Wellcome Principal Research Fellow, Professor of RNA Biology and Director, Wellcome Centre for Cell Biology
David Tollervey studied for a BSc in Microbiology in Edinburgh and then for a PhD in Genetics at Cambridge in the lab of Herb Arst. He then moved to the University of California, San Francisco, as a postdoctoral fellow in the laboratory of Christine Guthrie. In 1983 he relocated to a permanent post at the Institut Pasteur in Paris, which he left in 1988 to move to the European Molecular Biology Laboratory (EMBL) in Heidelberg as a group leader. He returned to Edinburgh in 1997 as Professor of RNA Biology and a Wellcome Trust Principal Research Fellow. Since 2011 he has served as Director of the Wellcome Centre for Cell Biology. He is a Fellow of the Royal Society, and of the Royal Society of Edinburgh, a member of EMBO and Past President of the international RNA Society. The aim of the Tollervey group is to understand the nuclear pathways that process newly transcribed RNAs and assemble RNA-protein complexes, the mechanisms that regulate these pathways and the surveillance activities that monitor their fidelity. His current research combines in vivo UV crosslinking and high-throughput sequencing to precisely identify sites of RNA-protein interaction and RNA-RNA basepairing, with genetics, biochemistry, transcriptomics and bioinformatics.
With the arrival of the COVID-19 pandemic, we have commenced work on SARS-CoV-2: https://spark.adobe.com/page/wl1eLDI6JEind/
Nuclear RNA processing and surveillance
We aim to understand the nuclear pathways that synthesise and process newly transcribed RNAs, the assembly of RNAprotein complexes and the surveillance activities that monitor their fidelity. RNA-binding proteins have important functions at all steps in gene expression, including transcription, RNA processing and mRNA translation. Defects in RNA-binding proteins underpin a large number of genetic diseases. However, mutations in proteins with “housekeeping” functions in RNA biology frequently generate tissue-specific disease phenotypes. We speculate that this reflects indirect, synergistic negative interactions between the precise molecular defect and wider, tissue-specific differences in RNA metabolism. To better understand this phenomenon, we developed a set of new techniques based on total RNA-associated protein purification (TRAPP) (Ref. 1). We are currently using TRAPP to determine the roles of altered RNA-protein interactions in the response to environmental stresses and the signalling pathways involved in driving these changes.
An outstanding question in nuclear RNA surveillance is how “defective” RNAs are identified and targeted for degradation. During surveillance, the RNA exosome functions together with the TRAMP complexes (Ref. 2). These include the DEAH-box RNA helicase Mtr4 together with an RNA-binding protein (Air1 or Air2) and a poly(A) polymerase (Trf4 or Trf5). To better determine how RNA substrates are targeted, we combined biochemistry, genetics and genomics, identifying three distinct TRAMP complexes formed in yeast, which preferentially assemble on different classes of transcripts. Surprisingly, the results indicate major roles for the poly(A) polymerases Trf4 and Trf5 in TRAMP targeting and recruitment, and a specific role for Trf5 in mRNA stability.
Transcription elongation rates are important for RNA processing, but sequence-specific regulation is poorly understood. Notably, elongation by RNA polymerases is only weakly processive, being based on a Brownian Ratchet rather than an energy-driven mechanism. To analyse RNA polymerase I elongation in S.cerevisiae (Ref. 3) we combined in vivo RNAPI profiling, in vitro biochemical analyses and a quantitative, mechanistic model of transcription elongation. Unexpectedly, these revealed that folding of the nascent pre-rRNA close to the transcribing polymerase has a major effect on the elongation rate, with a modest contribution from the stability of the RNA-DNA duplex in the active site (Figure). RNAPI from S.pombe was similarly sensitive to transcript folding, as were S.cerevisiae RNAPII and RNAPIII. For RNAPII, unstructured RNA, which favours slowed elongation, was associated with faster cotranscriptional splicing and proximal splice site usage, indicating regulatory significance for transcript folding.
Shchepachev, V., Bresson, S., Spanos, C., Petfalski, P., Fischer, L., Rappsilber, J. and Tollervey, D. (2019) Defining the RNA Interactome by Total RNA-Associated Protein Purification. Mol. Sys. Biol. 15, e8689. PMCID: PMC6452921
Delan-Forino, C., Spanos, C., Rappsilber, J. and Tollervey, D. (2020) Substrate Specificity of the TRAMP Nuclear Surveillance Complexes. BioRxiv.
Turowski, T.W. Petfalski, E., Goddard, B.D., French, S.L., Helwak, A., Tollervey, D. (2020) Nascent transcript folding plays a major role in determining RNA polymerase elongation rates. BioRxiv.
The contribution of different factors to the RNA polymerase elongation rate, which is important for folding, packaging and processing of the nascent transcript.