Integrin subunit alpha 4 (CD49d) (CD49d)

Integrin subunit alpha 4 is a key component of the integrin family, forming heterodimers with beta 1 (VLA-4, α4β1) or beta 7 (α4β7) subunits to create cell surface receptors involved in adhesion and signaling. These complexes bind ligands such as vascular cell adhesion molecule 1 (VCAM-1), mucosal addressin cell adhesion molecule 1 (MAdCAM-1), and fibronectin domains (CS-1, CS-5), facilitating lymphocyte homing to inflamed tissues, endothelial cell interactions, and immune cell migration. The alpha 4 cytoplasmic domain interacts with paxillin to regulate cell motility and spreading, with phosphorylation at Ser988 modulating these effects. In disease, upregulated α4 integrins contribute to pathological inflammation in conditions like multiple sclerosis and inflammatory bowel diseases by promoting leukocyte extravasation. Therapeutically, the monoclonal antibody natalizumab targets α4 subunits to block these interactions, reducing immune cell trafficking and providing efficacy in autoimmune disorders, though it carries risks like opportunistic infections. Overall, integrin subunit alpha 4 represents a validated target for modulating immune responses in inflammatory pathologies.

Other names

Integrin alpha 4integrin alpha-4ITGA4VLA-4 alpha subunitantigen CD49D

Monoclonal antibody inhibiting alpha4 integrin-mediated leukocyte migration