Objective In higher eukaryotes, the RNA polymerase III (Pol III) participates in the transcription of small RNAs such as the tRNAs. RNA polymerase recruitment to their specific promoter relies on the activity of several transcription factors. Brf2 is a transcription factor that exclusively recruits RNA Pol III at the selenocysteine tRNA (tRNASec). Unpublished work from our group has unravelled an unanticipated central role of Brf2 in the oxidative stress response pathway, by acting as a cellular blockade during prolonged oxidative stress.We are interested in understanding the molecular determinants that govern RNA Pol III recruitment at tRNASec promoter and its interaction with Brf2-bound promoters. In general, RNA Pol III subunit’s size is conserved amongst the eukaryotic kingdom. However, an exception is the human Rpc5 subunit, whose C terminus has 450 residues that are not present in its yeast counterpart C37. Similarly to Brf2, the Rpc5 C-terminal extension is only present in higher metazoans, which suggests a phylogenetic link between these two proteins. The recruiting mechanism of RNA Pol III to Brf2-dependent promoters has not been described to date. Preliminary results in our lab provide evidences that indeed Rpc5 C terminus is responsible for the accurate recruitment of RNA Pol III at TBP/Brf2/DNA complex. Interestingly, structural homology predictions indicated that the human Rpc5 C-terminal extension is a eukaryotic homologue of the prokaryotic protein SelB, a factor that interacts with the tRNASec and with a specific region of mRNAs, the SECIS-element, during translation of SeCys containing proteins. This similarity suggests a regulatory role for Rpc5 C terminus in the interaction with the SECIS-element and/or the tRNASec.Our main objectives are to determine the structure of the Rpc5 C terminus in isolation and in complex with Brf2/TBP/DNA by X-ray crystallography and to characterise the role of Rpc5 C terminus in the context of tRNASec transcription. Fields of science natural sciencesbiological sciencesgeneticsDNAnatural sciencesearth and related environmental sciencesgeologymineralogycrystallographymedical and health sciencesclinical medicineoncologynatural sciencesbiological sciencesgeneticsRNAnatural sciencesbiological sciencesbiochemistrybiomoleculesproteinsenzymes Programme(s) H2020-EU.1.3. - EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions Main Programme H2020-EU.1.3.2. - Nurturing excellence by means of cross-border and cross-sector mobility Topic(s) MSCA-IF-2014-EF - Marie Skłodowska-Curie Individual Fellowships (IF-EF) Call for proposal H2020-MSCA-IF-2014 See other projects for this call Funding Scheme MSCA-IF-EF-ST - Standard EF Coordinator INSTITUTE OF CANCER RESEARCH: THE ROYAL CANCER HOSPITAL LBG Net EU contribution € 183 454,80 Address Old brompton road 123 SW7 3RP London United Kingdom See on map Region London Inner London — West Kensington & Chelsea and Hammersmith & Fulham Activity type Higher or Secondary Education Establishments Links Contact the organisation Opens in new window Website Opens in new window Participation in EU R&I programmes Opens in new window HORIZON collaboration network Opens in new window Other funding € 0,00
