title: The elusive role of 5'-hydroxymethylcytosine.
abstract: 5'-hydroxymethylcytosine (5hmC) is a variant of the common covalent epigenetic modification of DNA 5'-methylcytosine (5mC). Although the presence of this modified base in mammalian DNA has been recognized for several decades, it has recently gained center stage as a suspected intermediate in enzymatic active demethylation of 5mC. The role of 5hmC remains elusive in spite of a large body of studies. It is proposed that 5hmC is a variant of the 5mC epigenetic signal and is involved in epigenetic regulation of gene function. Recent data support a role for 5hmC in the activation of lineage-specific enhancers.
authors.affiliation: Department of Pharmacology & Therapeutics, McGill University Medical School, 3655 Sir William Osler Promenade #1309, Montreal, QC, H3G 1Y6, Canada.
authors.forename: Moshe
authors.initials: M
authors.lastname: Szyf
mesh_terms: D044503:5-Methylcytosine / Q000031:analogs & derivatives* / Q000378:metabolism; D000818:Animals; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D006657:Histones / Q000378:metabolism; D006801:Humans; D010084:Oxidation-Reduction
chemical_list: D006657:Histones; C011865:5-hydroxymethylcytosine; D044503:5-Methylcytosine
keywords: DNA methylation; active demethylation; cellular differentiation; enhancers; global demethylation; hydroxymethylation; oxidases; stem cells