Dentin sialophosphoprotein is the only protein produced uniquely by odontoblasts, the cells that produce tooth dentin. It is a non-collagenous SIBLING protein that is later cleaved into three functional proteins: dentin phosphoprotein (also known as phosphophoryn), taken from the C-terminal end, dentin sialoprotein from the N-terminal end, and dentin glycoprotein from the middle of the molecule. Their distribution in the collagen matrix of the forming dentin suggests these proteins play an important role in the regulation of mineral deposition. Additional evidence for this correlation is phenotypically manifested in patients with mutant forms of dentin sialophosphoprotein. Such patients suffer dental anomalies including type III dentinogenesis imperfecta.
It is coded for by a gene of the same name.