D-Xylose Sensing in Saccharomyces cerevisiae: Insights from D-Glucose Signaling and Native D-Xylose Utilizers

Brink, Daniel P.; Borgström, Celina; Persson, Viktor C.; Osiro, Karen Ofuji; Gorwa-Grauslund, Marie-Françoise

doi:10.3390/ijms222212410

Cited by 21 publications

(26 citation statements)

References 335 publications

(551 reference statements)

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“…It was shown that expression of a nuclear-localized Hxk2 activated xylose fermentation [ 25 ]. Effects of engineering the Snf3/Rgt2, SNF1/Mig1 and cAMP/PKA signalling pathways on xylose metabolism and fermentation in S. cerevisiae have been recently reviewed [ 26 ]. The role of xylose sensing/signalling in xylose metabolism and fermentation in the natural xylose-utilizing yeasts remains poorly understood.…”

Section: Discussionmentioning

confidence: 99%

The role of hexose transporter-like sensor hxs1 and transcription activator involved in carbohydrate sensing azf1 in xylose and glucose fermentation in the thermotolerant yeast Ogataea polymorpha

et al. 2022

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Background Fuel ethanol from lignocellulose could be important source of renewable energy. However, to make the process feasible, more efficient microbial fermentation of pentose sugars, mainly xylose, should be achieved. The native xylose-fermenting thermotolerant yeast Ogataea polymorpha is a promising organism for further development. Efficacy of xylose alcoholic fermentation by O. polymorpha was significantly improved by metabolic engineering. Still, genes involved in regulation of xylose fermentation are insufficiently studied. Results We isolated an insertional mutant of O.polymorpha with impaired ethanol production from xylose. The insertion occurred in the gene HXS1 that encodes hexose transporter-like sensor, a close homolog of Saccharomyces cerevisiae sensors Snf3 and Rgt2. The role of this gene in xylose utilization and fermentation was not previously elucidated. We additionally analyzed O.polymorpha strains with the deletion and overexpression of the corresponding gene. Strains with deletion of the HXS1 gene had slower rate of glucose and xylose consumption and produced 4 times less ethanol than the wild-type strain, whereas overexpression of HXS1 led to 10% increase of ethanol production from glucose and more than 2 times increase of ethanol production from xylose. We also constructed strains of O.polymorpha with overexpression of the gene AZF1 homologous to S. cerevisiae AZF1 gene which encodes transcription activator involved in carbohydrate sensing. Such transformants produced 10% more ethanol in glucose medium and 2.4 times more ethanol in xylose medium. Besides, we deleted the AZF1 gene in O. polymorpha. Ethanol accumulation in xylose and glucose media in such deletion strains dropped 1.5 and 1.8 times respectively. Overexpression of the HXS1 and AZF1 genes was also obtained in the advanced ethanol producer from xylose. The corresponding strains were characterized by 20–40% elevated ethanol accumulation in xylose medium. To understand underlying mechanisms of the observed phenotypes, specific enzymatic activities were evaluated in the isolated recombinant strains. Conclusions This paper shows the important role of hexose sensor Hxs1 and transcription factor Azf1 in xylose and glucose alcoholic fermentation in the native xylose-fermenting yeast O. polymorpha and suggests potential importance of the corresponding genes for construction of the advanced ethanol producers from the major sugars of lignocellulose.

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Section: Discussionmentioning

confidence: 99%

The role of hexose transporter-like sensor hxs1 and transcription activator involved in carbohydrate sensing azf1 in xylose and glucose fermentation in the thermotolerant yeast Ogataea polymorpha

et al. 2022

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“…HXT1p induction at high d-glucose concentrations (20 g L −1 ) as well as repression at low-to-no d-glucose; full induction of SUC2p at low concentrations of d-glucose (1 g L −1 ), with repression at higher levels (> 5 g L −1 ) and only basal induction in carbon-free media; and TPS1p repression in response to preferred carbon sources such as d-glucose, d-fructose, and d-galactose (Fig. 7) [16]. Additionally, we observed the previously reported induction of SUC2p on d-xylose [18] as well as TPS1p induction, indicating both a carbon starvation response and a decrease in PKA activity, which further supports the [17]).…”

Section: Sugar Signaling Responses and Further Indications Of D-xylos...mentioning

confidence: 99%

“…Catabolite repression in S. cerevisiae is tightly regulated by the level of d-glucose and by the presence or absence of other naturally used carbon sources, such as d-galactose [15]. The absence of d-glucose, and the presence of certain sugars such as d-galactose or d-fructose, results in the expression of genes which enable the catabolism of these alternative sugars [16]. It remains unclear whether or not, and by extension how, d-xylose is sensed by S. cerevisiae.…”

Section: Introductionmentioning

confidence: 99%

Using phosphoglucose isomerase-deficient (pgi1Δ) Saccharomyces cerevisiae to map the impact of sugar phosphate levels on d-glucose and d-xylose sensing

et al. 2022

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Background Despite decades of engineering efforts, recombinant Saccharomyces cerevisiae are still less efficient at converting d-xylose sugar to ethanol compared to the preferred sugar d-glucose. Using GFP-based biosensors reporting for the three main sugar sensing routes, we recently demonstrated that the sensing response to high concentrations of d-xylose is similar to the response seen on low concentrations of d-glucose. The formation of glycolytic intermediates was hypothesized to be a potential cause of this sensing response. In order to investigate this, glycolysis was disrupted via the deletion of the phosphoglucose isomerase gene (PGI1) while intracellular sugar phosphate levels were monitored using a targeted metabolomic approach. Furthermore, the sugar sensing of the PGI1 deletants was compared to the PGI1-wildtype strains in the presence of various types and combinations of sugars. Results Metabolomic analysis revealed systemic changes in intracellular sugar phosphate levels after deletion of PGI1, with the expected accumulation of intermediates upstream of the Pgi1p reaction on d-glucose and downstream intermediates on d-xylose. Moreover, the analysis revealed a preferential formation of d-fructose-6-phosphate from d-xylose, as opposed to the accumulation of d-fructose-1,6-bisphosphate that is normally observed when PGI1 deletants are incubated on d-fructose. This may indicate a role of PFK27 in d-xylose sensing and utilization. Overall, the sensing response was different for the PGI1 deletants, and responses to sugars that enter the glycolysis upstream of Pgi1p (d-glucose and d-galactose) were more affected than the response to those entering downstream of the reaction (d-fructose and d-xylose). Furthermore, the simultaneous exposure to sugars that entered upstream and downstream of Pgi1p (d-glucose with d-fructose, or d-glucose with d-xylose) resulted in apparent synergetic activation and deactivation of the Snf3p/Rgt2p and cAMP/PKA pathways, respectively. Conclusions Overall, the sensing assays indicated that the previously observed d-xylose response stems from the formation of downstream metabolic intermediates. Furthermore, our results indicate that the metabolic node around Pgi1p and the level of d-fructose-6-phosphate could represent attractive engineering targets for improved d-xylose utilization.

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“…However, its utilization of xylose naturally is lacking, requiring genetic engineering steps to insert one of the two xylose metabolism pathways to ethanol. Although yeast strains with these pathways are already used extensively, the challenge of xylose consumption remains, related to the cofactor imbalance on the oxidoreductive pathway, the need to further engineer or evolve exogenous xylose isomerases on the isomerase pathway, or inhibition of the xylose pathway by glucose due to sugar phosphorylation mechanisms [ 9 , 11 – 14 ].…”

Section: Introductionmentioning

confidence: 99%

Machine learning and comparative genomics approaches for the discovery of xylose transporters in yeast

Fiamenghi

Bueno

Camargo

et al. 2022

Biotechnol Biofuels

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Background The need to mitigate and substitute the use of fossil fuels as the main energy matrix has led to the study and development of biofuels as an alternative. Second-generation (2G) ethanol arises as one biofuel with great potential, due to not only maintaining food security, but also as a product from economically interesting crops such as energy-cane. One of the main challenges of 2G ethanol is the inefficient uptake of pentose sugars by industrial yeast Saccharomyces cerevisiae, the main organism used for ethanol production. Understanding the main drivers for xylose assimilation and identify novel and efficient transporters is a key step to make the 2G process economically viable. Results By implementing a strategy of searching for present motifs that may be responsible for xylose transport and past adaptations of sugar transporters in xylose fermenting species, we obtained a classifying model which was successfully used to select four different candidate transporters for evaluation in the S. cerevisiae hxt-null strain, EBY.VW4000, harbouring the xylose consumption pathway. Yeast cells expressing the transporters SpX, SpH and SpG showed a superior uptake performance in xylose compared to traditional literature control Gxf1. Conclusions Modelling xylose transport with the small data available for yeast and bacteria proved a challenge that was overcome through different statistical strategies. Through this strategy, we present four novel xylose transporters which expands the repertoire of candidates targeting yeast genetic engineering for industrial fermentation. The repeated use of the model for characterizing new transporters will be useful both into finding the best candidates for industrial utilization and to increase the model’s predictive capabilities. Graphical Abstract

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D-Xylose Sensing in Saccharomyces cerevisiae: Insights from D-Glucose Signaling and Native D-Xylose Utilizers

Cited by 21 publications

References 335 publications

The role of hexose transporter-like sensor hxs1 and transcription activator involved in carbohydrate sensing azf1 in xylose and glucose fermentation in the thermotolerant yeast Ogataea polymorpha

The role of hexose transporter-like sensor hxs1 and transcription activator involved in carbohydrate sensing azf1 in xylose and glucose fermentation in the thermotolerant yeast Ogataea polymorpha

Using phosphoglucose isomerase-deficient (pgi1Δ) Saccharomyces cerevisiae to map the impact of sugar phosphate levels on d-glucose and d-xylose sensing

Machine learning and comparative genomics approaches for the discovery of xylose transporters in yeast

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