ADH1 deletion cells upon growth on alternative carbon sources; Steady-state grown cells upon environmental perturbations
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ABSTRACT:
ORGANISM(S): Saccharomyces cerevisiae
PROVIDER: GSE6302 | GEO | 2007/02/28
SECONDARY ACCESSION(S): PRJNA100503
REPOSITORIES: GEO
Similar Datasets
Project description:Cells must adjust their gene expression in order to compete in a constantly changing environment. Two alternative strategies could in principle ensure optimal coordination of gene expression with physiological requirement. First, the internal physiological state itself could feedback to regulated gene expression. Second, the expected physiological state could be inferred from the external environment, using evolutionary-tuned signaling pathways. Coordination of ribosomal biogenesis with the requirement for protein synthesis appears to be particularly important, since cells devote a large fraction of their biosynthetic capacity for ribosomal biogenesis. To define the relative importance of internal vs. external sensing to the regulation of ribosomal biogenesis gene expression, we subjected S. cerevisiae cells to conditions which decoupled the actual vs. environmentally-expected growth rate. Gene expression followed the environmental signal according to the expected, but not the actual, growth rate. Simultaneous monitoring of gene expression and growth rate in chemostat-grown cultures further confirmed that ribosome biogenesis genes responded rapidly to changes in the environments but were oblivious to longer-term changes in growth rate. Our results suggest that the capacity to anticipate and prepare for environmental changes presented a major selection force during yeast evolution. Keywords: Saccharomyces_Cerevisiae, Stress response, ADH1 deletion, time courses, chemostat Experiment 1: ADH1 deletion cells, which grow faster on glycerol rather then glucose medium, were grown in both glucose and glycerol medium. The cells expression on glycerol is compared to their expression glucose (5 microarrays). Experiment 2: Time course of ADH1 deletion cells upon growth on glycerol and on glucose (7 microarrays). Experiment 3: Response of steady state grown cells to environmental perturbations. Cells were grown in glucose or histidine limited chemostats and reached steady state. The cells were then subjected to perturbations such as DTT, heat shock, NaCl, Clotrimazole, H2O2, and addition of limiting factors (histidine and glucose, respectively). Overall we have examined 10 timecourses with 83 microarrays.
2007-02-28 | E-GEOD-6302 | biostudies-arrayexpress
Project description:In Saccharomyces cerevisiae growth, size control and cell cycle progression are strictly coordinated and regulated according to the nutritional conditions. In particular, ribosome biogenesis appears a key event in this regulatory network. SFP1 encodes a zinc-finger protein promoting the transcription of a large cluster of genes involved in ribosome biogenesis. It has been suggested that Sfp1 is a cell size modulator acting at Start. To better study the regulatory role of Sfp1 and its putative involvement in cell size and cycle control, we analysed the behaviour of an sfp1 null mutant strain and of an isogenic reference strain growing in chemostat cultures. This approach allowed us to analyze both strains at the same specific growth rate, thus eliminating the secondary effects due to the slow growing phenotype that the sfp1 null mutant shows in shake flask. We studied glucose(anaerobic)- and ethanol(aerobic)-limited cultures, as paradigms of two different metabolic states. Major alterations of the transcriptional profile were observed during growth on glucose, while no significant differences were observed when comparing ethanol growing cultures. In particular, in the former growth condition, Sfp1 appears involved in the control of ribosome biogenesis but not of ribosomal protein gene expression. Experiment Overall Design: The reference S. cerevisiae strain CEN.PK113.7D and the isogenic sfp1 null mutant were grown in chemostat cultures under ethanol(aerobic)- and glucose(anaerobic)- limitation. The dilution rate was set at 0.10 h-1 and 0.05 h-1 for ethanol- and glucose-limited cultures, respectively. A genome-wide transcriptional analysis was performed for the reference and the sfp1 null mutant strains for each growth condition. All data presented in this work were derived from three independent chemostat cultures (12 samples in total were analysed).
2008-06-13 | E-GEOD-5238 | biostudies-arrayexpress
Project description:Catabolic and anabolic processes are finely coordinated in microbes to provide optimized fitness under varying environmental conditions. Understanding this coordination and the resulting physiological traits identifies fundamental microbial strategies of acclimation. Here, we characterized the systems-level physiology of Methanococcus maripaludis, a niche-specialized methanogenic archaeon, at different growth rates under phosphate (i.e., anabolic) limitation. We observed a decoupling of catabolism and anabolism resulting in lower biomass yield relative to catabolically limited cells. In addition, the mass abundance of several coarse-grained proteome sectors exhibited a linear relationship with growth rate, most notably ribosomes and their biogenesis. Accordingly, cellular RNA content also correlated with growth rate. Although the methanogenesis proteome sector was invariant, the metabolic capacity for methanogenesis correlated with growth rate suggesting translationally independent regulation. These observations are in stark contrast to the physiology of M. maripaludis under formate (i.e., catabolic) limitation, where cells keep an invariant proteome including ribosomal content and a high methanogenesis capacity across a wide range of growth rates. Our findings reveal that although highly niche-specialized, M. maripaludis employs fundamentally different strategies to coordinate global physiology during anabolic phosphate and catabolic formate limitation.
2021-06-14 | MSV000087621 | MassIVE
Project description:Abstract: We studied the physiological response to glucose limitation in batch and steady-state (chemostat) cultures of Saccharomyces cerevisiae by following global patterns of gene expression. Glucose-limited batch cultures of yeast go through two sequential exponential growth phases, beginning with a largely fermentative phase, followed by an essentially completely aerobic use of residual glucose and evolved ethanol. Judging from the patterns of gene expression, the state of the cells growing at steady state in glucose-limited chemostats corresponds most closely with the state of cells in batch cultures just before they undergo this "diauxic shift." Essentially the same pattern was found between chemostats having a fivefold difference in steady-state growth rate (the lower rate approximating that of the second phase respiratory growth rate in batch cultures). Although in both cases the cells in the chemostat consumed most of the glucose, in neither case did they seem to be metabolizing it primarily through respiration. Although there was some indication of a modest oxidative stress response, the chemostat cultures did not exhibit the massive environmental stress response associated with starvation that also is observed, at least in part, during the diauxic shift in batch cultures. We conclude that despite the theoretical possibility of a switch to fully aerobic metabolism of glucose in the chemostat under conditions of glucose scarcity, homeostatic mechanisms are able to carry out metabolic adjustment as if fermentation of the glucose is the preferred option until the glucose is entirely depleted. These results suggest that some aspect of actual starvation, possibly a component of the stress response, may be required for triggering the metabolic remodeling associated with the diauxic shift. This SuperSeries is composed of the SubSeries listed below.
2006-03-08 | GSE4398 | GEO
Project description:Saccharomyces cerevisiae is bradytroph for class B vitamins, it means that yeast cells exhibit slower growth in the absence of an external source of these metabolites. Alleviating these nutritional requirements for optimal growth performance would represent a valuable phenotypic characteristic for industrial strains since this would result in cheaper processes that would also be less susceptible to contaminations. In the present study, suboptimal growth of S. cerevisiae in absence of either pantothenic acid, para-aminobenzoic acid (pABA), pyridoxine, inositol and biotin were corrected by single or double gene overexpression of ScFMS1, ScABZ1/ScABZ2, ScSNZ1/ScSNO1, ScINO1 and the Cyberlindnera fabianii BIO1, respectively. Several strategies were attempted to improve growth of S. cerevisiae CEN.PK113-7D in absence of thiamine, revealing that overexpression of ScTHI4 and ScTHI4/ScTHI5 improved growth up to 83% of the maximum specific growth rate of the reference CEN.PK113-7D in vitamins containing medium. By combining overexpression of solely seven S. cerevisiae genes and the heterologous CfBIO1, the strain IMX2816 was fast-growing at a maximum specific growth rate of 0.33 ± 0.01 h-1 in medium devoid of all vitamins. Secondly, this strain exhibited physiological performances in oxic glucose-limited chemostat cultures at a dilution rate of 0.1 h-1 in absence of vitamins similar to that of the reference strain CEN.PK113-7D grown in fully supplemented medium. These physiological similarities were further emphasized by the limited differences observed in comparative transcriptome analysis from the chemostat culture grown cells that were essentially affecting genes of the class B vitamins biosynthetic pathways. This work paves the way towards construction of the first fast growing vitamin-independent S. cerevisiae strain.
2023-02-21 | GSE225473 | GEO
Project description:This SuperSeries is composed of the following subset Series: GSE3205: Homeostatic Adjustment and Metabolic Remodeling in Glucose-limited Yeast Cultures Time Course 1 GSE3206: Homeostatic Adjustment and Metabolic Remodeling in Glucose-limited Yeast Cultures Time Course 2 Abstract: We studied the physiological response to glucose limitation in batch and steady-state (chemostat) cultures of Saccharomyces cerevisiae by following global patterns of gene expression. Glucose-limited batch cultures of yeast go through two sequential exponential growth phases, beginning with a largely fermentative phase, followed by an essentially completely aerobic use of residual glucose and evolved ethanol. Judging from the patterns of gene expression, the state of the cells growing at steady state in glucose-limited chemostats corresponds most closely with the state of cells in batch cultures just before they undergo this "diauxic shift." Essentially the same pattern was found between chemostats having a fivefold difference in steady-state growth rate (the lower rate approximating that of the second phase respiratory growth rate in batch cultures). Although in both cases the cells in the chemostat consumed most of the glucose, in neither case did they seem to be metabolizing it primarily through respiration. Although there was some indication of a modest oxidative stress response, the chemostat cultures did not exhibit the massive environmental stress response associated with starvation that also is observed, at least in part, during the diauxic shift in batch cultures. We conclude that despite the theoretical possibility of a switch to fully aerobic metabolism of glucose in the chemostat under conditions of glucose scarcity, homeostatic mechanisms are able to carry out metabolic adjustment as if fermentation of the glucose is the preferred option until the glucose is entirely depleted. These results suggest that some aspect of actual starvation, possibly a component of the stress response, may be required for triggering the metabolic remodeling associated with the diauxic shift. Refer to individual Series
2006-03-07 | E-GEOD-4398 | biostudies-arrayexpress
Project description:In Saccharomyces cerevisiae growth, size control and cell cycle progression are strictly coordinated and regulated according to the nutritional conditions. In particular, ribosome biogenesis appears a key event in this regulatory network. SFP1 encodes a zinc-finger protein promoting the transcription of a large cluster of genes involved in ribosome biogenesis. It has been suggested that Sfp1 is a cell size modulator acting at Start. To better study the regulatory role of Sfp1 and its putative involvement in cell size and cycle control, we analysed the behaviour of an sfp1 null mutant strain and of an isogenic reference strain growing in chemostat cultures. This approach allowed us to analyze both strains at the same specific growth rate, thus eliminating the secondary effects due to the slow growing phenotype that the sfp1 null mutant shows in shake flask. We studied glucose(anaerobic)- and ethanol(aerobic)-limited cultures, as paradigms of two different metabolic states. Major alterations of the transcriptional profile were observed during growth on glucose, while no significant differences were observed when comparing ethanol growing cultures. In particular, in the former growth condition, Sfp1 appears involved in the control of ribosome biogenesis but not of ribosomal protein gene expression. Keywords: global transcriptional profile, genetic modification, ribosome biogenesis
2007-11-10 | GSE5238 | GEO
Project description:Saccharomyces cerevisiae is bradytroph for class B vitamins, it means that yeast cells exhibit slower growth in the absence of an external source of these metabolites. Alleviating these nutritional requirements for optimal growth performance would represent a valuable phenotypic characteristic for industrial strains since this would result in cheaper processes that would also be less susceptible to contaminations. In the present study, suboptimal growth of S. cerevisiae in absence of either pantothenic acid, para-aminobenzoic acid (pABA), pyridoxine, inositol and biotin were corrected by single or double gene overexpression of native FMS1, ABZ1/ABZ2, SNZ1/SNO1, INO1 and the Cyberlindnera fabianii BIO1, respectively. Several strategies were attempted to improve growth of S. cerevisiae CEN.PK113-7D in absence of thiamine, revealing that overexpression of THI4 and THI4/THI5 was able to improve growth up to 83% of the maximum specific growth rate of the reference CEN.PK113-7D in medium including all vitamins. Although the initial aim of this study was to combine all identified mutations in a single strain, the engineered strain IMX2210 only harboured genes to correct biotin, pABA, pantothenate and inositol bradotrophies. Firstly, this strain was fast-growing at a maximum specific growth rate of 0.28 ± 0.01 h-1 in medium devoid of all vitamins. Secondly, this strain exhibited physiological variables in aerobic glucose limited chemostat cultures at a dilution rate of 0.1 h-1 in absence of vitamins similar to that of the reference strain CEN.PK113-7D grown in the same conditions but in a fully supplemented complete medium. These physiological similarities were further emphasized by the limited differences observed in comparative transcriptome analysis from the chemostat culture grown cells that were essentially affecting genes of the class B vitamins biosynthetic pathways. This work paves the way towards construction of the first fast growing vitamin-independent S. cerevisiae strain.
2023-12-01 | GSE191212 | GEO
Project description:The development of transcriptomic tools has allowed exhaustive description of stress responses. These responses always superimpose a general response associated to growth rate decrease and a specific one corresponding to the stress. The exclusive growth rate response can be achieved through chemostat cultivation, enabling all parameters to remain constant except the growth rate. We analysed metabolic and transcriptomic responses of Lactococcus lactis in continuous cultures at different growth rates ranging from 0.09 to 0.47 h-1. Growth rate was conditioned by isoleucine supply. Although the metabolism was constant and homolactic, a widespread transcriptomic response involving 30 % of the genome was observed. The expression of genes encoding physiological functions associated with biogenesis increased with growth rate (transcription, translation, fatty acid and phospholipids metabolism). Many phages, prophages and transposons related genes were down regulated by growth rate suggesting genome plasticity to be involved in the adaptation to slow growth. The growth rate response was compared to carbon and amino-acid starvation transcriptomic responses, revealing constant and significant involvement of growth rate regulations in these two stressful conditions (overlap 26%). Although stringent response mechanism is considered as the one governing growth deceleration in bacteria, the rigorous comparison of the two transcriptomic responses clearly indicated the mechanisms are distinct. Moreover it was established that genes positively regulated by growth rate are preferentially located in the vicinity of replication origin while those negatively regulated are mainly encountered at the opposite. This result demonstrates the often neglected relationship between genes expression and their location on chromosome. Keywords: growth rate impact, continuous cultures
2009-04-28 | GSE10256 | GEO
Project description:Catabolic and anabolic processes are finely coordinated in microbes to provide optimized fitness under varying environmental conditions. Understanding this coordination and the resulting physiological traits identifies fundamental microbial strategies of acclimation. Here, we characterized the systems-level physiology of Methanococcus maripaludis, a niche-specialized methanogenic archaeon, at different growth rates under phosphate (i.e., anabolic) limitation. We observed a decoupling of catabolism and anabolism resulting in lower biomass yield relative to catabolically limited cells. In addition, the mass abundance of several coarse-grained proteome sectors exhibited a linear relationship with growth rate, most notably ribosomes and their biogenesis. Accordingly, cellular RNA content also correlated with growth rate. Although the methanogenesis proteome sector was invariant, the metabolic capacity for methanogenesis correlated with growth rate suggesting translationally independent regulation. These observations are in stark contrast to the physiology of M. maripaludis under formate (i.e., catabolic) limitation, where cells keep an invariant proteome including ribosomal content and a high methanogenesis capacity across a wide range of growth rates. Our findings reveal that although highly niche-specialized, M. maripaludis employs fundamentally different strategies to coordinate global physiology during anabolic phosphate and catabolic formate limitation.
2021-06-14 | MSV000087621 | GNPS