Analysis of post-translational modifications of proteins secreted by Pseudomonas aeruginosa

Theme: Bioscience for Health

Pseudomonas aeruginosa (PA) is an opportunistic human pathogen which causes disease by secreting a welter of tissue-degrading exoenzymes and toxins. Analysis of these secreted proteins by 2D gel electrophoresis reveals an interesting phenomenon; many secreted proteins (but few intracellular proteins) appear on 2D gels as so-called "charge trains". These charge trains are comprised of several discrete spots of a single protein which differ in charge, but not (discernibly, on 2D gels) mass. In fact, most secreted PA proteins appear as charge trains, yet nobody has chased up the molecular basis for these. It has been proposed that such charge trains are caused by the presence of protective modifications on the secreted proteins, and we speculate that these modifications are present to prevent the secreted proteins from self-degrading or being degraded by host proteases. However, we do not yet know what these chemical modifications are, what carries them out, where they are carried out, or whether they really do function as we propose. Clearly, if these modifications do act to protect the secretome, then if we prevent them from happening, the bacteria will be severely disadvantaged (thereby offering hope in terms of potential therapeutic intervention). The aim of the project will be to investigate the nature of these post-translational modifications in considerable detail, with a view to establishing what happens to the virulence of the pathogen if they are blocked.

ENWW:
- Integrating classical molecular microbiology and biochemistry with "big data" arising from functional genomic analyses.
- Finding new ways of interrogating large multi-'omic datasets using systems biology approaches and the tools of in silico modelling.
- Applying the tools and know how of chemical biology to address an un-met emerging problem in clinical microbiology.