scholarly journals Importance of glucose-6-phosphate dehydrogenase in the adaptive response to hydrogen peroxide in Saccharomyces cerevisiae

1998 ◽  
Vol 330 (2) ◽  
pp. 811-817 ◽  
Author(s):  
Shingo IZAWA ◽  
Keiko MAEDA ◽  
Takeo MIKI ◽  
Junichi MANO ◽  
Yoshiharu INOUE ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Saccharomyces Cerevisiae ◽  
Adaptive Response ◽  
Yeast Cells ◽  
Wild Type ◽  
Total Glutathione ◽  
Dependent Activity ◽  
Increased Sensitivity ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Increased Susceptibility

Glucose-6-phosphate dehydrogenase (G6PDH)-deficient cells of Saccharomyces cerevisiae showed increased susceptibility and were unable to induce adaptation to oxidative stress. Historically, mainly in human erythrocytes, it has been suggested and accepted that decreased cellular GSH, due to loss of the NADPH-dependent activity of glutathione reductase (GR), is responsible for the increased sensitivity to oxidative stress in G6PDH-deficient cells. In the present study we investigated whether the increased susceptibility and the inability to induce adaptation to H2O2 stress of G6PDH-deficient yeast is caused by incompleteness of glutathione recycling. We constructed G6PDH- and GR-deficient mutants and analysed their adaptive response to H2O2 stress. Although G6PDH-deficient cells contained comparable amounts of GSH and GR activity to wild-type cells, GSSG was not reduced efficiently, and intracellular GSSG levels and the ratio of GSSG to total glutathione (GSSG/tGSH) were higher in G6PDH-deficient cells than in wild-type. On the other hand, GR-deficient cells showed a susceptibility identical with that of wild-type cells and induced adaptation to H2O2 stress, even though the GSSG/tGSH ratio in GR-deficient cells was higher than in G6PDH-deficient cells. These results indicate that incompleteness of glutathione recycling alone is not sufficient to account for the increased sensitivity and inability to induce adaptation to H2O2 stress of G6PDH-deficient yeast cells. In S. cerevisiae, G6PDH appears to play other important roles in the adaptive response to H2O2 stress besides supplying NADPH to the GR reaction.

scholarly journals Importance of catalase in the adaptive response to hydrogen peroxide: analysis of acatalasaemic Saccharomyces cerevisiae

1996 ◽  
Vol 320 (1) ◽  
pp. 61-67 ◽  
Author(s):  
Shingo IZAWA ◽  
Yoshiharu INOUE ◽  
Akira KIMURA
Keyword(s):  
Oxidative Stress ◽  
Saccharomyces Cerevisiae ◽  
Adaptive Response ◽  
Yeast Cells ◽  
Exponential Growth Phase ◽  
Wild Type ◽  
Single Mutant ◽  
Mutant Cells ◽  
Similar Growth

Controversy about the importance of catalase in the detoxification of H2O2 in human erythrocytes continues. It has been suggested that catalase has no role in the clearance of H2O2 in erythrocytes. In the present study we investigated the role of catalase in the defence mechanism against oxidative stress using Saccharomyces cerevisiae. S. cerevisiae has two catalases, catalase A and catalase T. We constructed a double mutant (acatalasaemic mutant) unable to produce either catalase A or catalase T, and compared it with wild-type and single-mutant cells. The acatalasaemic mutant cells showed a similar growth rate to wild-type cells under non-oxidative stress conditions, and showed a similar susceptibility to H2O2 stress in the exponential growth phase. The acatalasaemic mutant cells at stationary phase were, however, much more sensitive to H2O2 stress than wild-type and single-mutant cells. Moreover, the ability of acatalasaemic and single-mutant cells to show adaptation to 2 mM H2O2 was distinctly inferior to that of wild-type cells. These results suggest that catalase is not essential for yeast cells under normal conditions, but plays an important role in the acquisition of tolerance to oxidative stress in the adaptive response of these cells.

scholarly journals Screening for Modulators of Spermine Tolerance Identifies Sky1, the SR Protein Kinase of Saccharomyces cerevisiae, as a Regulator of Polyamine Transport and Ion Homeostasis

2001 ◽  
Vol 21 (1) ◽  
pp. 175-184 ◽  
Author(s):  
Omri Erez ◽  
Chaim Kahana
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Osmotic Shock ◽  
Ion Homeostasis ◽  
Inorganic Ions ◽  
Yeast Cells ◽  
Wild Type ◽  
Sr Protein ◽  
Polyamine Transport ◽  
Increased Sensitivity

ABSTRACT Although most cells are capable of transporting polyamines, the mechanism that regulates polyamine transport in eukaryotes is still largely unknown. Using a genetic screen for clones capable of restoring spermine sensitivity to spermine-tolerant mutants ofSaccharomyces cerevisiae, we have demonstrated that Sky1p, a recently identified SR protein kinase, is a key regulator of polyamine transport. Yeast cells deleted for SKY1 developed tolerance to toxic levels of spermine, while overexpression of Sky1p in wild-type cells increased their sensitivity to spermine. Expression of the wild-type Sky1p but not of a catalytically inactive mutant restored sensitivity to spermine. SKY1 disruption results in dramatically reduced uptake of spermine, spermidine, and putrescine. In addition to spermine tolerance, sky1Δ cells exhibit increased tolerance to lithium and sodium ions but somewhat increased sensitivity to osmotic shock. The observed halotolerance suggests potential regulatory interaction between the transport of polyamines and inorganic ions, as suggested in the case of the Ptk2p, a recently described regulator of polyamine transport. We demonstrate that these two kinases act in two different signaling pathways. While deletion or overexpression of SKY1 did not significantly affect Pma1p activity, the ability of overexpressed Sky1p, Ptk1p, and Ptk2p to increase sensitivity to LiCl depends on the integrity ofPPZ1 but not of ENA1.

scholarly journals Sml1 Inhibits the DNA Repair Activity of Rev1 in Saccharomyces cerevisiae during Oxidative Stress

2020 ◽  
Vol 86 (7) ◽  
Author(s):  
Rui Yao ◽  
Pei Zhou ◽  
Chengjin Wu ◽  
Liming Liu ◽  
Jing Wu
Keyword(s):  
Oxidative Stress ◽  
Saccharomyces Cerevisiae ◽  
Dna Damage ◽  
Survival Rate ◽  
Type Strain ◽  
Mutation Frequency ◽  
Wild Type Strain ◽  
Yeast Cells ◽  
Wild Type ◽  
Content Type

ABSTRACT In Saccharomyces cerevisiae, Y family DNA polymerase Rev1 is involved in the repair of DNA damage by translesion DNA synthesis (TLS). In the current study, to elucidate the role of Rev1 in oxidative stress-induced DNA damage in S. cerevisiae, REV1 was deleted and overexpressed; transcriptome analysis of these mutants along with the wild-type strain was performed to screen potential genes that could be associated with REV1 during response to DNA damage. When the yeast cells were treated with 2 mM H2O2, the deletion of REV1 resulted in a 1.5- and 2.8-fold decrease in the survival rate and mutation frequency, respectively, whereas overexpression of REV1 increased the survival rate and mutation frequency by 1.1- and 2.9-fold, respectively, compared to the survival rate and mutation frequency of the wild-type strain. Transcriptome and phenotypic analyses identified that Sml1 aggravated oxidative stress in the yeast cells by inhibiting the activity of Rev1. This inhibition was due to the physical interaction between the BRCA1 C terminus (BRCT) domain of Rev1 and amino acid residues 36 to 70 of Sml1; the cell survival rate and mutation frequency increased by 1.8- and 3.1-fold, respectively, when this interaction was blocked. We also found that Sml1 inhibited Rev1 phosphorylation under oxidative stress and that deletion of SML1 increased the phosphorylation of Rev1 by 46%, whereas overexpression of SML1 reduced phosphorylation of Rev1. Overall, these findings demonstrate that Sml1 could be a novel regulator that mediates Rev1 dephosphorylation to inhibit its activity during oxidative stress. IMPORTANCE Rev1 was critical for cell growth in S. cerevisiae, and the deletion of REV1 caused a severe growth defect in cells exposed to oxidative stress (2 mM H2O2). Furthermore, we found that Sml1 physically interacted with Rev1 and inhibited Rev1 phosphorylation, thereby inhibiting Rev1 DNA antioxidant activity. These findings indicate that Sml1 could be a novel regulator for Rev1 in response to DNA damage by oxidative stress.

scholarly journals Eukaryotic translation factor eIF5A contributes to acetic acid tolerance in Saccharomyces cerevisiae via transcriptional factor Ume6p

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yanfei Cheng ◽  
Hui Zhu ◽  
Zhengda Du ◽  
Xuena Guo ◽  
Chenyao Zhou ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Acetic Acid ◽  
Adaptive Response ◽  
Acid Tolerance ◽  
Peptide Bond ◽  
Transcriptional Factor ◽  
Yeast Cells ◽  
Acetic Acid Tolerance ◽  
Translation Factor ◽  
Industrial Strains

Abstract Background Saccharomyces cerevisiae is well-known as an ideal model system for basic research and important industrial microorganism for biotechnological applications. Acetic acid is an important growth inhibitor that has deleterious effects on both the growth and fermentation performance of yeast cells. Comprehensive understanding of the mechanisms underlying S. cerevisiae adaptive response to acetic acid is always a focus and indispensable for development of robust industrial strains. eIF5A is a specific translation factor that is especially required for the formation of peptide bond between certain residues including proline regarded as poor substrates for slow peptide bond formation. Decrease of eIF5A activity resulted in temperature-sensitive phenotype of yeast, while up-regulation of eIF5A protected transgenic Arabidopsis against high temperature, oxidative or osmotic stress. However, the exact roles and functional mechanisms of eIF5A in stress response are as yet largely unknown. Results In this research, we compared cell growth between the eIF5A overexpressing and the control S. cerevisiae strains under various stressed conditions. Improvement of acetic acid tolerance by enhanced eIF5A activity was observed all in spot assay, growth profiles and survival assay. eIF5A prompts the synthesis of Ume6p, a pleiotropic transcriptional factor containing polyproline motifs, mainly in a translational related way. As a consequence, BEM4, BUD21 and IME4, the direct targets of Ume6p, were up-regulated in eIF5A overexpressing strain, especially under acetic acid stress. Overexpression of UME6 results in similar profiles of cell growth and target genes transcription to eIF5A overexpression, confirming the role of Ume6p and its association between eIF5A and acetic acid tolerance. Conclusion Translation factor eIF5A protects yeast cells against acetic acid challenge by the eIF5A-Ume6p-Bud21p/Ime4p/Bem4p axles, which provides new insights into the molecular mechanisms underlying the adaptive response and tolerance to acetic acid in S. cerevisiae and novel targets for construction of robust industrial strains.

Functional interaction between p21rap1A and components of the budding pathway in Saccharomyces cerevisiae

1992 ◽  
Vol 12 (9) ◽  
pp. 4084-4092
Author(s):  
P C McCabe ◽  
H Haubruck ◽  
P Polakis ◽  
F McCormick ◽  
M A Innis
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mammalian Cells ◽  
Bound States ◽  
Yeast Cells ◽  
Temperature Sensitive ◽  
Wild Type ◽  
Amino Terminal ◽  
Loop Region

The rap1A gene encodes a 21-kDa, ras-related GTP-binding protein (p21rap1A) of unknown function. A close structural homolog of p21rap1A (65% identity in the amino-terminal two-thirds) is the RSR1 gene product (Rsr1p) of Saccharomyces cerevisiae. Although Rsr1p is not essential for growth, its presence is required for nonrandom selection of bud sites. To assess the similarity of these proteins at the functional level, wild-type and mutant forms of p21rap1A were tested for complementation of activities known to be fulfilled by Rsr1p. Expression of p21rap1A, like multicopy expression of RSR1, suppressed the conditional lethality of a temperature-sensitive cdc24 mutation. Point mutations predicted to affect the localization of p21rap1A or its ability to cycle between GDP and GTP-bound states disrupted suppression of cdc24ts, while other mutations in the 61-65 loop region improved suppression. Expression of p21rap1A could not, however, suppress the random budding phenotype of rsr1 cells. p21rap1A also apparently interfered with the normal activity of Rsrlp, causing random budding in diploid wild-type cells, suggesting an inability of p21rap1A to interact appropriately with Rsr1p regulatory proteins. Consistent with this hypothesis, we found an Rsr1p-specific GTPase-activating protein (GAP) activity in yeast membranes which was not active toward p21rap1A, indicating that p21rap1A may be predominantly GTP bound in yeast cells. Coexpression of human Rap1-specific GAP suppressed the random budding due to expression of p21rap1A or its derivatives, including Rap1AVal-12. Although Rap1-specific GAP stimulated the GTPase of Rsr1p in vitro, it did not dominantly interfere with Rsr1p function in vivo. A chimera consisting of Rap1A1-165::Rsr1p166-272 did not exhibit normal Rsr1p function in the budding pathway. These results indicated that p21rap1A and Rsr1p share at least partial functional homology, which may have implications for p21rap1A function in mammalian cells.

Evolution of ethylene by Saccharomyces cerevisiae as influenced by the carbon source for growth and the presence of air

1978 ◽  
Vol 24 (6) ◽  
pp. 637-642 ◽  
Author(s):  
K. C. Thomas ◽  
Mary Spencer
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Carbon Source ◽  
Ethylene Production ◽  
Atp Synthesis ◽  
Yeast Cells ◽  
Yeast Culture ◽  
Wild Type ◽  
Yeast Saccharomyces Cerevisiae ◽  
Absolute Requirement ◽  
Wild Type Yeast

Effects of the carbon source and oxygen on ethylene production by the yeast Saccharomyces cerevisiae have been studied. The amounts of ethylene evolved by the yeast culture were less than those detected in the blank (an equal volume of uninoculated medium), suggesting a net absorption of ethylene by the yeast cells. Addition of glucose to the lactate-grown yeast culture induced ethylene production. This glucose-induced stimulation of ethylene production was inhibited to a great extent by cycloheximide. Results suggested that the yeast cells in the presence of glucose synthesized an ethylene precursor and passed it into the medium. The conversion of this precursor to ethylene might be stimulated by oxygen. The fact that ethylene was produced by the yeast growing anaerobically and also by respiration-deficient mutants isolated from the wild-type yeast suggested that mitochondrial ATP synthesis was not an absolute requirement for ethylene biogenesis.

A novel role for DNA photolyase: binding to DNA damaged by drugs is associated with enhanced cytotoxicity in Saccharomyces cerevisiae

1994 ◽  
Vol 14 (12) ◽  
pp. 8071-8077
Author(s):  
M E Fox ◽  
B J Feldman ◽  
G Chu
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Uv Radiation ◽  
Excision Repair ◽  
Yeast Cells ◽  
Repair System ◽  
Dna Photolyase ◽  
Yeast Saccharomyces Cerevisiae ◽  
Pyrimidine Dimers ◽  
Increased Sensitivity ◽  
Nitroquinoline Oxide

DNA photolyase binds to and repairs cyclobutane pyrimidine dimers induced by UV radiation. Here we demonstrate that in the yeast Saccharomyces cerevisiae, photolyase also binds to DNA damaged by the anticancer drugs cis-diamminedichloroplatinum (cis-DDP) and nitrogen mustard (HN2) and by the alkylating agent N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Surprisingly, mutations in photolyase were associated with resistance of yeast cells to cis-DDP, MNNG, 4-nitroquinoline oxide (4NQO), and HN2. Transformation of yeast photolyase mutants with the photolyase gene increased sensitivity to these agents. Thus, while the binding of photolyase to DNA damaged by UV radiation aids survival of the cell, binding to DNA damaged by other agents may interfere with cell survival, perhaps by making the lesions inaccessible to the nucleotide excision repair system.

Analysis of the essential and excision repair functions of the RAD3 gene of Saccharomyces cerevisiae by mutagenesis

1986 ◽  
Vol 6 (4) ◽  
pp. 1218-1227
Author(s):  
L Naumovski ◽  
E C Friedberg
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dna Binding ◽  
Excision Repair ◽  
Random Mutagenesis ◽  
Nucleotide Binding ◽  
Yeast Cells ◽  
Wild Type ◽  
Binding Region ◽  
Site Specific ◽  
Essential Function

The RAD3 gene of Saccharomyces cerevisiae, which is involved in excision repair of DNA and is essential for cell viability, was mutagenized by site-specific and random mutagenesis. Site-specific mutagenesis was targeted to two regions near the 5' and 3' ends of the coding region, selected on the basis of amino acid sequence homology with known nucleotide binding and with known specific DNA-binding proteins, respectively. Two mutations in the putative nucleotide-binding region and one in the putative DNA-binding region inactivate the excision repair function of the gene, but not the essential function. A gene encoding two tandem mutations in the putative DNA-binding region is defective in both excision repair and essential functions of RAD3. Seven plasmids were isolated following random mutagenesis with hydroxylamine. Mutations in six of these plasmids were identified by gap repair of mutant plasmids from the chromosome of strains with previously mapped rad3 mutations, followed by DNA sequencing. Three of these contain missense mutations which inactivate only the excision repair function. The other three carry nonsense mutations which inactivate both the excision repair and essential functions. Collectively our results indicate that the RAD3 excision repair function is more sensitive to inactivation than is the essential function. Overexpression of wild-type Rad3 protein and a number of rad3 mutant proteins did not affect the UV resistance of wild-type yeast cells. However, overexpression of Rad3-2 protein rendered wild-type cells partially UV sensitive, indicating that excess Rad3-2 protein is dominant to the wild-type form. These and other results suggest that Rad3-2 protein retains its affinity for damaged DNA or other substrates, but is not catalytically active in excision repair.

scholarly journals Purification of profilin from Saccharomyces cerevisiae and analysis of profilin-deficient cells.

1990 ◽  
Vol 110 (1) ◽  
pp. 105-114 ◽  
Author(s):  
B K Haarer ◽  
S H Lillie ◽  
A E Adams ◽  
V Magdolen ◽  
W Bandlow ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Actin Polymerization ◽  
Yeast Cells ◽  
Predicted Amino Acid Sequence ◽  
Temperature Sensitive ◽  
Wild Type ◽  
Yeast Saccharomyces Cerevisiae ◽  
Ellipsoidal Shape ◽  
Hydrolysis Of

We have isolated profilin from yeast (Saccharomyces cerevisiae) and have microsequenced a portion of the protein to confirm its identity; the region microsequenced agrees with the predicted amino acid sequence from a profilin gene recently isolated from S. cerevisiae (Magdolen, V., U. Oechsner, G. Müller, and W. Bandlow. 1988. Mol. Cell. Biol. 8:5108-5115). Yeast profilin resembles profilins from other organisms in molecular mass and in the ability to bind to polyproline, retard the rate of actin polymerization, and inhibit hydrolysis of ATP by monomeric actin. Using strains that carry disruptions or deletions of the profilin gene, we have found that, under appropriate conditions, cells can survive without detectable profilin. Such cells grow slowly, are temperature sensitive, lose the normal ellipsoidal shape of yeast cells, often become multinucleate, and generally grow much larger than wild-type cells. In addition, these cells exhibit delocalized deposition of cell wall chitin and have dramatically altered actin distributions.

scholarly journals Inactivation ofclpBin the Pathogen Leptospira interrogans Reduces Virulence and Resistance to Stress Conditions

2011 ◽  
Vol 79 (9) ◽  
pp. 3711-3717 ◽  
Author(s):  
Kristel Lourdault ◽  
Gustavo M. Cerqueira ◽  
Elsio A. Wunder ◽  
Mathieu Picardeau
Keyword(s):  
Oxidative Stress ◽  
Stress Conditions ◽  
Leptospira Interrogans ◽  
Wild Type ◽  
Content Type ◽  
General Stress Response ◽  
Growth Defects ◽  
Resistance To Stress ◽  
Increased Susceptibility

ABSTRACTLeptospira interrogansis the causative agent of leptospirosis, which is an emerging zoonotic disease. Resistance to stress conditions is largely uncharacterized for this bacterium. We therefore decided to analyze aclpBmutant that we obtained by random transposon mutagenesis. The mutant did not produce any of the two isoforms of ClpB. TheclpBmutant exhibited growth defects at 30° and 37°C and in poor nutrient medium and showed increased susceptibility to oxidative stress, whereas the genetically complemented strain was restored in ClpB expression andin vitrowild-type growth. We also showed that theclpBmutant was attenuated in virulence in an animal model of acute leptospirosis. Our findings demonstrate that ClpB is involved in the general stress response. The chaperone is also necessary, either directly or indirectly, for the virulence of the pathogenL. interrogans.

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