title: The PprA-PprB two-component system activates CupE, the first non-archetypal Pseudomonas aeruginosa chaperone-usher pathway system assembling fimbriae.
abstract: The opportunistic pathogen Pseudomonas aeruginosa has redundant molecular systems that contribute to its pathogenicity. Those assembling fimbrial structures promote complex organized community lifestyle. We characterized a new 5.8 kb genetic locus, cupE, that includes the conserved usher- and chaperone-encoding genes. This locus, widely conserved in different bacterial species, contains four additional genes encoding non-archetypal fimbrial subunits. We first evidenced that the cupE gene cluster was specifically expressed in biofilm conditions and was responsible for fibre assembly containing at least CupE1 protein, at the bacterial cell surface. These fimbriae not only played a significant role in the early stages (microcolony and macrocolony formation) but also in shaping 3D mushrooms during P. aeruginosa biofilm development. Using wide-genome transposon mutagenesis, we identified the PprAB two-component system (TCS) as a regulator of cupE expression, and further demonstrated the involvement of the PprAB TCS in direct CupE fimbrial assembly activation. Thus, this TCS represents a new regulatory element controlling the transition between planktonic and community lifestyles in P. aeruginosa.
authors.affiliation: Laboratoire d'Ingénierie des Systèmes Macromoléculaires, CNRS - Aix Marseille Université, 31 Chemin Joseph Aiguier, Marseille, France.
authors.forename: Caroline
authors.initials: C
authors.lastname: Giraud
authors.forename: Christophe S
authors.initials: CS
authors.lastname: Bernard
authors.forename: Virginie
authors.initials: V
authors.lastname: Calderon
authors.forename: Liang
authors.initials: L
authors.lastname: Yang
authors.forename: Alain
authors.initials: A
authors.lastname: Filloux
authors.forename: Søren
authors.initials: S
authors.lastname: Molin
authors.forename: Gwennaele
authors.initials: G
authors.lastname: Fichant
authors.forename: Christophe
authors.initials: C
authors.lastname: Bordi
authors.forename: Sophie
authors.initials: S
authors.lastname: de Bentzmann
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018441:Biofilms / Q000254:growth & development*; D036781:Fimbriae Proteins / Q000502:physiology; D010861:Fimbriae, Bacterial / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D018832:Molecular Chaperones / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology
chemical_list: D001426:Bacterial Proteins; D018832:Molecular Chaperones; D036781:Fimbriae Proteins