Comparing the transcriptional profiles of a Caulobacter crescentus CB15N (NA1000) wild-type to a SpoT null in carbon starvation.
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ABSTRACT:
ORGANISM(S): Caulobacter vibrioides
PROVIDER: GSE21206 | GEO | 2011/05/01
SECONDARY ACCESSION(S): PRJNA126293
REPOSITORIES: GEO
Similar Datasets
Project description:SpoT is an Rsh (Rel / Spo homolog) protein, which synthesizes the alarmone ppGpp in response to starvation. This experiment is quantifying transcription in two Caulobacter strains after 5 minutes of glucose starvation: one strain is wild-type CB15N (NA1000); the other strain is NA1000 which has a chromosomal in-frame deletion of the spoT gene. The wild-type strain can synthesize the alarmone ppGpp in response to starvation and the spoT null strain cannot. Both strains were cultured in M2 defined medium with glucose as the sole carbon source, and then washed and incubated in M2 medium lacking glucose for 5 minutes before RNA isolation. Triplicate cultures of: 1) C. crescentus strain CB15N , and 2) CB15N ?SpoT, cultured in M2-glucose media, then starved for glucose for 5 minutes.
2011-05-01 | E-GEOD-21206 | biostudies-arrayexpress
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2015-08-08 | GSE70092 | GEO
Project description:Transcriptional profiles of wildtype and mutant strains bt0700 and bt0700 bt3998 (ppGpp0) of human gut commensal B. thetaiotaomicron were collected to investigate the relevance of the stringent response mediated by the alarmone (p)ppGpp for growth and survival in three different conditions. RNAseq samples were taken during growth in glucose minimal medium, after 1h of carbon starvation, and after 6 days of monocolonizing germ-free mice (from cecum material).
2018-07-04 | E-MTAB-6412 | biostudies-arrayexpress
Project description:Growth curves and (p)ppGpp accumulation assays showed that RelA inactivation could influence S. suis growth and led to incapacity of (p)ppGpp synthesis during glucose starvation. To identify the roles of RelA/(p)ppGpp in global gene regulation in S. suis, we compared the transcriptional profiles of SC-19 [a (p)ppGpp+ strain] and ΔrelA [a (p)ppGpp0 strain during glucose starvation] in both glucose-abundant and -deficient CDM in exponential phase by microarray analysis. A less stringent cut-off limit, 2-fold change, was used. qRT-PCR validation displayed the same trends observed in the microarrays relA mutant strain and its parents strain SC-19 were cultured in both glucose-abundant CDM (CDM containing 1% glucose) and glucose-deficient CDM (CDM containing 2% glucose) respectively. The bacteriain in exponential phase were collected for microarray analysis. Three independent experiments were performed.
2015-08-08 | E-GEOD-70092 | biostudies-arrayexpress
Project description:All organisms are exposed to various stresses, necessitating adaptive strategies for survival and homeostasis. In bacteria, the main stress-coping mechanism is stringent response triggered by the accumulation of the “alarmone” (p)ppGpp to trigger proliferation arrest and transcriptional reprogramming. Mammalian genomes encode MESH1 —the homologue of the (p)ppGpp hydrolase SpoT, with unknown function. Therefore, we used microarrays to determine the transcriptional response to MESH1 silencing.
2022-08-31 | GSE135358 | GEO
Project description:Transcription profiling of wild type, relA-, and relA-spoT-, crp-, dksA-, rpoS-, lrp- mutant strains of E. coli starved for isoleucine Bacteria comprehensively reorganize their global gene expression when faced with nutrient exhaustion. In Escherichia coli and other free-living bacteria, the alarmone ppGpp facilitates this massive response by directly or indirectly coordinating the down-regulation of genes of the translation apparatus, and the induction of biosynthetic genes and the general stress response. Such a large reorientation likely requires the cooperative activities of many different genetic regulators, yet the structure of the transcription network below the level of ppGpp remains poorly defined. Using isoleucine starvation as an experimental model system for amino acid starvation, we identified genes that required ppGpp, Lrp, and RpoS for their induction. Surprisingly, despite the fact that the overwhelming majority of genes controlled by Lrp and RpoS required ppGpp for their activation, we found that these two regulons were not induced simultaneously. The data reported here suggest that metabolic genes, such as those of the Lrp regulon, require only a low basal level of ppGpp for their efficient induction. In contrast, the RpoS-dependent general stress response is not robustly induced until relatively high levels of ppGpp accumulate. Here we describe a data-driven conceptual model that explains how bacterial cells allocate transcriptional resources between metabolic and stress survival processes by discretely tuning regulatory activities to a central indicator of cellular physiology. The regulatory structure that emerges is consistent with a rheostatic model of the stringent response that allows cells to efficiently adapt to a wide range of nutritional environments. Keywords: genetic modification design; stress response; isoleucine starvation Two experiments were run. First experiment: WT and several mutant strains were starved for isoleucine (exhaustion of 60 uM ile). 40 minutes after starvation, RNA was extracted. All samples were compared to RNA from rapidly growing WT cells in identical medium replete with isoleucine (400 uM). 16 samples were hybridized: duplicates of 8 strains/conditions. Wildtype in log phase (OD = 0.4) with replete ile was control for ile starved samples. Second experiment: WT strain was starved for isoleucine (exhaustion of 60 uM ile). RNA was extracted at 12 timepoints as the cells entered stationary phase. All samples were compared to RNA from rapidly growing WT cells in identical medium replete with isoleucine (400 uM). 14 samples were hybridized: duplicates of the control condition and single timepoints during starvation. Wildtype in log phase (OD = 0.4) with replete ile was control for ile starved samples.
2008-04-08 | E-GEOD-11087 | biostudies-arrayexpress
Project description:The alarmone species ppGpp and pppGpp are an important part of bacterial physiology as they both coordinate the bacterial stress response to nutrient deficiency and also contribute to the maintenance of cell homeostasis. Recently, all components of the (p)ppGpp metabolism for the industrially relevant actinobacterial model organism Corynebacterium glutamicum could be functionally characterized by in vitro analysis and heterologous expression in the model system Escherichia coli. Based on these results, the strain C. glutamicum CR099 ΔrelΔrelSΔrelH is the first C. glutamicum (p)ppGpp0 strain available. The aim of this study was to investigate the effects of the alarmone species on transcriptome regulation in C. glutamicum by differential transcriptome analysis of the parental strain and the (p)ppGpp0 mutant. An RNAseq analysis of the early exponential growth phase was performed to analyze the (p)ppGpp basal level effects (Illumina TruSeq stranded mRNA libraries sequenced on Illumina HiSeq rapid mode 2 x 25nt PE). Due to the direct association of the alarmones with the bacterial stress response, the transcriptional response to the induction of a total starvation situation was investigated in form of a time series. Following an analysis of pooled replicates for 5 time points (Illumina TruSeq stranded mRNA libraries sequenced on Illumina HiSeq rapid mode 2 x 50nt PE), a detailed investigation was carried out for two stress exposure durations using three biological replicates per strain and time point each (Illumina TruSeq stranded mRNA libraries sequenced on Illumina HiSeq rapid mode 2 x 25nt PE).
2019-12-02 | E-MTAB-8070 | biostudies-arrayexpress
Project description:Transcription profiling of wild type, relA-, and relA-spoT-, crp-, dksA-, rpoS-, lrp- mutant strains of E. coli starved for isoleucine Bacteria comprehensively reorganize their global gene expression when faced with nutrient exhaustion. In Escherichia coli and other free-living bacteria, the alarmone ppGpp facilitates this massive response by directly or indirectly coordinating the down-regulation of genes of the translation apparatus, and the induction of biosynthetic genes and the general stress response. Such a large reorientation likely requires the cooperative activities of many different genetic regulators, yet the structure of the transcription network below the level of ppGpp remains poorly defined. Using isoleucine starvation as an experimental model system for amino acid starvation, we identified genes that required ppGpp, Lrp, and RpoS for their induction. Surprisingly, despite the fact that the overwhelming majority of genes controlled by Lrp and RpoS required ppGpp for their activation, we found that these two regulons were not induced simultaneously. The data reported here suggest that metabolic genes, such as those of the Lrp regulon, require only a low basal level of ppGpp for their efficient induction. In contrast, the RpoS-dependent general stress response is not robustly induced until relatively high levels of ppGpp accumulate. Here we describe a data-driven conceptual model that explains how bacterial cells allocate transcriptional resources between metabolic and stress survival processes by discretely tuning regulatory activities to a central indicator of cellular physiology. The regulatory structure that emerges is consistent with a rheostatic model of the stringent response that allows cells to efficiently adapt to a wide range of nutritional environments. Keywords: genetic modification design; stress response; isoleucine starvation
2008-04-08 | GSE11087 | GEO
Project description:The gene encoding the conserved bacterial G protein CgtA (Obg) is essential for viability in every organism in which it has been studied. CgtA has been reported to be involved in several diverse bacterial functions, including ribosome assembly, DNA repair, sporulation and morphological development. However, none of these functions have been identified as essential. Here we show that depletion of CgtA in Vibrio cholerae causes global changes in gene expression that are consistent with induction of a classical low nutrient stress response or “stringent” response. We show that depletion of CgtA leads to increased ppGpp levels which correlates with induction of the global stress response and cessation of growth. The enzyme RelA is responsible for synthesis of the alarmone ppGpp during the stringent response. We show that CgtA is no longer essential in a relA deletion mutant and thus conclude that the essentiality of CgtA is directly linked to its ability to affect ppGpp levels. The enzyme SpoT degrades ppGpp and here we show that SpoT is essential in a RelA+ CgtA+ background but not in a relA deletion mutant. We also confirmed that CgtA interacts with SpoT in a two-hybrid assay. We suggest that the essential function of CgtA is a repressor of the stringent response, and acts by regulating SpoT activity to maintain low ppGpp levels when bacteria are growing in a nutrient rich environment. This SuperSeries is composed of the SubSeries listed below.
2006-12-28 | GSE6618 | GEO
Project description:Guanosine 3 ,5 -bispyrophosphate (ppGpp), also known as ‘‘magic spot,’’ has been shown to bind prokaryotic RNA polymerase to down-regulate ribosome production and increase transcription of amino acid biosynthesis genes during the stringent response to amino acid starvation. Because many environmental growth perturbations cause ppGpp to accumulate, we hypothesize ppGpp to have an overarching role in regulating the genetic program that coordinates transitions between logarithmic growth (feast) and growth arrest (famine). We used the classic glucose-lactose diauxie as an experimental system to investigate the temporal changes in transcription that accompany growth arrest and recovery in wildtype Escherichia coli and in mutants that lack RelA (ppGpp synthetase) and other global regulators, i.e., RpoS and Crp. When cultured on a mixture of glucose and lactose, E. coli grows preferentially on glucose until it is exhausted, resulting in growth arrest while the cells adjust to growth on lactose, i.e., diauxie. Diauxie was delayed in the relA mutant and was accompanied by a 15% decrease in the number of carbon sources used and a 3-fold overall decrease in the induction of RpoS and Crp regulon genes. Thus the data significantly expand the previously known role of ppGpp and support a model wherein the ppGpp-dependent redistribution of RNA polymerase across the genome is the driving force behind control of the stringent response, general stress response, and starvation-induced carbon scavenging. Our conceptual model of diauxie describes these global control circuits as dynamic, interconnected, and dependent upon ppGpp for the efficient temporal coordination of gene expression that programs the cell for transitions between feast and famine.
2007-03-17 | GSE7265 | GEO