Delta-arcS versus wild-type
Ontology highlight
ABSTRACT:
ORGANISM(S): Shewanella oneidensis MR-1
PROVIDER: GSE21044 | GEO | 2010/03/25
SECONDARY ACCESSION(S): PRJNA126425
REPOSITORIES: GEO
Similar Datasets
Project description:The availability of oxygen is a major environmental factor for many microbes, in particular for bacteria, such as Shewanella species, which thrive in redox-stratified environments. One of the best studied systems involved in mediating the response to changes in environmental oxygen levels is the Arc two-component system of Escherichia coli, consisting of the sensor kinase ArcB and the cognate response regulator ArcA. An ArcA ortholog was previously identified in Shewanella, and as in E. coli, Shewanella ArcA is involved in regulating the response to shifts in oxygen levels. Here, we identified the hybrid sensor kinase SO_0577, now designated ArcS, as the previously elusive cognate sensor kinase of the Arc system in S. oneidensis MR-1. Phenotypic mutant characterization, transcriptomic analysis, protein-protein interaction and phosphotransfer studies revealed that the Shewanella Arc system consists of the sensor kinase ArcS, the single phosphotransfer domain protein HptA, and the response regulator ArcA. Phylogenetic analysis suggests that HptA might be a relict of ArcB. Conversely, ArcS is substantially different with respect to overall sequence homologies and domain organization. Thus, we speculate ArcS might have adopted the role of ArcB after loss of the original sensor kinase, perhaps as a consequence of regulatory adaptation to a redox-stratified environment. In the study presented, expression profiles of three independent replicates of Shewanella oneidensis MR-1 delta-arcS were compared to three independent replicates of Shewanella oneidensis MR-1 wild type cells. All samples were obtained from exponentially aerobically grown cells in LB
2010-06-05 | E-GEOD-21044 | biostudies-arrayexpress
Project description:The BarA/UvrY two-component system is well conserved in numerous species of the γ-proteobacteria. However, the regulatory output of this system differs significantly between the species. In this study, we characterized the BarA/UvrY two-component system in Shewanella oneidensis MR-1. Sensor kinase BarA and the cognate response regulator UvrY were identified by bioinformatic analysis and subsequent in vivo interaction and phosphotransfer studies. The expression of two putative small regulatory RNAs (sRNAs), CsrB1 and CsrB2, was demonstrated to be dependent on UvrY. In contrast, a third predicted sRNA, CsrC, was expressed independently of UvrY. Transcriptomic analysis by microarrays revealed that UvrY is a global regulator and affects transcription of key enzymes of carbon metabolism such as ackA, aceAB, and pflAB. Subsequent growth experiments demonstrated that mutants lacking UvrY have a significant growth advantage over the wild type during aerobic growth on N-acetylglucosamine while under under anaerobic conditions the mutant grew more slowly. This effect was absent during growth with lactate as carbon source or in complex medium. Based on these results, we conclude that, in S.oneidensis MR-1, the global BarA/UvrY regulatory system is involved in central carbon metabolism processes. In the study presented, expression profiles of three independent replicates of Shewanella oneidensis MR-1 ∆uvrY were compared to three independent replicates of Shewanella oneidensis MR-1 wild type cells. All samples were obtained from exponentially aerobically grown cells in LB to stationary phase (OD600nm=4.0)
2011-01-01 | E-GEOD-24994 | biostudies-arrayexpress
Project description:The BarA/UvrY two-component system is well conserved in numerous species of the γ-proteobacteria. However, the regulatory output of this system differs significantly between the species. In this study, we characterized the BarA/UvrY two-component system in Shewanella oneidensis MR-1. Sensor kinase BarA and the cognate response regulator UvrY were identified by bioinformatic analysis and subsequent in vivo interaction and phosphotransfer studies. The expression of two putative small regulatory RNAs (sRNAs), CsrB1 and CsrB2, was demonstrated to be dependent on UvrY. In contrast, a third predicted sRNA, CsrC, was expressed independently of UvrY. Transcriptomic analysis by microarrays revealed that UvrY is a global regulator and affects transcription of key enzymes of carbon metabolism such as ackA, aceAB, and pflAB. Subsequent growth experiments demonstrated that mutants lacking UvrY have a significant growth advantage over the wild type during aerobic growth on N-acetylglucosamine while under under anaerobic conditions the mutant grew more slowly. This effect was absent during growth with lactate as carbon source or in complex medium. Based on these results, we conclude that, in S.oneidensis MR-1, the global BarA/UvrY regulatory system is involved in central carbon metabolism processes.
2011-01-01 | GSE24994 | GEO
Project description:Pathogenic bacteria can rapidly respond to stress environments, such as exposure to reactive oxygen species (ROS). The thiol (-SH) groups of cysteine residues in many proteins serve as redox-sensitive switches, providing triggers for ROS-mediated signaling events. In this study, we profiled the reversible thiol oxidation during ROS exposure of the proteome of Vibrio cholerae, a Gram-negative human pathogen that causes cholera. We identified posttranslational modifications of two cysteine residues of ArcA, a response regulator that is known to be phosphorylated under oxygen limiting conditions and regulates global carbon oxidation pathways. We showed that although ROS exposure abolished ArcA phosphorylation, it induced the formation of an intramolecular disulfide that promoted ArcA-ArcA interaction. Thiol oxidation of ArcA led to sustained ArcA activity and ROS resistance. We further demonstrated that V. cholerae ArcA cysteine residues were oxidized in cholera patient diarrheal stools, and that ArcA thiol oxidation is crucial for V. cholerae in vitro ROS resistance, colonization of ROS-rich gut niches, and environmental survival. Moreover, in other enteric pathogens such as Salmonella enterica, the cysteine residues in ArcA orthologs are conserved and thiol oxidation of ArcA plays important roles in ROS resistance both in vitro and in host cells. These results suggest that in enteric pathogens, as a response to ROS insults, thiol oxidation of ArcA is able to functionally mimic phosphorylation and retain ArcA activity, allowing for a balance in the expression of stress-related and pathogenesis-related genetic programs.
2021-08-02 | MSV000087932 | MassIVE
Project description:Purpose:The oxygen-regulated genes FNR and ARCA were combined with Komagataeibacter xylinus CGMCC 2955 to provide a new perspective for the study of the mechanism of oxygen environment on BC synthesis. Methods:The FNR and Arca overexpressing strains and the control strains were fermented under different partial oxygen pressures. The bacterial cellulose membrane in the logarithmic period of fermentation was enzymolyzed, and the bacteria were collected for transcriptome analysis.Sequencing was performed with Illumina and transcriptome analysis was performed on the bacteria under different conditions. Results:Transcriptome sequencing was performed using Illumina high-throughput sequencing technology on K. xylinus cultured under different oxygen tensions. The differentially expressed genes in the arcA overexpressing strains were mainly in the sulfur metabolism, two-component system, purine metabolism, and amino acid metabolism pathways compared to the control strains. Analysis showed that the arcA overexpression strain activated the sulfur metabolic pathway in K. xylinus. Due to the insufficient oxygen electron acceptors in the hypoxia, sulfate acted as the final electron acceptor and enhanced the growth ability of the strain. Through global regulation of the pathways of bacterial growth and metabolism as well as BC synthesis under low oxygen conditions, the arcA gene has enabled the strain to reach new levels of BC production. This study lays the foundation for further investigation of the mechanism of the effect of oxygen on BC synthesis in K. xylinus.
2021-05-22 | GSE174847 | GEO
Project description:Background: Salmonella enterica serovar Typhimurium (S. Typhimurium) is a Gram-negative pathogen that must successfully adapt to the broad fluctuations in the concentration of dissolved dioxygen encountered in the host. In Escherichia coli, ArcA (Aerobic Respiratory Control) helps the cells to sense and respond to the presence of dioxygen. The global role of ArcA in E. coli is well characterized; however, little is known about its role in anaerobically grown S. Typhimurium. Results: We compared the transcriptional profiles of the virulent wild-type (WT) strain (ATCC 14028s) and its isogenic arcA mutant grown under anaerobic conditions. We found that ArcA directly or indirectly regulates 392 genes (8.5% of the genome); of these, 138 genes are poorly characterized. Regulation by ArcA in S. Typhimurium is similar, but distinct from that in E. coli. Thus, genes/operons involved in core metabolic pathways (e.g., succinyl-CoA, fatty acid degradation, cytochrome oxidase complexes, flagellar biosynthesis, motility, and chemotaxis) were regulated similarly in the two organisms. However, genes/operons present in both organisms, but regulated differently by ArcA in S. Typhimurium included those coding for ethanolamine utilization, lactate transport and metabolism, and succinate dehydrogenases. Salmonella-specific genes/operons regulated by ArcA included those required for propanediol utilization, flagellar genes (mcpAC, cheV), Gifsy-1 prophage genes, and a few SPI-3 genes (mgtBC, slsA, STM3784). In agreement with our microarray data, the arcA mutant was non-motile, lacked flagella, and was as virulent in mice as the WT. Furthermore, we identified a set of 120 genes whose regulation was shared with the anaerobic redox regulator, Fnr. Conclusion(s): We have identified the ArcA regulon in anaerobically grown S. Typhimurium. Our results demonstrated that in S. Typhimurium, ArcA serves as a transcriptional regulator coordinating cellular metabolism, flagella biosynthesis, and motility. Furthermore, ArcA and Fnr share in the regulation of 120 S. Typhimurium genes.
2011-02-10 | GSE24564 | GEO
Project description:The human pathogenic fungus Aspergillus fumigatus is readily eradicated by the innate immunity of immunocompetent human hosts, but can cause severe infections, such as invasive aspergillosis (IA), in immunocompromised individuals. During infection, the fungal redox homeostasis can be challenged by reactive oxygen (ROS) species, either derived from the oxidative burst of innate immune cells or the action of antifungal drugs. The peroxiredoxin Asp f3 was found to be essential to cause IA in mice, but how Asp f3 integrates to fungal redox homeostasis remains unknown. Here, we show that in vivo, Asp f3 acts as a sensor for ROS. While global transcription in fungal hyphae under minimal growth conditions was fully independent of Asp f3, a robust induction of the oxidative stress response required the presence of the peroxiredoxin. Hyphae devoid of Aspf 3 failed to activate several redox active genes, like members of the gliotoxin biosynthesis gene cluster and integral members of the Afyap1 regulon, the central activator of the ROS defence machinery in fungi. Upon deletion of the asp f3 gene Afyap1 displayed significantly reduced nuclear localization during ROS exposure, indicating that Asp f3 can act as an intracellular redox sensor for several target proteins
2021-06-03 | GSE173349 | GEO
Project description:The MalNO is a putative two-component signal transduction system, previously known as the VirJI sytem. MalO is the putative cognate response regulator of the MalN sensor histidine kinase. Based on previous evidence that suggested the plc gene, encoding ?-toxin, was upregulated during stationary phase in the malO mutant, microarrays were used to analyse the transcriptome of a malO mutant during stationary phase growth. Total RNA was isolated from stationary phase cells of the malO mutant and the wild-type control. Gene expression levels were compared between the malO mutant and wild-type strain 13
2014-12-22 | E-GEOD-28699 | biostudies-arrayexpress
Project description:Salmonella enterica serovar Typhimurium is a Gram-negative bacterium, facultative anaerobe and intracellular pathogen that causes enteric fever in mice. Once orally ingested, Salmonella invades and traverse the mucosal intestinal epithelia, where it is phagocytized by specialized cells including macrophages, dendritic cells and neutrophils. Within these cells, the bacterium is kept in a compartment termed Salmonella containing vacuole where it is exposed to different adverse conditions including nutrient deprivation, acid pH, reactive oxygen (ROS) as well as nitrogen (RNS) species and low oxygen levels. Among the signals encountered by the bacteria, oxidative stress is one of the main challenges that it has to overcome in order to survive. In this context, the OxyR and SoxRS proteins are the most studied regulators involved in response to ROS. However, in the past years growing evidence suggests that the ArcAB two-component system might play a key role in modulating gene expression in response to ROS. Furthermore, the global regulator ArcA is required for the resistance of Escherichia coli, S. Enteritidis and Typhimurium to hydrogen peroxide (H2O2), however, the ArcA regulon under oxidative stress conditions remains elusive. Therefore, the aim of this work was to demonstrate that ArcAB regulates the expression of genes in response to hydrogen peroxide and determine the ArcA regulon under this condition. To achieve this, we evaluated transcriptomic changes in strain 14028s, ∆arcA in response to H2O2. Total RNA was harvested from three biological replicates of wt and arcA mutant cultures exposed or unexposed to 1.5 mM hydrogen peroxide for 20 min in LB medium.
2013-09-18 | E-GEOD-34134 | biostudies-arrayexpress
Project description:The MalNO is a putative two-component signal transduction system, previously known as the VirJI sytem. MalO is the putative cognate response regulator of the MalN sensor histidine kinase. Based on previous evidence that suggested the plc gene, encoding α-toxin, was upregulated during stationary phase in the malO mutant, microarrays were used to analyse the transcriptome of a malO mutant during stationary phase growth.
2014-12-22 | GSE28699 | GEO