Integrin alpha-3/beta-1 is a receptor for fibronectin, laminin, collagen, epiligrin, thrombospondin and CSPG4. Integrin alpha-3/beta-1 provides a docking site for FAP (seprase) at invadopodia plasma membranes in a collagen-dependent manner and hence may participate in the adhesion, formation of invadopodia and matrix degradation processes, promoting cell invasion. Alpha-3/beta-1 may mediate with LGALS3 the stimulation by CSPG4 of endothelial cells migration. (Microbial infection) Integrin ITGA3:ITGB1 may act as a receptor for R.delemar CotH7 in alveolar epithelial cells, which may be an early step in pulmonary mucormycosis disease progression. Heterodimer of an alpha and a beta subunit. The alpha subunit is composed of a heavy and a light chain linked by a disulfide bond. Alpha-3 associates with beta-1. Interacts with HPS5. Interacts with FAP (seprase); the interaction occurs at the cell surface of invadopodia membrane in a collagen-dependent manner. Enriched preferentially at invadopodia, cell membrane protrusions that correspond to sites of cell invasion, in a collagen-dependent manner. Isoform 1 is widely expressed. Isoform 2 is expressed in brain and heart. In brain, both isoforms are exclusively expressed on vascular smooth muscle cells, whereas in heart isoform 1 is strongly expressed on vascular smooth muscle cells, isoform 2 is detected only on endothelial vein cells. Isoform 1, but not isoform 2, is phosphorylated on serine residues. Phosphorylation increases after phorbol 12-myristate 13-acetate stimulation. The disease is caused by variants affecting the gene represented in this entry. Antibodies against integrin alpha-3 ITGA3 protects epithelial cells from invasion by the fungus R.delemar, a causative agent of mucormycosis, and could thus potentially be used to treat mucormycosis disease. Belongs to the integrin alpha chain family.