Osteopontin is an arginine-glycine-aspartic acid (RGD)-containing glycoprotein that interacts with integrins and CD44 as major receptors. It is a multifunctional protein involved in bone mineralization, cell adhesion, cell migration, chronic inflammatory disease and transformation. Proteolytic cleavage by thrombin and matrix metalloproteinases close to the integrin-binding Arg-Gly-Asp sequence modulates the function of OPN and its integrin binding properties. Thrombin-cleaved fragments of Osteopontin are overexpressed in malignant glial tumors and provide a molecular niche with survival advantage and provide a novel substrate for plasmin and cathepsin D.
Protein Aliases: 2AR; 44 kDa bone phosphoprotein; Bone sialoprotein 1; Calcium oxalate crystal growth inhibitor protein; early T-lymphocyte activation 1; Early T-lymphocyte activation 1 protein; HGNC:11255; MGC110940; Minopontin; Nephropontin; Osteopontin; osteopontin-like protein; osteopontin/immunoglobulin alpha 1 heavy chain constant region fusion protein; Secreted phosphoprotein 1; secreted phosphoprotein 1 (osteopontin, bone sialoprotein I, early T-lymphocyte activation 1); secreted phosphoprotein 1 variant 6; Sialoprotein (osteopontin); SPP-1; SPP1/CALPHA1 fusion; urinar; Urinary stone protein; Uropontin
Gene Aliases: 2AR; 2b7; Apl-1; BNSP; Bsp; BSPI; Eta; ETA-1; OP; OPN; Opnl; OSP; PSEC0156; Ric; Spp-1; SPP1