Quantitative transcriptome analysis of a high-GSH producing Saccharomyces cerevisiae and the wild type based on the second generation sequencing.
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ABSTRACT: The mutant Saccharomyces cerevisiae Y518 generated much more intracellular glutathione (GSH) than its counterpart dose. The RNA-seq based global transcriptome analysis was performed for exploring the potential mechanisms. Statistical analysis indicated that 1125 differentially expressed genes (fold-change>=2.0, FDR<=0.001) were up-regulated and 503 were down-regulated. There were 12 genes involved in glutathione metabolism. Of which GSH1, encodes gamma-glutamine cysteine synthetase, the rate-limiting enzyme in GSH biosynthesis process, was up-regulated. And MET17, encodes cysteine synthase A, an enzyme catalyzes the biosynthesis of one of the precursor amino acids L- cysteine, was also up-regulated. Besides, regulator SKN7 and several genes involved in oxidative stress response (GPX2, CTT1, SOD1, TRX2) were up-regulated. Intracellular ROS level of Y518 was also enhanced compared to that of 2-10515. Our results indicate that up-regulations of GSH1 and MET17 might be associated with the increased intracellular GSH content of the mutant, and up-regulated GSH1 may be caused by increased intracellular ROS level. Saccharomyces cerevisiae mRNA profiles of 24-h wild type 2-10515 and mutant Y518 were generated by deep sequencing using Illumina HiSeqTM 2000
Project description:The mutant Saccharomyces cerevisiae Y518 generated much more intracellular glutathione (GSH) than its counterpart dose. The RNA-seq based global transcriptome analysis was performed for exploring the potential mechanisms. Statistical analysis indicated that 1125 differentially expressed genes (fold-change>=2.0, FDR<=0.001) were up-regulated and 503 were down-regulated. There were 12 genes involved in glutathione metabolism. Of which GSH1, encodes gamma-glutamine cysteine synthetase, the rate-limiting enzyme in GSH biosynthesis process, was up-regulated. And MET17, encodes cysteine synthase A, an enzyme catalyzes the biosynthesis of one of the precursor amino acids L- cysteine, was also up-regulated. Besides, regulator SKN7 and several genes involved in oxidative stress response (GPX2, CTT1, SOD1, TRX2) were up-regulated. Intracellular ROS level of Y518 was also enhanced compared to that of 2-10515. Our results indicate that up-regulations of GSH1 and MET17 might be associated with the increased intracellular GSH content of the mutant, and up-regulated GSH1 may be caused by increased intracellular ROS level.
Project description:Keeping imbibed seeds at low temperatures for a certain period, so called seed vernalization (SV) treatment, promotes seed germination and subsequent flowering in various plants. Vernalization-promoting flowering requires GSH. However, the expression patterns analyzed by GeneChip arrays showed that increased GSH biosynthesis partially mimics SV treatment in Arabidopsis thaliana. SV treatment (keeping imbibed seeds at 4°C for 24 h) induced a specific pattern of gene expression and promoted subsequent flowering in wild-type plants. A similar pattern was observed at 22°C in transgenic plants (35S-GSH1 plants) overexpressing the γ-glutamylcysteine synthetase gene GSH1, coding an enzyme limiting GSH biosynthesis, under the control of the cauliflower mosaic virus 35S promoter. This pattern was strengthened at 4°C but flowering was less responsive to SV treatment. There was a difference in the transcript behaviour of the flowering repressor FLC between wild-type and 35S-GSH1 plants. Unlike other genes responsive to SV treatment, SV-dependent decrease in FLC in wild-type plants was reversed in 35S-GSH1 plants. SV treatment increased GSSG level in wild-type seeds, whereas GSSG level was high in 35S-GSH1 plants, even at a non-vernalizing temperature. Taking into consideration that low temperatures stimulate GSH biosynthesis and bring about oxidative stress, GSSG is considered to trigger low temperature response, but enhanced GSH synthesis was not enough for mimicking SV treatment. To complete it, it essentially required the cellular redox retransition from the oxidized to the reduced state that is observed after the seed vernalization treatment. Four samples (Col-0 and 35S-GSH1 seeds imbibed at 22˚C or 4˚C). Two replicates for each samples.
Project description:The essential thiol antioxidant, glutathione (GSH) is recruited into the nucleus of mammalian cells early in cell proliferation, suggesting a key role of the nuclear thiol pool in cell cycle regulation. However, the functions of nuclear GSH (GSHn) and its integration with the cytoplasmic GSH (GSHc) pools in whole cell redox homeostasis and signaling are unknown. Here we show that GSH is recruited into the nucleus early in cell proliferation in Arabidopsis thaliana, confirming the requirement for localization of GSH in the nucleus as a universal feature of cell cycle regulation. GSH accumulation in the nucleus was triggered by treatments that synchronize cells at G1/S as identified by flow cytometry and marker transcripts. Significant decreases in transcripts associated with oxidative signaling and stress tolerance occurred when GSH was localized in the nucleus. Increases in GSH1 and GSH2 transcripts accompanied the large increase in total cellular GSH observed during cell proliferation, but only GSH2 was differentially expressed in cells with high GSHn relative to those with an even intracellular distribution of GSH. Of the 7 Bcl-2 associated (BAG) genes in A. thaliana, only the nuclear-localized BAG 6 was differentially expressed in cells with high GSHn compared to GSHc. We conclude that GSHn is associated with decreased oxidative signaling and stress responses and that whole cell redox homeostasis is restored as the cell cycle progresses by enhanced GSH synthesis and accumulation in the cytoplasm. Arabidopsis cells were harvested at points during cell proliferation where GSH was localized either in the nucleus (GSHn) or where GSH was distributed throughout the cytoplasm (GSHc) for RNA extraction and hybridization on Affymetrix microarrays. We selected three stages where the GSH was into the nucleus and three stages where the GSH was distributed throughout the cells.
Project description:Keeping imbibed seeds at low temperatures for a certain period, so called seed vernalization (SV) treatment, promotes seed germination and subsequent flowering in various plants. Vernalization-promoting flowering requires GSH. However, the expression patterns analyzed by GeneChip arrays showed that increased GSH biosynthesis partially mimics SV treatment in Arabidopsis thaliana. SV treatment (keeping imbibed seeds at 4°C for 24 h) induced a specific pattern of gene expression and promoted subsequent flowering in wild-type plants. A similar pattern was observed at 22°C in transgenic plants (35S-GSH1 plants) overexpressing the γ-glutamylcysteine synthetase gene GSH1, coding an enzyme limiting GSH biosynthesis, under the control of the cauliflower mosaic virus 35S promoter. This pattern was strengthened at 4°C but flowering was less responsive to SV treatment. There was a difference in the transcript behaviour of the flowering repressor FLC between wild-type and 35S-GSH1 plants. Unlike other genes responsive to SV treatment, SV-dependent decrease in FLC in wild-type plants was reversed in 35S-GSH1 plants. SV treatment increased GSSG level in wild-type seeds, whereas GSSG level was high in 35S-GSH1 plants, even at a non-vernalizing temperature. Taking into consideration that low temperatures stimulate GSH biosynthesis and bring about oxidative stress, GSSG is considered to trigger low temperature response, but enhanced GSH synthesis was not enough for mimicking SV treatment. To complete it, it essentially required the cellular redox retransition from the oxidized to the reduced state that is observed after the seed vernalization treatment.
Project description:The essential thiol antioxidant, glutathione (GSH) is recruited into the nucleus of mammalian cells early in cell proliferation, suggesting a key role of the nuclear thiol pool in cell cycle regulation. However, the functions of nuclear GSH (GSHn) and its integration with the cytoplasmic GSH (GSHc) pools in whole cell redox homeostasis and signaling are unknown. Here we show that GSH is recruited into the nucleus early in cell proliferation in Arabidopsis thaliana, confirming the requirement for localization of GSH in the nucleus as a universal feature of cell cycle regulation. GSH accumulation in the nucleus was triggered by treatments that synchronize cells at G1/S as identified by flow cytometry and marker transcripts. Significant decreases in transcripts associated with oxidative signaling and stress tolerance occurred when GSH was localized in the nucleus. Increases in GSH1 and GSH2 transcripts accompanied the large increase in total cellular GSH observed during cell proliferation, but only GSH2 was differentially expressed in cells with high GSHn relative to those with an even intracellular distribution of GSH. Of the 7 Bcl-2 associated (BAG) genes in A. thaliana, only the nuclear-localized BAG 6 was differentially expressed in cells with high GSHn compared to GSHc. We conclude that GSHn is associated with decreased oxidative signaling and stress responses and that whole cell redox homeostasis is restored as the cell cycle progresses by enhanced GSH synthesis and accumulation in the cytoplasm.
Project description:Glutathione (GSH) is a critical endogenous antioxidant that protects against intracellular oxidative stress. As such, pathological alterations in GSH levels are linked to a myriad of diseases including cancer, neurodegeneration and cataract. The rate limiting step in GSH biosynthesis is catalyzed by the glutamate cysteine ligase catalytic subunit (GCLC). The high expression of GCLC in the lens supports the synthesis of millimolar concentrations of GSH in this tissue. Herein, we describe the morphological consequences of deleting (knocking out) Gclc from surface ectoderm-derived ocular tissues (using the Le-Cre transgene; Gclc KO) which includes an overt microphthalmia phenotype and severely disrupted formation of multiple ocular structures (i.e., cornea, iris, lens, retina). Controlling for the Le-Cre transgene revealed that the deletion of Gclc significantly exacerbated the microphthalmia phenotype in Le-Cre hemizygous mice and resulted in dysregulated gene expression that was unique to only the lenses of KO mice. We further characterized the impaired lens development by conducting an RNA-seq experiment on KO and Gclc control (CON) mouse lens at the day of birth. RNA-sequencing revealed significant differences between Gclc knockout (KO) and Gclc control (CON) lenses, including down-regulation of crystallins and lens fiber cell identity genes, and up-regulation of lens epithelial cell identity genes. In addition, genes related to the immune system (e.g., immune system process, inflammatory response, neutrophil chemotaxis) were upregulated, and genes related to eye/lens development were downregulated. TRANSFAC analysis of differentially expressed genes (DEGs) in the lens of Gclc KO mice implicated PAX6 as a key upstream regulator of Gclc KO sensitive genes. This was further supported by a strong positive correlation between the transcriptomes of the lenses of Gclc KO and Pax6 KO mice. Strikingly, the dysregulation of PAX6-regulated genes in Gclc KO mice was observed despite no change in the ocular localization of PAX6 or decrease in the expression of PAX6 in the lens. In vitro experiments demonstrated that suppression of intracellular GSH concentrations resulted in impairment of PAX6 transactivation activity. Taken together, the present results elucidate a novel mechanism wherein intracellular GSH concentrations may modulate PAX6 activity.
Project description:Here, gene profiles in rat spermatogonial stem cell lines are compared to publicly available mouse, monkey and human spermatogonial gene profiles. Interestingly, rat spermatogonia expressed metabolic control factors Foxa1, Foxa2 and Foxa3. Germline Foxa2 was enriched in Gfra1Hi and Gfra1Low undifferentiated A-single spermatogonia. Foxa2-bound loci in spermatogonial chromatin were over-represented by conserved stemness genes (Dusp6, Gfra1, Etv5, Rest, Nanos2, Foxp1) that intersect bioinformatically with conserved glutathione/pentose phosphate metabolism genes (Tkt, Gss, Gclc, Gclm, Gpx1, Gpx4, Fth), marking elevated spermatogonial GSH:GSSG. Cystine-uptake and intracellular conversion to cysteine typically couple glutathione biosynthesis to pentose phosphate metabolism. Rat spermatogonia, curiously, displayed poor germline stem cell viability in cystine-containing media, and, like primate spermatogonia, exhibited reduced transsulfuration pathway markers. Exogenous cysteine, cysteine-like mercaptans, somatic testis cells and ferroptosis inhibitors counteracted the cysteine starvation-induced spermatogonial death and stimulated spermatogonial growth factor activity in vitro.
Project description:The rate-limiting step in glutathione (GSH) synthesis is controlled by glutamate-cysteine ligase catalytic subunit. To investigate the impact of GSH in vivo, we induced a deletion of Gclc using a Gclcf/f Rosa26-CreERT2 mouse model and harvested liver tissue for analysis.
Project description:GSH, being a versatile molecule, is actively involved in various bilogical processe of plant system. Our previous studies identifies an active role of GSH in plant defense signaling network. Here, we used microarray under GSH treated condition to obtain a global expression profiling under this altered GSH conditions. We used microarrays to detail the global programme of gene expression underlying cellularisation and identified distinct classes of up-regulated genes during this process. A.thaliana, much accalimed model system of plant biology and being fully sequenced, we used this system to explore the specific relation of GSH with metabolic processes, phisiological conditions, etc.