Integrin alpha-3
Integrin alpha-3 (CD49c), encoded by ITGA3, associates with beta-1 to form the principal laminin-332 (laminin-5) receptor of epithelial cells. Like alpha-6, it is post-translationally cleaved into disulfide-linked heavy and light chains. Alpha-3 beta-1 localizes to focal contacts and drives keratinocyte migration during re-epithelialization; in the kidney it is essential for podocytes to organize the glomerular basement membrane, and in the lung it maintains alveolar epithelial integrity. Biallelic ITGA3 mutations cause a syndrome of interstitial lung disease, nephrotic syndrome and epidermolysis bullosa, underscoring its role in basement membrane-dependent tissues. The subunit is also implicated in tumor cell invasion and has been explored in antibody-based cancer therapy.
