Anti-Smoothelin antibody [R4A] (ab8969)

Relevance

Smoothelin is a constituent of the smooth muscle cell (SMC) cytoskeleton. Antibodies directed to smoothelin are a useful tool to monitor SMC differentiation. Smoothelin is exclusively expressed in fully differentiated (contractile) SMCs. RNA and protein analyses reveal a broad species distribution of this protein. Cells with SMC like characteristics, such as myofibroblasts, myoepithelial cells, and skeletal and cardiac muscle do not contain smoothelin. Confocal scanning laser microscopy of tissue sections, as well as transfection studies, show a filamentous organization of smoothelin that is different from that of desmin and vimentin. Smoothelin colocalizes with actin stress fibers. Two major isoforms of smoothelin have been reported, a 59-kDa smoothelin A in visceral smooth muscle cells and a 110-kDa smoothelin B in vascular smooth muscle cells. Both gene products are encoded by a single copy gene which is located on chromosome 22 and regulated by a dual promoter system in a tissue specific manner. The variation in the smoothelin proteins is achieved by alternative splicing in the calponin homology domain. The distribution of smoothelin positive cells indicates a correlation between smoothelin expression and smooth muscle tissue contractility. Antibodies to smoothelin are powerful tools in evaluation of smooth muscle cell differentiation as occurs in atherosclerotic lesions.

Cellular localization

Cytoplasmic

Alternative names

Database links