Post-synthetic modifications of nucleic acids have long been known to affect their functional and structural properties. For instance, numerous different chemical modifications modulate the structural organization, stability or translation efficiency of tRNAs and rRNAs. In contrast, little is known about modifications of poly(A)RNAs. Here, researchers from the Innsbruck Medical University, Austria demonstrate for the first time that the two well-studied regulatory long non-coding RNAs HOTAIR and XIST are targets of site-specific cytosine methylation. In both XIST and HOTAIR, they found methylated cytosines located within or near functionally important regions that are known to mediate interaction with chromatin-associated protein complexes. They show that cytosine methylation in the XIST A structure strongly affects binding to the chromatin-modifying complex PRC2 in vitro. These results suggest that cytosine methylation may serve as a general strategy to regulate the function of long non-coding RNAs.
- Amort T, Soulière MF, Wille A, Jia XY, Fiegl H, Wörle H, Micura R, Lusser A. (2013) Long non-coding RNAs as targets for cytosine methylation. RNA Biol 10(6). [Epub ahead of print]. [article]