Binds to actin filaments in muscle and non-muscle cells. Plays a central role, in association with the troponin complex, in the calcium dependent regulation of vertebrate striated muscle contraction. Smooth muscle contraction is regulated by interaction with caldesmon. In non-muscle cells is implicated in stabilizing cytoskeleton actin filaments. The non-muscle isoform may have a role in agonist-mediated receptor internalization.
Subcellular locations: Cytoplasm, Cytoskeleton
Associates with F-actin stress fibers.
Present in primary breast cancer tissue, absent from normal breast tissue.