Ralph Kleiner

Date: 

Thursday, October 20, 2022, 4:15pm to 5:15pm

Location: 

Pfizer Lecture Hall

Professor Ralph Kleiner, Princeton University. Title: Illuminating RNA biology with metabolically incorporated ribonucleoside probes. Woodward CCB Departmental Colloquium.

 

RNA plays a central role in biological processes and characterizing the regulatory mechanisms governing its behavior can reveal fundamental insights into gene expression programs in normal and disease contexts. Towards this end, our lab has developed general approaches based upon RNA metabolic labeling with artificial nucleoside probes in order to study RNA-associated processes transcriptome-wide in live cells and organisms. In the first part, we present RNA-mediated activity-based protein profiling (RNABPP), a chemoproteomic strategy using mechanism-based nucleosides that enables characterization of RNA modifying enzymes and their associated post-transcriptional RNA modifications. We apply RNABPP with diverse C5-modified pyrimidine nucleosides in order to identify RNA methyltransferase, dihydrouridine synthase, and dioxygenase enzymes. Further, we combine quantitative RNA mass spectrometry and modification-specific sequencing technologies in order to characterize the abundance and distribution of individual RNA modifications and understand their function in cellular processes. In the second part, we combine protein engineering of the nucleotide salvage pathway with bioorthogonal and fluorescent nucleoside chemistry to develop an approach for live-cell imaging of global RNA dynamics. We apply our method to study RNA trafficking and metabolism upon oxidative stress. Taken together, our work provides powerful and general strategies for interrogating RNA regulation and reveals the presence of novel mechanisms controlling RNA function in biological systems.