title: Roles of rpoS-activating small RNAs in pathways leading to acid resistance of Escherichia coli.
abstract: Escherichia coli and related enteric bacteria can survive under extreme acid stress condition at least for several hours. RpoS is a key factor for acid stress management in many enterobacteria. Although three rpoS-activating sRNAs, DsrA, RprA, and ArcZ, have been identified in E. coli, it remains unclear how these small RNA molecules participate in pathways leading to acid resistance (AR). Here, we showed that overexpression of ArcZ, DsrA, or RprA enhances AR in a RpoS-dependent manner. Mutant strains with deletion of any of three sRNA genes showed lowered AR, and deleting all three sRNA genes led to more severe defects in protecting against acid stress. Overexpression of any of the three sRNAs fully rescued the acid tolerance defects of the mutant strain lacking all three genes, suggesting that all three sRNAs perform the same function in activating RpoS required for AR. Notably, acid stress led to the induction of DsrA and RprA but not ArcZ.
authors: Department of Chemistry, KAIST, Daejeon, 305-701, Korea.
authors: Geunu
authors: G
authors: Bak
authors: Kook
authors: K
authors: Han
authors: Daun
authors: D
authors: Kim
authors: Younghoon
authors: Y
authors: Lee
mesh_terms: D000143:Acids / Q000494:pharmacology*; D000222:Adaptation, Physiological; D051777:AraC Transcription Factor / Q000502:physiology; D001426:Bacterial Proteins / Q000378:metabolism*; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D004789:Enzyme Activation; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D015964:Gene Expression Regulation, Bacterial; D005968:Glutamate Decarboxylase / Q000096:biosynthesis / Q000235:genetics; D006863:Hydrogen-Ion Concentration; D008565:Membrane Proteins / Q000096:biosynthesis / Q000235:genetics; D020871:RNA Stability; D012329:RNA, Bacterial / Q000502:physiology*; D058727:RNA, Small Untranslated / Q000235:genetics / Q000502:physiology*; D012808:Sigma Factor / Q000378:metabolism*
chemical_list: D000143:Acids; D051777:AraC Transcription Factor; D001426:Bacterial Proteins; C405431:DsrA RNA, E coli; D029968:Escherichia coli Proteins; C446316:GadX protein, E coli; D008565:Membrane Proteins; D012329:RNA, Bacterial; D058727:RNA, Small Untranslated; D012808:Sigma Factor; C069567:sigma factor KatF protein, Bacteria; C121044:gadA protein, E coli; C584507:gadB protein, E coli; D005968:Glutamate Decarboxylase
keywords: Acid resistance; Escherichia coli; RpoS; small noncoding RNA.