Ubiquitin conjugating enzymes as novel drug targets in Leishmania

Medical Research Scotland
PhD Studentship Award

This project is one of 15 PhD Studentships funded by Medical Research Scotland (http://www.medicalresearchscotland.org.uk) to be delivered jointly by the named University and Company. The Studentship will provide the first-class academic and commercial training needed to equip the successful candidate for a science career in an increasingly competitive market.

"Ubiquitin conjugating enzymes as novel drug targets in Leishmania" to be delivered by the University of Glasgow [Supervisors: Dr Richard Burchmore and Professor Jeremy Mottram (Institute of Infection, Immunology and Immunity)] and UbiQ (www.ubiqbio.com) [Company supervisor: Dr Boris Rodenko].

Leishmania parasites cause extensive morbidity, mortality, and economic hardship. Every year leishmaniasis affects 1.3 million people of which 20,000 die. Treatment is difficult as parasites evade the immune system by hiding in host blood cells. Without vaccines for use in humans, control relies on chemotherapy. Novel targets and drugs are urgently needed because current chemotherapy is limited, toxic and hampered by drug resistance. This project addresses this unmet medical need.

In eukaryotic cells the ubiquitination and deubiquitination balance, regulating e.g. protein degradation and trafficking and DNA repair is critical for maintaining cellular homeostasis. Ubiquitin is conjugated onto a target substrate via a cascade involving the consecutive action of ubiquitin activating enzymes (E1), ubiquitin conjugating enzymes (E2) and ubiquitin ligases (E3). The reverse reaction is executed by deubiquitinating enzymes (DUBs). Both ubiquitin conjugating enzymes and DUBs are emerging as drug targets, for example in oncology and neurodegenerative disease (1). UbiQ has developed activity-based probes that allow the visualisation of the activity of not only E1 (2, 3), but for the first time also E2 and E3 enzymes. This project aims to identify and validate these enzymes, present in Leishmania parasites, as drug targets.

The Leishmania genome predicts four E1, fourteen E2 and twenty E3 enzymes. However, the activity of most of these enzymes has not been confirmed and little is known about their function. In trypanosomes, one DUB has been validated as a tractable drug target, which initiated a full drug discovery programme run by the pharmaceutical company GSK. Key to this success was the combination of chemical biology and genomics and chemical proteomics involving the use of ubiquitin-based activity probes.

Project Objectives:
1) proteomic target identification: to profile and identify cysteine dependent E1, E2 and E3 enzymes active in Leishmania amastigotes in a chemical proteomic strategy using UbiQ’s activity-based probes.
2) to generate recombinant labelled fusion variants of leishmanial ubiquitinating enzymes in a heterologous expression system for drug screening purposes and raising antibodies for target localisation studies.
3) validation of target tractability: to test the efficacy and selectivity of UbiQ’s inhibitors of ubiquitinating enzymes on recombinant leishmanial ubiquitinating enzymes, on Leishmania cells and host cells and on in vitro models of leishmaniasis.

ENQUIRIES:

Enquiries should be sent by email to Dr Richard Burchmore:
[Email Address Removed]

APPLICATIONS:

Candidates must have obtained, or expect to obtain, a first or 2.1 UK honours degree, or equivalent for degrees obtained outside the UK, in biochemistry, biomedical sciences, pharmacology or a related area of biological sciences.

Applicants should send a CV, the contact details of 2 references (including email addresses) and a covering letter, explaining why the applicant is suitably qualified to carry out this project, by email to:
[Email Address Removed]

Interviews are expected to take place 3-4 weeks after the closing date for applications.

It is anticipated that the PhD Studentship will start in October 2016.