Recombinant Human Integrin alpha V beta 1 Protein, CF

Integrin alpha V beta 1 is one of five alpha V and twelve beta 1 containing Integrin family adhesion receptor heterodimers (1‑3). The non-covalent heterodimer of 170 kDa alpha V and 130 kDa beta 1/CD29 is present on cells that express both subunits, and dimer formation is dependant on the availability of the individual subunits (4). Since the alpha V and beta 1 subunits are widely expressed, the alpha V beta 1 heterodimer potentially forms in many cell types. The 962 aa human alpha V extracellular domain (ECD) shares 92‑95% aa sequence identity with mouse, rat and bovine alpha V, while the 708 aa human beta 1 ECD shares 92‑96% aa sequence identity with mouse, rat, bovine and feline  beta 1. The alpha V ECD contains an N‑terminal beta ‑propeller structure, followed by domains termed thigh, calf-1 and calf-2 (1). The beta 1 ECD contains a vWFA domain, which participates in binding. Each subunit then has a transmembrane sequence and a short cytoplasmic tail. The dimer is folded when it is least active. Divalent cations and intracellular (inside-out) signaling convert it to its most active, extended and open conformation (1). alpha V integrins bind ligands that contain an RGD motif, including vitronectin, fibronectin and osteopontin (4‑9). The relatively weak binding affinity of alpha V beta 1 to vitronectin and fibronectin is thought to facilitate its activity in cyclic binding and release during cell migration (4, 5). In oligodendrocytes, astrocytes and pancreatic beta cells, alpha V beta 1 is expressed early in differentiation when cells are migrating and is down‑regulated when differentiation is complete (5‑7). alpha V beta 1 has also been found to be a receptor for angiopoietin-2 in Tie2-deficient glioma cells, and to mediate cell entry of viruses such as foot‑and‑mouth disease virus and human metaneumovirus (10‑12).