The Role Of MSX1 On Dentin Sialophosphoprotein' Transcript

Dentin is the principal mineralized tissue of teeth and originates from odontoblasts that synthesize and secrete collagenous and noncoUagenous proteins to form the dentin extracellular matrix (ECM). It is believed that some noncoUagenous proteins are associated at specific sites on collagen and act to promote the nucleation and growth of hydroxyapatite crystals. These non-collagenous DECM proteins are believed to be essential for initiation and control of mineralization in the transition of predentin to dentin.Among noncoUagenous proteins, dentin sialoprotein (DSP) and dentin phosphoprotein (DPP) are expressed at high levels in tooth. DSP and DPP have been shown to be cleavage products of a primary transcript precursor encoded by a single gene termed dentin sialophosphoprotein (DSPP). DSPP plays an important role in tooth formation and mineralization .Heterogeneous mutations of human DSPP are associated with dentinogenesis imperfecta type II and type III and dentin dysplasia type II .The DSPP gene of mouse, rat, human, and pig has been cloned.Mouse and rat DSPP gene promoters have been characterized. The immunohistochemical study,nucleic acid hybridization in situ,gene mutation study have showed the DSPP temporal and spatial expression.However, the precise /ram-acting transcription factors associated with cis-acting elements underlying tissue-specific DSPP gene expression are unknown. gene expression is controlled by transcriptional regulators, activators and repressors, which interact either directly or indirectly with cis-regulatory elements and modulate the expression levels of their target genes. Recently,a study show that there are six potential binding sites of transcription factor-MSX1 in the promoter of DSPP.Base on this result,we...