Hypothesis: RNA editing of microRNA target sites in humans?

Adenosine (A) to inosine (I) RNA editing occurs widely in the human transcriptome, and a large proportion of editing sites are within untranslated regions (UTRs). MicroRNAs (miRNAs), an abundant class of regulatory genes, specify the expression of a large number of target genes by pairing to their 3' UTRs. To study the interplay between these two post-transcriptional events, we developed a computational pipeline to integrate sequence and miRNA tissue specificity data. The results show that some A-to-I RNA editing positions have a potential to block the miRNA:target recognition, although further computational simulation suggests that RNA editing tends to avoid miRNA target sites in general. We propose that a small proportion of RNA editing events may provide an additional layer of control on miRNA-mediated repression. Further investigation is needed to elucidate the functional effect of these special RNA editing events.