DNA Methyltransferase Enzymes
Regulation of Gene Expression
Several lines of evidence suggest that the methyl group in some cases directly interferes with the binding of transcription factors that activate transcription. In an alternative process, CpG-binding domain (MBD) proteins bind to the methyl group and subsequently to chromatin remodeling proteins (such as histone deacetylases) to silence the gene by making it transcriptionally unavailable. Genes that are methylated tend to be packaged more tightly, which causes them to be silenced. Genes that are not methylated tend to exhibit looser packaging, which allows their expression.
Current Topics in DNA Methylation Research
Interesting Review Articles
Dobosy, J.R. and Selker, E.U. Emerging Connections between DNA Methylation and Histone Acetylation. 2001. Cellular & Molecular Life Sciences. 58: 721-727.
Jaenisch J. and Bird, A. Epigenetic regulation of gene expression: how the genome integrates intrinsic and environmental signals. Nature Genetics. 2003, 33: 245-254.
Bird, A. and Wolffe, AP. Methylation-induced Repression: Belts, Braces and Chromatin. Cell. 1999. 99: 451-454.
Jaenisch, R. et. al. DNA Methylation, Retroviruses, and Embryogenesis. Journal of Cellular Biochemistry. 1982, 20: 331-336.
Okano, M., et al. DNA Methyltranferases Dnmt3a and Dnmt3b are Essential for de novo Methylation and Mammalian Development. Cell. 1999; 99: 247-257.