Recombinant Human Integrin alpha 11 beta 1 Protein, CF

Integrin alpha 11 beta 1 is a noncovalent, heterodimeric collagen receptor that contains a 150 kDa alpha 11 subunit complexed to a 130 kDa beta 1/CD29 subunit.  alpha 11 beta 1 is the only known alpha 11-containing integrin. By contrast, at least twelve alpha -integrins share the beta 1 subunit (1-5). alpha 11 beta 1 is expressed on fibroblasts from cornea, skin and periodontal ligament (3‑9). It is also expressed on mesenchymal stem cells and is considered a marker for non‑muscle mesenchymal tissue (3, 8‑10). Expression of alpha 11 beta 1 is stimulated by TGF‑ beta 1, activin A, and type I interferons, and down‑regulated by FGF-2 (6, 9‑11). The alpha 11 extracellular domain (ECD) contains a vWFA domain which includes the ligand binding site (2‑5). The beta 1 ECD also contains a vWFA domain, which participates in binding. Each subunit has a transmembrane sequence and a short cytoplasmic tail. The dimer assumes a folded configuration at "rest". Divalent cations and intracellular (inside‑out) signaling convert it to an active, extended and open conformation (1, 2). The 1120 amino acid (aa) human alpha 11 ECD shares 90‑93% aa sequence identity with mouse, rat, equine, canine and bovine alpha 11, while the 708 aa human beta 1 ECD shares 92‑96% aa sequence identity with rat, bovine, mouse, and feline beta 1. I domain-containing beta 1 integrins alpha 1 beta 1, alpha 2 beta 1, alpha 10 beta 1 and alpha 11 beta 1 all bind collagens (3‑5). alpha 11 beta 1 preferentially binds interstitial collagens such as type I (5, 8, 12). It can contract collagen matrices and influence inflammatory edema (3, 13). Depending on context, alpha 11 beta 1 can support or inhibit cell migration on collagen (7, 8). It is frequently up‑regulated in the stroma of lung adenocarcinomas and enhances tumorigenicity (14, 15).