ToxR is a c-di-GMP binding protein that modulates surface-associated behaviour in Pseudomonas aeruginosa

Camara, Miguel; Dubern, Jean; Romero, Manuel; Mai-Prochnow, Anne; Messina, Marco; Trampari, Eleftheria; Gijzel, Hardeep Naghra-van; Chan, Kok-Gan; Carabelli, Alessandro; Barraud, Nicolas; Lazenby, James; Chen, Ye; Robertson, Shaun; Malone, Jacob; Williams, Paul; Heeb, Stephan

Abstract

Pseudomonas aeruginosa uses multiple protein regulators that work in tandem to control the production of a wide range of virulence factors and facilitate rapid adaptation to diverse environmental conditions. In this opportunistic pathogen, ToxR was known to positively regulate the production of the major virulence factor exotoxin A and now, through analysis of genetic changes between two sublines of P. aeruginosa PAO1 and functional complementation of swarming, we have identified a previously unknown role of ToxR in surface-associated motility in P. aeruginosa . Further analysis revealed that ToxR had an impact on swarming motility by regulating the Rhl quorum sensing system and subsequent production of rhamnolipid surfactants. Additionally, ToxR was found to tightly bind cyclic diguanylate (c-di-GMP) and negatively affect traits controlled by this second messenger including reducing biofilm formation and the expression of Psl and Pel exopolysaccharides, necessary for attachment and sessile communities’ matrix scaffolding, in P. aeruginosa . Moreover, a link between the post-transcriptional regulator RsmA and toxR expression via the alternative sigma factor PvdS, induced under iron-limiting conditions, is established. This study reveals the importance of ToxR in a novel sophisticated regulation of free-living and biofilm-associated lifestyles, appropriate for establishing acute or chronic P. aeruginosa infections.

Citation

Camara, M., Dubern, J., Romero, M., Mai-Prochnow, A., Messina, M., Trampari, E., …Heeb, S. (2022). ToxR is a c-di-GMP binding protein that modulates surface-associated behaviour in Pseudomonas aeruginosa. npj Biofilms and Microbiomes, 8, Article 64. https://doi.org/10.1038/s41522-022-00325-9

• Journal Article Type: Article
• Acceptance Date: Jul 26, 2022
• Online Publication Date: Aug 18, 2022
• Publication Date: Aug 18, 2022
• Deposit Date: Jul 29, 2022
• Publicly Available Date: Aug 25, 2022
• Journal: NPJ Biofilms and Microbiomes
• Peer Reviewed: Peer Reviewed
• Volume: 8
• Article Number: 64
• DOI: https://doi.org/10.1038/s41522-022-00325-9
• Public URL: https://nottingham-repository.worktribe.com/output/8398574
• Publisher URL: https://www.nature.com/articles/s41522-022-00325-9