Harnessing human ADAR2 for RNA repair - Recoding a PINK1 mutation rescues mitophagy.

Site-directed A-to-I RNA editing is a technology for re-programming genetic information at the RNA-level. We describe here the first design of genetically encodable guideRNAs that enable the re-addressing of human ADAR2 toward specific sites in user-defined mRNA targets. Up to 65% editing yield has been achieved in cell culture for the recoding of a premature Stop codon (UAG) into tryptophan (UIG). In the targeted gene, editing was very specific. We applied the technology to recode a recessive loss-of-function mutation in PINK1 (W437X) in HeLa cells and showed functional rescue of PINK1/Parkin-mediated mitophagy, which is linked to the etiology of Parkinson's disease. In contrast to other editing strategies, this approach requires no artificial protein. Our novel guideRNAs may allow for the development of a platform technology that requires only the administration or expression of a guideRNA to recode genetic information, with high potential for application in biology and medicine.