DentinMatrixProtein

Dentin matrix protein 1 (DMP1) is a non-collagenous extracellular matrix protein found in mineralized tissues, notably dentin and bone. It is a member of the SIBLING family of proteins and is encoded by the DMP1 gene. DMP1 is produced by odontoblasts in teeth and by osteocytes and osteoblasts in bone, and it is secreted into the extracellular matrix where mineralization occurs.

DMP1 plays a key role in the regulation of mineralization. It binds to hydroxyapatite and interacts with other matrix components to influence crystal nucleation, growth, and orientation, thereby contributing to the proper mineralization of dentin and bone. The protein is subject to proteolytic processing, generating fragments that may have distinct functional roles in the mineralization process. In addition to its local effects in the matrix, DMP1 participates in systemic phosphate homeostasis, with osteocytic DMP1 influencing the expression of fibroblast growth factor 23 (FGF23); loss of DMP1 activity can lead to elevated FGF23 and hypophosphatemia.

Clinical significance of DMP1 is highlighted by its involvement in inherited bone and dentin disorders. Mutations or loss of function of DMP1 cause autosomal recessive hypophosphatemic rickets type 3 (HHR-3), characterized by low serum phosphate, rickets or osteomalacia, and dental abnormalities. In affected teeth, dentin may exhibit abnormal mineralization, tubule structure, and increased dentin fragility. Mouse models with DMP1 deficiency show impaired dentin and bone mineralization and skeletal defects, underscoring DMP1’s essential role in mineralized tissue biology.

References to DMP1 continue to inform studies of mineralization biology, dental pathology, and phosphate regulation.