Comparative microarray analysis of S. pombe wild type, pka1-, pka1- rst2- and pka1- atf1- strains.
Ontology highlight
ABSTRACT: To identify common gene targets regulated by the Pka1-Rst2 and Sty1-Atf1 transcriptional branches involved in the glucose-dependent induction of autophagy at a global scale. DNA microarrays were used to comparatively measure the gene expression profile in wild type, pka1∆, pka1∆ rst2∆, and pka1∆ atf1∆ cells growing exponentially in glucose-rich medium. Data from two biological replicates were included for each strain genotype.
Project description:Gene expression was monitored in the knockout of two transcription factors, Pcr1 and Atf1, in the presence and absence of oxidative stress induced by KCl.
Project description:Atf1 was overexpressed in wt S. pombe cells for 24 hours and gene expression changes were analysed all samples were processed in duplicates. Gene expression in cells overexpressing ATf1 was compared with respect to the levels in control cells transformed with the empty vector.
Project description:Here we present the study on ChIP-chip mapping of the genomic binding sites for Sty1, Atf1, and the Atf1's binding partner Pcr1; the genome-wide transcriptional profiling of the atf1 and pcr1 strains in response to H2O2; and the phenotypic assessment of ~90 Atf1/Pcr1-bound or unbound genes for growth fitness under H2O2 conditions. ChIP-chip analysis shows that Atf1 and Pcr1 binding sites are overlapped in the genome and constitutively present before H2O2 stress. On the other hand, Sty1 recruitment primarily occurs at the Atf1/Pcr1 binding sites and is induced by H2O2. We found that Atf1/Pcr1 is clearly responsible for the high-level transcriptional response to H2O2. Furthermore, phenotypic assessment indicates that among the H2O2-induced genes, Atf1/Pcr1-bound genes exhibit a higher likelihood of functional requirement for growth fitness under the stress condition than the Atf1/Pcr1-unbound genes do. Notably, we found that the Atf1/Pcr1-bound genes regardless of their responsiveness to H2O2 show a high probability of requirement for growth fitness. . Expression level of genes in triplicates at 0min (without stress) is compared with that at 10, 30, 60, and 120min after stress treatment. ChIP-chip analyses is done for Atf1-HA, pcr1-HA, sty1-HA, Sty1-HA allele in the atf1D or pcr1D background without and with H2O2 (0.5mM for 30min).
Project description:Cells that have been pre-exposed to mild stress (priming stress) acquire transient resistance to subsequent severe stress even under different combinations of stresses. This phenomenon is called cross-tolerance. Although it has been reported that cross-tolerance occurs in many organisms, the molecular basis is not clear yet. Here, we identified slm9+ as a responsible gene for the cross-tolerance in the fission yeast Schizosaccharomyces pombe. Slm9 is a homolog of mammalian HIRA histone chaperone. HIRA forms a conserved complex and gene disruption of other HIRA complex components, Hip1, Hip3, and Hip4, also yielded a cross-tolerance-defective phenotype, indicating that the fission yeast HIRA is involved in the cross-tolerance as a complex. We also revealed that Slm9 was recruited to the stress-responsive gene loci upon stress treatment in an Atf1-dependent manner. The expression of stress-responsive genes under stress conditions was compromised in HIRA disruptants. Consistent with this, Pol II recruitment and nucleosome eviction at these gene loci were impaired in slm9D cells. Furthermore, we found that the priming stress enhanced the expression of stress-responsive genes in wild-type cells that were exposed to the severe stress. These observations suggest that HIRA functions in stress response through transcriptional regulation. To determine whether fission yeast HIRA specifically regulates stress-responsive genes under stress condition, we performed genome-wide analysis by using Affymetrix GeneChip oligonucleotide microarrays. Fission yeast cells (WT, slm9D, hip1D) were grown in quadruplicate at 32°C to the logarithmic phase and an aliquot was collected as the unstressed control. The other three aliquots were exposed to 40°C for 1 h, 25 mM H2O2 for 1 h, or 40°C for 1 h followed by 25 mM H2O2 for 1 h, respectively. Total RNA was purified and all the 12 RNA samples were analyzed with GeneChip Yeast Genome 2.0 Array (Affymetrix).
Project description:This is parallel comparison of gene regulation by Gcn5 in evolutionarily divergent yeasts S. pombe and S. cerevisiae. Our study showed Gcn5 is required for a similar spectrum of stress responses in both organisms, including the response to KCl. This DNA microarray studies is to find conserved or diverged gene regulation pattern under KCl stress condition in the two yeasts. There are 6 subsets in total, 3 subsets in each evolutionarily divergent yeasts including the following: 1 gcn5 mutant compared to wt under rich medium without treatment, 2 gcn5 mutant compared to wild type both under KCl treatment, 3 wild type strains under KCl treatment compared to wild type without treatment. Keywords: stress response, Gcn5, Comparative genomics, Transcriptional co-activator Gene expression profiling experiment in which gene expression in logarithmically growing cultures of test groups was compared to that of the control groups in rich medium at 25C. There are 6 subsets in total, 3 subsets in each yeast including the following: 1 gcn5 mutant compared to wt under rich medium without treatment, 2 gcn5 mutant compared to wild type both under KCl treatment, 3 wild type strains under KCl treatment compared to wild type without treatment. RNA was extracted and subjected to cDNA expression profiling analysis using the established protocols (Xue et al, 2004). Independent RNA preparations were used to hybridize to microarray slides with dye swap. Data normalized with 'Lowess' per chip per spot normalization.
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)
Project description:Here we present the study on ChIP-chip mapping of the genomic binding sites for Sty1, Atf1, and the Atf1's binding partner Pcr1; the genome-wide transcriptional profiling of the atf1 and pcr1 strains in response to H2O2; and the phenotypic assessment of ~90 Atf1/Pcr1-bound or unbound genes for growth fitness under H2O2 conditions. ChIP-chip analysis shows that Atf1 and Pcr1 binding sites are overlapped in the genome and constitutively present before H2O2 stress. On the other hand, Sty1 recruitment primarily occurs at the Atf1/Pcr1 binding sites and is induced by H2O2. We found that Atf1/Pcr1 is clearly responsible for the high-level transcriptional response to H2O2. Furthermore, phenotypic assessment indicates that among the H2O2-induced genes, Atf1/Pcr1-bound genes exhibit a higher likelihood of functional requirement for growth fitness under the stress condition than the Atf1/Pcr1-unbound genes do. Notably, we found that the Atf1/Pcr1-bound genes regardless of their responsiveness to H2O2 show a high probability of requirement for growth fitness. .
Project description:Analysis of histone acetyl transferases (HATs) from the MYST and GNAT families in S. pombe to identify functional differences or overlap with regard to gene expression. Mutations were made to Elp3 and Gcn5 (GNAT family), and to Mst2 (MYST family). Mutants showed distinct phenotypes which were repressed or enhanced by mutant combinations. Mutations were made to Gcn5 (GNAT family), and to Mst2 (MYST family) in S. pombe. A treatment of 1M KCl was applied for 60min to some samples. RNA was extracted from the various mutants and hybridized on Eurogentec arrays.
Project description:Clear cell sarcoma (CCS) is an aggressive soft tissue malignant tumor characterized by a unique t(12; 22) translocation, leading to the expression of a chimeric EWS/ATF1 fusion gene. However, little is known about the mechanisms underlying how EWS/ATF1 is involved in the development of CCSs. In addition, the cells of origin for CCSs remain to be determined. We generated EWS/ATF1-inducible mice, and examined the effects of EWS/ATF1 expression in adult cells. We show that the forced expression of EWS/ATF1 results in the development of EWS/ATF1-dependent sarcomas in mice. The histology of EWS/ATF1-induced sarcomas resembles that of CCSs and EWS/ATF1-induced tumor cells express CCS-markers, such as S100, Sox10, and Mitf. A lineage tracing experiment revealed that such sarcomas are derived from neural crest-lineage cells. Finally, we found that EWS/ATF1 directly induces Fos in an ERK-independent manner, and demonstrated that the increased Fos expression is important for the active cell proliferation in not only EWS/ATF1-induced sarcomas, but also in human CCSs. Our results indicate that FOS, as well as EWS/ATF1 itself, could be a promising therapeutic target for the treatment of EWS/ATF1-related sarcomas.
Project description:In the fission yeast Schizosaccharomyces pombe, heterochromatic silencing is quite stable at pericentromeres but unstable at the mating-type (mat) locus under chronic heat stress. We found that the compromised gene silencing at the mat locus at elevated temperature is linked to the phosphorylation status of Atf1 (a member of the ATF/CREB superfamily) by Sty1, one of the mitogen-activated protein kinases (MAPKs). To gain a full picture of Sty1-dependent phosphosite map of Atf1 under heat stress, we purified HA-Atf1 protein from cultures of wild type and sty1Δ strains shifted from 25℃ to either 30℃ or 37℃ for 5 hr followed by immunoprecipitation. Samples were separated by SDS-PAGE, and Coomassie blue-stained gel slices were excised and submitted for mass spectrometry analyses.