Integrative cell biology of escherichia coli phage shock protein (Psp) response. (360G-Wellcome-080000_Z_06_Z)

The phage shock protein (Psp) F regulon genes are conserved in enterobacteria and are important in infectious processes including biofilm formation in Escherichia coli, swarming in Salmonella typhimurium, and virulence in Yersinia enterocolitica. The PspF regulon is induced in response to many membrane stresses, probably linked by their effect in dissipating the proton motive force (pmf) across the bacterial inner membrane. Psp proteins are thought to have a role in maintaining pmf. The precise mechanism by which Psp proteins carry out their effector functions and the nature of the signal transduction process required for Psp induction remains undetermined. We propose to: (i) study the signal transduction pathway upstream of Psp to determine how the inducing signal is transduced (ii) determine the mechanism by which Psp functions and visualise the localisation of Psp proteins to probethe importance of their in vivo organisation for function and (iii) study the role of Psp in pathogenic strains of E. coli and Citrobacter rodentium. It is anticipated that the results from this proposed work will lead to a better understanding of the signalling and function of the PspF regulon and in establishing its role in pathogenicity.