title: Helicobacter pylori perceives the quorum-sensing molecule AI-2 as a chemorepellent via the chemoreceptor TlpB.
abstract: Helicobacter pylori moves in response to environmental chemical cues using a chemotaxis two-component signal-transduction system. Autoinducer-2 (AI-2) is a quorum-sensing signal produced by the LuxS protein that accumulates in the bacterial environment in a density-dependent manner. We showed previously that a H. pylori luxS mutant was defective in motility on soft agar plates. Here we report that deletion of the luxS gene resulted in swimming behaviour with a reduced frequency of stops as compared to the wild-type strain. Stopping frequency was restored to wild-type levels by genetic complementation of the luxS mutation or by addition of synthetic 4,5-dihydroxy-2,3-pentanedione (DPD), which cyclizes to form AI-2. Synthetic DPD also increased the frequency of stops in wild-type H. pylori, similar to the behaviour induced by the known chemorepellent HCl. We found that whereas mutants lacking the chemoreceptor genes tlpA, tlpC or tlpD responded to an exogenous source of synthetic DPD, the chemoreceptor mutant tlpB was non-responsive to a gradient or uniform distribution of the chemical. Furthermore, a double mutant lacking both tlpB and luxS exhibited chemotactic behaviour similar to the tlpB single mutant, whereas a double mutant lacking both tlpB and the chemotransduction gene cheA behaved like a nonchemotactic cheA single mutant, supporting the model that tlpB functions in a signalling pathway downstream of luxS and upstream of cheA. We conclude that H. pylori perceives LuxS-produced AI-2 as a chemorepellent via the chemoreceptor TlpB.
authors: Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA.
authors: Bethany A
authors: BA
authors: Rader
authors: Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA.
authors: Christopher
authors: C
authors: Wreden
authors: Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA.
authors: Kevin G
authors: KG
authors: Hicks
authors: Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA.
authors: Emily Goers
authors: EG
authors: Sweeney
authors: Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, CA 95064, USA.
authors: Karen M
authors: KM
authors: Ottemann
authors: Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA.
authors: Karen
authors: K
authors: Guillemin
references: Infect Immun. 2005 Feb;73(2):803-11
references: 15664919
references: Infect Immun. 1997 May;65(5):1949-52
references: 9125586
references: Infect Immun. 2000 Apr;68(4):2016-23
references: 10722597
references: J Bacteriol. 2004 May;186(10):3124-32
references: 15126474
references: J Med Microbiol. 2004 Jul;53(Pt 7):585-593
references: 15184527
references: Infect Immun. 2007 Aug;75(8):3747-57
references: 17517875
references: J Clin Invest. 2003 Nov;112(9):1291-9
references: 14597753
references: Adv Microb Physiol. 1999;41:229-89
references: 10500847
references: J Med Microbiol. 2002 Nov;51(11):958-970
references: 12448680
references: Proc Natl Acad Sci U S A. 2004 Apr 6;101(14):5024-9
references: 15044704
references: J Bacteriol. 2008 May;190(9):3244-55
references: 18245281
references: Infect Immun. 2004 Sep;72(9):5506-10
references: 15322055
references: J Clin Invest. 2004 Feb;113(3):321-33
references: 14755326
references: J Bacteriol. 2011 Feb;193(3):768-73
references: 21097621
references: Nature. 2002 Jan 31;415(6871):545-9
references: 11823863
references: Infect Immun. 2005 Mar;73(3):1820-7
references: 15731083
references: Appl Environ Microbiol. 2006 Oct;72(10):6615-22
references: 16936059
references: J Med Microbiol. 2006 Nov;55(Pt 11):1477-1485
references: 17030905
references: J Bacteriol. 2007 Sep;189(17):6109-17
references: 17586631
references: Appl Microbiol Biotechnol. 2008 Apr;78(5):811-9
references: 18256823
references: Infect Immun. 2002 Apr;70(4):1984-90
references: 11895962
references: Microbiology (Reading). 2001 Sep;147(Pt 9):2493-2504
references: 11535789
references: Mol Microbiol. 2001 Jul;41(2):463-76
references: 11489131
references: J Bacteriol. 2000 Jul;182(13):3638-43
references: 10850976
references: Proc Natl Acad Sci U S A. 1997 Sep 30;94(20):10541-6
references: 9380671
references: Mol Cell. 2004 Sep 10;15(5):677-87
references: 15350213
references: J Bacteriol. 2007 Aug;189(15):5559-65
references: 17526716
references: Infect Immun. 2002 Oct;70(10):5877-81
references: 12228322
references: BMC Microbiol. 2010 Aug 06;10:210
references: 20691071
references: J Med Microbiol. 1992 Aug;37(2):123-7
references: 1629897
references: J Bacteriol. 2006 Apr;188(7):2656-65
references: 16547053
references: Proc Natl Acad Sci U S A. 2006 Jan 17;103(3):732-7
references: 16407106
references: Annu Rev Physiol. 1982;44:501-17
references: 6280591
references: J Bacteriol. 1993 Sep;175(18):5899-906
references: 8376337
references: Infect Immun. 2000 Jun;68(6):3193-9
references: 10816463
references: Org Lett. 2005 Feb 17;7(4):569-72
references: 15704896
references: Proc Natl Acad Sci U S A. 1993 Jun 15;90(12):5791-5
references: 8516329
references: FEMS Microbiol Lett. 2003 Jul 29;224(2):175-81
references: 12892880
references: Microbes Infect. 2000 Aug;2(10):1207-14
references: 11008110
references: Annu Rev Genet. 2009;43:197-222
references: 19686078
references: Microbiol Mol Biol Rev. 2004 Jun;68(2):301-19
references: 15187186
references: J Bacteriol. 2010 Mar;192(5):1184-92
references: 20061483
references: Mol Microbiol. 2008 Jan;67(1):155-70
references: 18078442
references: Microbiology (Reading). 2009 Apr;155(Pt 4):1181-1191
references: 19332820
references: Mol Microbiol. 2006 Aug;61(4):871-82
references: 16879644