title: Analysis of HilC/D-dependent invF promoter expression under different culture conditions.
abstract: In Salmonella enterica serovar Typhimurium, many of the genes required for intestinal penetration and invasion of host cells are encoded within the Salmonella pathogenicity island 1 (SPI1). The expression of invF, which is a positive transcriptional activator of SPI1, is controlled by HilA-dependent (invF-1) and HilC/D-dependent (invF-2) promoters. Transcriptional analysis of invF revealed that the invF-2 promoter (P(invF-2)) was not activated when cells were grown in standing culture conditions (which are known to induce SPI1) and that hilD mutation decreased the expression of P(invF-2) only in shaking culture conditions. In the absence of invF-1 promoter (P(invF-1)), P(invF-2) promoted InvF production and sipC expression (which is regulated by InvF) in shaking culture conditions. An analysis of the transcription patterns of plasmids harboring the lacZY reporter gene under various P(invF-2) derivatives with truncations or mutations revealed that the downstream region of the P(invF-2) transcription start site (i.e., +148 to +363) plays a role in repressing P(invF-2) in standing culture and in HilD-dependent activation of P(invF-2) in shaking culture conditions. The expression of invH overlaps with P(invF-2), but they are transcribed in opposite directions. However, invH expression did not influence P(invF-2) activity. This suggests that independent regulation of the two invF promoters allows Salmonella to respond quickly to environmental changes.
authors.affiliation: Radiation Research Division for Biotechnology, Korea Atomic Energy Research Institute, Jeongeup 580-185, Republic of Korea.
authors.forename: Sangyong
authors.initials: S
authors.lastname: Lim
authors.forename: Boyoung
authors.initials: B
authors.lastname: Lee
authors.forename: Minjeong
authors.initials: M
authors.lastname: Kim
authors.forename: Dongho
authors.initials: D
authors.lastname: Kim
authors.forename: Hyunjin
authors.initials: H
authors.lastname: Yoon
authors.forename: Kyeonghwa
authors.initials: K
authors.lastname: Yong
authors.forename: Dong-Hyun
authors.initials: DH
authors.lastname: Kang
authors.forename: Sangryeol
authors.initials: S
authors.lastname: Ryu
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000096:biosynthesis*; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D023061:Gene Order; D017930:Genes, Reporter; D006801:Humans; D008954:Models, Biological; D010957:Plasmids; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012486:Salmonella typhimurium / Q000235:genetics / Q000502:physiology*; D014157:Transcription Factors / Q000096:biosynthesis* / Q000378:metabolism*; D001616:beta-Galactosidase / Q000096:biosynthesis / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C119659:HilC protein, Salmonella typhimurium; C119660:HilD protein, Salmonella typhimurium; D014157:Transcription Factors; C090990:invF protein, Salmonella; D001616:beta-Galactosidase