Integrin alpha-6
Integrin alpha-6 (CD49f), encoded by ITGA6, is the dedicated laminin-binding alpha subunit that pairs with either beta-1 or beta-4. Before reaching the cell surface it is cleaved into disulfide-linked heavy and light chains. With beta-1 it mediates adhesion and migration of endothelial, neuronal and hematopoietic cells on laminins, while with beta-4 it anchors stratified epithelia to the basement membrane through hemidesmosomes. CD49f is widely used as a stem and progenitor cell marker, notably for isolating mammary gland and epidermal stem cells. Biallelic ITGA6 mutations cause epidermolysis bullosa with pyloric atresia, and altered alpha-6 expression correlates with aggressiveness in several carcinomas, including prostate and breast cancer.
