Recombinant Human Integrin alpha 10 beta 1 Protein, CF

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