Chromate tolerance caused by reduced hydroxyl radical production and decreased glutathione reductase activity in <i>Schizosaccharomyces pombe</i>

Gazdag, Zoltán; Pócsi, István; Belágyi, József; Emri, Tamás; Blaskó, Ágnes; Takács, Krisztina; Pesti, Miklós

doi:10.1002/jobm.200390018

Cited by 21 publications

(17 citation statements)

References 36 publications

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“…Using such models, some metabolites and enzymes have been shown to be responsible for the modulation of yeast cell tolerance to chromate, e.g. glutathione and glutathione reductase [15][16][17], glucose-6-phosphate dehydrogenase [15], mitochondrial Mn-dependent superoxide dismutase [17], cytosolic Cu,Zn-superoxide dismutase and methionine sulfoxide reductase [18]. NADH-dependent chromate reductase was found in a chromate-resistant strain of Candida maltosa [19].…”

Section: Introductionmentioning

confidence: 99%

Extra-cellular chromate-reducing activity of the yeast cultures

et al. 2006

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This paper reports on the experimental data supporting an essential role of extracellular reduction in chromate detoxification by baker's and non-conventional yeasts. A decrease of chromate content in the yeast culture coincides with an increase of Cr(III) content in extracellular liquid. At these conditions, cell-bound chromium level was insignificant and a dominant part of extra-cellular Cr(III) species was detected in the reaction with chromazurol S only after mineralization of the cell-free samples. This phenomenon of chromium "disappearance" can be explained by the formation of Cr(III) stable complexes with extra-cellular yeast-secreted components which are "inaccessible" in the reaction with chromazurol S without mineralization. It was shown that increasing sucrose concentration in a growth medium resulted in an increase of chromate reduction. A strong inhibition of chromate reduction by 0.25 mM sodium azide, a respiration inhibitor and a protonophore, testifies that extra-cellular chromate detoxification depends on energetic status of the yeast cells. It was shown that Cr(III)-biochelates produced in extra-cellular medium are of a different chemical nature and can be separated into at least two components by ion-exchange chromatography on anionit Dowex 1x10. A total yield of the isolated Cr(III)-biocomplexes is approximately 65 % (from initial level of chromate) with a relative molar ratio 8:5.

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Section: Introductionmentioning

confidence: 99%

Extra-cellular chromate-reducing activity of the yeast cultures

et al. 2006

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“…Fe 2+ and Cu 2+ ) of strain RE007 [10]. As already suggested, this may be an atypical reaction because the addition of NADPH to the Cr(VI)-tolerant strain of S. pombe resulted in increased •OH production [9].…”

Section: Acta Biologica Hungarica 66 2015mentioning

confidence: 65%

Regulation of unbalanced redox homeostasis induced by the expression of wild-type HIV-1 viral protein R (NL4-3Vpr) in fission yeast

Gazdag

Stromájer-Rácz

Belágyi

et al. 2015

Acta Biologica Hungarica

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The wild-type viral protein R (Vpr) of human immunodeficiency virus type 1 exerts multiple effects on cellular activities during infection, including the induction of cell cycle G 2 arrest and the death of human cells and cells of the fission yeast Schizosaccharomyces pombe. In this study, wild-type Vpr (NL4-3Vpr) integrated as a single copy gene in S. pombe chromosome was used to investigate the molecular impact of Vpr on cellular oxidative stress. NL4-3Vpr triggered an atypical response in early (14-h), and a wellregulated oxidative stress response in late (35-h) log-phase cultures. Specifically, NL4-3Vpr expression induced oxidative stress in the 14-h cultures leading, to decreased levels of superoxide anion (O 2 • -), hydroxyl radical ( • OH) and glutathione (GSH), and significantly decreased activities of catalase, glutathione peroxidase, glutathione reductase, glucose-6-phosphate dehydrogenase and glutathione S-transferase. In the 35-h cultures, elevated levels of O 2 • -and peroxides were accompanied by increased activities of most antioxidant enzymes, suggesting that the Vpr-induced unbalanced redox state of the cells might contribute to the adverse effects in HIV-infected patients.

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“…The chr1-66T mutant was sensitive to oxidative stressgenerating agents such as H 2 O 2 , menadione, tert-butyl hydroperoxide and Cd 2+ . Both the Cr(VI) tolerance and the oxidative stress sensitivity were attributed to decreased specific GR and mitochondrial superoxide dismutase (Mn-SOD) activities [37]. As expected, the mutant cells were characterized by significantly decreased GSH and elevated intracellular superoxide concentrations [37].…”

Section: Mechanisms Of Chromium Sensitivity and Resistancementioning

confidence: 90%

“…Exposure to Cr(VI) also increases the level of the Hsp 104 chaperone protein in C. intermedia, elevates the intracellular level of the oxidized form of GSH, GSSG [107,108], regulates the yeast S. cerevisiae transcriptional activator MSN1 [109], and induces intracellular signal transduction processes [110]. This indicates that oxidative cell damage plays a pivotal role in cytotoxicity [37,111], but has left the crucial targets of ROS awaiting identification [112]. Sumner et al [112] concluded that the Cr-induced oxidative damage of proteins (oxidation of methionine moieties and carbonylation) had greater consequences on the cell physiology than the oxidation of other biomolecules (lipids and nucleic acids).…”

Section: Chromium Toxicity 41 Mechanisms Of Chromium Toxicitymentioning

confidence: 97%

“…Antioxidants have been shown to protect yeasts against the deleterious effects of Cr(VI), and Cr(VI) treatment influences the specific activities of antioxidant enzymes and the production of various ROS [36,37] (more on the antioxidant protection is described in Section 4.3). Exposure to Cr(VI) also increases the level of the Hsp 104 chaperone protein in C. intermedia, elevates the intracellular level of the oxidized form of GSH, GSSG [107,108], regulates the yeast S. cerevisiae transcriptional activator MSN1 [109], and induces intracellular signal transduction processes [110].…”

Section: Chromium Toxicity 41 Mechanisms Of Chromium Toxicitymentioning

confidence: 99%

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Interference of chromium with biological systems in yeasts and fungi: a review

Poljšak

Pócsi

Raspor

et al. 2010

J. Basic Microbiol.

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This paper deals with the interactions of chromium (Cr) with biological systems, focusing in particular on yeasts and fungi. These interactions are analysed with primarily regard to biochemical functions, but higher levels of organization are also considered. Thus, the morphological and cytological characteristics of selected microorganisms in response to exposure to chromium ions are evaluated. The different oxidation states of chromium and reactive oxygen species (ROS) generated in redox reactions with chromium ions are presented and characterized. The interactions of the most exposed subcellular structures, including the cell wall, plasma membrane and nuclei, have been deeply investigated in recent years, for two major reasons. The first is the toxicity of chromium ions and their strong impact on the metabolism of many species, ranging from microbes to humans. The second is the still disputed usefulness of chromium ions, and in particular trivalent chromium, in the glucose and fat metabolisms. Chromium pollution is still an important issue in many regions of the world, and various solutions have been proposed for the bioremediation of soil and water with selected microbial species. Yeasts and especially moulds have been most widely investigated from this aspect, and the biosorption and bioaccumulation of chromium for bioremediation purposes have been demonstrated. Accordingly, the mechanisms of chromium tolerance or resistance of selected microbes are of particular importance in both bioremediation and waste water treatment technologies. The mechanisms of chromium toxicity and detoxification have been studied extensively in yeasts and fungi, and some promising results have emerged in this area.

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Chromate tolerance caused by reduced hydroxyl radical production and decreased glutathione reductase activity in Schizosaccharomyces pombe

Cited by 21 publications

References 36 publications

Extra-cellular chromate-reducing activity of the yeast cultures

Extra-cellular chromate-reducing activity of the yeast cultures

Regulation of unbalanced redox homeostasis induced by the expression of wild-type HIV-1 viral protein R (NL4-3Vpr) in fission yeast

Interference of chromium with biological systems in yeasts and fungi: a review

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