dentin matrix acidic phosphoprotein 1; dentin matrix protein 1; DMP-1 (DMP1)

Function: - may have a dual function during osteoblast differentiation - in the nucleus of undifferentiated osteoblasts, unphosphorylated form acts as a transcriptional component for activation of osteoblast-specific genes like osteocalcin - during the osteoblast to osteocyte transition phase, it is phosphorylated & exported into the extracellular matrix, where it regulates nucleation of hydroxyapatite - phosphorylated in the cytosol & extracellular matrix; unphosphorylated in the nucleus - phosphorylation is necessary for nucleocytoplasmic transport & may be catalyzed by a nuclear isoform of CK2 & can be augmented by Ca⁺² - interacts with importin alpha Compartment: - nucleus, cytoplasm - secreted, extracellular space, extracellular matrix - in proliferating preosteoblasts, it is nuclear, during early maturation stage is cytoplasmic & in mature osteoblast localizes in the mineralizated matrix - export from the nucleus of differentiating osteoblast is triggered by the release of Ca⁺² from intracellular stores followed by a massive influx of this pool of Ca⁺² into the nucleus Alternative splicing: named isoforms=2 Expression: - expressed in tooth particularly in odontoblast, ameloblast & cementoblast Pathology: - defects in DMP1 are the cause of hypophosphatemic rickets, autosomal recessive

General

glycoprotein matrix protein phosphoprotein

Properties

SIZE: entity length = 513 aa MW = 56 kD COMPARTMENT: cytoplasm cell nucleus MOTIF: signal sequence {1-16} N-glycosylation site {N25} N-glycosylation site {N285} N-glycosylation site {N324} N-glycosylation site {N345} N-glycosylation site {N351} peptide motif {364-366} N-glycosylation site {N413} N-glycosylation site {N426} N-glycosylation site {N467}

Database Correlations

OMIM correlations MORBIDMAP 600980 UniProt Q13316 Pfam PF07263 Entrez Gene 1758 Kegg hsa:1758