DNA Methyltransferases and Methyl-CpG Binding Proteins as Multi-Functional Regulators of Chromatin Structure and Development in Mammalian Cells
Beth O. Van Emburgh and Keith D. Robertson
from: Epigenetics (Edited by: Jörg Tost). Caister Academic Press, U.K. (2008)
The epigenetic modification of DNA with 5-methylcytosine is an important regulatory event involved in chromatin structure, genomic imprinting, inactivation of the X chromosome, transcription, and retrotransposon silencing. This modification is catalyzed and maintained by the DNA methyltransferases and is interpreted by the methyl-CpG binding proteins. DNA methyltransferases are not limited to catalyzing DNA methylation, but also take part in the regulation of gene expression through interactions with other proteins that repress transcription and modify chromatin structure. The use of mouse models, as well as human diseases resulting from deficiencies in the methylation machinery, have been integral parts of understanding the role of these proteins in development and cellular homeostasis. More and more studies are reporting additional roles within the cell beyond their DNA methyltransferase and methyl-CpG binding properties. There is at this point, though, only limited understanding of how these enzymes and proteins are targeted to specific genomic regions. The methyltransferases that will be discussed in this review include DNMT1, DNMT2, and the DNMT3 family of enzymes as well as the methyl-CpG binding proteins MeCP2, MBD1, MBD2, MBD3, and MBD4. The function of these enzymes, as well as their interactions with other cellular proteins and each other, will be discussed along with the diseases attributed to aberrations in the DNA methylation machinery read more ...