|FUNCTION: Binds to actin filaments in muscle and nonmuscle 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 nonmuscle cells is implicated in stabilizing cytoskeleton actin filaments.
* SUBUNIT: Heterodimer of an alpha and a beta chain.
* ALTERNATIVE PRODUCTS: At least 3 isoforms; 1/Skeletal muscle (shown here) and 2/Cytoskeletal/TM30nm and 3; are produced by alternative splicing.
* DOMAIN: THE MOLECULE IS IN A COILED COIL STRUCTURE. THE SEQUENCE EXHIBITS A PROMINENT SEVEN-RESIDUES PERIODICITY.
* DISEASE: THE AMINO END OF ISOFORM 2 HAS BEEN FOUND FUSED WITH THE PROTEIN TYROSINE KINASE DOMAIN ENCODED BY NTRK1. THESE SOMATIC REARRANGEMENT CREATES AN ONCOGENIC PROTEIN.
* DISEASE: Defects in TPM3 are a cause of nemaline myopathy type (NEM1). NEM1 is an autosomal dominant nonprogressive form of congenital myopathy with abnormal threadlike structures (nemaline rods) in muscle cells on histologic examination.
* SIMILARITY: BELONGS TO THE TROPOMYOSIN FAMILY.
* DATABASE: NAME=Atlas Genet. Cytogenet. Oncol. Haematol.; WWW="http://www.infobiogen.fr/services/chromcancer/Genes/TPM3ID225.html".
Last Update 13-Mar-03