Integrin alpha-2
Integrin alpha-2, encoded by ITGA2 and also known as CD49b, is a collagen-binding I-domain alpha subunit that pairs predominantly with beta-1 to form the VLA-2 receptor. Its inserted I-domain coordinates a divalent cation that directly engages triple-helical collagens, and the subunit also supports adhesion to laminin. Expression is prominent on platelets, activated T cells, fibroblasts and epithelial cells, where alpha-2 beta-1 contributes to collagen matrix remodeling, wound contraction and angiogenesis. In platelets it cooperates with GP VI and alpha-IIb beta-3 in adhesion to exposed subendothelial collagen. Because of this role in fibrotic and inflammatory tissue remodeling, alpha-2 is investigated as a therapeutic target in fibrosis, arthritis and other autoimmune settings.
