Post-transcriptional regulation by cytosine-5 methylation of RNA.

The recent advent of high-throughput sequencing technologies coupled with RNA modifications detection methods has allowed the detection of RNA modifications at single nucleotide resolution giving a more comprehensive landscape of post-transcriptional gene regulation pathways. In this review, we focus on the occurrence of 5-methylcytosine (mC) in the transcriptome. We summarise the main findings of the molecular role in post-transcriptional regulation that governs mC deposition in RNAs. Functionally, mC deposition can regulate several cellular and physiological processes including development, differentiation and survival to stress stimuli. Despite many aspects concerning mC deposition in RNA, such as position or sequence context and the fact that many readers and erasers still remain elusive, the overall recent findings indicate that RNA cytosine methylation is a powerful mechanism to post-transcriptionally regulate physiological processes. In addition, mutations in RNA cytosine-5 methyltransferases are associated to pathological processes ranging from neurological syndromes to cancer.