Site-directed RNA editing with endogenous ADARs

• Applicant: Professor Dr. Thorsten Stafforst
• Subject Area: Biochemistry
• Term: from 2019 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 428802479

Site-directed RNA editing is a novel approach to manipulate genetic information at the RNA level. Currently, the biggest unmet challenge is to achieve high editing yields while keeping off-target editing low. In this project, we focus on the recruitment of endogenous ADARs for site-directed RNA editing. This strategy has two major advantages, as we have recently demonstrated: a) reprogramming genetic information solely requires administration/expression of a short RNA (analog), thus is technically very simple, and b): the off-targted issue has been solved since no hyperactive deaminase needs to be ectopically overexpressed. Nevertheless, the current methods are yet far from being optimal and result in too little editing efficiency at endogenous transcripts. In project A), we aim to recruit endogenous ADAR with a conceptually new, multivalent and genetically encodable guideRNA design to edit endogenous transcripts efficiently, which was not yet possible. We further aim to deliver such guides virally to prepare for the in vivo application. In part B), we recruit endogenous ADARs with chemically stabilised antisense oligonucleotides. Again, we start from a new design, which is much smaller than the preceding one and which may allow us to achieve much higher editing efficiencies by recruiting a more apropriate ADAR isoform. In part C), we aim to apply the guideRNAs and ASOs from part A) and B) for in vivo editing in mice. The latter is a key technology to establish in our lab with regard to study the full therapeutic potential of this technology in the future.

• DFG Programme: Research Grants