Recombinant Human Integrin alpha 10 beta 1 Protein, CF

Integrin alpha10 beta1 is one of twelve integrin family adhesion receptors that share the beta1 subunit (1-3). The non-covalent heterodimer of 160 kDa alpha11 and 130 kDa beta1/CD29 type I transmembrane glycoprotein subunits is expressed mainly on chondrocytes within cartilage, but also in fibrous connective tissues such as heart valves and ligaments (3, 4). The alpha10 extracellular domain (ECD) contains an I (inserted) domain which includes the ligand binding site (2, 3, 5). The beta1 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, 2). The 1100 amino acid (aa) human alpha10 extracellular domain (ECD) shares 88-92% aa sequence identity with mouse, rat, canine and bovine alpha10, while the 708 aa human beta1 ECD shares 92‑96% aa sequence identity with rat, bovine, mouse, and feline beta1. A reported alpha10 splice variant lacking ECD aa 974-1012 was not expressed on the cell surface (6). I domain-containing beta1 integrins alpha1 beta1, alpha2 beta1, alpha10 beta1 and alpha11 beta1 all bind collagens; all but alpha11 beta1 also bind laminins (5, 7, 8). During cartilage differentiation, alpha10 beta1 is thought to be the main integrin binding type II and IX cartilage collagens (3‑5, 7-10). However, deletion of mouse alpha10 causes a mild phenotype including slightly shortened bones and narrowed hypertrophic zones, indicating that another collagen-binding integrin, likely alpha2 beta1, may compensate for alpha10 beta1 functions (11). Migration of melanoma cells has been noted to correlate with alpha10 beta1 expression (12).