A-to-I RNA editing – thinking beyond the single nucleotide

ABSTRACT

Adenosine-to-inosine RNA editing is a conserved process, which is performed by ADAR enzymes. By changing nucleotides in coding regions of genes and altering codons, ADARs expand the cell's protein repertoire. This function of the ADAR enzymes is essential for human brain development. However, most of the known editing sites are in non-coding repetitive regions in the transcriptome and the purpose of editing in these regions is unclear. Recent studies, which have shown that editing levels of transcripts vary between tissues and developmental stages in many organisms, suggest that the targeted RNA and ADAR editing are both regulated. We discuss the implications of these findings, and the possible role of RNA editing in innate immunity.

KEYWORDS:

• ADAR
• RNAi
• dsRNA
• non-coding RNA
• Dicer

Acknowledgments

We thank Orna Ben-Naim Zgayer, Alla Fishman, and Noa Ben-Asher for critical reading of the manuscript. This work was funded by The Israeli Centers of Research Excellence (I-CORE) program, (Center No. 1796/12 to ATL), Israel Cancer Research Fund (ICRF), and the Binational Israel-USA Science Foundation (grant no. 2015091).