Metabolomics,Unknown,Transcriptomics,Genomics,Proteomics

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Reactive oxygen species-inducible ECF M-OM-^C factor involved in singlet-oxygen responsiveness of Bradyrhizobium japonicum

ABSTRACT: Expression data from B. japonicum strains 110spc4 (wild type), 0202 (Dbll1028), 9688 (Dblr3038-39) grown micro-oxically unstressed or stressed with 2 mM H2O2 for 10 min and strain 9692 (Dblr3039) grown micro-oxically Comparative transcriptome analysis of B. japonicum strains 110spc4, 0202, 9688, and 9692 grown micro-oxically with or without exposure to 2 mM H2O2 for 10 min

ORGANISM(S): Bradyrhizobium japonicum

SUBMITTER: Hans-Martin Fischer

PROVIDER: E-GEOD-39165 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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Publications

Reactive oxygen species-inducible ECF σ factors of Bradyrhizobium japonicum.

Masloboeva Nadezda N Reutimann Luzia L Stiefel Philipp P Follador Rainer R Leimer Nadja N Hennecke Hauke H Mesa Socorro S Fischer Hans-Martin HM

PloS one 20120816 8

Extracytoplasmic function (ECF) σ factors control the transcription of genes involved in different cellular functions, such as stress responses, metal homeostasis, virulence-related traits, and cell envelope structure. The genome of Bradyrhizobium japonicum, the nitrogen-fixing soybean endosymbiont, encodes 17 putative ECF σ factors belonging to nine different ECF σ factor families. The genes for two of them, ecfQ (bll1028) and ecfF (blr3038), are highly induced in response to the reactive oxyge ...[more]

PMID: 22916258

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Project description:Bradyrhizobium japonicum RegSR regulatory proteins belong to the family of two-component regulatory systems, and orthologs are present in many Proteobacteria where they globally control gene expression mostly in a redox-responsive manner. In this work, we have performed a transcriptional profiling of wild-type and regR mutant cells grown under anoxic denitrifying conditions. The comparative analyses of wild-type and regR strains revealed that almost 620 genes induced in the wild type under denitrifying conditions were regulated (directly or indirectly) by RegR, pointing out the important role of this protein as a global regulator of denitrification. Genes controlled by RegR included nor and nos structural genes encoding nitric oxide and nitrous oxide reductase, respectively, genes encoding electron transport proteins such as cycA (blr7544), or cy2 (bll2388), genes involved in nitric oxide detoxification (blr2806-09), copper homeostasis (copCAB), as well as two regulatory genes (bll3466, bll4130). Purified RegR interacted with the promoters of norC (blr3214), nosR (blr0314), a fixK-like gene (bll3466), and bll4130 which encodes a LysR-type regulator. By using fluorescently labeled oligonucleotide extension (FLOE), we were able to identify two transcriptional start sites located at about 35 (P1) and 22 (P2) bp upstream of the putative translational start codon of norC. P1 matched with the previously mapped 5M-bM-^@M-^Yend of norC mRNA which we demonstrate in this work to be under FixK2 control. P2 is a start site modulated by RegR and specific for anoxic conditions. Moreover, qRT-PCR experiments, expression studies with a norC-lacZ fusion, and heme c-staining analyses revealed that anoxia and nitrate are required for RegR-dependent induction of nor genes, and that this control is independent of the sensor protein RegS. A total of eight Affymetrix GeneChips are included in this study. Per strain (wild-type B. japonicum 110spc4, delta regR mutant 2426) four biological replicates were processed and analyzed. Strains were grown under anoxic conditions in Bergersen minimal medium supplemented with succinate as carbon source and KNO3 as terminal electron acceptor. For comparison, a microarray expression dataset generated with B. japonicum wild-type (Hauser et al., Mol. Genet. Genomics 278:255-271, 2007) and delta regR mutant cells (Lindemann et al., J. Bacteriol. 189:8928-8943, 2007) was used.

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Dataset Information

Reactive oxygen species-inducible ECF M-OM-^C factor involved in singlet-oxygen responsiveness of Bradyrhizobium japonicum

Publications

Reactive oxygen species-inducible ECF σ factors of Bradyrhizobium japonicum.

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