5-hydroxymethyl C

FULL NAME: 5-hydroxymethylcytosine (HMC)

5-hydroxymethylcytosine is a DNA pyrimidine nitrogen base. It is formed from the DNA base cytosine by adding a methyl group and then a hydroxy group. It is important in epigenetics, because the hydroxymethyl group on the cytosine can possibly switch a gene on and off. It was first seen in bacteriophages in 1952. However, it was recently found to be abundant in human and mouse brains, as well as in embryonic stem cells. In mammals, it can be generated by oxidation of 5-methylcytosine, a reaction mediated by the Tet family of enzymes. Its molecular formula is C5H7N3O2. Every mammalian cell seems to contain 5-Hydroxymethylcytosine, but the levels vary significantly depending on the cell type. The highest levels are found in neuronal cells of the central nervous system. The amount of hydroxymethylcytosine increases with age, as shown in mouse hippocampus and cerebellum.

DAMAGE TYPE: epigenetic modification (no DAMAGE)

no mutagenesis

Last modification date: Nov. 6, 2012