title: Dual regulation by phospho-OmpR of ssrA/B gene expression in Salmonella pathogenicity island 2.
abstract: Expression of genes located on Salmonella pathogenicity island 2 (SPI-2) is required for systemic infection in mice. This region encodes a type III secretion system, secreted effectors and the two-component regulatory system SsrA/B (also referred to as SpiR), as well as additional uncharacterized genes. In the present work, we demonstrate that phospho-OmpR (OmpR-P) functions as an activator at the spiC-ssrA/B locus. There are two promoters at spiR; one is upstream of ssrA and the other upstream of ssrB. Our results indicate that, in contrast to many two-component regulatory systems, regulation of the sensor kinase SsrA appears to be uncoupled and distinct from regulation of the response regulator SsrB. OmpR regulation of ssrA/B is one of only a few examples known in which a two-component response regulator directly regulates the expression of another two-component regulatory system.
authors.affiliation: Department of Molecular Microbiology and Immunology, L-220, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239-3098, USA.
authors.forename: Xiuhong
authors.initials: X
authors.lastname: Feng
authors.forename: Ricardo
authors.initials: R
authors.lastname: Oropeza
authors.forename: Linda J
authors.initials: LJ
authors.lastname: Kenney
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D004268:DNA-Binding Proteins; D015964:Gene Expression Regulation, Bacterial; D018272:Porins / Q000502:physiology; D012486:Salmonella typhimurium / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity; D015534:Trans-Activators / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C113724:OmpC protein; C109237:OmpF protein; D018272:Porins; C119761:SsrB protein, Salmonella typhimurium; D015534:Trans-Activators; D014157:Transcription Factors; C112177:osmolarity response regulator proteins