DNA methylation is the addition of a methyl group to the DNA that happens at cytosine. The image shows a cytosine single ring base and a methyl group added on to the 5 carbon. In mammals, DNA methylation occurs almost exclusively at a cytosine that is followed by a guanine.

Active DNA demethylation refers to an enzymatic process that removes or modifies the methyl group from 5mC. By contrast, passive DNA demethylation refers to loss of 5mC during successive rounds of replication in the absence of functional DNA methylation maintenance machinery.

DNA demethylation is the process of removal of a methyl group from the nucleotide in a DNA residue that occurs either via oxidation or deamination. You might find these chapters and articles relevant to this topic. Jacob H. Goell, Isaac B. Hilton, in Trends in Biotechnology, 2021.

In this Perspective, we focus on recent reports that now identify enzymes capable of mediating DNA demethylation in mammalian cells. These findings raise the possibility that epigenetic regulation by DNA methylation is at times quite dynamic, providing exciting insights into why reprogramming of cell fates is possible.

In this review, we examine the enzymes involved in oxidative demethylation, which is mediated by the class of mononuclear Fe (II)-containing enzymes. Members of this class were discovered as DNA-repairing proteins that directly demethylate damaged DNA …

2013年10月23日 · Active DNA demethylation refers to an enzymatic process that removes or modifies the methyl group from 5mC. By contrast, passive DNA demethylation refers to loss of 5mC during successive...

2017年5月30日 · Active DNA demethylation is regulated at various levels, including substrate and cofactor availability, post-transcriptional and post-translational regulation of TET and TDG, and genomic...

DNA demethylation refers to the process of removing a methyl group from cytosines in DNA. This process can be either passive, occurring during DNA replication, or active, occurring independently of replication. It is used in cancer treatment to …

1999年3月26日 · DNA methylation patterns are generated during development by a sequence of methylation and demethylation events. We have recently demonstrated that mammals bear a bona fide demethylase enzyme that removes methyl groups from methylated cytosines.

Eukaryotic DNA methylation is performed by DNA-methyltransferases that catalyze transfer of a methyl group from S-adenosyl-l-methionine to carbon 5 of cytosine bases in DNA, giving rise to 5-methylcytosine (5-meC). Cytosine methylation is used as an epigenetic mark for maintenance of gene silencing across cellular divisions.