GO:0006098 pentose-phosphate shunt: Metabolic Pathway, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0006098 (pentose-phosphate shunt) is the oxidative and non-oxidative metabolic route that converts glucose-6-phosphate into ribulose-5-phosphate, CO2 and NADPH, while also generating ribose-5-phosphate, erythrose-4-phosphate, fructose-6-phosphate and glyceraldehyde-3-phosphate.
• The pathway is a major source of NADPH for reductive biosynthesis and antioxidant defense, and of ribose-5-phosphate for nucleotide and nucleic acid synthesis.
• The oxidative branch is initiated by glucose-6-phosphate dehydrogenase (G6PD), and its activity is required for T cell activation and antitumor immunity.
• Inhibition of the pentose-phosphate shunt metabolically reprograms CD8+ T cells and can disrupt CNS autoimmunity, indicating a role in immune-mediated disease.
• The pathway also supports nervous system sensory homeostasis and axonal regeneration through a glycolytic shunt mechanism.
• In photosynthesizing cells, the oxidative pentose-phosphate shunt operates alongside the Calvin-Benson cycle and is important for carbon and redox balance.
Description
The pentose-phosphate shunt (GO:0006098) is a central metabolic pathway that branches from glycolysis at glucose-6-phosphate and produces NADPH, ribose-5-phosphate, and a series of sugar phosphate intermediates. It is one of the oldest and most conserved metabolic routes in cells, and it is essential for balancing redox metabolism with biosynthetic demand. The pathway is particularly important in proliferating cells, immune cells, and neurons, where it supplies reducing power and nucleotide precursors. In photosynthesizing cells, the oxidative pentose-phosphate shunt also contributes to carbon metabolism and redox homeostasis. Because of its broad roles, the pathway is a frequent subject of genetic and pharmacological studies using CRISPR-based models.
pentose-phosphate shunt At A Glance
| GO ID | GO:0006098 |
|---|---|
| GO term | pentose-phosphate shunt |
| Ontology | biological_process |
| Synonym | hexose monophosphate pathway; pentose phosphate pathway; pentose-phosphate pathway; pentose phosphate shunt |
| Major function | Oxidation of glucose-6-phosphate to ribulose-5-phosphate with NADPH production; generation of ribose-5-phosphate, erythrose-4-phosphate, fructose-6-phosphate and glyceraldehyde-3-phosphate |
| Key enzymes | Glucose-6-phosphate dehydrogenase (G6PD), 6-phosphogluconolactonase, 6-phosphogluconate dehydrogenase, ribulose-5-phosphate isomerase, ribulose-5-phosphate epimerase, transketolase, transaldolase |
| Cellular location | Cytoplasm |
| Pathway branches | Oxidative branch and non-oxidative branch |
| Related pathways | Glycolysis, nucleotide biosynthesis, glutathione metabolism, photosynthesis |
What Is GO:0006098?
The pentose-phosphate shunt is the metabolic process in which glucose-6-phosphate is oxidized to form carbon dioxide and ribulose-5-phosphate, coupled to the reduction of NADP+ to NADPH; ribulose-5-phosphate then enters a series of reactions that can yield biosynthetic precursors such as ribose-5-phosphate and erythrose-4-phosphate, as well as glycolytic intermediates such as fructose-6-phosphate and glyceraldehyde-3-phosphate.
Why Is pentose-phosphate shunt Important in Cell Biology?
The pentose-phosphate shunt is important because it links glucose metabolism to NADPH-dependent reductive biosynthesis and antioxidant defense, and it supplies ribose-5-phosphate for nucleotide synthesis. In immune cells, the oxidative branch is required for T cell activation and antitumor immunity, and its inhibition can reprogram CD8+ T cells and modulate CNS autoimmunity. In the nervous system, a glycolytic shunt via the pentose-phosphate pathway acts as a metabolic checkpoint for sensory homeostasis and axonal regeneration. In photosynthesizing cells, the oxidative pentose-phosphate shunt contributes to carbon and redox balance. These roles make the pathway a key target for metabolic, immunological, and neurological research.
• Provides NADPH for reductive biosynthesis and antioxidant systems such as glutathione.
• Supplies ribose-5-phosphate for nucleotide and nucleic acid synthesis.
• Required for T cell activation and antitumor immunity.
• Inhibition metabolically reprograms CD8+ T cells and disrupts CNS autoimmunity.
• Acts as a metabolic checkpoint for nervous system sensory homeostasis and axonal regeneration.
• Operates in photosynthesizing cells and contributes to carbon and redox balance.
• Linked to stem cell redox regulation and pulmonary hypertension biology.
• Studied in cartilage and bone metabolism using chick growth cartilage models.
• A frequent target for CRISPR knockout and metabolic flux studies.
• Relevant to cancer metabolism and immune evasion through NADPH supply.
What Happens During pentose-phosphate shunt?
Oxidative branch: glucose-6-phosphate oxidation
In simple terms: The pathway starts by stripping electrons from glucose-6-phosphate to make NADPH and a five-carbon sugar phosphate.
The oxidative branch begins with glucose-6-phosphate dehydrogenase (G6PD), which oxidizes glucose-6-phosphate to 6-phosphogluconolactone while reducing NADP+ to NADPH. The lactone is then hydrolyzed by 6-phosphogluconolactonase, and 6-phosphogluconate dehydrogenase further oxidizes the intermediate to ribulose-5-phosphate, generating a second NADPH and releasing CO2. This branch is the primary source of NADPH in many cell types and is required for T cell activation and antitumor immunity.
Non-oxidative branch: interconversion of sugar phosphates
In simple terms: The five-carbon sugar phosphate is reshuffled into other sugars that can be used for building blocks or fed back into glycolysis.
Ribulose-5-phosphate can be converted to ribose-5-phosphate by ribulose-5-phosphate isomerase or to xylulose-5-phosphate by ribulose-5-phosphate epimerase. Transketolase and transaldolase then catalyze a series of reversible reactions that interconvert these sugars with glycolytic intermediates, yielding fructose-6-phosphate, glyceraldehyde-3-phosphate, erythrose-4-phosphate, and sedoheptulose-7-phosphate. These reactions allow the pathway to adapt to cellular demand for ribose-5-phosphate or NADPH.
Metabolic checkpoint in neurons and axonal regeneration
In simple terms: In nerve cells, the pentose-phosphate shunt acts like a gate that controls energy and redox balance needed for nerve repair.
A glycolytic shunt via the pentose-phosphate pathway has been identified as a metabolic checkpoint for nervous system sensory homeostasis and axonal regeneration. This suggests that the pathway is not only a housekeeping route but also a regulatory node in neuronal metabolism.
Role in photosynthesizing cells
In simple terms: In plants, the oxidative pentose-phosphate shunt works alongside photosynthesis to manage carbon and reducing power.
In photosynthesizing cells, the oxidative pentose-phosphate shunt operates and is important for carbon and redox balance. The pathway is required for normal photosynthetic metabolism and is a tale of two shunts in plant cells.
Immune cell activation and autoimmunity
In simple terms: The pathway helps immune cells turn on and can influence autoimmune attacks.
The oxidative pentose-phosphate pathway is required for T cell activation and antitumor immunity. Inhibition of the pathway metabolically reprograms CD8+ T cells and disrupts CNS autoimmunity, indicating a role in immune-mediated disease.
Key Genes Involved in GO:0006098 pentose-phosphate shunt
The following genes and enzymes are core components or regulators of the pentose-phosphate shunt (GO:0006098) and are frequently studied using CRISPR-based models.
| Gene | Major Role | Research Relevance |
|---|---|---|
| G6PD | Glucose-6-phosphate dehydrogenase; rate-limiting enzyme of the oxidative branch | Target for metabolic and immune studies; required for T cell activation |
| PGLS | 6-phosphogluconolactonase; hydrolyzes 6-phosphogluconolactone | Supports oxidative branch flux |
| PGD | 6-phosphogluconate dehydrogenase; produces ribulose-5-phosphate and NADPH | Key oxidative branch enzyme |
| RPIA | Ribulose-5-phosphate isomerase; converts ribulose-5-phosphate to ribose-5-phosphate | Supplies ribose-5-phosphate for nucleotide synthesis |
| RPE | Ribulose-5-phosphate epimerase; converts ribulose-5-phosphate to xylulose-5-phosphate | Non-oxidative branch enzyme |
| TKT | Transketolase; transfers two-carbon units in non-oxidative branch | Links pentose-phosphate shunt to glycolysis |
| TALDO1 | Transaldolase; interconverts sugar phosphates in non-oxidative branch | Non-oxidative branch enzyme |
| GPI | Glucose-6-phosphate isomerase; interconverts glucose-6-phosphate and fructose-6-phosphate | Connects glycolysis and pentose-phosphate shunt |
| PFKL | Phosphofructokinase; glycolytic enzyme | Affects glycolytic shunt and pathway balance |
| PKM | Pyruvate kinase; glycolytic enzyme | Modulates metabolic flux into the shunt |
| LDHA | Lactate dehydrogenase A; anaerobic glycolysis | Affects NAD+ regeneration and pathway balance |
| IDH1 | Isocitrate dehydrogenase 1; produces NADPH | Contributes to cellular NADPH pool |
| IDH2 | Isocitrate dehydrogenase 2; produces NADPH | Mitochondrial NADPH source |
| NNT | Nicotinamide nucleotide transhydrogenase; NADPH production | Supports redox balance |
| SLC7A11 | Cystine/glutamate antiporter; supports glutathione synthesis | Links NADPH demand to antioxidant defense |
| GCLC | Glutamate-cysteine ligase catalytic subunit; glutathione synthesis | Consumes NADPH indirectly |
| GCLM | Glutamate-cysteine ligase modifier subunit; glutathione synthesis | Redox-related pathway |
How Is pentose-phosphate shunt Regulated?
The pentose-phosphate shunt is regulated by the availability of glucose-6-phosphate, the redox state of the cell, and the demand for NADPH and ribose-5-phosphate. G6PD activity is a key control point and is influenced by NADP+ levels and cellular oxidative stress. In immune cells, pathway activity is required for T cell activation and can be modulated by metabolic reprogramming. In neurons, the pathway acts as a metabolic checkpoint for sensory homeostasis and axonal regeneration. In photosynthesizing cells, the oxidative pentose-phosphate shunt is regulated in coordination with photosynthetic carbon metabolism.
pentose-phosphate shunt and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| G6PD | T cell activation and antitumor immunity | G6PD knockout T cells |
| G6PD | CNS autoimmunity and CD8+ T cell reprogramming | G6PD inhibition in CD8+ T cells |
| G6PD | Pulmonary hypertension and stem cell redox | Stem cell models with G6PD modulation |
| TKT | Metabolic reprogramming in immune cells | TKT knockout cell lines |
| TALDO1 | Non-oxidative branch and metabolic disease | TALDO1 knockout models |
| PGD | Oxidative branch and NADPH supply | PGD knockout cell lines |
Cancer and tumor immunity
The oxidative pentose-phosphate pathway is required for T cell activation and antitumor immunity, and its inhibition can affect immune responses against tumors. Because the pathway supplies NADPH and ribose-5-phosphate, it supports the metabolic demands of proliferating cells and immune cells.
Autoimmune and neuroinflammatory disease
Inhibition of the pentose-phosphate pathway metabolically reprograms CD8+ T cells and disrupts CNS autoimmunity, suggesting that targeting this pathway could modulate neuroinflammatory disease.
Nervous system injury and regeneration
A glycolytic shunt via the pentose-phosphate pathway is a metabolic checkpoint for nervous system sensory homeostasis and axonal regeneration, linking the pathway to nerve repair.
Pulmonary hypertension and stem cell biology
The pentose shunt, glucose-6-phosphate dehydrogenase, and NADPH redox have been studied in stem cells in pulmonary hypertension, indicating a role in vascular and stem cell biology.
From pentose-phosphate shunt-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does G6PD loss affect T cell activation? | G6PD knockout T cells |
| Does pentose-phosphate pathway inhibition reprogram CD8+ T cells? | Pharmacological or genetic inhibition in CD8+ T cells |
| Is the pentose-phosphate shunt required for axonal regeneration? | Neuronal knockout models |
| How does the oxidative pentose-phosphate shunt affect photosynthesis? | Plant knockout or knockdown models |
| What is the role of G6PD in pulmonary hypertension stem cells? | Stem cell knockout or overexpression models |
| How does transketolase loss affect metabolic flux? | TKT knockout cell lines |
How to Study the pentose-phosphate shunt Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Metabolic flux analysis | Carbon flow through oxidative and non-oxidative branches | Quantifying pathway activity |
| NADPH/NADP+ ratio | Redox state and reducing power | Assessing pathway output |
| RNA-seq | Gene expression changes | Identifying pathway regulation |
| Proteomics | Protein abundance of pathway enzymes | Validating expression changes |
| T cell activation assays | Immune cell function | Testing requirement for oxidative branch |
| CD8+ T cell reprogramming assays | Metabolic and functional changes | Autoimmunity studies |
| Axonal regeneration assays | Neuronal repair capacity | Nervous system studies |
| Photosynthesis assays | Carbon and redox balance | Plant cell studies |
Metabolic flux analysis
Metabolic flux analysis using labeled glucose can quantify carbon flow through the oxidative and non-oxidative branches of the pentose-phosphate shunt. This approach helps determine how genetic perturbations alter pathway activity.
NADPH and redox measurements
NADPH levels and redox state can be measured to assess the functional output of the pentose-phosphate shunt. These measurements are important in immune and neuronal studies.
Transcriptomics and proteomics
RNA-seq and proteomics can reveal changes in expression of pentose-phosphate shunt enzymes after genetic or pharmacological perturbation. Such data help identify regulatory nodes and compensatory pathways.
Functional immune assays
T cell activation and antitumor immunity assays can be used to test the requirement for the oxidative pentose-phosphate pathway. CD8+ T cell reprogramming can be assessed in autoimmunity models.
How CRISPR Can Be Used to Study GO:0006098 pentose-phosphate shunt
Knockout
CRISPR knockout of G6PD, PGD, TKT, or TALDO1 can be used to disable specific branches of the pentose-phosphate shunt and assess metabolic, immune, and neuronal phenotypes.
Point Mutation
Point mutations can be introduced into catalytic residues of G6PD or other pathway enzymes to dissect enzymatic activity from other functions.
Knock-in
Knock-in of tagged or reporter alleles can enable tracking of pathway enzyme expression and localization in live cells.
Overexpression
Overexpression of G6PD or other pathway enzymes can increase NADPH production and test sufficiency in immune activation or neuronal regeneration.
How EDITGENE Supports pentose-phosphate shunt Research
Researchers studying pentose-phosphate shunt-related genes often need to determine whether a candidate gene is causally involved in metabolic, immune, or neuronal phenotypes. EDITGENE provides CRISPR-based cell model services to support these studies.
Contact EDITGENE today to design your custom CRISPR model for pentose-phosphate shunt research.
Frequently Asked Questions About pentose-phosphate shunt
What is the pentose-phosphate shunt (GO:0006098)?
The pentose-phosphate shunt is the metabolic process in which glucose-6-phosphate is oxidized to form CO2 and ribulose-5-phosphate, coupled to NADPH production, and ribulose-5-phosphate then enters reactions that yield ribose-5-phosphate, erythrose-4-phosphate, fructose-6-phosphate, and glyceraldehyde-3-phosphate.
What genes are involved in the pentose-phosphate shunt?
Key genes include G6PD, PGLS, PGD, RPIA, RPE, TKT, and TALDO1, which encode enzymes of the oxidative and non-oxidative branches.
Why is the pentose-phosphate shunt important for immune cells?
The oxidative pentose-phosphate pathway is required for T cell activation and antitumor immunity, and its inhibition can reprogram CD8+ T cells and disrupt CNS autoimmunity.
How is the pentose-phosphate shunt studied?
It is studied using metabolic flux analysis, NADPH measurements, RNA-seq, proteomics, and functional immune or neuronal assays.
What is the role of G6PD in the pentose-phosphate shunt?
G6PD is the rate-limiting enzyme of the oxidative branch and catalyzes the first oxidation step that produces NADPH.
Does the pentose-phosphate shunt affect neurons?
Yes, a glycolytic shunt via the pentose-phosphate pathway acts as a metabolic checkpoint for nervous system sensory homeostasis and axonal regeneration.
Is the pentose-phosphate shunt active in plants?
Yes, the oxidative pentose-phosphate shunt operates in photosynthesizing cells and contributes to carbon and redox balance.
What diseases are linked to the pentose-phosphate shunt?
It has been linked to cancer immunity, CNS autoimmunity, nervous system regeneration, and pulmonary hypertension stem cell biology.
Can CRISPR be used to study the pentose-phosphate shunt?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models can be used to dissect pathway gene function.
What are the synonyms for pentose-phosphate shunt?
Synonyms include hexose monophosphate pathway, pentose phosphate pathway, pentose-phosphate pathway, and pentose phosphate shunt.
Conclusion
The pentose-phosphate shunt (GO:0006098) is a fundamental metabolic pathway that supplies NADPH and ribose-5-phosphate while interconverting sugar phosphates for biosynthetic and glycolytic needs. Its roles in immune activation, autoimmunity, neuronal regeneration, and photosynthesis make it a high-value target for genetic and pharmacological studies. CRISPR-based models from EDITGENE can accelerate research into the causal roles of pathway genes in health and disease.
References
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- 2. Stincone A et al.. 2015. The return of metabolism: biochemistry and physiology of the pentose phosphate pathway.. Biol Rev Camb Philos Soc 90(3):927-63 PMID: 25243985
- 3. Chen Z et al.. 2025. Oxidative pentose phosphate pathway is required for T cell activation and antitumor immunity.. Proc Natl Acad Sci U S A 122(49):e2516288122 PMID: 41337482
- 4. Sharkey TD. 2021. Pentose Phosphate Pathway Reactions in Photosynthesizing Cells.. Cells 10(6) PMID: 34207480
- 5. Hashimoto R et al.. 2017. Pentose Shunt, Glucose-6-Phosphate Dehydrogenase, NADPH Redox, and Stem Cells in Pulmonary Hypertension.. Adv Exp Med Biol 967:47-55 PMID: 29047080
- 6. Silverton SF et al.. 1989. Pentose phosphate shunt metabolism by cells of the chick growth cartilage.. Bone 10(1):45-51 PMID: 2736155
- 7. Grund EM et al.. 2025. Pentose phosphate pathway inhibition metabolically reprograms CD8+ T cells and disrupts CNS autoimmunity.. JCI Insight 10(14) PMID: 40493395
- 8. Xu Y et al.. 2024. The oxidative pentose phosphate pathway in photosynthesis: a tale of two shunts.. New Phytol 242(6):2453-2463 PMID: 38567702
