Osteopontin

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Osteopontin (OPN), also known as bone sialoprotein I (BSP-1), early T-lymphocyte activation (ETA-1), and secreted phosphoprotein 1 (SPP1), is a human gene product,which is also conserved in other species. Osteopontin is a SIBLING glycoprotein that was first identified in 1986 in osteoblasts. The prefix of the word "osteo" indicates that the protein is expressed in bone, although it is also expressed in other tissues. The suffix "-pontin" is derived from "pons," the Latin word for bridge, and signifies osteopontin's role as a linking protein. Osteopontin is an extracellular structural protein and therefore an organic component of bone. Synonyms for this protein include sialoprotein I and 44K BPP (bone phosphoprotein).