Formation and abundance of 5-hydroxymethylcytosine in RNA

Chembiochem. 2015 Mar 23;16(5):752-5. doi: 10.1002/cbic.201500013. Epub 2015 Feb 12.


RNA methylation is emerging as a regulatory RNA modification that could have important roles in the control and coordination of gene transcription and protein translation. Herein, we describe an in vivo isotope-tracing methodology to demonstrate that the ribonucleoside 5-methylcytidine (m(5)C) is subject to oxidative processing in mammals, forming 5-hydroxymethylcytidine (hm(5)C) and 5-formylcytidine (f(5)C). Furthermore, we have identified hm(5)C in total RNA from all three domains of life and in polyA-enriched RNA fractions from mammalian cells. This suggests m(5)C oxidation is a conserved process that could have critical regulatory functions inside cells.

Keywords: 5-hydroxymethylcytosine; 5-methylcytosine; LC-MS/MS; RNA modifications; isotope tracing.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 5-Methylcytosine / analogs & derivatives
  • Animals
  • Chromatography, High Pressure Liquid
  • Cytosine / analogs & derivatives*
  • Cytosine / biosynthesis
  • Cytosine / chemistry
  • Cytosine / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Molecular Structure
  • Oxidation-Reduction
  • RNA / chemistry*
  • RNA / metabolism*
  • Tandem Mass Spectrometry


  • 5-hydroxymethylcytosine
  • RNA
  • 5-Methylcytosine
  • Cytosine