Actins are highly conserved proteins that are involved in various types of cell motility, and maintenance of the cytoskeleton. In vertebrates, three main groups of actin isoforms, alpha, beta and Y have been identified. The alpha actins are found in muscle tissues and are a major constituent of the contractile apparatus. The beta and Y actins co-exist in most cell types as components of the cytoskeleton, and as mediators of internal cell motility. Actin, Y 1, encoded by this gene, is a cytoplasmic actin found in nonmuscle cells. Actins are highly conserved proteins that are involved in various types of cell motility and are ubiquitously expressed in all eukaryotic cells.