title: The small RNA RyhB homologs from Salmonella typhimurium participate in the response to S-nitrosoglutathione-induced stress.
abstract: Typically, the expression of sRNAs is activated in response to environmental stimuli in order to regulate gene expression through post-transcriptional mechanisms. In the present work we show that the Salmonellatyphimurium paralogous sRNAs RyhB-1 and RyhB-2 are induced in response to the nitrosating agent S-nitrosoglutathione (GSNO). Inactivation of these sRNAs decreased S. typhimurium resistance to GSNO and increased the levels of nitrosylated proteins. These results prompted us to evaluate a possible role of these sRNAs in nitrosative stress resistance. RNA profiling was used as a screen to identify novel RyhB-1 and RyhB-2 regulated targets. A subset of genes was filtered based on their potential role in the response to nitrosative stress and their expression was analyzed by quantitative RT-PCR in wild type, single and double mutant strains (ΔryhB1, ΔryhB2 and ΔryhB1 ΔryhB2) treated with GSNO. In response to GSNO RyhB-1 and RyhB-2 negatively regulate the expression of the genes cyoABC (cytochrome bo oxidase), cydB (cytochrome bd oxidase), cybC (cytochrome b-562), and positively regulate the nirBCD operon (nitrite reductase system). Together, these results suggest that RyhB-1 and RyhB-2 finely tune the expression of genes coding for cytochrome oxidases and the nitrate reductase system, allowing the cell to cope with GSNO-induced stress.
authors.affiliation: Laboratorio de Microbiología Molecular, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile. Electronic address: pau.calderon@uandresbello.edu.
authors.forename: Paulina F
authors.initials: PF
authors.lastname: Calderón
authors.affiliation: Great Lakes Bioenergy Research Center and Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, USA. Electronic address: emorales2@wisc.edu.
authors.forename: Eduardo H
authors.initials: EH
authors.lastname: Morales
authors.affiliation: Laboratorio de Ecofisiología Microbiana, Fundación Ciencia & Vida, Santiago, Chile. Electronic address: lillian.gabriela@gmail.com.
authors.forename: Lillian G
authors.initials: LG
authors.lastname: Acuña
authors.affiliation: Laboratorio de Microbiología Molecular, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile. Electronic address: danit.fuentes@uandresbello.edu.
authors.forename: Danitza N
authors.initials: DN
authors.lastname: Fuentes
authors.affiliation: Laboratorio de Microbiología Molecular, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile. Electronic address: fernandogil@unab.cl.
authors.forename: Fernando
authors.initials: F
authors.lastname: Gil
authors.affiliation: Department of Microbiology and Molecular Genetics, B240 Medical Sciences Building, University of California, Irvine, CA 92697, USA. Electronic address: sporwoll@uci.edu.
authors.forename: S
authors.initials: S
authors.lastname: Porwollik
authors.affiliation: Department of Microbiology and Molecular Genetics, B240 Medical Sciences Building, University of California, Irvine, CA 92697, USA. Electronic address: mmcclell@uci.edu.
authors.forename: Michael
authors.initials: M
authors.lastname: McClelland
authors.affiliation: Laboratorio de Microbiología Molecular, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile. Electronic address: csaavedra@unab.cl.
authors.forename: Claudia P
authors.initials: CP
authors.lastname: Saavedra
authors.affiliation: Laboratorio de Microbiología Molecular, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile. Electronic address: lcalderon@unab.cl.
authors.forename: Iván L
authors.initials: IL
authors.lastname: Calderón
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology*; D012329:RNA, Bacterial / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D026422:S-Nitrosoglutathione / Q000494:pharmacology*; D012486:Salmonella typhimurium / Q000187:drug effects / Q000502:physiology*
chemical_list: D000890:Anti-Infective Agents; D012329:RNA, Bacterial; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D026422:S-Nitrosoglutathione
keywords: GSNO; Nitrosative stress; RNS; RyhB; sRNA