Mechanisms of Transcriptional Regulation

DNA methylation contributes to transcriptional regulation through several interconnected molecular mechanisms.

One important mechanism involves the direct inhibition of transcription factor binding. Methylation of specific cytosine residues can modify the recognition properties of DNA-binding proteins, preventing certain transcription factors from interacting efficiently with their target sequences.

Another mechanism involves methyl-CpG-binding proteins, which recognize methylated DNA and recruit additional regulatory complexes.

Proteins such as MeCP2 and members of the methyl-CpG-binding domain family can interact with chromatin-modifying enzymes and transcriptional corepressors.

These interactions may promote histone deacetylation, chromatin compaction and reduced accessibility of transcriptional machinery.

Consequently, DNA methylation functions as part of a broader regulatory system connecting chemical modifications of DNA with chromatin architecture and gene expression.