Recombinant Human Integrin alpha 11 beta 1 Protein, CF

Integrin alpha11 beta1 is a noncovalent, heterodimeric collagen receptor that contains a 150 kDa alpha11 subunit complexed to a 130 kDa beta1/CD29 subunit.  alpha11 beta1 is the only known alpha11-containing integrin. By contrast, at least twelve alpha-integrins share the beta1 subunit (1-5). alpha11 beta1 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 alpha11 beta1 is stimulated by TGF‑ beta1, activin A, and type I interferons, and down‑regulated by FGF-2 (6, 9‑11). The alpha11 extracellular domain (ECD) contains a vWFA domain which includes the ligand binding site (2‑5). The beta1 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 alpha11 ECD shares 90‑93% aa sequence identity with mouse, rat, equine, canine and bovine alpha11, while the 708 aa human beta1 ECD shares 92‑96% aa sequence identity with rat, bovine, mouse, and feline beta1. I domain-containing beta1 integrins alpha1 beta1, alpha2 beta1, alpha10 beta1 and alpha11 beta1 all bind collagens (3‑5). alpha11 beta1 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, alpha11 beta1 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).