A high copy number of yeast ?-glutamylcysteine synthetase suppresses a nuclear mutation affecting mitochondrial translation

Lisowsky, Thomas

doi:10.1007/bf00312627

Cited by 31 publications

(20 citation statements)

References 37 publications

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“…The gsh2 mutant showed wild-type growth rates on rich glucosebased medium and on nonfermentable carbon sources, such as glycerol and ethanol. This is in contrast to gshl mutants, which are unable to grow on nonfermentable carbon sources, reflecting the importance of GSH for mitochondrial function (Kistler et al, 1986;Lisowsky, 1993;Grant et al, 1996b;Schmidt et al, 1996). In addition, strains deleted for GSH1, required exogenous GSH for growth under nonstress conditions on minimal medium (Grant et al, 1996b).…”

Section: Gsh2 Encodes Gsh Synthetasementioning

confidence: 94%

“…This rate limiting step in GSH synthesis is feedback inhibited by the end product GSH (Huang et al, 1988;Meister, 1988). The GSH1 gene, encoding y-glutamylcysteine synthetase, has been cloned from yeast by complementation of a gshl mutation (Ohtake and Yabuuchi, 1991) and as a high-copy suppressor of a temperature-sensitive mutation affecting mitochondrial biogenesis (Lisowsky, 1993). The predicted protein sequence of the yeast enzyme shows high homology with other eukaryotic Gshl sequences but only limited homology with the bacterial enzyme consistent with a high degree of conservation among eukaryotes (Ohtake and Yabuuchi, 1991).…”

Section: Introductionmentioning

confidence: 99%

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Glutathione synthetase is dispensable for growth under both normal and oxidative stress conditions in the yeast Saccharomyces cerevisiae due to an accumulation of the dipeptide gamma-glutamylcysteine.

Grant

MacIver

Dawes

1997

MBoC

180

147

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Glutathione (GSH) synthetase (Gsh2) catalyzes the ATP-dependent synthesis of GSH from y-glutamylcysteine (y-Glu-Cys) and glycine. GSH2, encoding the Saccharomyces cerevisiae enzyme, was isolated and used to construct strains that either lack or overproduce Gsh2. The identity of GSH2 was confirmed by the following criteria: 1) the predicted Gsh2 protein shared 37-39% identity and 58-60% similarity with GSH synthetases from other eukaryotes, 2) increased gene dosage of GSH2 resulted in elevated Gsh2 enzyme activity, 3) a strain deleted for GSH2 was dependent on exogenous GSH for wild-type growth rates, and 4) the gsh2 mutant lacked GSH and accumulated the dipeptide y-Glu-Cys intermediate in GSH biosynthesis. Overexpression of GSH2 had no effect on cellular GSH levels, whereas overexpression of GSH1, encoding the enzyme for the first step in GSH biosynthesis, lead to an approximately twofold increase in GSH levels, consistent with Gshl catalyzing the rate-limiting step in GSH biosynthesis. In contrast to a strain deleted for GSH1, which lacks both GSH and y-Glu-Cys, the strain deleted for GSH2 was found to be unaffected in mitochondrial function as well as resistance to oxidative stress induced by hydrogen peroxide, tert-butyl hydroperoxide, and the superoxide anion. Furthermore, y-Glu-Cys was at least as good as GSH in protecting yeast cells against an oxidant challenge, providing the first evidence that -y-Glu-Cys can act as an antioxidant and substitute for GSH in a eukaryotic cell. However, the dipeptide could not fully substitute for the essential function of GSH in the cell as shown by the poor growth of the gsh2 mutant on minimal medium. We suggest that this function may be the detoxification of harmful intermediates that are generated during normal cellular metabolism.

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Section: Gsh2 Encodes Gsh Synthetasementioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

Glutathione synthetase is dispensable for growth under both normal and oxidative stress conditions in the yeast Saccharomyces cerevisiae due to an accumulation of the dipeptide gamma-glutamylcysteine.

Grant

MacIver

Dawes

1997

MBoC

180

147

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“…g-Glutamylcysteine synthetase (Gsh1) catalyzes the first and rate-limiting step where the dipeptide g-Glu-Cys is formed from glutamate and cysteine (Lisowsky and Meister 1993). The second step is catalyzed by glutathione synthetase (Gsh2), which ligates g-Glu-Cys with glycine .…”

Section: Antioxidant Defensesmentioning

confidence: 99%

The Response to Heat Shock and Oxidative Stress inSaccharomyces cerevisiae

2012

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A common need for microbial cells is the ability to respond to potentially toxic environmental insults. Here we review the progress in understanding the response of the yeast Saccharomyces cerevisiae to two important environmental stresses: heat shock and oxidative stress. Both of these stresses are fundamental challenges that microbes of all types will experience. The study of these environmental stress responses in S. cerevisiae has illuminated many of the features now viewed as central to our understanding of eukaryotic cell biology. Transcriptional activation plays an important role in driving the multifaceted reaction to elevated temperature and levels of reactive oxygen species. Advances provided by the development of whole genome analyses have led to an appreciation of the global reorganization of gene expression and its integration between different stress regimens. While the precise nature of the signal eliciting the heat shock response remains elusive, recent progress in the understanding of induction of the oxidative stress response is summarized here. Although these stress conditions represent ancient challenges to S. cerevisiae and other microbes, much remains to be learned about the mechanisms dedicated to dealing with these environmental parameters.

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“…GSH performs many functions, among them protection against ROS, especially H 2 O 2 (see reference 207 for a review). The GSH1 gene, encoding the first enzyme of the two-step biosynthesis of GSH, was cloned by complementation of a gsh1 mutant (224) and rediscovered as a multicopy suppressor of a pet mutation impairing mitochondrial translation (185). Strains carrying a deletion of GSH1 are unable to grow in the absence of exogenous GSH (110,331).…”

Section: The World Of Carriers and Transportersmentioning

confidence: 99%

Maintenance and Integrity of the Mitochondrial Genome: a Plethora of Nuclear Genes in the Budding Yeast

Contamine

Picard

2000

Microbiol Mol Biol Rev

264

209

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SUMMARY Instability of the mitochondrial genome (mtDNA) is a general problem from yeasts to humans. However, its genetic control is not well documented except in the yeast Saccharomyces cerevisiae. From the discovery, 50 years ago, of the petite mutants by Ephrussi and his coworkers, it has been shown that more than 100 nuclear genes directly or indirectly influence the fate of the rho+ mtDNA. It is not surprising that mutations in genes involved in mtDNA metabolism (replication, repair, and recombination) can cause a complete loss of mtDNA (rho0 petites) and/or lead to truncated forms (rho−) of this genome. However, most loss-of-function mutations which increase yeast mtDNA instability act indirectly: they lie in genes controlling functions as diverse as mitochondrial translation, ATP synthase, iron homeostasis, fatty acid metabolism, mitochondrial morphology, and so on. In a few cases it has been shown that gene overexpression increases the levels of petite mutants. Mutations in other genes are lethal in the absence of a functional mtDNA and thus convert this petite-positive yeast into a petite-negative form: petite cells cannot be recovered in these genetic contexts. Most of the data are explained if one assumes that the maintenance of the rho+ genome depends on a centromere-like structure dispensable for the maintenance of rho− mtDNA and/or the function of mitochondrially encoded ATP synthase subunits, especially ATP6. In fact, the real challenge for the next 50 years will be to assemble the pieces of this puzzle by using yeast and to use complementary models, especially in strict aerobes.

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A high copy number of yeast ?-glutamylcysteine synthetase suppresses a nuclear mutation affecting mitochondrial translation

Cited by 31 publications

References 37 publications

Glutathione synthetase is dispensable for growth under both normal and oxidative stress conditions in the yeast Saccharomyces cerevisiae due to an accumulation of the dipeptide gamma-glutamylcysteine.

Glutathione synthetase is dispensable for growth under both normal and oxidative stress conditions in the yeast Saccharomyces cerevisiae due to an accumulation of the dipeptide gamma-glutamylcysteine.

The Response to Heat Shock and Oxidative Stress inSaccharomyces cerevisiae

Maintenance and Integrity of the Mitochondrial Genome: a Plethora of Nuclear Genes in the Budding Yeast

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