scholarly journals Zinc suppresses the iron-accumulation phenotype of Saccharomyces cerevisiae lacking the yeast frataxin homologue (Yfh1)

2003 ◽  
Vol 375 (2) ◽  
pp. 247-254 ◽  
Author(s):  
Renata SANTOS ◽  
Andrew DANCIS ◽  
David EIDE ◽  
Jean-Michel CAMADRO ◽  
Emmanuel LESUISSE
Keyword(s):  
Oxidative Stress ◽  
Saccharomyces Cerevisiae ◽  
Growth Rate ◽  
Zinc Metabolism ◽  
Wild Type ◽  
Iron Deprivation ◽  
Zinc Nutrition ◽  
Cell Transcriptome ◽  
Haem Proteins ◽  
Excess Zinc

Analysis of Saccharomyces cerevisiae cell transcriptome revealed that iron deprivation/supplementation affects genes other than those of the iron regulon (controlled by Aft proteins). Several genes regulated by zinc (induced by zinc deprivation) were induced by iron. Cells lacking the yeast frataxin homologue Yfh1 accumulate large amounts of iron in their mitochondria. We have shown that the zinc metabolism of these cells is also impaired: zinc uptake and zinc accumulation were both much lower in Δyfh1 cells than in wild-type cells. Excess zinc in the growth medium also influenced the phenotypes of Δyfh1 cells. It prevented the accumulation of iron in the mitochondria of Δyfh1 cells and increased the growth rate of these cells and their resistance to oxidative stress. However, zinc did not restore the deficiency of Fe–S and haem proteins of Δyfh1 cells. Zinc inhibited mitochondrial respiration and protected Yah1p, the mitochondrial ferredoxin. These results suggest that zinc nutrition may be important in the aetiology of Friedreich's ataxia.

Sensitivity of Saccharomyces cerevisiae to tannic acid is due to iron deprivation

2001 ◽  
Vol 47 (4) ◽  
pp. 290-293 ◽  
Author(s):  
T Wauters ◽  
D Iserentant ◽  
H Verachtert
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fatty Acids ◽  
Growth Rate ◽  
Tannic Acid ◽  
Unsaturated Fatty Acids ◽  
Acid Resistance ◽  
Maximal Growth ◽  
Wild Type ◽  
Iron Deprivation ◽  
Maximal Growth Rate

Tannic acid inhibited the growth of the yeast Saccharomyces cerevisiae. Growth medium supplementation with more nitrogen or metal ions showed that only iron ions could restore the maximal growth rate of S. cerevisiae. Tannic acid resistant mutants were previously isolated by screening for tannic acid resistance and were all cytoplasmic petite mutants. While the wild type was very sensitive to iron deprivation conditions when grown in aerobic conditions, the mutants, whether grown aerobically or anaerobically, showed the same growth rate under iron-limited conditions as under iron-repleted conditions. Also, the wild type grown anaerobically was not affected by iron-limited conditions. Cytoplasmic petite mutants obtained by ethidium bromide mutagenesis behaved like the other mutants. During iron limitation, the wild type showed a reduced oxygen uptake rate. Maximal growth rate of the wild type in iron-limited conditions could be restored by the addition to the media of unsaturated fatty acids and sterol. Iron deprivation caused by tannic acid may thus affect the synthesis of a functional respiratory chain as well as the synthesis of unsaturated fatty acids and (or) sterol.Key words: Saccharomyces cerevisiae, tannic acid resistance, iron deprivation, cytoplasmic petite mutant.

scholarly journals The effect of calnexin deletion on the expression level of PDI in Saccharomyces cerevisiae under heat stress conditions

2008 ◽  
Vol 13 (1) ◽  
Author(s):  
Huili Zhang ◽  
Jianwei He ◽  
Yanyan Ji ◽  
Akio Kato ◽  
Youtao Song
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Growth Rate ◽  
Heat Stress ◽  
Protein Expression ◽  
Molecular Chaperone ◽  
Mrna Level ◽  
Stress Conditions ◽  
Mrna Levels ◽  
Wild Type ◽  
Wild Type Yeast

AbstractWe cultured calnexin-disrupted and wild-type Saccharomyces cerevisiae strains under conditions of heat stress. The growth rate of the calnexin-disrupted yeast was almost the same as that of the wild-type yeast under those conditions. However, the induced mRNA level of the molecular chaperone PDI in the ER was clearly higher in calnexin-disrupted S. cerevisiae relative to the wild type at 37°C, despite being almost the same in the two strains under normal conditions. The western blotting analysis for PDI protein expression in the ER yielded results that show a parallel in their mRNA levels in the two strains. We suggest that PDI may interact with calnexin under heat stress conditions, and that the induction of PDI in the ER can recover part of the function of calnexin in calnexin-disrupted yeast, and result in the same growth rate as in wild-type yeast.

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 Random T-DNA Mutagenesis Identifies a Cu/Zn Superoxide Dismutase Gene as a Virulence Factor of Sclerotinia sclerotiorum

2013 ◽  
Vol 26 (4) ◽  
pp. 431-441 ◽  
Author(s):  
Liangsheng Xu ◽  
Weidong Chen
Keyword(s):  
Oxidative Stress ◽  
Growth Rate ◽  
Superoxide Dismutase ◽  
Sclerotinia Sclerotiorum ◽  
Virulence Factor ◽  
Wild Type ◽  
Expression Levels ◽  
Sclerotial Formation ◽  
Increased Sensitivity ◽  
And Oxidative Stress

Agrobacterium-mediated transformation (AMT) was used to identify potential virulence factors in Sclerotinia sclerotiorum. Screening AMT transformants identified two mutants showing significantly reduced virulence. The mutants showed growth rate, sclerotial formation, and oxalate production similar to that of the wild type. The mutation was due to a single T-DNA insertion at 212 bp downstream of the Cu/Zn superoxide dismutase (SOD) gene (SsSOD1, SS1G_00699). Expression levels of SsSOD1 were significantly increased under oxidative stresses or during plant infection in the wild-type strain but could not be detected in the mutant. SsSOD1 functionally complemented the Cu/Zn SOD gene in a Δsod1 Saccharomyces cerevisiae mutant. The SOD mutant had increased sensitivity to heavy metal toxicity and oxidative stress in culture and reduced ability to detoxify superoxide in infected leaves. The mutant also had reduced expression levels of other known pathogenicity genes such as endo-polygalacturanases sspg1 and sspg3. The functions of SsSOD1 were further confirmed by SsSOD1-deletion mutation. Like the AMT insertion mutant, the SsSOD1-deletion mutant exhibited normal growth rate, sclerotial formation, oxalate production, increased sensitivity to metal and oxidative stress, and reduced virulence. These results suggest that SsSOD1, while not being required for saprophytic growth and completion of the life cycle, plays critical roles in detoxification of reactive oxygen species during host–pathogen interactions and is an important virulence factor of Sclerotinia sclerotiorum.

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 U1 small nuclear ribonucleoprotein particle-protein interactions are revealed in Saccharomyces cerevisiae by in vivo competition assays.

1993 ◽  
Vol 13 (4) ◽  
pp. 2126-2133 ◽  
Author(s):  
F Stutz ◽  
X C Liao ◽  
M Rosbash
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Growth Rate ◽  
Mammalian Cells ◽  
Wild Type ◽  
Ribonucleoprotein Particle ◽  
Yeast Saccharomyces Cerevisiae ◽  
Small Nuclear Ribonucleoprotein ◽  
U1 Snrna ◽  
Nuclear Ribonucleoprotein ◽  
Small Nuclear Ribonucleoprotein Particle

Two highly conserved regions of the 586-nucleotide yeast (Saccharomyces cerevisiae) U1 small nuclear RNA (snRNA) can be mutated or deleted with little or no effect on growth rate: the universally conserved loop II (corresponding to the metazoan A loop) and the yeast core region (X. Liao, L. Kretzner, B. Séraphin, and M. Rosbash, Genes Dev. 4:1766-1774, 1990). To examine the contribution of these regions to U1 small nuclear ribonucleoprotein particle (snRNP) activity, a competitor U1 gene, encoding a nonfunctional U1 snRNA molecule, was introduced into a number of strains carrying a U1 snRNA gene with loop II or yeast core mutations. The presence of the nonfunctional U1 gene lowered the growth rate of these mutant strains but not wild-type strains, consistent with the notion that mutant U1 RNAs are less active than wild-type U1 snRNAs. A detailed analysis of the U1 snRNA levels and half-lives in a number of merodiploid strains suggests that these mutant U1 snRNAs interact with U1 snRNP proteins less well than do their wild-type counterparts. Competition for protein factors during snRNP assembly could account for a number of previous observations in both yeast and mammalian cells.

U1 small nuclear ribonucleoprotein particle-protein interactions are revealed in Saccharomyces cerevisiae by in vivo competition assays

1993 ◽  
Vol 13 (4) ◽  
pp. 2126-2133
Author(s):  
F Stutz ◽  
X C Liao ◽  
M Rosbash
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Growth Rate ◽  
Mammalian Cells ◽  
Wild Type ◽  
Ribonucleoprotein Particle ◽  
Yeast Saccharomyces Cerevisiae ◽  
Small Nuclear Ribonucleoprotein ◽  
U1 Snrna ◽  
Nuclear Ribonucleoprotein ◽  
Small Nuclear Ribonucleoprotein Particle

Two highly conserved regions of the 586-nucleotide yeast (Saccharomyces cerevisiae) U1 small nuclear RNA (snRNA) can be mutated or deleted with little or no effect on growth rate: the universally conserved loop II (corresponding to the metazoan A loop) and the yeast core region (X. Liao, L. Kretzner, B. Séraphin, and M. Rosbash, Genes Dev. 4:1766-1774, 1990). To examine the contribution of these regions to U1 small nuclear ribonucleoprotein particle (snRNP) activity, a competitor U1 gene, encoding a nonfunctional U1 snRNA molecule, was introduced into a number of strains carrying a U1 snRNA gene with loop II or yeast core mutations. The presence of the nonfunctional U1 gene lowered the growth rate of these mutant strains but not wild-type strains, consistent with the notion that mutant U1 RNAs are less active than wild-type U1 snRNAs. A detailed analysis of the U1 snRNA levels and half-lives in a number of merodiploid strains suggests that these mutant U1 snRNAs interact with U1 snRNP proteins less well than do their wild-type counterparts. Competition for protein factors during snRNP assembly could account for a number of previous observations in both yeast and mammalian cells.

scholarly journals The effect of calnexin deletion on the expression level of binding protein (BiP) under heat stress conditions in Saccharomyces cerevisiae

2008 ◽  
Vol 13 (4) ◽  
Author(s):  
Huili Zhang ◽  
Bingjie Hu ◽  
Yanyan Ji ◽  
Akio Kato ◽  
Youtao Song
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Growth Rate ◽  
Heat Stress ◽  
Western Blot ◽  
Molecular Chaperone ◽  
Stress Conditions ◽  
Mrna Levels ◽  
Wild Type ◽  
In The Wild ◽  
Wild Type Yeast

AbstractIn order to investigate the effect of calnexin deletion on the induction of the main ER molecular chaperone BiP, we cultured the wild-type and calnexin-disrupted Saccharomyces cerevisiae strains under normal and stressed conditions. The growth rate of the calnexin-disrupted yeast was almost the same as that of the wild-type yeast under those conditions. However, the induced level of BiP mRNA in the ER was evidently higher in calnexin-disrupted S. cerevisiae than in the wild-type at 37°C, but was almost the same in the two strains under normal conditions. The Western blot analysis results for BiP protein expression in the ER showed a parallel in the mRNA levels in the two strains. It is suggested that under heat stress conditions, the induction of BiP in the ER might recover part of the function of calnexin in calnexin-disrupted yeast, and result in the same growth rate as in wild-type yeast.

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 Impaired Cutinase Secretion in Saccharomyces cerevisiae Induces Irregular Endoplasmic Reticulum (ER) Membrane Proliferation, Oxidative Stress, and ER-Associated Degradation

2002 ◽  
Vol 68 (5) ◽  
pp. 2155-2160 ◽  
Author(s):  
C. M. J. Sagt ◽  
W. H. Müller ◽  
L. van der Heide ◽  
J. Boonstra ◽  
A. J. Verkleij ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Saccharomyces Cerevisiae ◽  
Endoplasmic Reticulum ◽  
Protein Aggregation ◽  
Fold Increase ◽  
Proteasomal Degradation ◽  
Wild Type ◽  
Unfolded Protein ◽  
Protein Response ◽  
And Oxidative Stress

ABSTRACT Impaired secretion of the hydrophobic CY028 cutinase invokes an unfolded protein response (UPR) in Saccharomyces cerevisiae cells. Here we show that the UPR in CY028-expressing S. cerevisiae cells is manifested as an aberrant morphology of the endoplasmic reticulum (ER) and as extensive membrane proliferation compared to the ER morphology and membrane proliferation of wild-type CY000-producing S. cerevisiae cells. In addition, we observed oxidative stress, which resulted in a 21-fold increase in carbonylated proteins in the CY028-producing S. cerevisiae cells. Moreover, CY028-producing S. cerevisiae cells use proteasomal degradation to reduce the amount of accumulated CY028 cutinase, thereby attenuating the stress invoked by CY028 cutinase expression. This proteasomal degradation occurs within minutes and is characteristic of ER-associated degradation (ERAD). Our results clearly show that impaired secretion of the heterologous, hydrophobic CY028 cutinase in S. cerevisiae cells leads to protein aggregation in the ER, aberrant ER morphology and proliferation, and oxidative stress, as well as a UPR and ERAD.

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