tropomyosin alpha-4 chain; tropomyosin-4; TM30p1 (TPM4)

Function

• binds to actin filaments in muscle & non-muscle cells
• role, in association with the troponin complex, in the Ca+2 dependent regulation of vertebrate striated muscle contraction
• smooth muscle contraction is regulated by interaction with caldesmon
• in non-muscle cells, implicated in stabilizing cytoskeleton actin filaments
• binds Ca+2

Structure

• heterodimer of an alpha & a beta chain (putative)
• molecule is in a coiled coil structure that is formed by 2 polypeptide chains
• prominent 7-residue periodicity
• belongs to the tropomyosin family

Compartment

cytoplasm, cytoskeleton

Alternative splicing

named isoforms=2

Expression

• detected in cardiac tissue & platelets; form found in cardiac tissue is a higher molecular weight than form found in platelets

Pathology

• expressed at higher levels in platelets of hypertensive patients with cardiac hypertrophy than in platelets of hypertensive patients without cardiac hypertrophy (at protein level)

More general terms

• tropomyosin-alpha; tropomyosin-1; alpha-tropomyosin

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=7171
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:7171
• OMIM: https://mirror.omim.org/entry/600317
• UniProt: http://www.uniprot.org/uniprot/P67936.html