Saccharomyces cerevisiae
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA132331 | ENA |
REPOSITORIES: ENA
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Project description:The basic unit of genome packaging is the nucleosome, and nucleosomes have long been proposed to restrict DNA accessibility both to damage and to transcription. However, nucleosome number in cells was considered fixed, and no condition was described where nucleosome number was reduced. We show here that mammalian cells lacking High Mobility Group Box 1 protein (HMGB1) contain a reduced amount of core, linker and variant histones, and a correspondingly reduced number of nucleosomes. Yeast nhp6 mutants lacking NHP6A and –B proteins, which are related to HMGB1, also have a reduced amount of histones and fewer nucleosomes. Nucleosome limitation in both mammalian and yeast cells increases the sensitivity of DNA to damage, increases transcription globally, and the relative expression of about 10% of genes. In yeast nhp6 cells the loss of more than one nucleosome in four does not affect the location of nucleosomes and their spacing, but nucleosomal occupancy. The decrease in nucleosomal occupancy is non-uniform, and our results can be modelled assuming that different nucleosomal sites compete for the available histones: sites with high affinity are almost always packaged into nucleosomes both in wt and nucleosome-depleted cells, whereas sites with low affinity are less frequently packaged in nucleosome-depleted cells. We suggest that by modulating the occupancy of nucleosomes histone availability may constitute a novel layer of epigenetic regulation. This microarray experiment forms part of a larger study of the effects of nucleosome depletion on transcription Using the Affymetrix Yeast Genome 2.0 Array, yeast nhp6 mutants (lacking NHP6A and NHP6B proteins) were compared to wildtype yeast cells (3 biological replicates per condition)
2011-05-19 | E-GEOD-23711 | biostudies-arrayexpress
Project description:The basic unit of genome packaging is the nucleosome, and nucleosomes have long been proposed to restrict DNA accessibility both to damage and to transcription. However, nucleosome number in cells was considered fixed, and no condition was described where nucleosome number was reduced. We show here that mammalian cells lacking High Mobility Group Box 1 protein (HMGB1) contain a reduced amount of core, linker and variant histones, and a correspondingly reduced number of nucleosomes. Yeast nhp6 mutants lacking NHP6A and –B proteins, which are related to HMGB1, also have a reduced amount of histones and fewer nucleosomes. Nucleosome limitation in both mammalian and yeast cells increases the sensitivity of DNA to damage, increases transcription globally, and the relative expression of about 10% of genes. In yeast nhp6 cells the loss of more than one nucleosome in four does not affect the location of nucleosomes and their spacing, but nucleosomal occupancy. The decrease in nucleosomal occupancy is non-uniform, and our results can be modelled assuming that different nucleosomal sites compete for the available histones: sites with high affinity are almost always packaged into nucleosomes both in wt and nucleosome-depleted cells, whereas sites with low affinity are less frequently packaged in nucleosome-depleted cells. We suggest that by modulating the occupancy of nucleosomes histone availability may constitute a novel layer of epigenetic regulation.
2011-05-19 | GSE23711 | GEO
Project description:The canonical role of eEF1A is to deliver the aminoacyl tRNA to the ribosome, we have used the yeast model system to investigate further roles for this protein. We used microarray to study the transcriptomic effects of elevated levels of eEF1A on yeast cells during log phase growth
2016-10-29 | GSE89286 | GEO
Project description:A High Resolution Profile of NMD Substrates in Yeast
| PRJNA341846 | ENA
Project description:Oxidative stress is a key attribute that one should considered when using yeast cells for industrial applications due to its direct impact on yeast growth, viability, and productivity. However, little information is currently available regarding the molecular mechanisms of oxidative stress induction and the antioxidant response to increased reactive oxygen species (ROS) in yeasts. In this study, we generated experimentally evolved and genetically stable oxidative stress-resistant S. cerevisiae strain. This evolved strain has elevated trehalose and glycogen production, and up-regulated gene expression profile for that related to stress response, transport, carbohydrate, lipid and co-factor metabolic processes, protein phosphorylation, cell wall organization or biogenesis. In contrast, down-regulated genes were related to ribosome and RNA processing, nuclear transport, tRNA, cell cycle etc. In addition to that, comparative physiological, transcriptomic, and genomic analyses revealed that this oxidative stress resistant strain was also cross-resistant against other stress types including heat, freeze-thaw, ethanol, copper, and salt stress. Single variants identified via whole genome sequencing were primarily related to stress response, cell wall organization, carbohydrate metabolism/transport which support the physiological and transcriptomic results. Overall, this shed light how yeast cells can cope with oxidative stress pressure using their complex molecular mechanisms for the stress resistance and hints on how oxidative stress resistant S. cerevisiae strain can be generated for industrial applications.
2022-02-14 | GSE184952 | GEO
Project description:Second fermentation in a bottle supposes such specific conditions that undergo yeasts to a set of stress situations like high ethanol, low nitrogen, low pH or sub-optimal temperature. Also, yeast have to grow until 1 or 2 generations and ferment all sugar available while they resist increasing CO2 pressure produced along with fermentation. Because of this, yeast for second fermentation must be selected depending on different technological criteria such as resistance to ethanol, pressure, high flocculation capacity, and good autolytic and foaming properties. All of these stress factors appear sequentially or simultaneously, and their superposition could amplify their inhibitory effects over yeast growth. Considering all of the above, it has supposed interesting to characterize the adaptive response of commercial yeast strain EC1118 during second-fermentation experiments under oenological/industrial conditions by transcriptomic profiling. We have pointed ethanol as the most relevant environmental condition in the induction of genes involved in respiratory metabolism, oxidative stress, autophagy, vacuolar and peroxisomal function, after comparison between time-course transcriptomic analysis in alcoholic fermentation and transcriptomic profiling in second fermentation. Other examples of parallelism include overexpression of cellular homeostasis and sugar metabolism genes. Finally, this study brings out the role of low-temperature on yeast physiology during second-fermentation.
2011-05-31 | GSE29273 | GEO
Project description:The yeast protein kinases Sat4/Hal4 and Hal5 are required for the plasma membrane stability of the K+ transporter Trk1 and some amino acid and glucose permeases. The transcriptomic analysis presented here indicates alterations in the general control of both nitrogen and carbon metabolism. Accordingly, we observed reduced uptake of methionine and leucine in the hal4 hal5 mutant. This decrease correlates with activation of the Gcn2-Gcn4 pathway, as measured by expression of the lacZ gene under the control of the Gcn4 promoter. However, with the exception of methionine biosynthetic genes, few amino acid biosynthetic genes are induced in the hal4 hal5 mutant, whereas several genes involved in amino acid catabolism are repressed. Concerning glucose metabolism, we found that this mutant exhibits derepression of respiratory genes in the presence of glucose, leading to an increased activity of mitochondrial enzymes, as measured by SDH activity. In addition, the reduced glucose consumption in the hal4 hal5 mutant correlates with a more acidic intracellular pH and with low activity of the plasma membrane H+-ATPase. As a compensatory mechanism for the low glycolytic rate, the hal4 hal5 mutant overexpresses the HXT4 high affinity glucose transporter and the hexokinase genes. These results indicate that the hal4 hal5 mutant presents defects in the general control of nitrogen and carbon metabolism, which correlate with reduced transport of amino acids and glucose, respectively. A more acidic intracellular pH may contribute to some defects of this mutant.
2010-07-17 | GSE22976 | GEO
Project description:The yeast protein kinases Sat4/Hal4 and Hal5 are required for the plasma membrane stability of the K+ transporter Trk1 and some amino acid and glucose permeases. The transcriptomic analysis presented here indicates alterations in the general control of both nitrogen and carbon metabolism. Accordingly, we observed reduced uptake of methionine and leucine in the hal4 hal5 mutant. This decrease correlates with activation of the Gcn2-Gcn4 pathway, as measured by expression of the lacZ gene under the control of the Gcn4 promoter. However, with the exception of methionine biosynthetic genes, few amino acid biosynthetic genes are induced in the hal4 hal5 mutant, whereas several genes involved in amino acid catabolism are repressed. Concerning glucose metabolism, we found that this mutant exhibits derepression of respiratory genes in the presence of glucose, leading to an increased activity of mitochondrial enzymes, as measured by SDH activity. In addition, the reduced glucose consumption in the hal4 hal5 mutant correlates with a more acidic intracellular pH and with low activity of the plasma membrane H+-ATPase. As a compensatory mechanism for the low glycolytic rate, the hal4 hal5 mutant overexpresses the HXT4 high affinity glucose transporter and the hexokinase genes. These results indicate that the hal4 hal5 mutant presents defects in the general control of nitrogen and carbon metabolism, which correlate with reduced transport of amino acids and glucose, respectively. A more acidic intracellular pH may contribute to some defects of this mutant. Four biological replicates were used to assess diferentially expression between wild type yeast strain and the hal4hal5 mutant strain for three sample sets: 1) cells grown in YPD pH 4.5 and BY4741 genetic background, 2) cells grown in YPD pH 4.5 and W303 genetic background, 3) cells grown in YPD pH 6.0 and W303 genetic background. Differentially expressed genes were identified using one-class significant analysis of microarrays (SAM; Tusher et al, 2004)
2010-07-17 | E-GEOD-22976 | biostudies-arrayexpress
Project description:Yeast cell cycle microarray to identify global trancription profile. Keywords: cell cycle time course
2006-06-01 | GSE3635 | GEO
Project description:Comparative transcriptomic analysis between a high and a low sulfite producers wine yeast strains
| PRJNA238483 | ENA