| The expression of mouse delta-opioid receptor (mDOR) is cell type-specific and under temporal and spatial control. Considerable evidence indicates that two epigenetic phenomena, DNA methylation and chromatin modification, play an important role in regulation of gene expression. To understand the molecular mechanisms of transcriptional regulation of mDOR gene expression, we analyzed the DNA methylation pattern and histone modification profiles within mDOR promoter region in two neuronal cells: NS20Y and Neuro2A. Here we have demonstrated that suppression of mDOR expression in Neuro2A cells is a result of promoter region DNA methylation and that Sp3 and MBD2 are involved in transcriptional repression of the mDOR promoter through binding of methylated CpG. Moreover, we have shown that DNA methylation-related histone modification, especially histone H3 acetylation and deacetylation, is the underlying mechanism of methylation induced repression of mDOR gene, which plays an important role in the regulation of cell type-specific expression of mDOR. Taken together, our results demonstrated that the mouse DOR gene is epigenetically regulated by promoter region CpG methylation and chromatin/histone modification. |
