Transcriptome-wide profiling of A-to-I RNA editing by Slic-seq.

Adenosine-to-inosine (A-to-I) RNA editing is a post-transcriptional processing event involved in diversifying the transcriptome and is responsible for various biological processes. In this context, we developed a new method based on the highly selective cleavage activity of Endonuclease V against Inosine and the universal activity of sodium periodate against all RNAs to enrich the inosine-containing RNA and accurately identify the editing sites. We validated the reliability of our method in human brain in both Alu and non-Alu elements. The conserved sites of A-to-I editing in human cells (HEK293T, HeLa, HepG2, K562 and MCF-7) primarily occurs in the 3'UTR of the RNA, which are highly correlated with RNA binding and protein binding. Analysis of the editing sites between the human brain and mouse brain revealed that the editing of exons is more conserved than that in other regions. This method was applied to three neurological diseases (Alzheimer's, epilepsy and ageing) of mouse brain, reflecting that A-to-I editing sites significantly decreased in neuronal activity genes.