RNA Editing Ligase 1 and F1-ATPase as novel drug targets for veterinary diseases caused by trypanosomatid parasites

Supervisors: Achim Schnaufer, Atlanta Cook

Project Description:

The goal of this project is to exploit the unique and essential functions of mitochondrial RNA editing and F1-ATPase in trypanosomatid parasites as targets for the identification of much-needed new drugs. Our validation of Trypanosoma brucei RNA editing ligase 1 (TbREL1) and F1-ATPase as drug targets (Schnaufer et al., 2001; 2005), and the availability of a high-resolution crystal structures (Deng et al., 2004; Montgomery et al., 2018) and high-throughput screening assays make these enzymes promising and ripe targets for drug discovery efforts.

The protist parasites Trypanosoma congolense, T. vivax and T. brucei brucei are responsible for devastating economic loss by causing disease in livestock (http://www.fao.org/ag/againfo/programmes/en/paat/home.html). All trypanosomatids are characterised by unusual mitochondrial biology. For example, they require a unique form of RNA editing for mitochondrial gene expression; a key enzyme in this process is REL1 (Schnaufer et al., 2001). Also, T. brucei uses the mitochondrial F1-ATPase not to generate ATP, but as an essential proton pump (Schnaufer et al., 2005). Orthologues of these enzymes in T. congolense, T. vivax and T. brucei are virtually identical, which offers exciting potential for the development of inhibitors with broad anti-trypanosomatid activity. We recently carried out a number of high-throughput screens for small molecule inhibitors of REL1 and F1-ATPase, and we identified and confirmed numerous structurally diverse inhibitors with low-micromolar IC50 values.

This PhD project will involve participating in further hit identification and in hit-to-lead development, specifically testing inhibitors in vitro (activity assays; biophysical characterisation using ITC and surface plasmon resonance; toxicology studies) and in vivo (against trypanosomes and control cells) and structural analysis of target-inhibitor complexes by crystallography, cryo-EM and/or computational predictions. Key collaborators on this project are Dr Atlanta Cook (2nd supervisor; Wellcome Centre for Cell Biology), an expert in the structural analysis of proteins, Prof Manfred Auer, an expert in chemical biology (Centre for Systems Biology), and Prof Asier Unciti-Broceta (Edinburgh Cancer Research UK Centre), an expert in medicinal chemistry. The combined expertise of the collaborating labs provides an ideal environment for the interdisciplinary training of PhD students.

Key references:
Schnaufer A, Panigrahi AK, Panicucci B, Igo RP Jr, Salavati R, Stuart K (2001). An RNA ligase essential for RNA editing and survival of the bloodstream form of Trypanosoma brucei. Science 291:2159-62.
Schnaufer A, Clark-Walker GD, Steinberg AG, Stuart K (2005).The F1-ATP synthase complex in bloodstream stage trypanosomes has an unusual and essential function. EMBO J 24(23):4029-40.
Deng J, Schnaufer A, Salavati R, Stuart KD, Hol WG (2004). High resolution crystal structure of a key editosome enzyme from Trypanosoma brucei: RNA editing ligase 1. J Mol Biol 343(3):601-13.
Montgomery MG, Gahura O, Leslie AGW, Zíková A, Walker JE (2018). ATP synthase from Trypanosoma brucei has an elaborated canonical F1-domain and conventional catalytic sites. Proc Natl Acad Sci USA 115(9):2102-2107.

If you wish to apply for this project, please go to this link.