Binds to actin and plays an important role in the assembly of the Z-disk. May functionally link sarcomeric actin to the desmin intermediate filaments in the heart muscle sarcomeres (PubMed:27733623). Isoform 2 might play a role in the assembly of focal adhesion (PubMed:15004028). Isoform 2 interacts with ZYX (Zyxin) (PubMed:15004028). Interacts (via nebulin repeats 1-5) with DESM (via rod region) (PubMed:27733623). Abundantly expressed in cardiac muscle, but not in skeletal or smooth muscle. Localized to Z-lines in cardiac cells and to dense bodies in nonmuscle cells. Isoform 2 is expressed in non-muscle cells such as in fibroblasts. Expressed in non-muscle cells. May be transcribed from an upstream promoter active in non-muscle cells.