The stringent response modulates 4-hydroxy-2-alkylquinoline biosynthesis and quorum-sensing hierarchy in Pseudomonas aeruginosa
| Autor: | James Schafhauser, Geoffrey McKay, Dao Nguyen, François Lépine, Malika Khakimova, Heather G. Ahlgren |
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| Přispěvatelé: | McGill University = Université McGill [Montréal, Canada], Institut Armand Frappier (INRS-IAF), Institut National de la Recherche Scientifique [Québec] (INRS)-Réseau International des Instituts Pasteur (RIIP) |
| Rok vydání: | 2014 |
| Předmět: |
Cell signaling
Stringent response Mutant Virulence Biology medicine.disease_cause MESH: Quorum Sensing Microbiology 03 medical and health sciences chemistry.chemical_compound Bacterial Proteins [SDV.MHEP.MI]Life Sciences [q-bio]/Human health and pathology/Infectious diseases medicine MESH: Bacterial Proteins Molecular Biology 030304 developmental biology Regulation of gene expression MESH: Gene Expression Regulation Bacterial 0303 health sciences 030306 microbiology Pseudomonas aeruginosa Rhamnolipid Quorum Sensing Gene Expression Regulation Bacterial Articles [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology Guanine Nucleotides Quorum sensing [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology chemistry MESH: Guanine Nucleotides MESH: Pseudomonas aeruginosa Quinolines MESH: Quinolines |
| Zdroj: | Journal of Bacteriology Journal of Bacteriology, American Society for Microbiology, 2014, 96 (9), pp.1641-1650. ⟨10.1128/JB.01086-13⟩ |
| ISSN: | 1098-5530 0021-9193 |
| DOI: | 10.1128/JB.01086-13⟩ |
| Popis: | As a ubiquitous environmental organism and an important human pathogen, Pseudomonas aeruginosa readily adapts and responds to a wide range of conditions and habitats. The intricate regulatory networks that link quorum sensing and other global regulators allow P. aeruginosa to coordinate its gene expression and cell signaling in response to different growth conditions and stressors. Upon nutrient transitions and starvation, as well as other environmental stresses, the stringent response is activated, mediated by the signal (p)ppGpp. P. aeruginosa produces a family of molecules called HAQ (4-hydroxy-2-alkylquinolines), some of which exhibit antibacterial and quorum-sensing signaling functions and regulate virulence genes. In this study, we report that (p)ppGpp negatively regulates HAQ biosynthesis: in a (p)ppGpp-null (ΔSR) mutant, HHQ (4-hydroxyl-2-heptylquinoline) and PQS (3,4-dihydroxy-2-heptylquinoline) levels are increased due to upregulated pqsA and pqsR expression and reduced repression by the rhl system. We also found that (p)ppGpp is required for full expression of both rhl and las AHL (acyl-homoserine lactone) quorum-sensing systems, since the ΔSR mutant has reduced rhlI , rhlR , lasI , and lasR expression, butanoyl-homoserine lactone (C 4 -HSL) and 3-oxo-dodecanoyl-homoserine lactone (3-oxo-C 12 -HSL) levels, and rhamnolipid and elastase production. Furthermore, (p)ppGpp significantly modulates the AHL and PQS quorum-sensing hierarchy, as the las system no longer has a dominant effect on HAQ biosynthesis when the stringent response is inactivated. |
| Databáze: | OpenAIRE |
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