The pentose phosphate pathway: evidence for the indispensable role of glucose-phosphate isomerase

Specific enzyme activities of the non-oxidative pentose phosphate pathway in Aspergillus oryzae mycelia grown on different carbon sources were determined. Mycelia grown on glucose, mannitol and ribose show the highest specific activities, ribose 5-phosphate isomerase being specially very enhanced. Moreover, transketolase, transaldolase, ribose 5-phosphate isomerase and ribulose 5-phosphate 3-epimerase were determined in different developmental stages of mycelia grown on glucose, mannitol and ribose. The non-oxidative pentose phosphate pathway is more active during conidiogenesis, except for ribulose 5-phosphate 3-epimerase, suggesting a fundamental role of this pathway during that stage to supply pentoses for nucleic acids biosynthesis. A general decrease of the enzyme activities was found in sporulated mycelia. Arabinose 5-phosphate was tested as metabolite of the pentose pathway. This pentose phosphate was not converted into hexose phosphates or triose phosphates and inhibits significantly the ribose 5-phosphate utilization, being therefore unappropriate to support the Aspergillus oryzae growth.

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Wnt5a Increases the Glycolytic Rate and the Activity of the Pentose Phosphate Pathway in Cortical Neurons

Neural Plasticity ◽

10.1155/2016/9839348 ◽

2016 ◽

Vol 2016 ◽

pp. 1-13 ◽

Cited By ~ 5

Author(s):

Pedro Cisternas ◽

Paulina Salazar ◽

Carmen Silva-Álvarez ◽

L. Felipe Barros ◽

Nibaldo C. Inestrosa

Keyword(s):

Glucose Metabolism ◽

Wnt Signaling ◽

Pentose Phosphate Pathway ◽

Neurodegenerative Disorders ◽

Metabolic Flux ◽

High Energy ◽

Pentose Phosphate ◽

The Brain ◽

Glycolytic Rate

In the last few years, several reports have proposed that Wnt signaling is a general metabolic regulator, suggesting a role for this pathway in the control of metabolic flux. Wnt signaling is critical for several neuronal functions, but little is known about the correlation between this pathway and energy metabolism. The brain has a high demand for glucose, which is mainly used for energy production. Neurons use energy for highly specific processes that require a high energy level, such as maintaining the electrical potential and synthesizing neurotransmitters. Moreover, an important metabolic impairment has been described in all neurodegenerative disorders. Despite the key role of glucose metabolism in the brain, little is known about the cellular pathways involved in regulating this process. We report here that Wnt5a induces an increase in glucose uptake and glycolytic rate and an increase in the activity of the pentose phosphate pathway; the effects of Wnt5a require the intracellular generation of nitric oxide. Our data suggest that Wnt signaling stimulates neuronal glucose metabolism, an effect that could be important for the reported neuroprotective role of Wnt signaling in neurodegenerative disorders.

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The role of maslinic acid in the pentose phosphate pathway during growth of gilthead sea bream(Sparus Aurata)

Aquaculture Nutrition ◽

10.1111/anu.12018 ◽

2013 ◽

Vol 19 (5) ◽

pp. 709-720 ◽

Cited By ~ 8

Author(s):

Eva E. Rufino-Palomares ◽

Fernando J. Reyes-Zurita ◽

Leticia García-Salguero ◽

Juan Peragón ◽

Manuel de la Higuera ◽

...

Keyword(s):

Pentose Phosphate Pathway ◽

Sparus Aurata ◽

Pentose Phosphate ◽

Gilthead Sea Bream ◽

Sea Bream ◽

Maslinic Acid

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Emerging Role of the Pentose Phosphate Pathway in Hepatocellular Carcinoma

Frontiers in Oncology ◽

10.3389/fonc.2017.00087 ◽

2017 ◽

Vol 7 ◽

Cited By ~ 48

Author(s):

Marta Anna Kowalik ◽

Amedeo Columbano ◽

Andrea Perra

Keyword(s):

Hepatocellular Carcinoma ◽

Pentose Phosphate Pathway ◽

Pentose Phosphate

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Death of mouse embryos that lack a functional gene for glucose phosphate isomerase

Genetics Research ◽

10.1017/s0016672300035321 ◽

1990 ◽

Vol 56 (2-3) ◽

pp. 223-236 ◽

Cited By ~ 14

Author(s):

John D. West ◽

Jean H. Flockhart ◽

Josephine Peters ◽

Simon T. Ball

Keyword(s):

Null Allele ◽

Phosphoglycerate Kinase ◽

Maternal Blood ◽

Pentose Phosphate ◽

Glucose Phosphate Isomerase ◽

Lethal Mutant ◽

Glucose Phosphate ◽

Extraembryonic Membranes ◽

Mutant Cells ◽

Better Than

SummaryA null allele of theGpi-1sstructural gene, that encodes glucose phosphate isomerase (GPI-1;E.C.5.3.1.9), arose in a mutation experiment and was designatedGpi-1sa-m1H. The viability of homozygotes has been investigated. No offspring homozygous for the null allele were produced by intercrossing two heterozygotes, so the homozygous condition was presumed to be embryonic lethal. Embryos were produced by crossingGpi-1sa/null heterozygous females andGpi-1sb/null heterozygous males. Homozygous null embryos were identified at different stages of development by electrophoresis and staining either for GPI-1 alone or GPI-1 plus phosphoglycerate kinase (PGK) activity. At 6½ and 7½ dayspost coitumhomozygous null embryos were present at approximately the expected 25% frequency (37/165; 22·4% overall) although at 7½ days the homozygous null embryos tended to be small. By 8½ days most homozygous null embryos were developmentally retarded and had not developed significantly further than at 7½ days; some were dead or dying. By 9½ days the homozygous null conceptus was characterised by a small implantation site that contained trophoblast and often a small amount of extraembryonic membrane. Surviving trophoblast tissue was also detectable at 10½ days. Previous studies have shown that oocyte-coded GPI-1 persists only until 5½ or 6½ days. Survival of homozygous null embryos to 7½ or 8½ days and survival of certain extraembryonic tissue to 10½ days suggests that the homozygous null condition may not be cell-lethal although it is certainly embryo-lethal. Mutant cells that are deficient in glycolysis may use the pentose phosphate shunt to bypass the block in glycolysis created by the deficiency of glucose phosphate isomerase, and/or might be rescued by the transport, from the maternal blood, of energy sources other than glucose (such as glutamine). Either strategy may only permit slow cell growth that would not be adequate to support normal embryogenesis. Transport of maternal nutrients would be more efficient to the trophoblast and extraembryonic membranes and this may help to explain why these tissues survive for longer than the embryo itself. The morphological similarity between homozygous nulls and androgenetic conceptuses, where the trophoblast also survives better than the embryo, is discussed.

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The pentose phosphate pathway constitutes a major metabolic hub in pathogenic Francisella

PLoS Pathogens ◽

10.1371/journal.ppat.1009326 ◽

2021 ◽

Vol 17 (8) ◽

pp. e1009326

Author(s):

Héloise Rytter ◽

Anne Jamet ◽

Jason Ziveri ◽

Elodie Ramond ◽

Mathieu Coureuil ◽

...

Keyword(s):

Pentose Phosphate Pathway ◽

Metabolic Pathways ◽

Pathogenic Bacteria ◽

Metabolic Networks ◽

Tricarboxylic Acid Cycle ◽

Sulfur Metabolism ◽

Time Lapse ◽

Pentose Phosphate ◽

Francisella Novicida

Metabolic pathways are now considered as intrinsic virulence attributes of pathogenic bacteria and thus represent potential targets for antibacterial strategies. Here we focused on the role of the pentose phosphate pathway (PPP) and its connections with other metabolic pathways in the pathophysiology of Francisella novicida. The involvement of the PPP in the intracellular life cycle of Francisella was first demonstrated by studying PPP inactivating mutants. Indeed, we observed that inactivation of the tktA, rpiA or rpe genes severely impaired intramacrophage multiplication during the first 24 hours. However, time-lapse video microscopy demonstrated that rpiA and rpe mutants were able to resume late intracellular multiplication. To better understand the links between PPP and other metabolic networks in the bacterium, we also performed an extensive proteo-metabolomic analysis of these mutants. We show that the PPP constitutes a major bacterial metabolic hub with multiple connections to glycolysis, the tricarboxylic acid cycle and other pathways, such as fatty acid degradation and sulfur metabolism. Altogether our study highlights how PPP plays a key role in the pathogenesis and growth of Francisella in its intracellular niche.

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