Chemoproteomic Profiling of 8‑Oxoguanosine-Sensitive RNA–Protein Interactions

Cellular nucleic acids are subject to assault by endogenous
and
exogenous agents that can perturb the flow of genetic information.
Oxidative stress leads to the accumulation of 8-oxoguanine (8OG) in
DNA and RNA. 8OG lesions on mRNA negatively impact translation, but
their effect on global RNA–protein interactions is largely
unknown. Here, we apply an RNA chemical proteomics approach to investigate
the effect of 8OG on RNA–protein binding. We find proteins
that bind preferentially to 8OG-modified RNA, including IGF2BP1–3
and hnRNPD, and proteins that are repelled by 8OG such as RBM4. We
characterize these interactions using biochemical and biophysical
assays to quantify the effect of 8OG on binding and show that a single
8OG abolishes the binding of RBM4 to its preferred CGG-containing
substrate. Taken together, our work establishes the molecular consequences
of 8OG on cellular RNA–protein binding and provides a framework
for interrogating the role of RNA oxidation in biological systems.