Talk abstracts
Talk on Saturday 09:30-09:45am submitted by Jessica Willi
Rusty ribosomes: how oxidation damages rRNA and affects translation
Jessica Willi (Department of Chemistry and Biochemistry, University of Bern), Norbert Polacek (Department of Chemistry and Biochemistry, University of Bern), Pat A. Limbach (Department of Chemistry, University of Cincinnati)
Abstract:
Oxidative stress is emerging as a serious source of damage to RNA, which might contribute to numerous aspects of aging and diseases such as Alzheimer’s, Parkinson’s, Diabetes, and Huntington’s. Among all RNAs, the ribosomal RNA (rRNA) stands out for its central role in catalyzing protein synthesis.
We found that oxidative stress indeed damages rRNA and disrupts in vitro translation capabilities in a dose-dependent manner [1]. Using an established chemical engineering approach [2], we have introduced single base oxidations 8-oxorA, 8-oxorG, 5-HOrC and 5-HOrU into the catalytic heart of the ribosome, the peptidyl transferase center. This revealed how oxidation can influence ribosomal function: strength and type of the effect heavily depends on the position of the base oxidized, ranging from no effect to almost complete inhibition of translation [1].
Additionally, we employ immunoprecipitation sequencing (IP-Seq) and highly sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) [3] to quantify and map where rRNA oxidations occur both in vitro and in vivo. These oxidation maps enable us to link previous biochemical assays to biology and deepen our molecular understanding of the ribosomal machinery as well as how translation fails in age-related diseases.
References:
[1] Willi, J., Küpfer, P., Evéquoz, D., Fernandez, G., Katz, A., Leumann, C. & Polacek, N. Oxidative stress damages rRNA inside the ribosome and differentially affects the catalytic center. Nucleic Acids Res. 46, 1945–1957 (2018).
[2] Erlacher, M. D., Chirkova, A., Voegele, P. & Polacek, N. Generation of chemically engineered ribosomes for atomic mutagenesis studies on protein biosynthesis. Nat. Protoc. 6, 580–92 (2011).
[3] Limbach, P. A. & Paulines, M. J. Going global: the new era of mapping modifications in RNA. Wiley Interdiscip. Rev. RNA (2016).
Keywords: ribosome, oxidative stress, rRNA