title: SOS System Induction Inhibits the Assembly of Chemoreceptor Signaling Clusters in Salmonella enterica.
abstract: Swarming, a flagellar-driven multicellular form of motility, is associated with bacterial virulence and increased antibiotic resistance. In this work we demonstrate that activation of the SOS response reversibly inhibits swarming motility by preventing the assembly of chemoreceptor-signaling polar arrays. We also show that an increase in the concentration of the RecA protein, generated by SOS system activation, rather than another function of this genetic network impairs chemoreceptor polar cluster formation. Our data provide evidence that the molecular balance between RecA and CheW proteins is crucial to allow polar cluster formation in Salmonella enterica cells. Thus, activation of the SOS response by the presence of a DNA-injuring compound increases the RecA concentration, thereby disturbing the equilibrium between RecA and CheW and resulting in the cessation of swarming. Nevertheless, when the DNA-damage decreases and the SOS response is no longer activated, basal RecA levels and thus polar cluster assembly are reestablished. These results clearly show that bacterial populations moving over surfaces make use of specific mechanisms to avoid contact with DNA-damaging compounds.
authors.affiliation: Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Eix Central, Edifici C, 08193, Bellaterra (Barcelona), Spain.
authors.forename: Oihane
authors.initials: O
authors.lastname: Irazoki
authors.affiliation: Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Eix Central, Edifici C, 08193, Bellaterra (Barcelona), Spain.
authors.forename: Albert
authors.initials: A
authors.lastname: Mayola
authors.affiliation: Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Eix Central, Edifici C, 08193, Bellaterra (Barcelona), Spain.
authors.forename: Susana
authors.initials: S
authors.lastname: Campoy
authors.affiliation: Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Eix Central, Edifici C, 08193, Bellaterra (Barcelona), Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Barbé
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002633:Chemotaxis; D011485:Protein Binding; D011938:Rec A Recombinases / Q000235:genetics / Q000378:metabolism; D013014:SOS Response, Genetics; D019779:Salmonella enterica / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D001426:Bacterial Proteins; C051236:CheW protein, Bacteria; D011938:Rec A Recombinases