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. Interacts with DDN (By similarity). Interacts with PSD (PubMed:17298598). Interacts with MICALL2 (PubMed:23100251). Interacts with DNM2 and CTTN. Interacts with PDLIM1. Interacts with PDLIM2. Interacts with PDLIM4 (via PDZ domain) (By similarity). Colocalizes with MYOZ2 and PPP3CA at the Z-line of heart and skeletal muscle (PubMed:11114196). Colocalizes with PSD in membrane ruffles and central reticular structures (PubMed:17298598). Belongs to the alpha-actinin family.