Actin, alpha skeletal muscle (ACTA1) (ACTA1)

Actin alpha skeletal muscle, encoded by the ACTA1 gene, is a highly conserved structural protein that serves as the primary component of the thin filaments in the sarcomeres of adult skeletal muscle (UniProt, 2024; Wikipedia, 2024). It plays a fundamental role in muscle contraction by interacting with myosin thick filaments in an ATP-dependent manner, a process regulated by calcium ions and the troponin-tropomyosin complex (MedlinePlus, 2016; NIH, 2024). Beyond its mechanical role, ACTA1 is involved in maintaining the cytoskeleton, cell motility, and potentially nuclear signaling (GeneCards, 2024). Mutations in the ACTA1 gene are a major cause of congenital myopathies, most notably nemaline myopathy, which is characterized by muscle weakness and the presence of rod-like protein aggregates (NIH, 2024). Other associated conditions include actin myopathy, cap myopathy, and congenital fiber-type disproportion (MedlinePlus, 2016). While there are currently no approved targeted therapies, research is focused on gene therapy approaches, such as the upregulation of the fetal isoform cardiac alpha-actin (ACTC) to compensate for ACTA1 deficiency, and the use of small-molecule calcium sensitizers to enhance contractile force (NIH, 2024). Additionally, serum levels of alpha-actin are being explored as biomarkers for skeletal muscle injury (NIH, 2024).

Other names

Alpha-actin-1Skeletal muscle alpha-actinASMACFTDNEM1NEM2NEM3Actin alpha 1

Direct binding to actin monomers or filaments to modulate polymerization and stability (research tools); gene therapy to replace or supplement functional actin; small-molecule sensitization of the contractile apparatus to calcium (indirect therapeutic approach).