1887

Abstract

exotoxin A (ETA) production depends on the virulence-factor regulator Vfr. Recent evidence indicates that the iron-starvation sigma factor PvdS also enhances ETA production through the ETA-regulatory gene . Mutants defective in , and , plasmids that overexpress these genes individually and transcriptional/translational fusion plasmids were utilized to examine the relationship between , and in regulating ETA production. ETA concentration and expression were reduced significantly in PAOΔ, but expression was not affected. Overexpression of Vfr produced a limited increase in ETA production in PAOΔ, but not PAOΔ. Additionally, overexpression of either RegA or PvdS did not enhance ETA production in PAOΔ. RT-PCR analysis showed that iron did not affect the accumulation of mRNA in PAO1. These results suggest that: (i) Vfr enhances expression in PAO1 both directly and indirectly through , but not through ; (ii) expression is not regulated by iron; and (iii) both Vfr and PvdS cooperate in the presence of RegA to achieve a maximum level of expression.

Loading

Article metrics loading...

/content/journal/micro/10.1099/mic.0.028373-0
2009-07-01
2019-09-23
Loading full text...

Full text loading...

/deliver/fulltext/micro/155/7/2265.html?itemId=/content/journal/micro/10.1099/mic.0.028373-0&mimeType=html&fmt=ahah

References

  1. Albus, A. M., Pesci, E. C., Runyen-Janecky, L. J., West, S. E. & Iglewski, B. H. ( 1997; ). Vfr controls quorum sensing in Pseudomonas aeruginosa. J Bacteriol 179, 3928–3935.
    [Google Scholar]
  2. Ambrosi, C., Leoni, L. & Visca, P. ( 2002; ). Different responses of pyoverdine genes to autoinduction in Pseudomonas aeruginosa and the group Pseudomonas fluorescensPseudomonas putida. Appl Environ Microbiol 68, 4122–4126.[CrossRef]
    [Google Scholar]
  3. Beare, P. A., For, R. J., Martin, L. W. & Lamont, I. L. ( 2003; ). Siderophore-mediated cell signalling in Pseudomonas aeruginosa: divergent pathways regulate virulence factor production and siderophore receptor synthesis. Mol Microbiol 47, 195–207.
    [Google Scholar]
  4. Bertani, I., Sevo, M., Kojic, M. & Venturi, V. ( 2003; ). Role of GacA, LasI, RhlI, Ppk, PsrA, Vfr and ClpXP in the regulation of the stationary-phase sigma factor rpoS/RpoS in Pseudomonas. Arch Microbiol 180, 264–271.[CrossRef]
    [Google Scholar]
  5. Carty, N. L., Rumbaugh, K. P. & Hamood, A. N. ( 2003; ). Regulation of toxA by PtxR in Pseudomonas aeruginosa PA103. Can J Microbiol 49, 450–464.[CrossRef]
    [Google Scholar]
  6. Carty, N. L., Layland, N., Colmer-Hamood, J. A., Calfee, M. W., Pesci, E. C. & Hamood, A. N. ( 2006; ). PtxR modulates the expression of QS-controlled virulence factors in the Pseudomonas aeruginosa strain PAO1. Mol Microbiol 61, 782–794.[CrossRef]
    [Google Scholar]
  7. Cunliffe, H. E., Merriman, T. R. & Lamont, I. L. ( 1995; ). Cloning and characterization of pvdS, a gene required for pyoverdine synthesis in Pseudomonas aeruginosa: PvdS is probably an alternative sigma factor. J Bacteriol 177, 2744–2750.
    [Google Scholar]
  8. Dasgupta, N., Ferrell, E. P., Kanack, K. J., West, S. E. & Ramphal, R. ( 2002; ). fleQ, the gene encoding the major flagellar regulator of Pseudomonas aeruginosa, is sigma70 dependent and is downregulated by Vfr, a homolog of Escherichia coli cyclic AMP receptor protein. J Bacteriol 184, 5240–5250.[CrossRef]
    [Google Scholar]
  9. Davis, P. B., Drumm, M. & Konstan, M. W. ( 1996; ). Cystic fibrosis. Am J Respir Crit Care Med 154, 1229–1256.[CrossRef]
    [Google Scholar]
  10. Fogle, M. R., Griswold, J. A., Oliver, J. W. & Hamood, A. N. ( 2002; ). Anti-ETA IgG neutralizes the effects of Pseudomonas aeruginosa exotoxin A. J Surg Res 106, 86–98.[CrossRef]
    [Google Scholar]
  11. Frank, D. W. ( 1997; ). The exoenzyme S regulon of Pseudomonas aeruginosa. Mol Microbiol 26, 621–629.[CrossRef]
    [Google Scholar]
  12. Frank, D. W., Storey, D. G., Hindahl, M. S. & Iglewski, B. H. ( 1989; ). Differential regulation by iron of regA and toxA transcript accumulation in Pseudomonas aeruginosa. J Bacteriol 171, 5304–5313.
    [Google Scholar]
  13. Gaines, J. M., Carty, N. L., Colmer-Hamood, J. A. & Hamood, A. N. ( 2005; ). Effect of static growth and different levels of environmental oxygen on toxA and ptxR expression in the Pseudomonas aeruginosa strain PAO1. Microbiology 151, 2263–2275.[CrossRef]
    [Google Scholar]
  14. Gaines, J. M., Carty, N. L., Tiburzi, F., Davinic, M., Visca, P., Colmer-Hamood, J. A. & Hamood, A. N. ( 2007; ). Regulation of the Pseudomonas aeruginosa toxA, regA and ptxR genes by the iron-starvation sigma factor PvdS under reduced levels of oxygen. Microbiology 153, 4219–4233.[CrossRef]
    [Google Scholar]
  15. Govan, J. R. & Deretic, V. ( 1996; ). Microbial pathogenesis in cystic fibrosis: mucoid Pseudomonas aeruginosa and Burkholderia cepacia. Microbiol Rev 60, 539–574.
    [Google Scholar]
  16. Hamood, A. N. & Iglewski, B. H. ( 1990; ). Expression of the Pseudomonas aeruginosa toxA positive regulatory gene (regA) in Escherichia coli. J Bacteriol 172, 589–594.
    [Google Scholar]
  17. Hamood, A. N., Griswold, J. A. & Duhan, C. M. ( 1996; ). Production of extracellular virulence factors by Pseudomonas aeruginosa isolates obtained from tracheal, urinary tract, and wound infections. J Surg Res 61, 425–432.[CrossRef]
    [Google Scholar]
  18. Hamood, A. N., Colmer-Hamood, J. A. & Carty, N. L. ( 2004; ). Regulation of Pseudomonas aeruginosa exotoxin A synthesis. In Pseudomonas: Virulence and Gene Regulation, pp. 389–423. Edited by J.-L. Ramos. New York: Kluwer Academic/Plenum.
  19. Hunt, T. A., Peng, W. T., Loubens, I. & Storey, D. G. ( 2002; ). The Pseudomonas aeruginosa alternative sigma factor PvdS controls exotoxin A expression and is expressed in lung infections associated with cystic fibrosis. Microbiology 148, 3183–3193.
    [Google Scholar]
  20. Iglewski, B. H. & Kabat, D. ( 1975; ). NAD-dependent inhibition of protein synthesis by Pseudomonas aeruginosa toxin. Proc Natl Acad Sci U S A 72, 2284–2288.[CrossRef]
    [Google Scholar]
  21. Kanack, K. J., Runyen-Janecky, L. J., Ferrell, E. P., Suh, S. J. & West, S. E. ( 2006; ). Characterization of DNA-binding specificity and analysis of binding sites of the Pseudomonas aeruginosa global regulator, Vfr, a homologue of the Escherichia coli cAMP receptor protein. Microbiology 152, 3485–3496.[CrossRef]
    [Google Scholar]
  22. Leoni, L., Orsi, N., de Lorenzo, V. & Visca, P. ( 2000; ). Functional analysis of PvdS, an iron starvation sigma factor of Pseudomonas aeruginosa. J Bacteriol 182, 1481–1491.[CrossRef]
    [Google Scholar]
  23. Liu, P. V. ( 1973; ). Exotoxins of Pseudomonas aeruginosa. I. Factors that influence the production of exotoxin A. J Infect Dis 128, 506–513.[CrossRef]
    [Google Scholar]
  24. Matsumoto, T., Furuya, N., Tateda, K., Miyazaki, S., Ohno, A., Ishii, Y., Hirakata, Y. & Yamaguchi, K. ( 1999; ). Effect of passive immunotherapy on murine gut-derived sepsis caused by Pseudomonas aeruginosa. J Med Microbiol 48, 765–770.[CrossRef]
    [Google Scholar]
  25. Miller, J. H. ( 1972; ). Experiments in Molecular Genetics. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory.
  26. Ochsner, U. A., Johnson, Z., Lamont, I. L., Cunliffe, H. E. & Vasil, M. L. ( 1996; ). Exotoxin A production in Pseudomonas aeruginosa requires the iron-regulated pvdS gene encoding an alternative sigma factor. Mol Microbiol 21, 1019–1028.[CrossRef]
    [Google Scholar]
  27. Ochsner, U. A., Wilderman, P. J., Vasil, A. I. & Vasil, M. L. ( 2002; ). GeneChip expression analysis of the iron starvation response in Pseudomonas aeruginosa: identification of novel pyoverdine biosynthesis genes. Mol Microbiol 45, 1277–1287.[CrossRef]
    [Google Scholar]
  28. Ohman, D. E., Sadoff, J. C. & Iglewski, B. H. ( 1980; ). Toxin A-deficient mutants of Pseudomonas aeruginosa PA103: isolation and characterization. Infect Immun 28, 899–908.
    [Google Scholar]
  29. Olsen, R. H., DeBusscher, G. & McCombie, W. R. ( 1982; ). Development of broad-host-range vectors and gene banks: self-cloning of the Pseudomonas aeruginosa PAO chromosome. J Bacteriol 150, 60–69.
    [Google Scholar]
  30. Palma, M., Worgall, S. & Quadri, L. E. ( 2003; ). Transcriptome analysis of the Pseudomonas aeruginosa response to iron. Arch Microbiol 180, 374–379.[CrossRef]
    [Google Scholar]
  31. Pollack, M. ( 2000; ). Pseudomonas aeruginosa. In Mandell, Douglas and Bennett's Principles and Practice of Infectious Diseases, pp. 2310–2335. Edited by G. L. Mandell, J. E. Bennett & R. Dolin. Philadelphia, PA: Churchill Livingstone.
  32. Raivio, T. L., Hoffer, D., Prince, R. W., Vasil, M. L. & Storey, D. G. ( 1996; ). Linker insertion scanning of regA, an activator of exotoxin A production in Pseudomonas aeruginosa. Mol Microbiol 22, 239–254.[CrossRef]
    [Google Scholar]
  33. Sambrook, J. & Russell, D. W. ( 2001; ). Molecular Cloning: a Laboratory Manual, 3rd edn. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory.
  34. Sato, H. & Frank, D. W. ( 2004; ). ExoU is a potent intracellular phospholipase. Mol Microbiol 53, 1279–1290.[CrossRef]
    [Google Scholar]
  35. Schweizer, H. P. ( 1991; ). EscherichiaPseudomonas shuttle vectors derived from pUC18/19. Gene 97, 109–121.[CrossRef]
    [Google Scholar]
  36. Smith, A. W. & Iglewski, B. H. ( 1989; ). Transformation of Pseudomonas aeruginosa by electroporation. Nucleic Acids Res 17, 10509 [CrossRef]
    [Google Scholar]
  37. Sobel, M. L., McKay, G. A. & Poole, K. ( 2003; ). Contribution of the MexXY multidrug transporter to aminoglycoside resistance in Pseudomonas aeruginosa clinical isolates. Antimicrob Agents Chemother 47, 3202–3207.[CrossRef]
    [Google Scholar]
  38. Spaink, H. P., Okker, R. J. H., Wijffelman, C. A., Pees, E. & Lugtenberg, B. J. J. ( 1987; ). Promoters in the nodulation region of the Rhizobium leguminosarum Sym plasmid pRL1J1. Plant Mol Biol 9, 27–39.[CrossRef]
    [Google Scholar]
  39. Stachel, S. E., An, G., Flores, C. & Nester, E. W. ( 1985; ). A Tn3 lacZ transposon for the random generation of β-galactosidase gene fusions: application to the analysis of gene expression in Agrobacterium. EMBO J 4, 891–898.
    [Google Scholar]
  40. Storey, D. G., Frank, D. W., Farinha, M. A., Kropinski, A. M. & Iglewski, B. H. ( 1990; ). Multiple promoters control the regulation of the Pseudomonas aeruginosa regA gene. Mol Microbiol 4, 499–503.[CrossRef]
    [Google Scholar]
  41. Storey, D. G., Ujack, E. E., Rabin, H. R. & Mitchell, I. ( 1998; ). Pseudomonas aeruginosa lasR transcription correlates with the transcription of lasA, lasB, and toxA in chronic lung infections associated with cystic fibrosis. Infect Immun 66, 2521–2528.
    [Google Scholar]
  42. Vasil, M. L. & Ochsner, U. A. ( 1999; ). The response of Pseudomonas aeruginosa to iron: genetics, biochemistry and virulence. Mol Microbiol 34, 399–413.[CrossRef]
    [Google Scholar]
  43. Walker, S. L., Hiremath, L. S. & Galloway, D. R. ( 1995; ). ToxR (RegA) activates Escherichia coli RNA polymerase to initiate transcription of Pseudomonas aeruginosa toxA. Gene 154, 15–21.[CrossRef]
    [Google Scholar]
  44. West, S. E., Kaye, S. A., Hamood, A. N. & Iglewski, B. H. ( 1994a; ). Characterization of Pseudomonas aeruginosa mutants that are deficient in exotoxin A synthesis and are altered in expression of regA, a positive regulator of exotoxin A. Infect Immun 62, 897–903.
    [Google Scholar]
  45. West, S. E., Sample, A. K. & Runyen-Janecky, L. J. ( 1994b; ). The vfr gene product, required for Pseudomonas aeruginosa exotoxin A and protease production, belongs to the cyclic AMP receptor protein family. J Bacteriol 176, 7532–7542.
    [Google Scholar]
  46. Wilson, M. J., McMorran, B. J. & Lamont, I. L. ( 2001; ). Analysis of promoters recognized by PvdS, an extracytoplasmic-function sigma factor protein from Pseudomonas aeruginosa. J Bacteriol 183, 2151–2155.[CrossRef]
    [Google Scholar]
  47. Wolfgang, M. C., Lee, V. T., Gilmore, M. E. & Lory, S. ( 2003; ). Coordinate regulation of bacterial virulence genes by a novel adenylate cyclase-dependent signaling pathway. Dev Cell 4, 253–263.[CrossRef]
    [Google Scholar]
  48. Woods, D. E. & Vasil, M. L. ( 1994; ). Pathogenesis of Pseudomonas aeruginosa infections. In Pseudomonas aeruginosa: Infections and Treatment, pp. 21–50. Edited by A. L. Baltch & R. P. Smith. New York: Marcel Dekker.
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/mic.0.028373-0
Loading
/content/journal/micro/10.1099/mic.0.028373-0
Loading

Data & Media loading...

vol. , part 7, pp. 2265 – 2273

Overexpression of Vfr does not enhance ETA production in PAOΔ [ PDF] (157 KB)



PDF
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error