Roles of close homologues SigB and SigD in heat and bright light acclimation of the cyanobacterium Synechocystis sp. PCC 6803
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ABSTRACT:
PROVIDER: PRJNA791245 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR17288300.fastq.gz | Fastqsanger.gz | |||
| SRR17288301.fastq.gz | Fastqsanger.gz | |||
| SRR17288302.fastq.gz | Fastqsanger.gz | |||
| SRR17288303.fastq.gz | Fastqsanger.gz | |||
| SRR17288304.fastq.gz | Fastqsanger.gz |
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Project description:Acclimation of cyanobacterium Synechocystis sp. PCC6803 to suboptimal conditions is largely dependent on adjustments of gene expression, which is highly controlled by the σ factor subunits of RNA polymerase (RNAP). The SigB and SigD σ factors are close homologues. Here we show that sigB and sigD genes are both induced in bright light and high temperature stresses. Comparison of transcriptomes of the control strain (CS), ΔsigB, ΔsigD, ΔsigBCE (SigD is an only functional group 2 σ factor), and ΔsigCDE (SigD is an only functional group 2 σ factor) strains in standard, bright light and high temperature conditions revealed that the SigB and SigD factors regulate different set of genes, and that SigB and SigD regulons are highly dependent on stress conditions. The SigB regulon is bigger than the SigD regulon at high temperature, whereas in bright light the SigD regulon is bigger the SigB regulon. Furthermore, our results show that favoring the SigB or SigD factor by deleting other group 2 σ factors do not lead to superior acclimation to bright light or high temperature conditions, indicating that all group 2 σ factors play roles in acclimation processes.
2022-01-19 | GSE192357 | GEO
Project description:Acclimation of cyanobacterium Synechocystis sp. PCC6803 to suboptimal conditions is largely dependent on adjustments of gene expression, which is highly controlled by the σ factor subunits of RNA polymerase (RNAP). The SigB and SigD σ factors are close homologues. Here we show that the sigB and sigD genes are both induced in high light and heat stresses. Comparison of transcriptomes of the control strain (CS), ΔsigB, ΔsigD, ΔsigBCE (containing SigD as the only functional group 2 σ factor), and ΔsigCDE (SigB as the only functional group 2 σ factor) strains in standard, high light, and high temperature conditions revealed that the SigB and SigD factors regulate different sets of genes and SigB and SigD regulons are highly dependent on stress conditions. The SigB regulon is bigger than the SigD regulon at high temperature, whereas, in high light, the SigD regulon is bigger than the SigB regulon. Furthermore, our results show that favoring the SigB or SigD factor by deleting other group 2 σ factors does not lead to superior acclimation to high light or high temperature, indicating that all group 2 σ factors play roles in the acclimation processes.
| S-EPMC8875361 | biostudies-literature
Project description:In eubacteria, replacement of one σ factor in the RNA polymerase (RNAP) holoenzyme by another one changes the transcription pattern. Cyanobacteria are eubacteria characterized by oxygenic photosynthesis and they typically encode numerous group 2 σ factors that closely resemble the essential primary σ factor. A mutant strain of the model cyanobacterium Synechocystis sp. PCC 6803 without functional group 2 σ factors (named as ΔsigBCDE) could not acclimate to heat, high salt, or bright light stress but in standard conditions ΔsigBCDE grew only 9% slower than the control strain. One-fifth of the genes in ΔsigBCDE were differently expressed compared to the control strain in standard growth conditions and several physiological changes in photosynthesis, and pigment and lipid compositions were detected. To directly analyze the σ factor content of RNAP holoenzyme in vivo, a His-tag was added to the γ subunit of RNAP in Synechocystis and RNAPs were collected. The results revealed that all group 2 σ factors were recruited by RNAP in standard conditions, but recruitment of SigB and SigC increased in heat stress, SigD in bright light, SigE in darkness and SigB, SigC and SigE in high salt, explaining the poor acclimation of ΔsigBCDE to these stress conditions.
2015-09-15 | GSE69981 | GEO
Project description:Bright null mouse embryonic stem cells and spontaneously reprogrammed Bright null cells compared to WT mouse embryonic stem cells;Work further described in Popowski et. al 2013 Bright null mouse embryonic stem cells and wildtype mouse embryonic stem cells differentiated in embryoid bodies at day 6 and day 15 Total RNA from each cell line using indicated replicates
2013-11-25 | E-GEOD-52692 | biostudies-arrayexpress
Project description:Bright null mouse embryonic stem cells and spontaneously reprogrammed Bright null cells compared to WT mouse embryonic stem cells;Work further described in Popowski et. al 2013 Bright null mouse embryonic stem cells and wildtype mouse embryonic stem cells differentiated in embryoid bodies at day 6 and day 15
2013-11-25 | GSE52692 | GEO
Project description:Background: The Bacillus cereus Sigma B (SigB) dependent general stress response is activated via the two-component RsbKY system, which involves a phosphate transfer from RsbK to RsbY. It has been hypothesized that the Hpr-like phosphocarrier protein (Bc1009) encoded by bc1009 in the SigB gene cluster may play a role in this transfer, thereby acting as a regulator of SigB activation. Alternatively, Bc1009 may be involved in the activation of a subset of SigB regulon members. Results: We first investigated the potential role of bc1009 to act as a SigB regulator but ruled out this possibility as the deletion of bc1009 did not affect the expression of sigB and other SigB gene cluster members. The SigB-dependent functions of Bc1009 were further examined in B. cereus ATCC14579 via comparative proteome profiling (backed up by transcriptomics) of wt, Δbc1009 and ΔsigB deletion mutants under heat stress at 42°C. This revealed 284 proteins displaying SigB-dependent alterations in protein expression levels in heat-stressed cells, including a subgroup of 138 proteins for which alterations were also Bc1009-dependent. Next to proteins with roles in stress defense, newly identified SigB and Bc1009-dependent proteins have roles in cell motility, signal transduction, transcription, cell wall biogenesis, and amino acid transport and metabolism. Analysis of lethal stress survival at 50°C after pre-adaptation at 42°C showed intermediate survival efficacy of Δbc1009 cells, highest survival of wt, and lowest survival of ΔsigB cells, respectively. Additional comparative proteome analysis of non-stressed wt and mutant cells at 30°C revealed 96 proteins with SigB and Bc1009-dependent differences in levels, 51 were also identified under heat stress, and 45 showed significant differential expression at 30°C, including proteins with roles in carbohydrate/ion transport and metabolism. Overlapping functions at 30°C and 42°C included proteins involved in motility, and ΔsigB and Δbc1009 cells showed reduced motility compared to wt cells in swimming assays at both temperatures. Conclusion: our results extend the B. cereus SigB regulon to >300 members, with a novel role of SigB-dependent Bc1009 in the activation of a subregulon of >180 members, conceivably via phosphotransfer-based interactions with other transcriptional regulatory networks.
2023-03-02 | GSE213958 | GEO
Project description:In eubacteria, replacement of one σ factor in the RNA polymerase (RNAP) holoenzyme by another one changes the transcription pattern. Cyanobacteria are eubacteria characterized by oxygenic photosynthesis and they typically encode numerous group 2 σ factors that closely resemble the essential primary σ factor. A mutant strain of the model cyanobacterium Synechocystis sp. PCC 6803 without functional group 2 σ factors (named as ΔsigBCDE) could not acclimate to heat, high salt, or bright light stress but in standard conditions ΔsigBCDE grew only 9% slower than the control strain. One-fifth of the genes in ΔsigBCDE were differently expressed compared to the control strain in standard growth conditions and several physiological changes in photosynthesis, and pigment and lipid compositions were detected. To directly analyze the σ factor content of RNAP holoenzyme in vivo, a His-tag was added to the γ subunit of RNAP in Synechocystis and RNAPs were collected. The results revealed that all group 2 σ factors were recruited by RNAP in standard conditions, but recruitment of SigB and SigC increased in heat stress, SigD in bright light, SigE in darkness and SigB, SigC and SigE in high salt, explaining the poor acclimation of ΔsigBCDE to these stress conditions. Cells from cyanobacteria Synechocystis sp. PCC 6803 named as control strain (CS) and a mutant strain without any functional group 2 sigma factors, ΔsigBCDE, were harvested (A730=1, 40 mL) directly from standard growth conditions (continuous illumination at the PPFD of 40 µmol m-2s-1, 32°C, ambient CO2). From three to four independent experiments were performed at each conditions.
2015-09-15 | E-GEOD-69981 | biostudies-arrayexpress
Project description:Listeria monocytogenes SigB and PrfA are pleiotropic regulators of stress response and virulence gene expression, which have been shown to co-regulate genes in L. monocytogenes. We performed whole genome transcriptional profiling in the presence of PrfA* and active SigB, to identify the overlaps between the PrfA virulence regulon and the SigB stress response regulon. In L. monocytogenes, the PrfA* allele contributes to the activation of virulence genes to a level comparable to that of intracellular growing L. monocytogenes. Our results showed that the core PrfA regulon consists of 12 genes previously described as PrfA regulated. Furthermore, we found that the role of SigB during virulence gene regulation changes, dependent on the presence or absence of PrfA*. In the absence of PrfA*, SigB activated the transcription of virulence genes such as inlA and inlB. In the presence of PrfA*, SigB negatively influenced the transcription of genes in the PrfA core regulon. The observed effect of SigB on the transcript level of PrfA regulated genes was shown to reduce the cytotoxic effect of the PrfA* allele in HepG-2 cells. Our results indicate that the SigB-PrfA regulatory network is important for the adjustment of virulence gene transcription to ensure L. monocytogenes success as an intracellular pathogen. Keywords: comparison of gene expression of regulatory mutants
2008-10-01 | GSE11347 | GEO
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2016-11-14 | GSE87036 | GEO
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