Dentin sialophosphoprotein (DSPP) cleavage products are the most abundant
non-collagenous proteins in dentin. Among the genes encoding the dentin noncollagenous
proteins, only mutations in DSPP are known to cause inherited dental
malformations. Characterization of DSPP-derived protein from developing porcine teeth
has allowed a better understanding of DSPP structure and function, which has provided
important insights into how dentin biomineralization might be controlled. Porcine DSPP
is a chimera of three structural domains: dentin sialoprotein (DSP), dentin glycoprotein
(DGP) and dentin phosphoprotein (DPP). DSPP is expressed by odontoblasts and is
rapidly processed after its secretion by BMP1 to generate DPP. Following this initial
processing, DSPP-derived proteins are further processed by matrix metalloproteinases
(MMP20 and MMP2) into DSP and DGP. DSP has a heavily N-glycosylated, sialylated
N-terminal domain and a C-terminal domain with two glycosaminoglycan attachments,
three potential O-glycosylations, and three potential phosphoserines. DGP is a
phosphorylated glycoprotein that has an affinity for hydroxyapatite, while DPP is a
highly phosphorylated intrinsically disordered protein with extensive length
polymorphisms resulted from genetic heterogeneity.
Keywords: DSPP, biomineralizations, dentin sialoprotein, dentin glycoprotein,
dentin phosphoprotein, DSPP derived proteins, proteolytic cleavage, BMP1,
MMP20, N-terminal, C-terminal, O-glycosylations, phosphoserines, polymorphisms,
biomineralizations.