Chemoproteomic discovery of a human RNA ligase
Yizhi Yuan, Florian M. Stumpf, Lisa A. Schlor, Olivia P. Schmidt, Philip Saumer, Luisa B. Huber, Matthias Frese, Eva Höllmüller, Martin Scheffner, Florian Stengel, Kay Diederichs, Andreas Marx
Abstract
Abstract RNA ligases are present across all forms of life. While enzymatic RNA ligation between 5′-PO 4 and 3′-OH termini is prevalent in viruses, fungi, and plants, such RNA ligases are yet to be identified in vertebrates. Here, using a nucleotide-based chemical probe targeting human AMPylated proteome, we have enriched and identified the hitherto uncharacterised human protein chromosome 12 open reading frame 29 (C12orf29) as a human enzyme promoting RNA ligation between 5′-PO 4 and 3′-OH termini. C12orf29 catalyses ATP-dependent RNA ligation via a three-step mechanism, involving tandem auto- and RNA AMPylation. Knock-out of C12ORF29 gene impedes the cellular resilience to oxidative stress featuring concurrent RNA degradation, which suggests a role of C12orf29 in maintaining RNA integrity. These data provide the groundwork for establishing a human RNA repair pathway.