5metüültsosiin
5-methylcytosine (5mC) is a modified form of the DNA base cytosine. It is one of the most extensively studied epigenetic modifications in eukaryotes and plays a crucial role in regulating gene expression without altering the underlying DNA sequence. In mammals, 5mC is primarily found in the context of CpG dinucleotides, where a methyl group is attached to the carbon at the fifth position of the cytosine ring. This methylation is catalyzed by DNA methyltransferases (DNMTs).
The presence of 5mC can lead to gene silencing. Methylated DNA can recruit proteins that either physically
Conversely, demethylation, the removal of the methyl group from cytosine, is also an active process mediated