Methylation of DNA plays a crucial role in transcriptional regulation, imprinting, and chromatin structure. DNA methyltransferases add a methyl group to cytosine or adenine DNA nucleotides. DNA methylation is a dynamic and reversible process and alters the expression of genes during cell division and differentiation from embryonic stem cells to specific tissues. The process is usually permanent, preventing cells e.g. from re-differentiation. During zygote formation, methyl groups are removed and subsequently re-established during development.
The reducing effect of gene expression is mediated by methylation at the 5 position of cytosine and it is present on all vertebrates. In adult somatic cells methylation is seen in a CgG context, while non-CpG methylation is current in embryogenic stem cells. Enzymes that catalyze DNA methylation are well characterized and already used as target enzymes for drug discovery screenings. BPS Biosciences offers a range of active DNA methyltransferases and DNA methyltransferase assays for inhibitor screenings (see Fig.1).