Oseteopontin is a extracellular linking protein which is also known by the names of bone sialoprotein I , early T-lymphocyte activation 1, secreted phosphoprotein 1, 2ar and Rickettsia resistance.
It is a glycoprotein that was first identified in 1986 in osteoblasts.
Apart from bone, the protein is also expressed in other tissues.
Osteopontin gene is located on the long arm of chromosome 4 region 13 (4q13).
Osteopontin is synthesized in fibroblasts, preosteoblasts, osteoblasts, osteocytes, odontoblasts, some bone marrow cells, hypertrophic chondrocytes, dendritic cells, macrophages, smooth muscle, skeletal muscle, endothelial cells, and extraosseous cells in the inner ear, brain, kidney, and placenta.
Synthesis of osteopontin is stimulated by calcitriol. Regulation of the osteopontin gene is incompletely understood.
Osteopontin has been implicated as an important factor in bone remodeling, immune functions, chemotaxis and T cell activation and apoptosis.
Osteopontin gene might find clinical application in wound healing, bone turnover, tumorigenesis, inflammation, ischemia and immune responses, allergy and asthma ad immune disorders« Back to Glossary Index