Protein Domain : Bone sialoprotein 2 IPR008412

Type	Family
Description	The major non-collagenous matrix proteins (chondroitin-sulphate glycoproteins decorin and biglycan, sialoproteins osteopontin and bone sialoprotein, osteocalcin and osteonectin) have important roles in formation and organisation of the collagen matrix and nucleation and growth of hydroxyapatite crystals.Bone sialoprotein (BSP) is a major structural protein of the bone matrix that is specifically expressed by fully differentiated osteoblasts [ ], [] and is highly specific for mineralising tissues. The expression of bone sialoprotein (BSP) is normally restricted to mineralised connective tissues of bones and teeth; it is thought to be responsible for nucleation of hydroxyapatite crystals. BSP also displays a high affinity for calcium ions. The mature protein has a molecular weight of around 33kDa and consists predominantly of Glu and Gly residues. It is subject to extensive post-translational modification, and is predominantly phosphorylated at Ser residues. Post-translational modifications can also cause BSP to act as an inhibitor of hydroxyapatite crystal formation. Ectopic expression of BSP occurs in various lesions, including oral and extraoral carcinomas, in which it has been associated both with the formation of microcrystalline deposits and with the metastasis of cancer cells to bone. The expression of this protein may be altered with the cancer secretome [ , , ]. It has also been related to osteoarthritis ]. This entry represents the Bone sialoprotein 2 and similar proteins mainly found in animals.
Short Name	BSP_II