title: RpoS and quorum sensing control expression and polar localization of Vibrio cholerae chemotaxis cluster III proteins in vitro and in vivo.
abstract: The diarrheal pathogen Vibrio cholerae contains three gene clusters that encode chemotaxis-related proteins, but only cluster II appears to be required for chemotaxis. Here, we present the first characterization of V. cholerae's 'cluster III' chemotaxis system. We found that cluster III proteins assemble into foci at bacterial poles, like those formed by cluster II proteins, but the two systems assemble independently and do not colocalize. Cluster III proteins are expressed in vitro during stationary phase and in conjunction with growth arrest linked to carbon starvation. This expression, as well as expression in vivo in suckling rabbits, is dependent upon RpoS. V. cholerae's CAI-1 quorum sensing (QS) system is also required for cluster III expression in stationary phase and modulates its expression in vivo, but is not required for cluster III expression in response to carbon starvation. Surprisingly, even though the CAI-1 and AI-2 QS systems are thought to feed into the same signaling pathway, the AI-2 system inhibited cluster III gene expression, revealing that the outputs of the two QS systems are not always the same. The distinctions between genetic determinants of cluster III expression in vitro and in vivo highlight the distinctive nature of the in vivo environment.
authors.affiliation: Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, 35043, Germany.|Division of Infectious Diseases, Brigham and Women's Hospital, Boston, MA, 02115, USA.|Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, 02115, USA.
authors.forename: Simon
authors.initials: S
authors.lastname: Ringgaard
authors.affiliation: Division of Infectious Diseases, Brigham and Women's Hospital, Boston, MA, 02115, USA.|Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, 02115, USA.
authors.forename: Troy
authors.initials: T
authors.lastname: Hubbard
authors.affiliation: Division of Infectious Diseases, Brigham and Women's Hospital, Boston, MA, 02115, USA.|Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, 02115, USA.
authors.forename: Anjali
authors.initials: A
authors.lastname: Mandlik
authors.affiliation: Division of Infectious Diseases, Brigham and Women's Hospital, Boston, MA, 02115, USA.|Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, 02115, USA.
authors.forename: Brigid M
authors.initials: BM
authors.lastname: Davis
authors.affiliation: Division of Infectious Diseases, Brigham and Women's Hospital, Boston, MA, 02115, USA.|Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, 02115, USA.|Howard Hughes Medical Institute, Brigham and Women's Hospital, Boston, MA, 02115, USA.
authors.forename: Matthew K
authors.initials: MK
authors.lastname: Waldor
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism*; D002633:Chemotaxis / Q000502:physiology*; D002771:Cholera / Q000382:microbiology; D015964:Gene Expression Regulation, Bacterial; D008565:Membrane Proteins / Q000378:metabolism; D000072236:Methyl-Accepting Chemotaxis Proteins; D005810:Multigene Family; D053038:Quorum Sensing / Q000502:physiology*; D011817:Rabbits; D012808:Sigma Factor / Q000378:metabolism*; D015398:Signal Transduction; D014734:Vibrio cholerae / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D008565:Membrane Proteins; D000072236:Methyl-Accepting Chemotaxis Proteins; D012808:Sigma Factor; C069567:sigma factor KatF protein, Bacteria; C051236:CheW protein, Bacteria