Alpha actinin is an actin-binding protein with multiple roles in different cell types.

In nonmuscle cells, the cytoskeletal isoform is found along microfilament bundles and adherens-type junctions, where it is involved in binding actin to the membrane.

In contrast, skeletal, cardiac, and smooth muscle isoforms are localized to the Z-disc and analogous dense bodies, where they help anchor the myofibrillar actin filaments.

This gene encodes a nonmuscle, alpha actinin isoform which is concentrated in the cytoplasm, and thought to be involved in metastatic processes.

[5] Alpha-actinin-4 has been shown to interact with PDLIM1,[6][7] Sodium-hydrogen exchange regulatory cofactor 2,[8] Collagen, type XVII, alpha 1,[9] CAMK2A,[10] CAMK2B,[10] MAGI1[11] and TRIM3.