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. Also forms heterodimers with ACTN3. Interacts with ADAM12, MYOZ1, MYOZ2 and MYOZ3. Interacts via its C-terminal region with the LDB3 PDZ domain. Interacts with XIRP2. Interacts with DST (via N-terminus). Interacts with PARVB. Interacts with SYNPO2 (By similarity). Colocalizes with MYOZ1 and FLNC at the Z-lines of skeletal muscle. Ubiquitinated by FBXL22, leading to proteasomal degradation. Belongs to the alpha-actinin family.