Modulation of Pseudomonas aeruginosa Quorum Sensing by Glutathione

• Published in: Journal of bacteriology 2019-05, Vol.201 (9)
• Main Authors: Zhou, Hui, Wang, Meizhen, Smalley, Nicole E, Kostylev, Maxim, Schaefer, Amy L, Greenberg, E Peter, Dandekar, Ajai A, Xu, Feng
• Format: Article
• Language: English
• Subjects: Bacteria; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Bacteriology; Casein; Cell density; Chemical communication; Communications systems; Culture Media - chemistry; Density; Detection; DNA Mutational Analysis; Elastase; Energy sources; Glutathione; Glutathione - metabolism; Glutathione Synthase - genetics; Glutathione Synthase - metabolism; Information processing; Mutation; Organic chemistry; Oxidation-Reduction; Pathogens; Pseudomonas aeruginosa; Pseudomonas aeruginosa - drug effects; Pseudomonas aeruginosa - growth & development; Pseudomonas aeruginosa - metabolism; Quorum sensing; Quorum Sensing - drug effects; Redox properties; Regulators; RhlR protein; Serial Passage; Trans-Activators - metabolism; Transcription factors
• ISSN: 0021-9193; 1098-5530
• DOI: 10.1128/JB.00685-18

uses quorum sensing (QS) to regulate the production of a battery of secreted products. At least some of these products are shared among the population and serve as public goods. When is grown on casein as the sole carbon and energy source, the QS-induced extracellular protease elastase is required for growth. We isolated a variant, which showed increased production of QS-induced factors after repeated transfers in casein broth. This variant, QS*, had a mutation in the glutathione synthesis gene We describe several experiments that show a coding variant and glutathione affect the QS response. The QS transcription factor LasR has a redox-sensitive cysteine (C79). We report that GshA variant cells with a LasR C79S substitution show a similar QS response to that of wild-type Surprisingly, it is not LasR but the QS transcription factor RhlR that is more active in bacteria containing the variant Our results demonstrate that QS integrates information about cell density and the cellular redox state via glutathione levels. and other bacteria coordinate group behaviors using a chemical communication system called quorum sensing (QS). The QS system of is complex, with several regulators and signals. We show that decreased levels of glutathione lead to increased gene activation in , which did not occur in a strain carrying the redox-insensitive variant of a transcription factor. The ability of QS transcription factors to integrate information about cell density and cellular redox state shows these transcription factors can fine-tune levels of the gene products they control in response to at least two types of signals or cues.