Improving site-directed RNA editing in vitro and in cell culture by chemical modification of the guideRNA

Adenosine-to-inosine deamination can be re-addressed to user-defined mRNAs by applying phosphothioate/2'-methoxy-modified guideRNAs. Dense chemical modification of the guideRNA clearly improves performance of the covalent conjugates inside the living cell. Furthermore, careful positioning of a few modifications controls editing selectivity in vitro and was exploited for the challenging repair of the Factor 5 Leiden missense mutation.