Alpha actinin 2 is an actin binding proteins that carry out different purposes in different different cell types. Skeletal, cardiac, and smooth muscle isoforms are localized to the Z disc and analogous dense bodies, where they help anchor the myofibrillar actin filaments. ACTN2 encodes a muscle-specific, alpha actinin isoform that is expressed in both skeletal and cardiac muscles. There are several known transcript variants that result from the use of multiple polyA+ sites. ACTN2 has the ability to form both homo- and heterodimers (with ACTN3).