ITGA4 Antibody from MyBioSource.com

Description: Integrins are alpha/beta heterodimeric cell surface receptors that play a pivotal role in cell adhesion and migration, as well as in growth and survival (1, 2). The integrin family contains at least 18 alpha and 8 beta subunits that form 24 known integrins with distinct tissue distribution and overlapping ligand specificities (3). Integrins not only transmit signals to cells in response to the extracellular environment (outside-in signaling), but also sense intracellular cues to alter their interaction with the extracellular environment (inside-out signaling) (1, 2).A pair of important alpha4 integrins, alpha4beta1 and alpha4beta7, interact with VCAM-1, fibronectin, and MAdCAM-1 at cell adhesions (3). Gene knockout and antibody blocking research reveal that alpha4 integrins play important roles in embryonic liver and heart development and in fetal lymphocyte homing (4-6). Phosphorylation at Ser988 within the cytoplasmic tail of integrin alpha4 blocks binding to paxillin and promotes leading edge migration (7, 8).On SDS-PAGE, integrin alpha4 can migrate at several different apparent molecular sizes, a 150 kDa mature protein and a 140 kDa precursor protein (a 180 kDa protein also exists under mild non-reducing conditions) (9). Integrin alpha4 has a cleavage site at Arg558, which results in a small portion of the protein as either an 80 kDa N-terminal or 70 kDa C-terminal fragment (10).
Function: Integrins alpha-4/beta-1 (VLA-4) and alpha-4/beta-7 are receptors for fibronectin. They recognize one or more domains within the alternatively spliced CS-1 and CS-5 regions of fibronectin. They are also receptors for VCAM1. Integrin alpha-4/beta-1 recognizes the sequence Q-I-D-S in VCAM1. Integrin alpha-4/beta-7 is also a receptor for MADCAM1. It recognizes the sequence L-D-T in MADCAM1. On activated endothelial cells integrin VLA-4 triggers homotypic aggregation for most VLA-4-positive leukocyte cell lines. It may also participate in cytolytic T-cell interactions with target cells. ITGA4:ITGB1 binds to fractalkine (CX3CL1) and may act as its coreceptor in CX3CR1-dependent fractalkine signaling (PubMed:23125415). ITGA4:ITGB1 binds to PLA2G2A via a site (site 2) which is distinct from the classical ligand-binding site (site 1) and this induces integrin conformational changes and enhanced ligand binding to site 1 (PubMed:18635536, PubMed:25398877).
Subunit Structure: Heterodimer of an alpha and a beta subunit. The alpha subunit can sometimes be cleaved into two non-covalently associated fragments. Alpha-4 associates with either beta-1 or beta-7. Alpha-4 interacts with PXN, LPXN, and TGFB1I1/HIC5. Interacts with CSPG4 through CSPG4 chondroitin sulfate glycosaminoglycan. Interacts with JAML; integrin alpha-4/beta-1 may regulate leukocyte to endothelial cells adhesion by controlling JAML homodimerization. ITGA4:ITGB1 is found in a ternary complex with CX3CR1 and CX3CL1 (PubMed:23125415).
Post-translational Modifications: Phosphorylation on Ser-1027 inhibits PXN binding.
Similarity: The SG1 motif is involved in binding to chondroitin sulfate glycosaminoglycan and cell adhesion. Belongs to the integrin alpha chain family