title: Virulence Gene Regulation by L-Arabinose in Salmonella enterica.
abstract: Invasion of the intestinal epithelium is a critical step in Salmonella enterica infection and requires functions encoded in the gene cluster known as Salmonella Pathogenicity Island 1 (SPI-1). Expression of SPI-1 genes is repressed by L-arabinose, and not by other pentoses. Transport of L-arabinose is necessary to repress SPI-1; however, repression is independent of L-arabinose metabolism and of the L-arabinose-responsive regulator AraC. SPI-1 repression by L-arabinose is exerted at a single target, HilD, and the mechanism appears to be post-translational. As a consequence of SPI-1 repression, l-arabinose reduces translocation of SPI-1 effectors to epithelial cells and decreases Salmonella invasion in vitro. These observations reveal a hitherto unknown role of L-arabinose in gene expression control and raise the possibility that Salmonella may use L-arabinose as an environmental signal.
authors.affiliation: Departamento de Genética, Facultad de Biología, Universidad de Sevilla, 41080 Sevilla, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: López-Garrido
authors.affiliation: Departamento de Genética, Facultad de Biología, Universidad de Sevilla, 41080 Sevilla, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: Puerta-Fernández
authors.affiliation: Departamento de Genética, Facultad de Biología, Universidad de Sevilla, 41080 Sevilla, Spain.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Cota
authors.affiliation: Departamento de Genética, Facultad de Biología, Universidad de Sevilla, 41080 Sevilla, Spain casadesus@us.es.
authors.forename: Josep
authors.initials: J
authors.lastname: Casadesús
mesh_terms: D051777:AraC Transcription Factor / Q000378:metabolism; D001089:Arabinose / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D044404:Genomic Islands; D019779:Salmonella enterica / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity*; D014774:Virulence / Q000235:genetics
chemical_list: D051777:AraC Transcription Factor; D001089:Arabinose
keywords: HilD; Salmonella invasion; Salmonella pathogenicity island 1; l-arabinose