Pseudomonas aeruginosa LasI/RhlI quorum sensing system controls protease-mediated autoaggregation behavior, cell envelope characteristics and extracellular proteome responses

Description Using Pseudomonas aeruginosa PA14 bacterial strain, we determined the contribution of the master regulator LasI/RhlI of Quorum sensing system (QS) to extracellular proteome responses quantitative mass spectrometry-based proteomics and bioinformatics. The LasI/RhlI QS system perturbed the extracellular abundance of a total of 545 extracellular proteins during late exponential and early stationary growth phases. We allocated most of these differentially expressed proteins to the following large functional groups: metabolism; transcription and translation; transport and secretion systems; cell envelope integrity; redox processes; invasiveness and toxicity; and motility. Remarkably, about 95% of the extracellular proteome was upregulated in the lasI-/rhlI- mutant in comparison to the wild type and returned to wild type-status when AHL was added.