title: Ail and PagC-related proteins in the entomopathogenic bacteria of Photorhabdus genus.
abstract: Among pathogenic Enterobacteriaceae, the proteins of the Ail/OmpX/PagC family form a steadily growing family of outer membrane proteins with diverse biological properties, potentially involved in virulence such as human serum resistance, adhesion and entry into eukaryotic culture cells. We studied the proteins Ail/OmpX/PagC in the bacterial Photorhabdus genus. The Photorhabdus bacteria form symbiotic complexes with nematodes of Heterorhabditis species, associations which are pathogenic to insect larvae. Our phylogenetic analysis indicated that in Photorhabdus asymbiotica and Photorhabdus luminescens only Ail and PagC proteins are encoded. The genomic analysis revealed that the Photorhabdus ail and pagC genes were present in a unique copy, except two ail paralogs from P. luminescens. These genes, referred to as ail1Pl and ail2Pl, probably resulted from a recent tandem duplication. Surprisingly, only ail1Pl expression was directly controlled by PhoPQ and low external Mg2+ conditions. In P. luminescens, the magnesium-sensing two-component regulatory system PhoPQ regulates the outer membrane barrier and is required for pathogenicity against insects. In order to characterize Ail functions in Photorhabdus, we showed that only ail2Pl and pagCPl had the ability, when expressed into Escherichia coli, to confer resistance to complement in human serum. However no effect in resistance to antimicrobial peptides was found. Thus, the role of Ail and PagC proteins in Photorhabdus life cycle is discussed.
authors.affiliation: INRA, UMR Diversité, Génomes et Interactions Microorganismes-Insectes (DGIMI), Montpellier, France; Université Montpellier 2, UMR Diversité, Génomes et Interactions Microorganismes-Insectes (DGIMI), Montpellier, France.
authors.forename: Annabelle
authors.initials: A
authors.lastname: Mouammine
authors.affiliation: INRA, UMR Diversité, Génomes et Interactions Microorganismes-Insectes (DGIMI), Montpellier, France; Université Montpellier 2, UMR Diversité, Génomes et Interactions Microorganismes-Insectes (DGIMI), Montpellier, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Lanois
authors.affiliation: INRA, UMR Diversité, Génomes et Interactions Microorganismes-Insectes (DGIMI), Montpellier, France; Université Montpellier 2, UMR Diversité, Génomes et Interactions Microorganismes-Insectes (DGIMI), Montpellier, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Pagès
authors.affiliation: Université de Lyon, Écully, France; CNRS, UMR5005 - Laboratoire Ampère, École Centrale de Lyon, Écully, France.
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Lafay
authors.affiliation: Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Universités de Montpellier 2 et 1, CNRS, UMR 5235, Montpellier, France.
authors.forename: Virginie
authors.initials: V
authors.lastname: Molle
authors.affiliation: Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Universités de Montpellier 2 et 1, CNRS, UMR 5235, Montpellier, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Canova
authors.affiliation: INRA, UMR Diversité, Génomes et Interactions Microorganismes-Insectes (DGIMI), Montpellier, France; Université Montpellier 2, UMR Diversité, Génomes et Interactions Microorganismes-Insectes (DGIMI), Montpellier, France.
authors.forename: Pierre-Alain
authors.initials: PA
authors.lastname: Girard
authors.affiliation: INRA, UMR Diversité, Génomes et Interactions Microorganismes-Insectes (DGIMI), Montpellier, France; Université Montpellier 2, UMR Diversité, Génomes et Interactions Microorganismes-Insectes (DGIMI), Montpellier, France.
authors.forename: Bernard
authors.initials: B
authors.lastname: Duvic
authors.affiliation: INRA, UMR Diversité, Génomes et Interactions Microorganismes-Insectes (DGIMI), Montpellier, France; Université Montpellier 2, UMR Diversité, Génomes et Interactions Microorganismes-Insectes (DGIMI), Montpellier, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Givaudan
authors.affiliation: INRA, UMR Diversité, Génomes et Interactions Microorganismes-Insectes (DGIMI), Montpellier, France; Université Montpellier 2, UMR Diversité, Génomes et Interactions Microorganismes-Insectes (DGIMI), Montpellier, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Gaudriault
mesh_terms: D023181:Antimicrobial Cationic Peptides / Q000494:pharmacology; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D024881:Drug Resistance, Bacterial; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D016680:Genome, Bacterial; D006801:Humans; D008278:Magnesium Sulfate / Q000494:pharmacology; D010641:Phenotype; D020637:Photorhabdus / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D010802:Phylogeny
chemical_list: D023181:Antimicrobial Cationic Peptides; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D008278:Magnesium Sulfate