F-actin cross-linking protein which is thought to anchor actin to a variety of intracellular structures. This is a bundling protein (By similarity). Homodimer; antiparallel. Interacts with MYOZ2, TTID and LPP (By similarity). Interacts with DDN (PubMed:16464232). Interacts with PSD. Interacts with MICALL2 (By similarity). Interacts with DNM2 and CTTN (PubMed:21210813). Interacts with PDLIM1 (PubMed:22659164). Interacts with PDLIM2 (PubMed:15505042). Interacts with PDLIM4 (via PDZ domain) (PubMed:14729062). Colocalizes with MYOZ2 and PPP3CA at the Z-line of heart and skeletal muscle. Colocalizes with PSD in membrane ruffles and central reticular structures. Belongs to the alpha-actinin family.