RNA oxidation HOCl Complement

RNA oxidation by reactive oxygen species has become of major interest in vitro as well as in in vivo settings. We characterized dominant oxidation events and products of RNA oxidation by hypochlorous acid. In addition to extensive cytidine chlorination, the predominant reactivity led to 8-oxoguanosine as an intermediate, which was further oxidized, thereby acting as a scavenger in protecting adjacent residues from oxidation, and eventually resulting in an abasic site, or a derivative with similar reactivity. We show that, while conventional aniline treatment does not induce 8 oxoguanosine to undergo ?-elimination, prior alkaline treatment does. The ensuing method development now allows us to map and discriminate oxidized guanosine and abasic sites in transcriptomes. An in vivo application to yeast showed that oxidation of ribosomal RNA proceeds differently in living cells, than it does in pure RNA or isolated ribosomes.