Figure 2.

DNA methylation in the regulation of gene expression. For gene transcription to occur, transcription factors, RNA polymerase II, and other elements of the transcriptional machinery need to be able to access and bind to the gene promoter or enhancer regions. Unmethylated CpG sites within these regulatory regions enable binding of the transcriptional machinery, and gene is actively transcribed. On the other hand, methylation of the CpG sites in promoter or enhancer regions leads to recruitment of repressor complexes that prevent binding of the elements of the transcriptional machinery which results in gene silencing