The adaptive response of <i>Saccharomyces cerevisiae</i> to mercury exposure

Westwater, John; McLaren, Niall F.; Dormer, Ulla H.; Jamieson, Derek J.

doi:10.1002/yea.835

Cited by 35 publications

(2 citation statements)

References 33 publications

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“…Reactive oxygen species (ROS) are formed from the reduction of one or two electrons of molecular oxygen creating hydroxyl radicals ( • OH), superoxide anions (O 2 – ), and hydrogen peroxide (H 2 O 2 ) [ 13 ]; all being causative factors in DNA mutations and genomic instability [ 14 ]. Although convincing evidence for MG-triggered ROS production and/or ROS-mediated MG content control is lacking, the scavenging mechanisms of ROS have been sufficiently elucidated; the superoxide anions scavenged by superoxide dismutases (Sods) generate the simplest form of peroxide, H 2 O 2 , which is detoxified by catalase (Cat) and/or GSH reductase (GR) [ 15 , 16 ]. ROS, antioxidative enzyme activities, and their resulting metabolite products have been postulated.…”

Section: Introductionmentioning

confidence: 99%

Methylglyoxal-Scavenging Enzyme Activities Trigger Erythroascorbate Peroxidase and Cytochrome c Peroxidase in Glutathione-Depleted Candida albicans

Kang

Kwak

2021

J. Microbiol. Biotechnol.

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Methylglyoxal (MG, CH 3 COCHO) reacts with nucleic acids and proteins, causing to cellular damage [1], and also inhibits cell division in eukaryotes [2]. MG non-specifically binds to amines, amino acids, and proteins and produces biologically active free radicals [3-5]. Advanced glycation end-products are derived from MG, leading to hyperglycemic damage in cells [1, 6]. This highly reactive α-ketoaldehyde inhibits human leukemia 60 cells, resulting in apoptosis [7]. In the fission yeast Schizosaccharomyces pombe, MG can activate stress-activated protein kinase signaling cascade [8]. As demonstrated in our previous studies at the microbial level, MG accumulation in cells results in the defective growth and the arrest of the G1-phase specific cell cycle in γ-glutamyl cysteinyl synthetase (GCS)-deficient gcsof Dictyostelium discoideum [9]. Glutathione (GSH)-depleted strains provide a working concept for cellular accumulation of MG via the inactive GSH-required glyoxalase system [9]. Investigations have focused on a number of MG scavengers, including aldehyde dehydrogenase, aldehyde reductase, aldose reductase, and αketoaldehyde dehydrogenase. These enzymes commonly catalyze the oxidation or reduction of MG into pyruvate or acetol [10]. Inspired by these findings, in Candida albicans, we previously purified and characterized two predominant MG-scavenging enzymes, NAD(H)-linked alcohol dehydrogenase 1 (CaO19.3997; Adh1) [11] and NAD(H)-linked MG oxidoreductase (CaO19.4309; Mgd1) [12]. The Mgd protein, Mgd1, has been revealed to be γ-Glutamylcysteine synthetase (Gcs1) and glutathione reductase (Glr1) activity maintains minimal levels of cellular methylglyoxal in Candida albicans. In glutathione-depleted Δgcs1, we previously saw that NAD(H)-linked methylglyoxal oxidoreductase (Mgd1) and alcohol dehydrogenase (Adh1) are the most active methylglyoxal scavengers. With methylglyoxal accumulation, disruptants lacking MGD1 or ADH1 exhibit a poor redox state. However, there is little convincing evidence for a reciprocal relationship between methylglyoxal scavenger genes-disrupted mutants and changes in glutathione-(in)dependent redox regulation. Herein, we attempt to demonstrate a functional role for methylglyoxal scavengers, modeled on a triple disruptant (Δmgd1/Δadh1/Δgcs1), to link between antioxidative enzyme activities and their metabolites in glutathione-depleted conditions. Despite seeing elevated methylglyoxal in all of the disruptants, the result saw a decrease in pyruvate content in Δmgd1/Δadh1/Δgcs1 which was not observed in double gene-disrupted strains such as Δmgd1/Δgcs1 and Δadh1/Δgcs1. Interestingly, Δmgd1/Δadh1/Δgcs1 exhibited a significantly decrease in H 2 O 2 and superoxide which was also unobserved in Δmgd1/Δgcs1 and Δadh1/Δgcs1. The activities of the antioxidative enzymes erythroascorbate peroxidase and cytochrome c peroxidase were noticeably higher in Δmgd1/Δadh1/Δgcs1 than in the other disruptants. Meanwhile, Glr1 activity severely diminished in Δmgd1/Δadh1/Δgcs1. Monitoring complementary gene transcrip...

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Section: Introductionmentioning

confidence: 99%

Methylglyoxal-Scavenging Enzyme Activities Trigger Erythroascorbate Peroxidase and Cytochrome c Peroxidase in Glutathione-Depleted Candida albicans

Kang

Kwak

2021

J. Microbiol. Biotechnol.

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“…The extent of the toxic effects depends on the chemical form of the metal species. Heavy metals generally cause oxidative stress, shifting the redox balance toward an oxidizing milieu ( − ). The redox cycling of glutathione is central to the cellular response to oxidative stress.…”

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confidence: 99%

Interaction of Glutathione Reductase with Heavy Metal: The Binding of Hg(II) or Cd(II) to the Reduced Enzyme Affects Both the Redox Dithiol Pair and the Flavin

Picaud

Desbois

2006

Biochemistry

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To determine the inhibition mechanism of yeast glutathione reductase (GR) by heavy metal, we have compared the electronic absorption and resonance Raman (RR) spectra of the enzyme in its oxidized (Eox) and two-electron reduced (EH2) forms, in the absence and the presence of Hg(II) or Cd(II). The spectral data clearly show a redox dependence of the metal binding. The metal ions do not affect the absorption and RR spectra of Eox. On the contrary, the EH2 spectra, generated by addition of NADPH, are strongly modified by the presence of heavy metal. The absorption changes of EH2 are metal-dependent. On the one hand, the main flavin band observed at 450 nm for EH2 is red-shifted at 455 nm for the EH2-Hg(II) complex and at 451 nm for the EH2-Cd(II) complex. On the other hand, the characteristic charge-transfer (CT) band at 540 nm is quenched upon metal binding to EH2. In NADPH excess, a new CT band is observed at 610 nm for the EH2-Hg(II)-NADPH complex and at 590 nm for EH2-Cd(II)-NADPH. The RR spectra of the EH2-metal complexes are not sensitive to the NADPH concentration. With reference to the RR spectra of EH2 in which the frequencies of bands II and III were observed at 1582 and 1547 cm-1, respectively, those of the EH2-metal complexes are detected at 1577 and 1542 cm-1, indicating an increased flavin bending upon metal coordination to EH2. From the frequency shifts of band III, a concomitant weakening of the H-bonding state of the N5 atom is also deduced. Taking into account the different chemical properties of Hg(II) and Cd(II), the coordination number of the bound metal ion was deduced to be different in GR. A mechanism of the GR inhibition is proposed. It proceeds primarily by a specific binding of the metal to the redox thiol/thiolate pair and the catalytic histidine of EH2. The bound metal ion then acts on the bending of the isoalloxazine ring of FAD as well as on the hydrophobicity of its microenvironment.

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The oxidative stress response of the yeast Candida intermedia to copper, zinc, and selenium exposure

Fujs

Gazdag

Poljšak

et al. 2005

J. Basic Microbiol.

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The yeast Candida intermedia, as a model organism, was used to examine the links between the metal ions exposure, reactive oxygen species generation and oxidative stress response. To estimate intracellular peroxide and superoxide levels, the fluorescence indicators dihydrorhodamine 123 and dihydroethidium were used, respectively. Antioxidant defence systems were investigated by measuring the activity of catalase, glutathione peroxidase and superoxide dismutase and the content of reduced glutathione. Altered superoxide, peroxide, glutathione levels, and the catalase activity were perceived after the treatment with copper. In the samples treated with selenium and zinc the altered peroxide and superoxide levels, and the glutathione peroxidase activity were perceived. The results indicate that the tolerance of the yeast C. intermedia to different metal ions was correlated with the reactive oxygen species generation in the cells and with the efficiency of antioxidative defence systems.

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The adaptive response of Saccharomyces cerevisiae to mercury exposure

Cited by 35 publications

References 33 publications

Methylglyoxal-Scavenging Enzyme Activities Trigger Erythroascorbate Peroxidase and Cytochrome c Peroxidase in Glutathione-Depleted Candida albicans

Methylglyoxal-Scavenging Enzyme Activities Trigger Erythroascorbate Peroxidase and Cytochrome c Peroxidase in Glutathione-Depleted Candida albicans

Interaction of Glutathione Reductase with Heavy Metal: The Binding of Hg(II) or Cd(II) to the Reduced Enzyme Affects Both the Redox Dithiol Pair and the Flavin

The oxidative stress response of the yeast Candida intermedia to copper, zinc, and selenium exposure

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