Role of Salmonella Typhimurium small RNAs RyhB-1 and RyhB-2 in the oxidative stress response.
As part of the response to specific stress conditions, bacteria express small molecules of non-coding RNA which maintain cellular homeostasis by regulating gene expression, commonly at the post-transcriptional level. Among these, in Salmonella enterica sv. Typhimurium, the paralog small non-coding RNAs RyhB-1 and RyhB-2 play an important role in iron homeostasis. In addition, in the present work, we show that RyhB-1 and RyhB-2 also participate in the response to hydrogen peroxide (H2O2). Deletion of RyhB-1 and/or RyhB-2 resulted in increased levels of intracellular reactive oxygen species, protein carbonylation and an altered NADH/NAD(+) ratio. Analyses of the transcriptional profiles of ryhB-1 and ryhB-2 by northern blot and qRT-PCR showed that they are induced in response to H2O2 in an OxyR-dependent manner. By using lacZ-fusions and electrophoretic mobility shift assays, we confirmed the requirement of OxyR for inducing expression of both ryhB-1 and ryhB-2. Taken together, our results support a model in which, in response to peroxide treatment, ryhB-1 and ryhB-2 are upregulated by OxyR through direct interaction with their promoter region.
Laboratorio de Microbiología Molecular, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile. Electronic address: lcalderon@unab.cl.
Iván L
IL
Calderón
Great Lakes Bioenergy Research Center and Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, USA. Electronic address: emorales2@wisc.edu.
Eduardo H
EH
Morales
Laboratorio de Microbiología Molecular, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile. Electronic address: b.collao@uandresbello.edu.
Bernardo
B
Collao
Laboratorio de Microbiología Molecular, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile. Electronic address: pau.calderon@uandresbello.edu.
Paulina F
PF
Calderón
Laboratorio de Microbiología Molecular, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile. Electronic address: c.chahuan@uandresbello.edu.
Catalina A
CA
Chahuán
Laboratorio de Ecofisiología Microbiana, Fundación Ciencia & Vida, Santiago, Chile. Electronic address: lillian.gabriela@gmail.com.
Lillian G
LG
Acuña
Laboratorio de Microbiología Molecular, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile. Electronic address: fernandogil@unab.cl.
Fernando
F
Gil
Laboratorio de Microbiología Molecular, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile. Electronic address: csaavedra@unab.cl.
Claudia P
CP
Saavedra
D024881:Drug Resistance, Bacterial / Q000235:genetics; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D006861:Hydrogen Peroxide / Q000378:metabolism / Q000494:pharmacology; D009154:Mutation; D009243:NAD / Q000378:metabolism; D018384:Oxidative Stress / Q000235:genetics*; D012329:RNA, Bacterial / Q000235:genetics*; D058727:RNA, Small Untranslated / Q000235:genetics*; D017382:Reactive Oxygen Species / Q000378:metabolism; D012486:Salmonella typhimurium / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*
D012329:RNA, Bacterial; D058727:RNA, Small Untranslated; D017382:Reactive Oxygen Species; D009243:NAD; D006861:Hydrogen Peroxide
Oxidative stress; RyhB; sRNA