Skip to main content
NCBI home page
Journal of Bacteriology logoLink to Journal of Bacteriology
. 1996 Oct;178(20):5995–6000. doi: 10.1128/jb.178.20.5995-6000.1996

Functional analysis of the Pseudomonas aeruginosa autoinducer PAI.

L Passador 1, K D Tucker 1, K R Guertin 1, M P Journet 1, A S Kende 1, B H Iglewski 1
PMCID: PMC178457  PMID: 8830697

Abstract

A series of structural analogs of the Pseudomonas aeruginosa autoinducer [PAI, N-3-oxo-dodecanoyl homoserine lactone] were obtained and tested for their ability to act as autoinducers in stimulating the expression of the gene for elastase (lasB) by measuring beta-galactosidase production from a lasB-lacZ gene fusion in the presence of the transcriptional activator LasR. The data suggest that the length of the acyl side chain of the autoinducer molecule is the most critical factor for activity. Replacement of the ring O by S in the homoserine lactone moiety can be tolerated. Tritium-labelled PAI ([3H]PAI) was synthesized and used to demonstrate the association of [3H]PAI with cells overexpressing LasR. The PAI analogs were also tested for their ability to compete with [3H]PAI for binding of LasR. Results from the competition assays suggest that once again the length of the acyl side chain appears to be crucial for antagonist activity. The presence of the 3-oxo moiety also plays a significant role in binding since analogs which lacked this moiety were much less effective in blocking binding of [3H]PAI. All analogs demonstrating competition with PAI in binding to LasR also exhibited the ability to activate lasB expression, suggesting that they are functional analogs of PAI.

Full Text

The Full Text of this article is available as a PDF (228.5 KB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Chhabra S. R., Stead P., Bainton N. J., Salmond G. P., Stewart G. S., Williams P., Bycroft B. W. Autoregulation of carbapenem biosynthesis in Erwinia carotovora by analogues of N-(3-oxohexanoyl)-L-homoserine lactone. J Antibiot (Tokyo) 1993 Mar;46(3):441–454. doi: 10.7164/antibiotics.46.441. [DOI] [PubMed] [Google Scholar]
  2. Eberhard A., Widrig C. A., McBath P., Schineller J. B. Analogs of the autoinducer of bioluminescence in Vibrio fischeri. Arch Microbiol. 1986 Oct;146(1):35–40. doi: 10.1007/BF00690155. [DOI] [PubMed] [Google Scholar]
  3. Fuqua W. C., Winans S. C., Greenberg E. P. Quorum sensing in bacteria: the LuxR-LuxI family of cell density-responsive transcriptional regulators. J Bacteriol. 1994 Jan;176(2):269–275. doi: 10.1128/jb.176.2.269-275.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Gambello M. J., Iglewski B. H. Cloning and characterization of the Pseudomonas aeruginosa lasR gene, a transcriptional activator of elastase expression. J Bacteriol. 1991 May;173(9):3000–3009. doi: 10.1128/jb.173.9.3000-3009.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Gambello M. J., Kaye S., Iglewski B. H. LasR of Pseudomonas aeruginosa is a transcriptional activator of the alkaline protease gene (apr) and an enhancer of exotoxin A expression. Infect Immun. 1993 Apr;61(4):1180–1184. doi: 10.1128/iai.61.4.1180-1184.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Gilson L., Kuo A., Dunlap P. V. AinS and a new family of autoinducer synthesis proteins. J Bacteriol. 1995 Dec;177(23):6946–6951. doi: 10.1128/jb.177.23.6946-6951.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Gray K. M., Passador L., Iglewski B. H., Greenberg E. P. Interchangeability and specificity of components from the quorum-sensing regulatory systems of Vibrio fischeri and Pseudomonas aeruginosa. J Bacteriol. 1994 May;176(10):3076–3080. doi: 10.1128/jb.176.10.3076-3080.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Hanzelka B. L., Greenberg E. P. Evidence that the N-terminal region of the Vibrio fischeri LuxR protein constitutes an autoinducer-binding domain. J Bacteriol. 1995 Feb;177(3):815–817. doi: 10.1128/jb.177.3.815-817.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Hwang I., Li P. L., Zhang L., Piper K. R., Cook D. M., Tate M. E., Farrand S. K. TraI, a LuxI homologue, is responsible for production of conjugation factor, the Ti plasmid N-acylhomoserine lactone autoinducer. Proc Natl Acad Sci U S A. 1994 May 24;91(11):4639–4643. doi: 10.1073/pnas.91.11.4639. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Kuo A., Blough N. V., Dunlap P. V. Multiple N-acyl-L-homoserine lactone autoinducers of luminescence in the marine symbiotic bacterium Vibrio fischeri. J Bacteriol. 1994 Dec;176(24):7558–7565. doi: 10.1128/jb.176.24.7558-7565.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Linn T., St Pierre R. Improved vector system for constructing transcriptional fusions that ensures independent translation of lacZ. J Bacteriol. 1990 Feb;172(2):1077–1084. doi: 10.1128/jb.172.2.1077-1084.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. McKenney D., Brown K. E., Allison D. G. Influence of Pseudomonas aeruginosa exoproducts on virulence factor production in Burkholderia cepacia: evidence of interspecies communication. J Bacteriol. 1995 Dec;177(23):6989–6992. doi: 10.1128/jb.177.23.6989-6992.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Ochsner U. A., Koch A. K., Fiechter A., Reiser J. Isolation and characterization of a regulatory gene affecting rhamnolipid biosurfactant synthesis in Pseudomonas aeruginosa. J Bacteriol. 1994 Apr;176(7):2044–2054. doi: 10.1128/jb.176.7.2044-2054.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Ochsner U. A., Reiser J. Autoinducer-mediated regulation of rhamnolipid biosurfactant synthesis in Pseudomonas aeruginosa. Proc Natl Acad Sci U S A. 1995 Jul 3;92(14):6424–6428. doi: 10.1073/pnas.92.14.6424. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Passador L., Cook J. M., Gambello M. J., Rust L., Iglewski B. H. Expression of Pseudomonas aeruginosa virulence genes requires cell-to-cell communication. Science. 1993 May 21;260(5111):1127–1130. doi: 10.1126/science.8493556. [DOI] [PubMed] [Google Scholar]
  16. Passador L., Linn T. Autogenous regulation of the RNA polymerase beta subunit of Escherichia coli occurs at the translational level in vivo. J Bacteriol. 1989 Nov;171(11):6234–6242. doi: 10.1128/jb.171.11.6234-6242.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Pearson J. P., Gray K. M., Passador L., Tucker K. D., Eberhard A., Iglewski B. H., Greenberg E. P. Structure of the autoinducer required for expression of Pseudomonas aeruginosa virulence genes. Proc Natl Acad Sci U S A. 1994 Jan 4;91(1):197–201. doi: 10.1073/pnas.91.1.197. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Pearson J. P., Passador L., Iglewski B. H., Greenberg E. P. A second N-acylhomoserine lactone signal produced by Pseudomonas aeruginosa. Proc Natl Acad Sci U S A. 1995 Feb 28;92(5):1490–1494. doi: 10.1073/pnas.92.5.1490. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Ralling G., Bodrug S., Linn T. Growth rate-dependent regulation of RNA polymerase synthesis in Escherichia coli. Mol Gen Genet. 1985;201(3):379–386. doi: 10.1007/BF00331327. [DOI] [PubMed] [Google Scholar]
  20. Schaefer A. L., Hanzelka B. L., Eberhard A., Greenberg E. P. Quorum sensing in Vibrio fischeri: probing autoinducer-LuxR interactions with autoinducer analogs. J Bacteriol. 1996 May;178(10):2897–2901. doi: 10.1128/jb.178.10.2897-2901.1996. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Seed P. C., Passador L., Iglewski B. H. Activation of the Pseudomonas aeruginosa lasI gene by LasR and the Pseudomonas autoinducer PAI: an autoinduction regulatory hierarchy. J Bacteriol. 1995 Feb;177(3):654–659. doi: 10.1128/jb.177.3.654-659.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Throup J. P., Camara M., Briggs G. S., Winson M. K., Chhabra S. R., Bycroft B. W., Williams P., Stewart G. S. Characterisation of the yenI/yenR locus from Yersinia enterocolitica mediating the synthesis of two N-acylhomoserine lactone signal molecules. Mol Microbiol. 1995 Jul;17(2):345–356. doi: 10.1111/j.1365-2958.1995.mmi_17020345.x. [DOI] [PubMed] [Google Scholar]
  23. Toder D. S., Gambello M. J., Iglewski B. H. Pseudomonas aeruginosa LasA: a second elastase under the transcriptional control of lasR. Mol Microbiol. 1991 Aug;5(8):2003–2010. doi: 10.1111/j.1365-2958.1991.tb00822.x. [DOI] [PubMed] [Google Scholar]
  24. Winson M. K., Camara M., Latifi A., Foglino M., Chhabra S. R., Daykin M., Bally M., Chapon V., Salmond G. P., Bycroft B. W. Multiple N-acyl-L-homoserine lactone signal molecules regulate production of virulence determinants and secondary metabolites in Pseudomonas aeruginosa. Proc Natl Acad Sci U S A. 1995 Sep 26;92(20):9427–9431. doi: 10.1073/pnas.92.20.9427. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Zhang L., Murphy P. J., Kerr A., Tate M. E. Agrobacterium conjugation and gene regulation by N-acyl-L-homoserine lactones. Nature. 1993 Apr 1;362(6419):446–448. doi: 10.1038/362446a0. [DOI] [PubMed] [Google Scholar]

Articles from Journal of Bacteriology are provided here courtesy of American Society for Microbiology (ASM)

RESOURCES