Integrin alpha-2/beta-1 is a collagen receptor, being responsible for adhesion of platelets and other cells to collagens, modulation of collagen and collagenase gene expression, force generation and organization of newly synthesized extracellular matrix. It is also a receptor for laminins, collagen C-propeptides and E-cadherin. Mice homozygous for a null mutation in the alpha-2 die very early in embryogenesis. Heterodimer of an alpha and a beta subunit. Alpha-2 associates with beta-1. Interacts with HPS5 and RAB21. The integrin I-domain (insert) is a VWFA domain. Integrins with I-domains do not undergo protease cleavage. Belongs to the integrin alpha chain family.