Genomic responses to copper in Synechocystis
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ABSTRACT:
ORGANISM(S): Synechocystis sp. PCC 6803
PROVIDER: GSE51671 | GEO | 2014/09/01
SECONDARY ACCESSION(S): PRJNA224306
REPOSITORIES: GEO
Similar Datasets
Project description:Analysis of genome-wide gene expression patterns in response to copper in WT and COPR mutant in the cyanobacterium Synechocystis sp PCC 6803. Here we have used microarrays to interrogate the global responses to copper additions at non-toxic (0.3 micromolar) and toxic concentrations (3 micromolar) of copper in WT and in a mutant in the copR gene. Addition of the non-toxic copper concentration stimulated the metabolism and induced the switch in the use from cyitochrome c6 to plastocyanin. In contrast, high copper addition induced a stress response and affected the metabolism of several other metals. This included repression of ribosomal, photosynthetic and metabolic genes and induction of chaperones and antioxidant enzymes genes. Finally CopRS seems to control only the expression of the copMRS and copBAC operons as all other genes that were differentially expressed by copper seemed to be unaffected in copR strains. Cells treated with 0.3 µM or 3µM copper for 1h.
2014-09-01 | E-GEOD-51671 | biostudies-arrayexpress
Project description:Copper is an essential cofactor for many enzymes but at high concentrations it is toxic for the cell. Copper ion concentrations ≥50 µM inhibited growth of Corynebacterium glutamicum. The transcriptional response to 20 µM Cu2+ was studied using DNA microarrays and revealed 26 genes that showed a ≥3-fold increased mRNA level, including cg3280-cg3289. Several genes in this genomic region code for proteins presumably involved in the adaption to copper-induced stress, e. g. a multicopper oxidase and a copper-transport ATPase. In addition, this region includes the copRS genes (previously named cgtRS9) which encode a two-component signal transduction system composed of the histidine kinase CopS and the response regulator CopR. Deletion of the copRS genes increased the sensitivity of C. glutamicum towards copper ions, but not to other heavy metal ions. Using comparative transcriptome analysis of the ΔcopRS mutant and the wild type in combination with electrophoretic mobility shift assays and reporter gene studies the CopR regulon and the DNA-binding motif of CopR were identified. Evidence was obtained that CopR binds only to the intergenic region between cg3285 and cg3286 in the genome of C. glutamicum and activates expression of the divergently oriented gene clusters cg3285-cg3280 and cg3286-cg3289. Altogether, our data suggest that CopRS is the key regulatory system in C. glutamicum for the extracytoplasmic sensing of elevated copper ion concentrations and for induction of a set of genes capable of diminishing copper stress. Four or five biological replicates of each experiment were performed. Experiment 1: Transcriptome comparison of wild type grown with 1.25 µM or with 21.25 µM CuSO4; Exp. 2: WT vs. copRS deletion mutant grown with 21.25 µM CuSO4; For analysis via DNA microarrays, the RNA was isolated from exponentially growing cells cultivated in CgXII medium containing glucose as carbon source and either 1.25 uM CuSO4 or 21.25 uM CuSO4.
2011-09-04 | E-GEOD-27510 | biostudies-arrayexpress
Project description:The function of ascorbate peroxidase-related (APX-R) proteins, present in all green photosynthetic eukaryotes, remains unclear. This study focuses on APX-R from Chlamydomonas reinhardtii, namely ascorbate peroxidase 2 (APX2). We showed that apx2 mutants exhibited a faster oxidation of the PSI primary electron donor, P700, upon sudden light increase and a slower re-reduction rate compared to the wild type, pointing to a limitation of plastocyanin. Spectroscopic, proteomic, and immunoblot analyses confirmed that the phenotype was a result of lower levels of plastocyanin in the apx2 mutants. The redox state of P700 did not differ between wild type and apx2 mutants when the loss of function in plastocyanin was nutritionally complemented by growing apx2 mutants under copper deficiency. In this case, cytochrome c6 functionally replaces plastocyanin, confirming that lower levels of plastocyanin was the primary defect caused by absence of APX2. Overall, the results presented here shed light on an unexpected regulation of plastocyanin level under copper replete conditions, induced by ascorbate peroxidase 2 in Chlamydomonas
2024-01-29 | PXD046605 | Pride
Project description:Copper is an essential cofactor for many enzymes but at high concentrations it is toxic for the cell. Copper ion concentrations ≥50 µM inhibited growth of Corynebacterium glutamicum. The transcriptional response to 20 µM Cu2+ was studied using DNA microarrays and revealed 26 genes that showed a ≥3-fold increased mRNA level, including cg3280-cg3289. Several genes in this genomic region code for proteins presumably involved in the adaption to copper-induced stress, e. g. a multicopper oxidase and a copper-transport ATPase. In addition, this region includes the copRS genes (previously named cgtRS9) which encode a two-component signal transduction system composed of the histidine kinase CopS and the response regulator CopR. Deletion of the copRS genes increased the sensitivity of C. glutamicum towards copper ions, but not to other heavy metal ions. Using comparative transcriptome analysis of the ΔcopRS mutant and the wild type in combination with electrophoretic mobility shift assays and reporter gene studies the CopR regulon and the DNA-binding motif of CopR were identified. Evidence was obtained that CopR binds only to the intergenic region between cg3285 and cg3286 in the genome of C. glutamicum and activates expression of the divergently oriented gene clusters cg3285-cg3280 and cg3286-cg3289. Altogether, our data suggest that CopRS is the key regulatory system in C. glutamicum for the extracytoplasmic sensing of elevated copper ion concentrations and for induction of a set of genes capable of diminishing copper stress.
2011-09-05 | GSE27510 | GEO
Project description:The cyanobacterium Microcystis aeruginosa PCC 7806 was used for a systematic survey of the relationship between copper and microcystins synthesis. Here we have used microarrays to interrogate the global responses to copper additions at 0.5 micromolar (µM) and 3 µM of copper. From the gene level, microarray studies (3 µM copper supplementation) showed effects on iron, sulfur, glutaredoxin and dehydratase homeostasis gene expression. However, in 0.5 µM groups, those genes that significantly enriched in 3 µM groups regulatory were not all found. In the microarray data for copper stress (3 µM) revealed a broad effect on the expression of iron-sulphur cluster associated pathways, such as cysteine biosynthesis. All of these data indicate that Fe / S cluster biogenesis and/or repair were affected by copper in M. aeruginosa.
2018-12-21 | GSE108380 | GEO
Project description:Arsenic is an ubiquitous contaminant and a toxic metalloid which presents two main redox states in nature: arsenite [AsIII] and arsenate [AsV]. Arsenic resistance in Synechocystis sp. strain PCC 6803 is mediated by the arsBHC operon and two additional arsenate reductases encoded by the arsI1 and arsI2 genes. Here we describe the genome-wide responses in response to the presence of arsenate and arsenite in wild type and in mutants in the arsenic resistance system. Both forms of arsenic produced similar responses in the wild type strain including induction of several stress related genes and repression of energy generation processes. The responses observed in the arsB mutant strain were similar to the wild type in short term but were maintained in time while they were only transient in the wild type strain. In contrast, the responses observed in a strain lacking all arsenate reductases (the SARS12 strain) were somewhat different and included lower induction of genes involved in metal homeostasis and Fe-S cluster biogenesis. These results suggest that these two processes are targeted by arsenite in the wild type strain. Finally, analysis of the arsR mutant strain revealed that ArsR seems to only control 5 genes in the genome. Furthermore, over-expression of ArsB conferred hypersentivity to nickel, copper and cadmium in an arsR mutant strain. Analysis of genome-wide gene expression patterns in response to arsenic in WT and mutants involved in arsenic detoxification in the cyanobacterium Synechocystis sp PCC 6803. Cells treated with arsenate or arsenite for 1h. Details: WT cells were treated with 1 mM arsenite for 1 h and its expression profile compared to untreated cells (grown in BG11C media). The effects of arsenate were analyzed in the same way but using a modified BG11C media that constains 15% of the normal phosphate concentration (BG11C low phosphate). A reduction in the phosphate concentration in the media is essential to detect grow inhibition after arsenate addition. In the same way that for arsenite cells were treated with 50 mM arsenate for 1 h and their expression profile was compared to untreated cells. Expression profiles of mutant strains lacking arsB gene (SARSB strain; this strain is hypersensitive to arsenite because it lacks the arsenite exporter) or arsR gene (SARSR strain; this strain expresses the arsBHC constitutively) in control conditions and in response to arsenite addition were also analyzed. In addition the expression profiles of a mutant lacking arsenate reductases (SARS12 strain that has interrupted arsC, arsI1 and arsI2 genes; this strain is hypersensitive to arsenate) were analyzed in both control conditions and after addition of 50 mM arsenate.
2014-05-13 | E-GEOD-51383 | biostudies-arrayexpress
Project description:Arsenic is an ubiquitous contaminant and a toxic metalloid which presents two main redox states in nature: arsenite [AsIII] and arsenate [AsV]. Arsenic resistance in Synechocystis sp. strain PCC 6803 is mediated by the arsBHC operon and two additional arsenate reductases encoded by the arsI1 and arsI2 genes. Here we describe the genome-wide responses in response to the presence of arsenate and arsenite in wild type and in mutants in the arsenic resistance system. Both forms of arsenic produced similar responses in the wild type strain including induction of several stress related genes and repression of energy generation processes. The responses observed in the arsB mutant strain were similar to the wild type in short term but were maintained in time while they were only transient in the wild type strain. In contrast, the responses observed in a strain lacking all arsenate reductases (the SARS12 strain) were somewhat different and included lower induction of genes involved in metal homeostasis and Fe-S cluster biogenesis. These results suggest that these two processes are targeted by arsenite in the wild type strain. Finally, analysis of the arsR mutant strain revealed that ArsR seems to only control 5 genes in the genome. Furthermore, over-expression of ArsB conferred hypersentivity to nickel, copper and cadmium in an arsR mutant strain.
2014-05-13 | GSE51383 | GEO
Project description:Comparison of gene expression of WT Synechocystis cells with cells overexpressing the sRNA PsrR1 in order to detect direct targets of the sRNA PsrR1. We monitored gene expression of an Synechocystis PCC6083 overexpressor strain (psrR1+) (Mitschke et al., 2011) harboring a self-replicating plasmid from which PsrR1 is transcribed under control of the copper responsive PpetJ promoter and a control strain (WT) harboring an empty plasmid 0h and 24 h after copper depletion. For the timepoint (0h) we sampled biological replicates and for timepoint (24h) we sampled biological triplicates.
2012-10-10 | E-GEOD-41411 | biostudies-arrayexpress
Project description:To investigate acclimation mechanisms employed under extreme high light conditions, gene expression analysis was performed using the model microalgae Synechocystis sp. PCC 6803 (PCC 6803) cultured under various light intensities. From the low to the mid light conditions, the expression of genes related to light harvesting systems was repressed, whereas that of CO2 fixation and of D1 protein turnover-related genes was induced. Gene expression data also revealed that the down-regulation of genes related to flagellum synthesis (pilA2), pyridine nucleotide transhydrogenase (pntA and pntB), and sigma factor (sigA and sigF) represents acclimation mechanisms of PCC 6803 under excessive high light conditions.
2018-03-06 | GSE111408 | GEO