Although DNA methylation mechanisms were described for several decades ago, the enzymes responsible for DNA demethylation were only discovered a few years ago: TET enzymes catalyse the conversion of 5-methylcytosine
to 5-hydroxymethylcytosine (5hmC) through a reaction requiring oxygen and 2-oxoglutarate (2OG).
The discovery in 2009 (Tahiliani et al, 2009) that this enzyme can convert the DNA methylation mark 5-methylcytosine
(5mC) to 5-hydroxymethylcytosine (5hmC) helped to usher in a new field of research in epigenetics.
Tet proteins can convert 5-methylcytosine
to 5-formylcytosine and 5-carboxylcytosine.
org/content/early/2012/11/21/1217927109) "Structural genes of wheat and barley 5-methylcytosine
DNA glycosylases and their potential applications for human health.
It consists of the covalent addition of a methyl group to the 5 position of a cytosine to generate 5-methylcytosine
and occurs mostly in the context of cytosines that precede guanines, known as 5'-CpG-3' dinucleotides (Portela & Esteller, 2010).
content of DNA from human tumors.
Age Related Changes in 5-methylcytosine
Content in Human Peripheral Leukocytes and Placentas: An HPLC-Based Study, 68 ANNALS HUM.
The sodium bisulfite sequencing method, which distinguishes between methylated and unmethylated cytosine residues, will be used to assess 5-methylcytosine
levels in WI-38 fetal lung fibroblasts, a well-characterized system for studying aging and telomerase.
Participants with the highest cadmium exposures had significantly higher blood levels of the DNA methylation marker 5-methylcytosine
than people with lower cadmium measurements.
Methylation of DNA at the C5 position of cytosine to give 5-methylcytosine
(5-mC)  is one of the best-characterized epigenetic modifications and has been implicated in numerous biological processes, including embryogenesis, X-chromosome inactivation, genetic imprinting, and cellular differentiation (1,2).
Ten-eleven translocation (TET) proteins hydroxylate the 5-methylcytosine
during the demethylation process synthesizing 5-hydroxymethylcytosine (5hmC).
Alcohol-induced DNA damage and the resulting repair reactions can lead to demethylation of 5-methylcytosine
nucleotides (Chen et al.