α-Actinin 4 (D7U5A) Rabbit mAb  #15145

α-Actinin belongs to the spectrin family of cytoskeletal proteins. It was first recognized as an actin cross-linking protein, forming an antiparallel homodimer with an actin binding head at the amino terminus of each monomer. The α-actinin protein interacts with a large number of proteins involved in signaling to the cytoskeleton, including those involved in cellular adhesion, migration, and immune cell targeting (1). The interaction of α-actinin with intercellular adhesion molecule-5 (ICAM-5) helps to promote neurite outgrowth (2). In osteoblasts, interaction of α-actinin with integrins stabilizes focal adhesions and may protect cells from apoptosis (3). The cytoskeletal α-actinin isoforms 1 and 4 (ACTN1, ACTN4) are non-muscle proteins that are present in stress fibers, sites of adhesion and intercellular contacts, filopodia, and lamellipodia. The muscle isoforms 2 and 3 (ACTN2, ACTN3) localize to the Z-discs of striated muscle and to dense bodies and plaques in smooth muscle (1).
The ubiquitously expressed α-actinin 4 (ACTN4) protein typically localizes to the cytoskeleton but extracellular stimuli will prompt nuclear translocation in some cells (4). Research studies suggest that ACTN4 can mediate cell signaling and regulate gene expression as a transcriptional coactivator (5,6). Increased expression of ACTN4 protein and amplification of the ACTN4 gene are seen in many cancers and correlates with poor prognosis and metastasis (7). Mutations in the corresponding ACTN4 gene are responsible for focal segmental glomerulosclerosis (FSGS1), a severe renal disorder characterized by reduced kidney function, proteinuria, and progressive kidney failure (8).