Osteopontin, OPN Protein (Active)

Osteopontin (OPN), also known as bone sialoprotein I (BSP-1 or BNSP), secreted phosphoprotein 1 (SPP1), is a human gene product. The gene has 7 exons, spans 5 kilobases in length and in humans it is located on 4q13. The protein is composed of ~300 amino acids residues and has ~30 carbohydrate residues attached including 10 sialic acid residues, which are attached to the protein during post-translational modification in the Golgi apparatus. Osteopontin has been implicated as an important factor in bone remodeling. Specifically, research suggests it plays a role in anchoring osteoclasts to the mineral matrix of bones.

Choi ST, Kim JH, Kang EJ, Lee SW, Park MC, Park YB, Lee SK (December 2008) . "Osteopontin might be involved in bone remodelling rather than in inflammation in ankylosing spondylitis". Rheumatology (Oxford) 47 (12) : 1775–9. Reinholt FP, Hultenby K, Oldberg A, Heinegård D (June 1990) . "Osteopontin--a possible anchor of osteoclasts to bone". Proc. Natl. Acad. Sci. U.S.A. 87 (12) : 4473–5.