Actin, alpha skeletal muscle and Actin, alpha smooth muscle (ACTA1, ACTA2)

Actin, alpha skeletal muscle (ACTA1) and Actin, alpha smooth muscle (ACTA2) are essential protein components of the contractile apparatus in skeletal and smooth muscle cells, respectively. ACTA1 is the primary actin isoform in adult skeletal muscle, where it polymerizes to form thin filaments that interact with myosin, troponin, and tropomyosin to facilitate muscle contraction [1.2.2, 1.2.5]. Mutations in the ACTA1 gene are a primary cause of congenital myopathies, most notably nemaline myopathy, which is characterized by severe muscle weakness and the presence of rod-like structures in muscle fibers [1.1.4, 1.2.2]. ACTA2, also known as alpha-smooth muscle actin (alpha-SMA), is essential for the contractility of vascular smooth muscle cells and serves as a definitive biomarker for the activation of myofibroblasts in fibrosis and the tumor microenvironment [1.2.1, 1.4.2]. Mutations in ACTA2 are associated with vascular diseases, including familial thoracic aortic aneurysms, Moyamoya disease, and multisystemic smooth muscle dysfunction syndrome [1.1.2, 1.2.4]. Therapeutic approaches targeting these proteins include the use of troponin activators to enhance muscle sensitivity in ACTA1-related diseases and the development of gene therapies or RNA-based inhibitors to modulate actin expression in vascular and fibrotic conditions [1.2.5, 1.3.1, 1.3.3].

Other names

Alpha-actinAlpha-SMASkeletal muscle alpha-actinSmooth muscle alpha-actinACTSAASMANEM1CFTDMYMY5Actin alpha 1Actin alpha 2

Modulation of thin filament calcium sensitivity, gene replacement therapy, and inhibition of myofibroblast activation and migration.