Skip to main content

Research Repository

Advanced Search

The Pseudomonas aeruginosa Chp chemosensory system regulates intracellular cAMP levels by modulating adenylate cyclase activity

Fulcher, NB; Holliday, PM; Klem, E; Cann, MJ; Wolfgang, MC

Authors

NB Fulcher

PM Holliday

E Klem

MC Wolfgang



Abstract

Multiple virulence systems in the opportunistic pathogen Pseudomonas aeruginosa are regulated by the second messenger signalling molecule adenosine 3′, 5′-cyclic monophosphate (cAMP). Production of cAMP by the putative adenylate cyclase enzyme CyaB represents a critical control point for virulence gene regulation. To identify regulators of CyaB, we screened a transposon insertion library for mutants with reduced intracellular cAMP. The majority of insertions resulting in reduced cAMP mapped to the Chp gene cluster encoding a putative chemotaxis-like chemosensory system. Further genetic analysis of the Chp system revealed that it has both positive and negative effects on intracellular cAMP and that it regulates cAMP levels by modulating CyaB activity. The Chp system was previously implicated in the production and function of type IV pili (TFP). Given that cAMP and the cAMP-dependent transcriptional regulator Vfr control TFP biogenesis gene expression, we explored the relationship between cAMP, the Chp system and TFP regulation. We discovered that the Chp system controls TFP production through modulation of cAMP while control of TFP-dependent twitching motility is cAMP-independent. Overall, our data define a novel function for a chemotaxis-like system in controlling cAMP production and establish a regulatory link between the Chp system, TFP and other cAMP-dependent virulence systems.

Citation

Fulcher, N., Holliday, P., Klem, E., Cann, M., & Wolfgang, M. (2010). The Pseudomonas aeruginosa Chp chemosensory system regulates intracellular cAMP levels by modulating adenylate cyclase activity. Molecular Microbiology, 76(4), 889-904. https://doi.org/10.1111/j.1365-2958.2010.07135.x

Journal Article Type Article
Publication Date May 1, 2010
Deposit Date May 19, 2011
Journal Molecular Microbiology
Print ISSN 0950-382X
Electronic ISSN 1365-2958
Publisher Wiley
Peer Reviewed Peer Reviewed
Volume 76
Issue 4
Pages 889-904
DOI https://doi.org/10.1111/j.1365-2958.2010.07135.x