Binds to actin filaments in muscle and non-muscle cells (PubMed:23170982). Plays a central role, in association with the troponin complex, in the calcium dependent regulation of vertebrate striated muscle contraction (PubMed:23170982). Smooth muscle contraction is regulated by interaction with caldesmon. In non-muscle cells is implicated in stabilizing cytoskeleton actin filaments. Homodimer (PubMed:23170982). Heterodimer of an alpha (TPM1, TPM3 or TPM4) and a beta (TPM2) chain (By similarity). Interacts with HRG (via the HRR domain); the interaction contributes to the antiangiogenic properties of the histidine/proline-rich region (HRR) of HRG (By similarity). Interacts (via N-terminus) with LMOD2 (via N-terminus) and TMOD1 (via N-terminus) (PubMed:26873245). Associates with F-actin stress fibers. Additional isoforms seem to exist. Detected in primary breast cancer tissues but undetectable in normal breast tissues in Sudanese patients. Isoform 1 is expressed in adult and fetal skeletal muscle and cardiac tissues, with higher expression levels in the cardiac tissues. Isoform 10 is expressed in adult and fetal cardiac tissues, but not in skeletal muscle. The molecule is in a coiled coil structure that is formed by 2 polypeptide chains. The sequence exhibits a prominent seven-residues periodicity. Phosphorylated at Ser-283 by DAPK1 in response to oxidative stress and this phosphorylation enhances stress fiber formation in endothelial cells. The measured range is 1-284. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. Incomplete sequence. Belongs to the tropomyosin family.