Global Analysis of the Expression of Salmonella RyhB regulon
ABSTRACT: Analysis of the Expression Change of RyhB Regulon in RyhB-deleted Mutant Strains. Wild-type Salmonella 14028 vs. three mutant strains (∆ryhB1, ∆ryhB2, and ∆ryhB1&∆ryhB2); One condition experiment, Iron-depleted condition by adding 200 µM of 2,2’-dipyridyl (dip).
Project description:Analysis of the Expression Change of RyhB Regulon in RyhB-deleted Mutant Strains. Overall design: Wild-type Salmonella 14028 vs. three mutant strains (∆ryhB1, ∆ryhB2, and ∆ryhB1&∆ryhB2); One condition experiment, Iron-depleted condition by adding 200 µM of 2,2’-dipyridyl (dip).
Project description:To study the regulatory outcome of Hfq-mediated sRNA-target interactions, we measured the change in gene expression following overexpression of each of five well-established sRNAs: GcvB, MicA, ArcZ, RyhB and CyaR. For each of the studied sRNAs we applied RNA-seq to two E. coli K-12 MG1655 strains: (1) a WT strain or a strain deleted of the sRNA gene; (2) a strain overexpressing the sRNA, either artificially from a plasmid or from the endogenous sRNA gene by changing the growth condition. For GcvB induction, the E. coli K-12 MG1655 Z1 gcvB::Cm, pZA12-gcvB and the E. coli K-12 MG1655 Z1 gcvB::Cm, pTP-011 strains were used. For MicA overexpression the E. coli K-12 MG1655lacIq pBRplac, pEF21-Hfq and the E. coli K-12 MG1655lacIq pMicA, pEF21-Hfq strains were used. For ArcZ induction the E. coli K-12 MG1655 Z1 arcZ::Cm, pZE12-ArcZ and the E. coli K-12 MG1655 Z1 arcZ::Cm, pJV300 strains were used. For RyhB overexpression the E. coli K-12 MG1655 ryhB::Cm and the E. coli K-12 MG1655 were used. For CyaR induction the E. coli K-12 MG1655 Z1 cyaR::Cm, pZE12-CyaR and the E. coli K-12 MG1655 Z1 cyaR::Cm, pJV300 strains were used. All E. coli strains used in this study were grown overnight in Luria Bertani (LB) medium at 37 °C with shaking (200 r.p.m.), diluted 100-fold in fresh LB medium, and re-grown with shaking at 37 °C to exponential phase, for GcvB (OD600 = 0.3) and for RyhB (OD600 = 0.5), or to stationary phase, for ArcZ WT, ArcZ M1, ArcZ M2 and CyaR (OD600 = 1.0) and for MicA (grown for 6 hr). For induction of ArcZ and GcvB, IPTG was added (1mM, 20 min). MicA was constitutively expressed and further induced at the end of growth with IPTG (1mM, 20 min). For induction of RyhB, the iron chelator 2,2'-Dipyridyl was added (200 μM, 30 min).
Project description: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 Salmonella Typhimurium paralog 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 screening to identify novel RyhB-1 and RyhB-2 regulated targets, and a subset of genes was filtered based on their potential role in the response to nitrosative stress. To confirm our observation, expression of the candidate targets was analyzed by quantitative RT-PCR in a 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 o oxidase complex), cydB (cytochrome d oxidase complex), 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 and the nitrate reductase system, allowing the cell to cope with GSNO-induced stress. Total RNA was harvested from two biological replicates of wt S. Typhimurium overexpressing the sRNA RyhB-2 grown in LB medium, in order to identify RhyB-2 targets that might be implicated in reactive nitrogen stress resistance.
Project description:Study of the roles played by Fur and RyhB in Shewanella oneidensis Overall design: Potential RyhB targets were identified by RNAseq of wild-type and mutant strains and a RyhB-overexpressing strain
Project description:We report gene expression profiling in the fission yeast Schizosaccharomyces pombe. We performed high-throughput sequencing of RNA isolated from wild-type, clr6-1, ago1∆, red1∆, rrp6∆, clr4∆, ccr4∆, ccr4∆fep1, wild-type cells treated with an iron chelator (2,2′-bipyridyl; DIP) grown at 30°C or 18°C and ccr4∆fep1 cells treated with DIP at 18C. We find that many stress response genes, transmembrane transporters, and non-coding RNAs are up-regulated in cells cultured at 18°C. Our analyses concluded that Clr4 and Ccr4 are important for controlling transcript levels at 18°C and uncovered a role for iron homeostasis in adaptive genome control. Overall design: RNA sequencing in wild-type, clr6-1, ago1∆, red1∆, rrp6∆, clr4∆, ccr4∆, ccr4∆fep1, wild-type cells treated with an iron chelator (2,2′-bipyridyl; DIP) grown at 30°C or 18°C and ccr4∆fep1 cells treated with DIP at 18C. Two biological replicates for wild-type strains grown at 30°C and 18°C.
Project description:A. baumannii ATCC 17978 cells were incubated under iron replete (mueller-hinton) and iron limiting (MH + 200 µM 2,2'-dipyridyl) conditions, total RNA was extracted when cultures reached OD600=0.7. The probes on the microarray cover all predicted open reading frames (at least 4 per ORF) and additional replicates of housekeeping genes of the A. baumannii ATCC 17978 genome
Project description:RyhB is a non-coding RNA regulated by the Fur repressor. It has previously been shown to cause the rapid degradation of a number of mRNAs that encode proteins that utilize iron. Here we examine the effect of ectopic RyhB production on global gene expression by microarray analysis. Many of the previously identified targets were found, as well as other mRNAs encoding iron-binding proteins, bringing the total number of regulated operons to at least 18, encoding 56 genes. The two major operons involved in Fe-S cluster assembly showed different behavior; the isc operon appears to be a direct target of RyhB action, while the suf operon does not. This is consistent with previous findings suggesting that the suf genes but not the isc genes are important for Fe-S cluster synthesis under iron-limiting conditions, presumably for essential iron-binding proteins. In addition, we observed repression of Fur-regulated genes upon RyhB expression, interpreted as due to intracellular iron-sparing resulting from reduced synthesis of iron-binding proteins. Our results demonstrate the broad effects of a single non-coding RNA on iron homeostasis. Experiment Overall Design: Derivatives of MG1655 carrying either pBAD-ryhB or the control vector pNM12 were used in all experiments. Experiment Overall Design: The strains used contain the (delta)ara714 allele to prevent catabolism of arabinose and the (delta)ryhB::cat allele to restrict RyhB expression to the inducible pBAD-ryhB vector. Experiment Overall Design: Overnight bacterial cultures were incubated in LB media with ampicillin at a final concentration of 50 ug/mL at 37oC and diluted 1000-fold into 50 mL of fresh LB-ampicillin media at 37oC with agitation. To induce RyhB expression, cultures carrying the pBAD-ryhB construct were grown to an O.D.600 of 0.5 and arabinose was added to the culture at a final concentration of 0.1%. In some experiments, 50 uM FeSO4 was added to the new culture after dilution from overnight culture. Total RNA was extracted from cells at the indicated time using the hot phenol procedure.
Project description:The effects of RyhB expression were examined by Ribo-seq and RNA-seq after 10 min to avoid indirect effects. Expression of RyhB was induced by arabinose from cells carrying pBAD-ryhB plasmid. The RyhB expression was confirmed by real-time PCR. As a control, cells with vector pNM12 were grown and induced. The cells were pulverized and total mRNAs were extracted from the pulverized cells and processed for Ribo-seq and RNA-seq.
Project description:Investigation of whole genome changes in six serotypes of Actinobacillus pleuropneumoniae in control cultures compared to bacteria grown in media containg the iron chelator 2,2'-dipyridyl. A 48 chip study using total RNA recovered from four different control cultures and four different iron depleted cultures of Actinobacillus pleuropneumoniea serotype 1 (4074), serotype 2 (4226), serotype 3 (1421), serotype 5b(L209, serotype 6 (7712640) and serotype 7 (WF87).