Oxidative demethylation of 3-methylthymine and 3-methyluracil in single-stranded DNA and RNA by mouse and human FTO
- FEBS Lett. 2008 Oct 15;582(23-24):3313-9. doi: 10.1016/j.febslet.2008.08.019.
- 1. Department of Chemistry, The University of Chicago, 929 East 57th Street, Chicago, IL 60637, USA.
The human obesity susceptibility gene, FTO, encodes a protein that is homologous to the DNA repair AlkB protein. The AlkB family proteins utilize iron(II), alpha-ketoglutarate (alpha-KG) and dioxygen to perform oxidative repair of alkylated nucleobases in DNA and RNA. We demonstrate here the oxidative demethylation of 3-methylthymine (3-meT) in single-stranded DNA (ssDNA) and 3-methyluracil (3-meU) in single-stranded RNA (ssRNA) by recombinant human FTO protein in vitro. Both human and mouse FTO proteins preferentially repair 3-meT in ssDNA over Other base lesions tested. They showed negligible activities against 3-meT in double-stranded DNA (dsDNA). In addition, these two proteins can catalyze the demethylation of 3-meU in ssRNA with a slightly higher efficiency over that of 3-meT in ssDNA, suggesting that methylated RNAs are the preferred substrates for FTO.