Disruption of the Pseudomonas aeruginosa Tat system perturbs PQS-dependent quorum sensing and biofilm maturation through lack of the Rieske cytochrome bc(1) sub-unit

Soh, Eliza Ye-Chen1,2; Smith, Frances1,2; Gimenez, Maxime Remi3,4; Yang, Liang5,7; Vejborg, Rebecca Munk6; Fletcher, Matthew R.1,2; Halliday, Nigel1,2; Bleves, Sophie3; Heeb, Stephan1,2; Camara, Miguel R.1,2; Givskov, Michael5,6; Hardie, Kim R. R.1,2; Tolker-Nielsen, Tim6; Ize, Berengere R.3,4; Williams, Paul1,2

2021-08-01

10.1371/journal.ppat.1009425

PLoS Pathogens   影响因子和分区

1553-7366

1553-7374

["Extracellular DNA (eDNA) is a major constituent of the extracellular matrix of Pseudomonas aeruginosa biofilms and its release is regulated via pseudomonas quinolone signal (PQS) dependent quorum sensing (QS). By screening a P. aeruginosa transposon library to identify factors required for DNA release, mutants with insertions in the twin-arginine translocation (Tat) pathway were identified as exhibiting reduced eDNA release, and defective biofilm architecture with enhanced susceptibility to tobramycin. P. aeruginosa tat mutants showed substantial reductions in pyocyanin, rhamnolipid and membrane vesicle (MV) production consistent with perturbation of PQS-dependent QS as demonstrated by changes in pqsA expression and 2-alkyl-4-quinolone (AQ) production. Provision of exogenous PQS to the tat mutants did not return pqsA, rhlA or phzA1 expression or pyocyanin production to wild type levels. However, transformation of the tat mutants with the AQ-independent pqs effector pqsE restored phzA1 expression and pyocyanin production. Since mutation or inhibition of Tat prevented PQS-driven auto-induction, we sought to identify the Tat substrate(s) responsible. A pqsA::lux fusion was introduced into each of 34 validated P. aeruginosa Tat substrate deletion mutants. Analysis of each mutant for reduced bioluminescence revealed that the primary signalling defect was associated with the Rieske iron-sulfur subunit of the cytochrome bc(1) complex. In common with the parent strain, a Rieske mutant exhibited defective PQS signalling, AQ production, rhlA expression and eDNA release that could be restored by genetic complementation. This defect was also phenocopied by deletion of cytB or cytC(1). Thus, either lack of the Rieske sub-unit or mutation of cytochrome bc(1) genes results in the perturbation of PQS-dependent autoinduction resulting in eDNA deficient biofilms, reduced antibiotic tolerance and compromised virulence factor production.","Author summary Pseudomonas aeruginosa is a highly adaptable human pathogen responsible for causing chronic biofilm-associated infections. Biofilms are highly refractory to host defences and antibiotics and thus difficult to eradicate. The biofilm extracellular matrix incorporates extracellular DNA (eDNA). This stabilizes biofilm architecture and helps confer tolerance to antibiotics. Since mechanisms that control eDNA release are not well understood, we screened a P. aeruginosa mutant bank for strains with defects in eDNA release and discovered a role for the twin-arginine translocation (Tat) pathway that exports folded proteins across the cytoplasmic membrane. Perturbation of the Tat pathway resulted in defective biofilms susceptible to antibiotic treatment as a consequence of perturbed pseudomonas quinolone (PQS) signalling. This resulted in the failure to produce or release biofilm components including eDNA, phenazines and rhamnolipids as well as microvesicles. Furthermore, we discovered that perturbation of PQS signalling was a consequence of the inability of tat mutants to translocate the Rieske subunit of the cytochrome bc(1) complex involved in electron transfer and energy transduction. Given the importance of PQS signalling and the Tat system to virulence and biofilm maturation in P. aeruginosa, our findings underline the potential of the Tat system as a drug target for novel antimicrobial agents."]

SCI

英语

其他

Biotechnology and Biological Sciences Research Council (BBSRC), U.K.[BB/F014392/1] ; BBSRC/National Biofilms Innovation Centre[BB/R012415/1] ; Medical Research Council U.K.[MR/N501852/1] ; Wellcome Trust["103884/Z/14/Z","108876/Z/15/Z"] ; European Union FP7 collaborative action grant (NABATIVI)[223670] ; Gregory Lemarchal association[RF20140501138] ; Danish Strategic Research Council[9040-00023B] ; Danish Council for Independent Research[09-065732] ; Lundbeck Foundation, Denmark[2015-486]

Microbiology ; Parasitology ; Virology

Microbiology ; Parasitology ; Virology

WOS:000724026700004

PUBLIC LIBRARY SCIENCE

Web of Science

1.Univ Nottingham, Natl Biofilms Innovat Ctr, Biodiscovery Inst, Nottingham, England
2.Univ Nottingham, Sch Life Sci, Nottingham, England
3.CNRS, Inst Microbiol Mediterrane, UMR7255, Lab Ingn Syst Macromol LISM, Marseille, France
4.Aix Marseille Univ, Marseille, France
5.Nanyang Technol Univ, Singapore Ctr Environm Life Sci Engn, Singapore, Singapore
6.Univ Copenhagen, Dept Immunol & Microbiol, Costerton Biofilm Ctr, Fac Hlth Sci, Copenhagen, Denmark
7.Southern Univ Sci & Technol, Sch Med, Shenzhen, Guangdong, Peoples R China

Soh, Eliza Ye-Chen,Smith, Frances,Gimenez, Maxime Remi,et al. Disruption of the Pseudomonas aeruginosa Tat system perturbs PQS-dependent quorum sensing and biofilm maturation through lack of the Rieske cytochrome bc(1) sub-unit[J]. PLoS Pathogens,2021,17(8).

Soh, Eliza Ye-Chen.,Smith, Frances.,Gimenez, Maxime Remi.,Yang, Liang.,Vejborg, Rebecca Munk.,...&Williams, Paul.(2021).Disruption of the Pseudomonas aeruginosa Tat system perturbs PQS-dependent quorum sensing and biofilm maturation through lack of the Rieske cytochrome bc(1) sub-unit.PLoS Pathogens,17(8).

Soh, Eliza Ye-Chen,et al."Disruption of the Pseudomonas aeruginosa Tat system perturbs PQS-dependent quorum sensing and biofilm maturation through lack of the Rieske cytochrome bc(1) sub-unit".PLoS Pathogens 17.8(2021).