The cooperative binding of fructose-1,6-bisphosphate to yeast pyruvate kinase.

Murcott, Toby H. L.; Gutfreund, H.; Muirhead, H.

doi:10.1002/j.1460-2075.1992.tb05472.x

Cited by 26 publications

(18 citation statements)

References 13 publications

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“…At the low F1,6bP 2 concentrations prevailing during gluconeogenic conditions, the enzyme showed cooperativity with respect to phosphoenolpyruvate. At high F1,6bP 2 concentrations, however, the enzyme exhibited hyperbolic Michaelis±Menten kinetics with increased affinity for phosphoenolpyruvate, in line with earlier findings [92,93]. We found that the activation is maximal at 0.5 mm of F1,6bP 2 , which is more than 10 times lower than the concentration that we have measured.…”

Section: Pyruvate Kinase: Pyksupporting

confidence: 92%

Can yeast glycolysis be understood in terms of in vitro kinetics of the constituent enzymes? Testing biochemistry

Teusink

Passarge

Reijenga

et al. 2000

European Journal of Biochemistry

623

733

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This paper examines whether the in vivo behavior of yeast glycolysis can be understood in terms of the in vitro kinetic properties of the constituent enzymes. In nongrowing, anaerobic, compressed Saccharomyces cerevisiae the values of the kinetic parameters of most glycolytic enzymes were determined. For the other enzymes appropriate literature values were collected. By inserting these values into a kinetic model for glycolysis, fluxes and metabolites were calculated. Under the same conditions fluxes and metabolite levels were measured.In our first model, branch reactions were ignored. This model failed to reach the stable steady state that was observed in the experimental flux measurements. Introduction of branches towards trehalose, glycogen, glycerol and succinate did allow such a steady state. The predictions of this branched model were compared with the empirical behavior. Half of the enzymes matched their predicted flux in vivo within a factor of 2. For the other enzymes it was calculated what deviation between in vivo and in vitro kinetic characteristics could explain the discrepancy between in vitro rate and in vivo flux.

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Section: Pyruvate Kinase: Pyksupporting

confidence: 92%

Can yeast glycolysis be understood in terms of in vitro kinetics of the constituent enzymes? Testing biochemistry

Teusink

Passarge

Reijenga

et al. 2000

European Journal of Biochemistry

623

733

View full text Add to dashboard Cite

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“…For example, the observed decrease in the intracellular trehalose-6-phosphate concentration was consistent with a gradual release of the inhibition of HXK by this metabolite (4). Similarly, the metabolite profiles for fructose-2,6-bisphosphate and fructose-1,6-bisphosphate are likely to have contributed to the activation of PFK and PYK, respectively (3,25).…”

Section: Discussionmentioning

confidence: 61%

“…For example, it has been shown that high glucose concentrations result in modification of V max by transcriptional repression of HXK1 and ADH2 (12) and also by covalent modification of enzymes (e.g., via the phosphorylation of Pyk1, Pyk2, and Hxk2 [28]). A sudden glucose excess also results in major changes in metabolite concentrations that, in turn, affect the in vivo activity of key enzymes, such as HXK (inhibited by trehalose-6-phosphate [4]), PFK (activated by fructose-2,6-bisphosphate [3]), and PYK (activated by fructose-1,6-bisphosphate [25]). …”

mentioning

confidence: 99%

Dynamics of Glycolytic Regulation during Adaptation of Saccharomyces cerevisiae to Fermentative Metabolism

Brink

Canelas

Gulik

et al. 2008

Appl Environ Microbiol

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The ability of baker's yeast (Saccharomyces cerevisiae) to rapidly increase its glycolytic flux upon a switch from respiratory to fermentative sugar metabolism is an important characteristic for many of its multiple industrial applications. An increased glycolytic flux can be achieved by an increase in the glycolytic enzyme capacities (V max ) and/or by changes in the concentrations of low-molecular-weight substrates, products, and effectors. The goal of the present study was to understand the time-dependent, multilevel regulation of glycolytic enzymes during a switch from fully respiratory conditions to fully fermentative conditions. The switch from glucose-limited aerobic chemostat growth to full anaerobiosis and glucose excess resulted in rapid acceleration of fermentative metabolism. Although the capacities (V max ) of the glycolytic enzymes did not change until 45 min after the switch, the intracellular levels of several substrates, products, and effectors involved in the regulation of glycolysis did change substantially during the initial 45 min (e.g., there was a buildup of the phosphofructokinase activator fructose-2,6-bisphosphate). This study revealed two distinct phases in the upregulation of glycolysis upon a switch to fermentative conditions: (i) an initial phase, in which regulation occurs completely through changes in metabolite levels; and (ii) a second phase, in which regulation is achieved through a combination of changes in V max and metabolite concentrations. This multilevel regulation study qualitatively explains the increase in flux through the glycolytic enzymes upon a switch of S. cerevisiae to fermentative conditions and provides a better understanding of the roles of different regulatory mechanisms that influence the dynamics of yeast glycolysis.Baker's yeast (Saccharomyces cerevisiae) can rapidly switch between respiratory and fermentative sugar metabolism in response to changes in the availability of oxygen and fermentable sugars. This metabolic flexibility is likely to have arisen during evolution in environments where there are strong temporal and/or spatial fluctuations in sugar and oxygen levels. Upon transfer from respiratory to fermentative conditions, S. cerevisiae can, within a short time, tremendously increase its catabolic rates and start accumulating ethanol, as well as smaller amounts of acetate, succinate, and glycerol (50). In the natural, evolutionary context, this may have helped this organism rapidly monopolize sugars and create a hostile environment for competing microorganisms. This metabolic flexibility of S. cerevisiae is also an important characteristic for its multiple industrial applications. For instance, yeast biomass starved for glucose during storage has to rapidly adapt to a very high sugar concentration when it is added to bread dough or wort. Ideally, S. cerevisiae cells should be able to increase their CO 2 and ethanol production rates within minutes following their introduction into a fresh production medium. Upon such a transfer, the pathways responsi...

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“…Most probably, the main control of the glycolytic rate in the mutant strain(s) is exerted by the sugar uptake system (8), but other control mechanisms may be operative as well. For instance, the low concentration of FBP may contribute, since this is a known allosteric activator of the pyruvate kinase reaction (15,21,23). However, the identity of the initial glucose repression signal(s) will be further elucidated by the use of the TM6* strains and other strains covering a range of glycolytic rates at high external sugar concentrations (8).…”

Section: Discussionmentioning

confidence: 99%

Engineering of a Novel Saccharomyces cerevisiae Wine Strain with a Respiratory Phenotype at High External Glucose Concentrations

Henricsson

Ferreira

Hedfalk

et al. 2005

Appl Environ Microbiol

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The recently described respiratory strain Saccharomyces cerevisiae KOY.TM6*P is, to our knowledge, the only reported strain of S. cerevisiae which completely redirects the flux of glucose from ethanol fermentation to respiration, even at high external glucose concentrations (27). In the KOY.TM6*P strain, portions of the genes encoding the predominant hexose transporter proteins, Hxt1 and Hxt7, were fused within the regions encoding transmembrane (TM) domain 6. The resulting chimeric gene, TM6*, encoded a chimera composed of the amino-terminal half of Hxt1 and the carboxy-terminal half of Hxt7. It was subsequently integrated into the genome of an hxt null strain. In this study, we have demonstrated the transferability of this respiratory phenotype to the V5 hxt1-7⌬ strain, a derivative of a strain used in enology. We also show by using this mutant that it is not necessary to transform a complete hxt null strain with the TM6* construct to obtain a nonethanol-producing phenotype. The resulting V5.TM6*P strain, obtained by transformation of the V5 hxt1-7⌬ strain with the TM6* chimeric gene, produced only minor amounts of ethanol when cultured on external glucose concentrations as high as 5%. Despite the fact that glucose flux was reduced to 30% in the V5.TM6*P strain compared with that of its parental strain, the V5.TM6*P strain produced biomass at a specific rate as high as 85% that of the V5 wild-type strain. Even more relevant for the potential use of such a strain for the production of heterologous proteins and also of low-alcohol beverages is the observation that the biomass yield increased 50% with the mutant compared to its parental strain.

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The cooperative binding of fructose-1,6-bisphosphate to yeast pyruvate kinase.

Cited by 26 publications

References 13 publications

Can yeast glycolysis be understood in terms of in vitro kinetics of the constituent enzymes? Testing biochemistry

Can yeast glycolysis be understood in terms of in vitro kinetics of the constituent enzymes? Testing biochemistry

Dynamics of Glycolytic Regulation during Adaptation of Saccharomyces cerevisiae to Fermentative Metabolism

Engineering of a Novel Saccharomyces cerevisiae Wine Strain with a Respiratory Phenotype at High External Glucose Concentrations

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