1887

Abstract

Hfq is a small RNA-binding protein involved in the post-transcriptional regulation of gene expression by affecting the stability of the mRNA and by mediating efficient pairing between small regulatory RNAs and their target mRNAs. In , the aetiological agent of Legionnaires’ disease, mutation of results in increased duration of the lag phase and reduced growth in low-iron medium. In an effort to uncover genes potentially regulated by Hfq, the transcriptome of an mutant strain was compared to that of the wild-type. Unexpectedly, many genes located within a 100 kb genomic island, including a section of the previously identified efflux island, were overexpressed in the mutant strain. Since this island contains a putative conjugative system and an integrase, it was postulated that it could be a new integrated mobile genetic element. PCR analysis revealed that this region exists both as an integrated and as an episomal form in the cell population and that it undergoes differential excision in the mutant background, which was further confirmed by -complementation of the mutation. This new plasmid-like element was named pLP100. Differential excision did not affect the copy number of pLP100 at the population level. This region contains a copper efflux pump encoded by , and increased resistance to copper was observed for the mutant strain that was abrogated in the complemented strain. A strain carrying a mutation of and a deletion of the right side recombination site, , showed that overexpression of pLP100 genes and increased copper resistance in the mutant strain were dependent upon excision of pLP100.

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2013-08-01
2019-10-18
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References

  1. Aiba H.. ( 2007;). Mechanism of RNA silencing by Hfq-binding small RNAs. . Curr Opin Microbiol 10:, 134–139. [CrossRef][PubMed]
    [Google Scholar]
  2. Altman E., Segal G.. ( 2008;). The response regulator CpxR directly regulates expression of several Legionella pneumophila icm/dot components as well as new translocated substrates. . J Bacteriol 190:, 1985–1996. [CrossRef][PubMed]
    [Google Scholar]
  3. Amaro F., Gilbert J. A., Owens S., Trimble W., Shuman H. A.. ( 2012;). Whole-genome sequence of the human pathogen Legionella pneumophila serogroup 12 strain 570-CO-H. . J Bacteriol 194:, 1613–1614. [CrossRef][PubMed]
    [Google Scholar]
  4. Beaber J. W., Hochhut B., Waldor M. K.. ( 2004;). SOS response promotes horizontal dissemination of antibiotic resistance genes. . Nature 427:, 72–74. [CrossRef][PubMed]
    [Google Scholar]
  5. Brassinga A. K. C., Hiltz M. F., Sisson G. R., Morash M. G., Hill N., Garduno E., Edelstein P. H., Garduno R. A., Hoffman P. S.. ( 2003;). A 65-kilobase pathogenicity island is unique to Philadelphia-1 strains of Legionella pneumophila.. J Bacteriol 185:, 4630–4637. [CrossRef][PubMed]
    [Google Scholar]
  6. Cazalet C., Rusniok C., Brüggemann H., Zidane N., Magnier A., Ma L., Tichit M., Jarraud S., Bouchier C.. & other authors ( 2004;). Evidence in the Legionella pneumophila genome for exploitation of host cell functions and high genome plasticity. . Nat Genet 36:, 1165–1173. [CrossRef][PubMed]
    [Google Scholar]
  7. Charpentier X., Faucher S. P., Kalachikov S., Shuman H. A.. ( 2008;). Loss of RNase R induces competence development in Legionella pneumophila.. J Bacteriol 190:, 8126–8136. [CrossRef][PubMed]
    [Google Scholar]
  8. Chen D.-Q., Huang S.-S., Lu Y.-J.. ( 2006;). Efficient transformation of Legionella pneumophila by high-voltage electroporation. . Microbiol Res 161:, 246–251. [CrossRef][PubMed]
    [Google Scholar]
  9. Chien M., Morozova I., Shi S., Sheng H., Chen J., Gomez S. M., Asamani G., Hill K., Nuara J.. & other authors ( 2004;). The genomic sequence of the accidental pathogen Legionella pneumophila.. Science 305:, 1966–1968. [CrossRef][PubMed]
    [Google Scholar]
  10. D’Auria G., Jiménez-Hernández N., Peris-Bondia F., Moya A., Latorre A.. ( 2010;). Legionella pneumophila pangenome reveals strain-specific virulence factors. . BMC Genomics 11:, 181. [CrossRef][PubMed]
    [Google Scholar]
  11. Dagan T., Artzy-Randrup Y., Martin W.. ( 2008;). Modular networks and cumulative impact of lateral transfer in prokaryote genome evolution. . Proc Natl Acad Sci U S A 105:, 10039–10044. [CrossRef][PubMed]
    [Google Scholar]
  12. de Felipe K. S., Glover R. T., Charpentier X., Anderson O. R., Reyes M., Pericone C. D., Shuman H. A.. ( 2008;). Legionella eukaryotic-like type IV substrates interfere with organelle trafficking. . PLoS Pathog 4:, e1000117. [CrossRef][PubMed]
    [Google Scholar]
  13. Doléans-Jordheim A., Akermi M., Ginevra C., Cazalet C., Kay E., Schneider D., Buchrieser C., Atlan D., Vandenesch F.. & other authors ( 2006;). Growth-phase-dependent mobility of the lvh-encoding region in Legionella pneumophila strain Paris. . Microbiology 152:, 3561–3568. [CrossRef][PubMed]
    [Google Scholar]
  14. Drolet M.. ( 2006;). Growth inhibition mediated by excess negative supercoiling: the interplay between transcription elongation, R-loop formation and DNA topology. . Mol Microbiol 59:, 723–730. [CrossRef][PubMed]
    [Google Scholar]
  15. Faucher S. P., Shuman H. A.. ( 2011;). Small regulatory RNA and Legionella pneumophila.. Front Microbiol 2:, 98. [CrossRef][PubMed]
    [Google Scholar]
  16. Faucher S. P., Shuman H. A.. ( 2012;). Methods to study Legionella transcriptome in vitro and in vivo. . Methods in Molecular Biology 954, 567–582.
    [Google Scholar]
  17. Faucher S. P., Porwollik S., Dozois C. M., McClelland M., Daigle F.. ( 2006;). Transcriptome of Salmonella enterica serovar Typhi within macrophages revealed through the selective capture of transcribed sequences. . Proc Natl Acad Sci U S A 103:, 1906–1911. [CrossRef][PubMed]
    [Google Scholar]
  18. Faucher S. P., Friedlander G., Livny J., Margalit H., Shuman H. A.. ( 2010;). Legionella pneumophila 6S RNA optimizes intracellular multiplication. . Proc Natl Acad Sci U S A 107:, 7533–7538. [CrossRef][PubMed]
    [Google Scholar]
  19. Faucher S., Mueller C., Shuman H.. ( 2011;). Legionella pneumophila transcriptome during intracellular multiplication in human macrophages. 2:, 60.
    [Google Scholar]
  20. Franco I. S., Shuman H. A., Charpentier X.. ( 2009;). The perplexing functions and surprising origins of Legionella pneumophila type IV secretion effectors. . Cell Microbiol 11:, 1435–1443. [CrossRef][PubMed]
    [Google Scholar]
  21. Franze de Fernandez M. T., Eoyang L., August J. T.. ( 1968;). Factor fraction required for the synthesis of bacteriophage Qbeta-RNA. . Nature 219:, 588–590. [CrossRef][PubMed]
    [Google Scholar]
  22. Gal-Mor O., Segal G.. ( 2003;). The Legionella pneumophila GacA homolog (LetA) is involved in the regulation of icm virulence genes and is required for intracellular multiplication in Acanthamoeba castellanii.. Microb Pathog 34:, 187–194. [CrossRef][PubMed]
    [Google Scholar]
  23. Glöckner G., Albert-Weissenberger C., Weinmann E., Jacobi S., Schunder E., Steinert M., Hacker J., Heuner K.. ( 2008;). Identification and characterization of a new conjugation/type IVA secretion system (trb/tra) of Legionella pneumophila Corby localized on two mobile genomic islands. . Int J Med Microbiol 298:, 411–428. [CrossRef][PubMed]
    [Google Scholar]
  24. Gomez-Valero L., Rusniok C., Jarraud S., Vacherie B., Rouy Z., Barbe V., Medigue C., Etienne J., Buchrieser C.. ( 2011;). Extensive recombination events and horizontal gene transfer shaped the Legionella pneumophila genomes. . BMC Genomics 12:, 536. [CrossRef][PubMed]
    [Google Scholar]
  25. Hovel-Miner G., Pampou S., Faucher S. P., Clarke M., Morozova I., Morozov P., Russo J. J., Shuman H. A., Kalachikov S.. ( 2009;). SigmaS controls multiple pathways associated with intracellular multiplication of Legionella pneumophila.. J Bacteriol 191:, 2461–2473. [CrossRef][PubMed]
    [Google Scholar]
  26. Jayakumar D., Early J. V., Steinman H. M.. ( 2012;). Virulence phenotypes of Legionella pneumophila associated with noncoding RNA lpr0035. . Infect Immun 80:, 4143–4153. [CrossRef][PubMed]
    [Google Scholar]
  27. Kessler A., Schell U., Sahr T., Tiaden A., Harrison C., Buchrieser C., Hilbi H.. ( 2013;). The Legionella pneumophila orphan sensor kinase LqsT regulates competence and pathogen-host interactions as a component of the LAI-1 circuit. . Environ Microbiol 15:, 646–662. [CrossRef][PubMed]
    [Google Scholar]
  28. Kim E.-H., Charpentier X., Torres-Urquidy O., McEvoy M. M., Rensing C.. ( 2009;). The metal efflux island of Legionella pneumophila is not required for survival in macrophages and amoebas. . FEMS Microbiol Lett 301:, 164–170. [CrossRef][PubMed]
    [Google Scholar]
  29. Kovach M. E., Elzer P. H., Hill D. S., Robertson G. T., Farris M. A., Roop R. M. II, Peterson K. M.. ( 1995;). Four new derivatives of the broad-host-range cloning vector pBBR1MCS, carrying different antibiotic-resistance cassettes. . Gene 166:, 175–176. [CrossRef][PubMed]
    [Google Scholar]
  30. Lin Y. E., Stout J. E., Yu V. L.. ( 2011;). Controlling Legionella in hospital drinking water: an evidence-based review of disinfection methods. . Infect Control Hosp Epidemiol 32:, 166–173. [CrossRef][PubMed]
    [Google Scholar]
  31. Livak K. J., Schmittgen T. D.. ( 2001;). Analysis of relative gene expression data using real-time quantitative PCR and the 2–ΔΔCT method. . Methods 25:, 402–408. [CrossRef][PubMed]
    [Google Scholar]
  32. Lu J., Struewing I., Buse H. Y., Kou J., Shuman H. A., Faucher S. P., Ashbolt N. J.. ( 2013;). Legionella pneumophila transcriptional response following exposure to CuO nanoparticles. . Appl Environ Microbiol 79:, 2713–2720. [CrossRef][PubMed]
    [Google Scholar]
  33. Lüneberg E., Mayer B., Daryab N., Kooistra O., Zähringer U., Rohde M., Swanson J., Frosch M.. ( 2001;). Chromosomal insertion and excision of a 30 kb unstable genetic element is responsible for phase variation of lipopolysaccharide and other virulence determinants in Legionella pneumophila.. Mol Microbiol 39:, 1259–1271. [CrossRef][PubMed]
    [Google Scholar]
  34. McNealy T. L., Forsbach-Birk V., Shi C., Marre R.. ( 2005;). The Hfq homolog in Legionella pneumophila demonstrates regulation by LetA and RpoS and interacts with the global regulator CsrA. . J Bacteriol 187:, 1527–1532. [CrossRef][PubMed]
    [Google Scholar]
  35. Molofsky A. B., Swanson M. S.. ( 2003;). Legionella pneumophila CsrA is a pivotal repressor of transmission traits and activator of replication. . Mol Microbiol 50:, 445–461. [CrossRef][PubMed]
    [Google Scholar]
  36. Morales V. M., Bäckman A., Bagdasarian M.. ( 1991;). A series of wide-host-range low-copy-number vectors that allow direct screening for recombinants. . Gene 97:, 39–47. [CrossRef][PubMed]
    [Google Scholar]
  37. Rasis M., Segal G.. ( 2009;). The LetA-RsmYZ-CsrA regulatory cascade, together with RpoS and PmrA, post-transcriptionally regulates stationary phase activation of Legionella pneumophila Icm/Dot effectors. . Mol Microbiol 72:, 995–1010. [CrossRef][PubMed]
    [Google Scholar]
  38. Reva O., Bezuidt O.. ( 2012;). Distribution of horizontally transferred heavy metal resistance operons in recent outbreak bacteria. . Mobile Genet Elements 2:, 96–100. [CrossRef][PubMed]
    [Google Scholar]
  39. Ross J. A., Wardle S. J., Haniford D. B.. ( 2010;). Tn10/IS10 transposition is downregulated at the level of transposase expression by the RNA-binding protein Hfq. . Mol Microbiol 78:, 607–621. [CrossRef][PubMed]
    [Google Scholar]
  40. Sadosky A. B., Wiater L. A., Shuman H. A.. ( 1993;). Identification of Legionella pneumophila genes required for growth within and killing of human macrophages. . Infect Immun 61:, 5361–5373.[PubMed]
    [Google Scholar]
  41. Sahr T., Brüggemann H., Jules M., Lomma M., Albert-Weissenberger C., Cazalet C., Buchrieser C.. ( 2009;). Two small ncRNAs jointly govern virulence and transmission in Legionella pneumophila.. Mol Microbiol 72:, 741–762. [CrossRef][PubMed]
    [Google Scholar]
  42. Segal G., Russo J. J., Shuman H. A.. ( 1999;). Relationships between a new type IV secretion system and the icm/dot virulence system of Legionella pneumophila.. Mol Microbiol 34:, 799–809. [CrossRef][PubMed]
    [Google Scholar]
  43. Tiaden A., Spirig T., Sahr T., Wälti M. A., Boucke K., Buchrieser C., Hilbi H.. ( 2010;). The autoinducer synthase LqsA and putative sensor kinase LqsS regulate phagocyte interactions, extracellular filaments and a genomic island of Legionella pneumophila.. Environ Microbiol 12:, 1243–1259. [CrossRef][PubMed]
    [Google Scholar]
  44. Tsui H. C., Leung H. C., Winkler M. E.. ( 1994;). Characterization of broadly pleiotropic phenotypes caused by an hfq insertion mutation in Escherichia coli K-12. . Mol Microbiol 13:, 35–49. [CrossRef][PubMed]
    [Google Scholar]
  45. Vogel J. P., Andrews H. L., Wong S. K., Isberg R. R.. ( 1998;). Conjugative transfer by the virulence system of Legionella pneumophila.. Science 279:, 873–876. [CrossRef][PubMed]
    [Google Scholar]
  46. Weissenmayer B. A., Prendergast J. G. D., Lohan A. J., Loftus B. J.. ( 2011;). Sequencing illustrates the transcriptional response of Legionella pneumophila during infection and identifies seventy novel small non-coding RNAs. . PLoS ONE 6:, e17570. [CrossRef][PubMed]
    [Google Scholar]
  47. Wozniak R. A. F., Waldor M. K.. ( 2010;). Integrative and conjugative elements: mosaic mobile genetic elements enabling dynamic lateral gene flow. . Nat Rev Microbiol 8:, 552–563. [CrossRef][PubMed]
    [Google Scholar]
  48. Zusman T., Aloni G., Halperin E., Kotzer H., Degtyar E., Feldman M., Segal G.. ( 2007;). The response regulator PmrA is a major regulator of the icm/dot type IV secretion system in Legionella pneumophila and Coxiella burnetii.. Mol Microbiol 63:, 1508–1523. [CrossRef][PubMed]
    [Google Scholar]
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