Pentose-phosphate pathway in Saccharomyces cerevisiae: analysis of deletion mutants for transketolase, transaldolase, and glucose 6-phosphate dehydrogenase

Schaaff-Gerstenschläger, Ine; Zimmermann, Friedrich K.

doi:10.1007/bf00351843

Cited by 41 publications

(28 citation statements)

References 17 publications

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“…(iii) Induction of the pentose phosphate pathway: Three enzymes of the pentose phosphate pathway are induced by H 2 O 2 . Glucose-6-phosphate dehydrogenase (Zwf1p) regulates the carbon flow through this pathway by catalyzing its first step, leading to ribulose 5-phosphate, the precursor of purine biosynthesis (48). Then, pentose phosphates are interconverted to glyceraldehyde 3-phosphate or fructose 6-phosphate by transketolases (Tkl1p and Tkl2p) and transaldolase (Tal1p).…”

Section: Strains and Growth Conditions-the Yeast Strain Yph98 (14) (Mmentioning

confidence: 99%

The H2O2 Stimulon in Saccharomyces cerevisiae

Godon¹,

Lagniel²,

Lee³

et al. 1998

Journal of Biological Chemistry

542

450

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The changes in gene expression underlying the yeast adaptive stress response to H 2 O 2 were analyzed by comparative two-dimensional gel electrophoresis of total cell proteins. The synthesis of at least 115 proteins is stimulated by H 2 O 2 , whereas 52 other proteins are repressed by this treatment. We have identified 71 of the stimulated and 44 of the repressed targets. The kinetics and dose-response parameters of the H 2 O 2 genomic response were also analyzed. Identification of these proteins and their mapping into specific cellular processes give a distinct picture of the way in which yeast cells adapt to oxidative stress. Aerobic organisms have to maintain a reduced cellular redox environment in the face of the prooxidative conditions characteristic of aerobic life. The incomplete reduction of oxygen to water during respiration leads to the formation of redox-active oxygen intermediates (ROI) 1 such as the superoxide anion radical (O 2 Ϫ ), hydrogen peroxide (H 2 O 2 ), and the hydroxyl radical (OH ⅐ ) (for review, see Refs. 1-3). ROI are also produced during the ␤-oxidation of fatty acids, and upon exposure to radiation, light, metals, and redox active drugs. Oxidative stress results from abnormally high levels of ROI which perturb the cell redox status and leads to damage to lipids, proteins, DNA, and eventually cell death. Living organisms constantly sense and adapt to such redox perturbations by the induction of batteries of genes or stimulons whose products act to maintain the cellular redox environment (4 (9,10). Yeast has the same defense mechanisms as higher eukaryotes (for review, see Refs. 11 and 12) and offers the power of genome-wide experimental approaches owing to the availability of the complete sequence of its genome. It therefore represents an ideal eukaryotic model in which to study the cellular redox control and ROI metabolism. We recently established a general method to identify yeast proteins based on two-dimensional gel electrophoresis (13). We used this genome-wide experimental approach to characterize proteins whose expression is altered upon exposure to low doses of H 2 O 2 . Such an oxidative stress challenge results in a dramatic genomic response involving at least 167 proteins. Identification of these proteins and their mapping into cellular processes give a global view of the ubiquitous cellular changes elicited by H 2 O 2 and provides the framework for understanding the mechanisms of cellular redox homeostasis and H 2 O 2 metabolism. ura3-52 lys2-801 amber ade2-101 ochre trp1-⌬1 leu2-⌬1) was used for the analysis of the H 2 O 2 response. The strain S288C (15) was used for protein spot identification. Strains were grown at 30°C in a medium containing 0.67% yeast nitrogen base without amino acids (Difco), 2% glucose, buffered to pH 5.8 with 1% succinate and 0.6% NaOH. For YPH98, uracil, adenine, lysine, tryptophan and leucine (30 mg/liter) were added to the culture medium. MATERIALS AND METHODS Strains and Growth Conditions-The yeast strain YPH98 (14) (MATaIdentification of P...

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Section: Strains and Growth Conditions-the Yeast Strain Yph98 (14) (Mmentioning

confidence: 99%

The H2O2 Stimulon in Saccharomyces cerevisiae

Godon¹,

Lagniel²,

Lee³

et al. 1998

Journal of Biological Chemistry

542

450

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“…Genes coding for DHAS from the methanolutilising yeast Hansenula polymorpha [70] [132,155] and E. coli [68,152]; three di erent forms of TK have been cloned from the desiccation-tolerant plant Craterostigma plantagineum [4].…”

Section: Sources Of Tkmentioning

confidence: 99%

“…In 1993 two groups independently cloned two S. cerevisiae TK genes which have approximately 70% identity [132,155]. This was the ®rst convincing evidence for genetic heterogeneity of any TK.…”

Section: Variant Forms Of Tkmentioning

confidence: 99%

Properties and functions of the thiamin diphosphate dependent enzyme transketolase

Schenk

Duggleby

Nixon

1998

The International Journal of Biochemistry & Cell Biology

220

164

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This review highlights recent research on the properties and functions of the enzyme transketolase, which requires thiamin diphosphate and a divalent metal ion for its activity. The transketolase-catalysed reaction is part of the pentose phosphate pathway, where transketolase appears to control the non-oxidative branch of this pathway, although the overall¯ux of labelled substrates remains controversial. Yeast transketolase is one of several thiamin diphosphate dependent enzymes whose three-dimensional structures have been determined. Together with mutational analysis these structural data have led to detailed understanding of thiamin diphosphate catalysed reactions. In the homodimer transketolase the two catalytic sites, where dihydroxyethyl groups are transferred from ketose donors to aldose acceptors, are formed at the interface between the two subunits, where the thiazole and pyrimidine rings of thiamin diphosphate are bound. Transketolase is ubiquitous and more than 30 full-length sequences are known. The encoded protein sequences contain two motifs of high homology; one common to all thiamin diphosphate-dependent enzymes and the other a unique transketolase motif. All characterised transketolases have similar kinetic and physical properties, but the mammalian enzymes are more selective in substrate utilisation than the nonmammalian representatives. Since products of the transketolase-catalysed reaction serve as precursors for a number of synthetic compounds this enzyme has been exploited for industrial applications. Putative mutant forms of transketolase, once believed to predispose to disease, have not stood up to scrutiny. However, a modi®cation of transketolase is a marker for Alzheimer's disease, and transketolase activity in erythrocytes is a measure of thiamin nutrition. The cornea contains a particularly high transketolase concentration, consistent with the proposal that pentose phosphate pathway activity has a role in the removal of light-generated radicals. #

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“…We first examined gene deletions that affect the pentose phosphate pathway. Deletion of the ZWF1 gene, which encodes a G6P dehydrogenase that catalyzes the first step of the oxidative pentose phosphate shunt (30,31), did not significantly change the fermentation profile of the X2180-1A strain when cultured in 20% glucose-containing YPD medium ( Fig. 4A; maximum fermentation rates, 200.2 ml/6 h for wild-type strain X2180-1A and 197.8 ml/6 h for the zwf1⌬ mutant).…”

Section: Fermentation Kinetics and Carbon Metabolic Profile Of Rim15⌬mentioning

confidence: 99%

Inhibitory Role of Greatwall-Like Protein Kinase Rim15p in Alcoholic Fermentation via Upregulating the UDP-Glucose Synthesis Pathway in Saccharomyces cerevisiae

Watanabe

Zhou

Hirata

et al. 2016

Appl Environ Microbiol

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The high fermentation rate of Saccharomyces cerevisiae sake yeast strains is attributable to a loss-of-function mutation in the RIM15 gene, which encodes a Greatwall-family protein kinase that is conserved among eukaryotes. In the present study, we performed intracellular metabolic profiling analysis and revealed that deletion of the RIM15 gene in a laboratory strain impaired glucose-anabolic pathways through the synthesis of UDP-glucose (UDPG). Although Rim15p is required for the synthesis of trehalose and glycogen from UDPG upon entry of cells into the quiescent state, we found that Rim15p is also essential for the accumulation of cell wall ␤-glucans, which are also anabolic products of UDPG. Furthermore, the impairment of UDPG or 1,3-␤-glucan synthesis contributed to an increase in the fermentation rate. Transcriptional induction of PGM2 (phosphoglucomutase) and UGP1 (UDPG pyrophosphorylase) was impaired in Rim15p-deficient cells in the early stage of fermentation. These findings demonstrate that the decreased anabolism of glucose into UDPG and 1,3-␤-glucan triggered by a defect in the Rim15p-mediated upregulation of PGM2 and UGP1 redirects the glucose flux into glycolysis. Consistent with this, sake yeast strains with defective Rim15p exhibited impaired expression of PGM2 and UGP1 and decreased levels of ␤-glucans, trehalose, and glycogen during sake fermentation. We also identified a sake yeast-specific mutation in the glycogen synthesis-associated glycogenin gene GLG2, supporting the conclusion that the glucose-anabolic pathway is impaired in sake yeast. These findings demonstrate that downregulation of the UDPG synthesis pathway is a key mechanism accelerating alcoholic fermentation in industrially utilized S. cerevisiae sake strains. S ake yeast strains, which belong to the species Saccharomyces cerevisiae, are capable of achieving ethanol yields as high as 22 vol% in fermenting sake mash (1-3). This characteristic phenotype is attributed in part to their high and sustained maximum fermentation rates, as observed in batch cultures containing high concentrations of glucose (4), and is due to the continuous supply of fermentable sugars to yeast cells in sake mash via the degradation of rice starch by enzymes produced by Aspergillus oryzae. In recent studies of the representative sake yeast strain Kyokai no. 7 (K7) and its relatives, we revealed that several stress-and/or nutrient-responsive transcription factors, particularly Msn2p and Msn4p (Msn2/4p), Hsf1p, Adr1p, and Cat8p, are significantly inactivated (5-7). Impairment of these transcriptional activators in laboratory strains of S. cerevisiae leads to increased fermentation rates, indicating that defective stress responses are linked with the superior fermentation properties of sake yeast (2, 5-7). Moreover, a loss-of-function mutation by insertion of an A residue at position 5055 in the RIM15 gene (rim15 5055insA ) was commonly found among K7-related strains (8). RIM15 encodes a conserved Greatwall-like protein kinase involved in the control of mitot...

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Pentose-phosphate pathway in Saccharomyces cerevisiae: analysis of deletion mutants for transketolase, transaldolase, and glucose 6-phosphate dehydrogenase

Cited by 41 publications

References 17 publications

The H2O2 Stimulon in Saccharomyces cerevisiae

The H2O2 Stimulon in Saccharomyces cerevisiae

Properties and functions of the thiamin diphosphate dependent enzyme transketolase

Inhibitory Role of Greatwall-Like Protein Kinase Rim15p in Alcoholic Fermentation via Upregulating the UDP-Glucose Synthesis Pathway in Saccharomyces cerevisiae

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