molecular Biology, Austrian Academy of Sciences, Salzburg.
Herzog
M
M
Vandekerckhove
J
J
Small
J V
JV
D000818:Animals; D000911:Antibodies, Monoclonal; D002135:Calcium-Binding Proteins / Q000032:analysis*; D004625:Embryo, Nonmammalian; D005455:Fluorescent Antibody Technique; D005895:Gizzard, Avian / Q000378:metabolism; D015151:Immunoblotting; D008840:Microfilament Proteins; D008970:Molecular Weight; D009124:Muscle Proteins / Q000032:analysis*; D009130:Muscle, Smooth / Q000378:metabolism*; D014422:Turkeys; D000096985:Calponins
D000911:Antibodies, Monoclonal; D002135:Calcium-Binding Proteins; D008840:Microfilament Proteins; D009124:Muscle Proteins; D000096985:Calponins