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. {ECO:0000250|UniProtKB:P58774, ECO:0000250|UniProtKB:P58775}. This is the function of Ensembl gene identifier ENSG00000198467 (TPM2, tropomyosin 2).