Deciphering the second messenger regulatory network(s) in Pseudomonas aeruginosa that control persistent infection. (360G-Wellcome-106063_Z_14_Z)

Biofilm formation by P. aeruginosa is central to its establishment of persistent infections, and is itself controlled by the nucleotide second messenger c-di-GMP. My proposed research builds upon work by the host laboratory that showed that the HD-GYP domain hydrolyses c-di-GMP and that all three proteins containing this domain in P. aeruginosa (PA2572, PA4108 and PA4781) have distinct and overlapping roles in biofilm formation and expression of virulence factors. I aim to dissect these signalli ng pathways utilising c-di-GMP and the HD-GYP domains, which are critical to the development of P. aeruginosa persistent infections. To achieve this I will address three questions: 1. What is the scope of regulation by HD-GYP domain proteins in P. aeruginosa? 2. How do PA2572, PA4108 and PA4781 exert their regulatory activity? 3. What is the mode of regulation of biofilm formation by PA2572, PA4108 and PA4781? Addressing these questions will establish the importance of the c-di-GMP signallin g pathway(s) in biofilm formation and other processes related to persistent infection, and could apply to other bacterial pathogens. Furthermore, elucidating the regulatory principles that control the development of biofilms during infection via the c-di-GMP system(s) will be invaluable for targeting the underlying molecular interactions and mechanisms pharmacologically.