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Expression of Pseudomonas aeruginosa exoS is controlled by quorum sensing and RpoS.
Microbiology (Reading). 2004 Apr; 150(Pt 4):843-851.M

Abstract

In Pseudomonas aeruginosa, virulence determinants and biofilm formation are coordinated via a hierarchical quorum sensing cascade, which involves the transcriptional regulators LasR and RhlR and their cognate homoserine lactone activators C12-HSL [N-(3-oxododecanoyl)-L-homoserine lactone] and c4-hsl (n-butanoyl-L-homoserine lactone), which are produced by LasI and RhlI, respectively. The exoenzyme S regulon of P. aeruginosa, comprises genes for a type III secretion system and for four anti-host effector proteins (ExoS, T, U and Y), which are translocated into host cells. It is a reasonable assumption that this ExoS regulon should be downregulated in the biofilm growth state and thus should also be under the regulatory control of the Las/Rhl system. Therefore, an exoS'-gfp reporter construct was used, and the influence of the Las and Rhl quorum sensing systems and the effect of the stationary-phase sigma factor RpoS on regulation of the exoS gene was examined. Evidence is provided for downregulation of exoS during biofilm formation of P. aeruginosa PAO1. The rhlI mutant PDO100 and rhlR mutant PDO111, but not the lasI mutant PDO-JP1, showed approximately twofold upregulation of the exoS'-gfp reporter in comparison to PAO1. Upregulation of exoS'-gfp in the PDO100 mutant could be repressed to normal level by adding C4-HSL autoinducer, indicating a negative regulatory effect of RhlR/C4-HSL on exoS expression. As RhlR/C4-HSL is also involved in regulation of RpoS, the P. aeruginosa rpoS mutant SS24 was examined and the exoS'-gfp reporter was found to be fivefold upregulated in comparison to PAO1. For the first time evidence is reported for a regulatory cascade linking RhlR/RhlI and RpoS with the expression of the anti-host effector ExoS, part of the exoenzyme S regulon. Moreover, these data suggest that the exoenzyme S regulon may be downregulated in P. aeruginosa biofilms.

Authors+Show Affiliations

Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Ludwig-Maximilians University Munich, Pettenkoferstraβe 9a, D-80336 Munich, Germany.Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Ludwig-Maximilians University Munich, Pettenkoferstraβe 9a, D-80336 Munich, Germany.Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Ludwig-Maximilians University Munich, Pettenkoferstraβe 9a, D-80336 Munich, Germany.Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Ludwig-Maximilians University Munich, Pettenkoferstraβe 9a, D-80336 Munich, Germany.Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Ludwig-Maximilians University Munich, Pettenkoferstraβe 9a, D-80336 Munich, Germany.

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

15073294

Citation

Hogardt, Michael, et al. "Expression of Pseudomonas Aeruginosa exoS Is Controlled By Quorum Sensing and RpoS." Microbiology (Reading, England), vol. 150, no. Pt 4, 2004, pp. 843-851.
Hogardt M, Roeder M, Schreff AM, et al. Expression of Pseudomonas aeruginosa exoS is controlled by quorum sensing and RpoS. Microbiology (Reading). 2004;150(Pt 4):843-851.
Hogardt, M., Roeder, M., Schreff, A. M., Eberl, L., & Heesemann, J. (2004). Expression of Pseudomonas aeruginosa exoS is controlled by quorum sensing and RpoS. Microbiology (Reading, England), 150(Pt 4), 843-851. https://doi.org/10.1099/mic.0.26703-0
Hogardt M, et al. Expression of Pseudomonas Aeruginosa exoS Is Controlled By Quorum Sensing and RpoS. Microbiology (Reading). 2004;150(Pt 4):843-851. PubMed PMID: 15073294.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Expression of Pseudomonas aeruginosa exoS is controlled by quorum sensing and RpoS. AU - Hogardt,Michael, AU - Roeder,Maximilian, AU - Schreff,Anna Maria, AU - Eberl,Leo, AU - Heesemann,Jürgen, PY - 2004/4/10/pubmed PY - 2004/7/10/medline PY - 2004/4/10/entrez SP - 843 EP - 851 JF - Microbiology (Reading, England) JO - Microbiology (Reading) VL - 150 IS - Pt 4 N2 - In Pseudomonas aeruginosa, virulence determinants and biofilm formation are coordinated via a hierarchical quorum sensing cascade, which involves the transcriptional regulators LasR and RhlR and their cognate homoserine lactone activators C12-HSL [N-(3-oxododecanoyl)-L-homoserine lactone] and c4-hsl (n-butanoyl-L-homoserine lactone), which are produced by LasI and RhlI, respectively. The exoenzyme S regulon of P. aeruginosa, comprises genes for a type III secretion system and for four anti-host effector proteins (ExoS, T, U and Y), which are translocated into host cells. It is a reasonable assumption that this ExoS regulon should be downregulated in the biofilm growth state and thus should also be under the regulatory control of the Las/Rhl system. Therefore, an exoS'-gfp reporter construct was used, and the influence of the Las and Rhl quorum sensing systems and the effect of the stationary-phase sigma factor RpoS on regulation of the exoS gene was examined. Evidence is provided for downregulation of exoS during biofilm formation of P. aeruginosa PAO1. The rhlI mutant PDO100 and rhlR mutant PDO111, but not the lasI mutant PDO-JP1, showed approximately twofold upregulation of the exoS'-gfp reporter in comparison to PAO1. Upregulation of exoS'-gfp in the PDO100 mutant could be repressed to normal level by adding C4-HSL autoinducer, indicating a negative regulatory effect of RhlR/C4-HSL on exoS expression. As RhlR/C4-HSL is also involved in regulation of RpoS, the P. aeruginosa rpoS mutant SS24 was examined and the exoS'-gfp reporter was found to be fivefold upregulated in comparison to PAO1. For the first time evidence is reported for a regulatory cascade linking RhlR/RhlI and RpoS with the expression of the anti-host effector ExoS, part of the exoenzyme S regulon. Moreover, these data suggest that the exoenzyme S regulon may be downregulated in P. aeruginosa biofilms. SN - 1350-0872 UR - https://www.unboundmedicine.com/medline/citation/15073294/Expression_of_Pseudomonas_aeruginosa_exoS_is_controlled_by_quorum_sensing_and_RpoS_ L2 - http://mic.microbiologyresearch.org/pubmed/content/journal/micro/10.1099/mic.0.26703-0 DB - PRIME DP - Unbound Medicine ER -