Alpha 4 subunit of VLA 4 receptor,ITG-_4: Antigen CD49D, CD 49d , CD49d, CD49d antigen, CDw49d, IA4, Integrin alpha IV, ITGA 4, ITGA4, LPAM23, MGC90518, Very Late Activation Antigen 4, Very Late Activation Protein 4 Receptor Alpha 4 Subunit, VLA 4, VLA4, integrin alpha-4, ITA4_HUMAN,
Integrin alpha 4 (also called CD49d) is a 150 kDa protein that possesses a large extracellular domain involved in ligand binding, a single transmembrane domain, and an intracellular regulatory domain possessing multiple sites for phosphorylation. Integrin alpha 4 forms heterodimers with integrins beta 1 and beta 7. Integrin alpha 4 is expressed on leukocytes and leukocyte precursors, neural crest cells, and developing skeletal muscles and is essential for embryogenesis, hematopoiesis, and immune responses. The presence of integrin alpha 4 promotes cell migration and inhibits cell spreading and contractility. Integrin alpha 4 function has been implicated in the pathogenesis of multiple diseases including asthma, rheumatoid arthritis, Crohns disease, ulcerative colitis, hepatitis C, and multiple sclerosis, and therefore, modulation of integrin alpha 4 function has become an important target for drug discovery.
