Actins are extremely highly conserved structural proteins found in all eukaryotic cell cytoskeletons that govern cell structure, movement, and shape integrity. Six distinct actin isoforms, each encoded by a different gene and developmentally-regulated as well as tissue-specific-regulated, have been identified in mammalian cells. The alpha and beta isotypes are cytoplasmic and expressed in a wide variety of cells.
Actins are highly conserved, commonly found and abundant proteins involved in several types of cell motility as well as cytoskeleton maintenance. In vertebrate species, three main groups of actin isoforms, the alpha, beta and gamma, have been identified. Alpha actins are found in muscle tissues and are a major constituent of the contractile apparatus.
