GO:0004345 glucose-6-phosphate dehydrogenase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0004345 defines the molecular function glucose-6-phosphate dehydrogenase activity, catalyzing the NADP+-dependent oxidation of D-glucose 6-phosphate to D-glucono-1,5-lactone 6-phosphate with production of NADPH.
• G6PD is the rate-limiting enzyme of the pentose phosphate pathway and a major source of cytosolic NADPH, which maintains reduced glutathione and redox homeostasis.
• G6PD activity modulates diverse disease processes including cancer progression, diabetes-associated arterial aging, epileptic seizures, and susceptibility to infections such as Leishmania major and Plasmodium vivax.
• G6PD can exert antistress effects independently of its catalytic activity, indicating non-enzymatic functions that complicate simple activity-based interpretations.
• Post-translational modifications such as lactylation regulate G6PD and promote malignant phenotypes in cancer cell lines.
• CRISPR-based knockout, point-mutation, knock-in, and overexpression models are essential to dissect the causal roles of G6PD and its regulatory network.
Description
Glucose-6-phosphate dehydrogenase (G6PD) activity, annotated as GO:0004345, is a molecular function that catalyzes the conversion of D-glucose 6-phosphate to D-glucono-1,5-lactone 6-phosphate while reducing NADP+ to NADPH. This reaction is the first and rate-limiting step of the pentose phosphate pathway, a central metabolic route that supplies ribose-5-phosphate for nucleotide synthesis and NADPH for reductive biosynthesis and antioxidant defense. Because NADPH is critical for regenerating reduced glutathione, G6PD activity is a key determinant of cellular redox balance and stress resistance. Researchers study GO:0004345 to understand how cells cope with oxidative stress, how metabolic reprogramming supports tumor growth, and how inherited or acquired changes in G6PD activity contribute to human disease. Beyond its canonical catalytic role, recent evidence indicates that G6PD can exert antistress effects independently of its enzymatic activity, suggesting that the protein has additional, non-catalytic functions that are only beginning to be defined. This dual nature makes G6PD a compelling target for mechanistic studies and for therapeutic strategies aimed at modulating redox and metabolic pathways.
glucose-6-phosphate dehydrogenase activity At A Glance
| GO ID | GO:0004345 |
|---|---|
| GO term | glucose-6-phosphate dehydrogenase activity |
| Ontology | molecular_function |
| Synonym | G6PD activity; glucose-6-phosphate 1-dehydrogenase activity; D-glucose-6-phosphate:NADP+ 1-oxidoreductase activity; Zwischenferment; Entner-doudoroff enzyme |
| Major function | Catalyzes the NADP+-dependent oxidation of D-glucose 6-phosphate to D-glucono-1,5-lactone 6-phosphate, generating NADPH |
| Pathway context | Rate-limiting step of the pentose phosphate pathway oxidative branch |
| Cofactor | NADP+ (nicotinamide adenine dinucleotide phosphate) |
| Substrate | D-glucose 6-phosphate |
| Products | D-glucono-1,5-lactone 6-phosphate, NADPH, H+ |
What Is GO:0004345?
GO:0004345 glucose-6-phosphate dehydrogenase activity is defined as the catalysis of the reaction: D-glucose 6-phosphate + NADP+ = D-glucono-1,5-lactone 6-phosphate + NADPH + H+. In other words, it is the enzyme activity that oxidizes glucose 6-phosphate using NADP+ as the electron acceptor, producing a lactone intermediate and NADPH. This activity is synonymous with G6PD activity, glucose-6-phosphate 1-dehydrogenase activity, and several historical names such as Zwischenferment and Entner-doudoroff enzyme. It is a molecular_function term in the Gene Ontology and represents the catalytic core of the pentose phosphate pathway's oxidative branch.
Why Is glucose-6-phosphate dehydrogenase activity Important in Cell Biology?
GO:0004345 is important because it controls the primary source of cytosolic NADPH, a cofactor required for glutathione recycling, lipid synthesis, and many biosynthetic reactions. Consequently, changes in G6PD activity influence oxidative stress, cell survival, and proliferation, and have been linked to cancer, diabetes-associated vascular aging, epilepsy, and infectious disease outcomes. Understanding this activity at molecular, cellular, and organismal levels is therefore essential for both basic metabolism research and translational medicine.
• Provides NADPH for glutathione regeneration and antioxidant defense, protecting cells from oxidative stress.
• Supports nucleotide biosynthesis via ribose-5-phosphate production in the pentose phosphate pathway.
• Modulates cancer cell phenotypes, including metastasis and therapy resistance, through metabolic reprogramming.
• Contributes to diabetes-associated arterial aging, where G6PD deficiency accelerates vascular damage.
• Influences seizure susceptibility by regulating reactive oxygen species and STAT1-mediated NMDA receptor inhibition.
• Affects host response to Leishmania major infection by modulating macrophage function.
• Impacts malaria treatment strategies through its kinetics during Plasmodium vivax infection.
• Can act independently of its enzymatic activity to confer antistress effects, revealing non-canonical roles.
• Is a target of post-translational regulation such as lactylation, linking metabolism to epigenetic-like modifications.
• Serves as a biomarker and potential therapeutic target across metabolic, oncological, and infectious diseases.
What Happens During glucose-6-phosphate dehydrogenase activity?
Substrate binding and cofactor recruitment
In simple terms: The enzyme grabs its sugar substrate and a helper molecule called NADP+.
G6PD binds D-glucose 6-phosphate and NADP+ in an ordered manner, positioning the substrate for oxidation. The enzyme's active site accommodates the phosphate group of glucose 6-phosphate and the nicotinamide ring of NADP+, facilitating hydride transfer.
Catalytic oxidation and lactone formation
In simple terms: The enzyme removes hydrogen from the sugar, creating a new molecule and a reduced cofactor.
The catalytic step involves oxidation of the C1 hydroxyl of glucose 6-phosphate, yielding D-glucono-1,5-lactone 6-phosphate and NADPH. This reaction is rate-limiting for the oxidative phase of the pentose phosphate pathway and is highly regulated by the NADP+/NADPH ratio.
NADPH production and redox balance
In simple terms: The reaction produces NADPH, which cells use to fight oxidative stress.
NADPH generated by G6PD is used by glutathione reductase to regenerate reduced glutathione, maintaining the cellular redox environment. Loss of G6PD function increases oxidative stress and shifts metabolism toward glutaminolysis, as observed in melanoma cells.
Non-catalytic and regulatory functions
In simple terms: The protein can do things beyond its enzymatic job.
G6PD can exert antistress effects independently of its catalytic activity, suggesting that protein-protein interactions or structural roles contribute to stress resistance. Additionally, lactylation of G6PD promotes malignant phenotypes in cancer cell lines, indicating that post-translational modifications regulate its function.
Key Genes Involved in GO:0004345 glucose-6-phosphate dehydrogenase activity
The following genes and proteins are central to glucose-6-phosphate dehydrogenase activity, its regulation, and its downstream effects.
| Gene | Major Role | Research Relevance |
|---|---|---|
| G6PD | Encodes glucose-6-phosphate dehydrogenase, the enzyme catalyzing GO:0004345 | Core enzyme; mutations cause G6PD deficiency and affect redox balance |
| GSR | Glutathione reductase, uses NADPH to regenerate reduced glutathione | Links G6PD activity to antioxidant defense |
| GCLC | Glutamate-cysteine ligase catalytic subunit, rate-limiting for glutathione synthesis | Glutathione synthesis depends on G6PD-derived NADPH |
| GCLM | Glutamate-cysteine ligase modifier subunit, regulates GCLC activity | Modulates glutathione levels in response to G6PD activity |
| STAT1 | Signal transducer and activator of transcription 1, mediates NMDA receptor inhibition | G6PD represses ROS to promote STAT1-mediated NMDA receptor inhibition in epilepsy |
| GRIN1 | NMDA receptor subunit 1, target of STAT1-mediated inhibition | Involved in seizure modulation downstream of G6PD |
| GRIN2A | NMDA receptor subunit 2A, contributes to NMDA receptor function | Part of the NMDA receptor complex affected by G6PD activity |
| LDHA | Lactate dehydrogenase A, produces lactate for lactylation | Lactate availability affects G6PD lactylation |
| EP300 | Histone acetyltransferase p300, may mediate lactylation | Potential writer of G6PD lactylation |
| SIRT1 | NAD+-dependent deacetylase, may regulate G6PD acetylation | Redox-sensitive regulation of G6PD |
| TP53 | Tumor suppressor, regulates metabolic genes including G6PD | Links G6PD activity to cancer metabolism |
| MYC | Oncogenic transcription factor, drives pentose phosphate pathway genes | MYC activation increases G6PD expression in cancers |
| NRF2 | Transcription factor controlling antioxidant response | Regulates G6PD expression under oxidative stress |
| ATF4 | Stress-responsive transcription factor, part of integrated stress response | May modulate G6PD under metabolic stress |
| HIF1A | Hypoxia-inducible factor 1 subunit alpha, regulates metabolic adaptation | Hypoxia increases G6PD expression in tumors |
| PKM | Pyruvate kinase, links glycolysis to pentose phosphate pathway | Metabolic crosstalk with G6PD |
| GAPDH | Glyceraldehyde-3-phosphate dehydrogenase, glycolytic enzyme | Provides glucose 6-phosphate for G6PD |
How Is glucose-6-phosphate dehydrogenase activity Regulated?
G6PD activity is regulated at multiple levels. Transcriptionally, NRF2 and HIF1A increase G6PD expression under oxidative stress and hypoxia, respectively. Post-translational modifications, including lactylation, modulate G6PD function and promote malignant phenotypes. The enzyme is also subject to feedback inhibition by NADPH and regulation by the NADP+/NADPH ratio, which reflects cellular redox state. Additionally, G6PD can exert antistress effects independently of its catalytic activity, indicating that regulatory mechanisms may involve protein interactions rather than enzymatic turnover.
glucose-6-phosphate dehydrogenase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| G6PD | Melanoma metastasis and oxidative stress | G6PD knockout melanoma cell lines and mouse metastasis models |
| G6PD | Diabetes-associated arterial aging | Endothelial cell-specific G6PD knockout mice |
| G6PD | Epileptic seizures | Neuron-specific G6PD knockout or overexpression in seizure models |
| G6PD | Leishmania major infection | Macrophage-specific G6PD knockout in infection models |
| G6PD | Plasmodium vivax malaria | G6PD-deficient erythrocyte models for drug testing |
Cancer metabolism and metastasis
G6PD activity supports cancer cell proliferation by supplying NADPH and ribose-5-phosphate. Loss of G6PD function increases oxidative stress and glutaminolysis in metastasizing melanoma cells, suggesting that G6PD is required for metastatic efficiency. Lactylation of G6PD promotes malignant phenotypes in cancer cell lines, linking metabolic state to post-translational regulation. Reviews highlight G6PD as a potential therapeutic target in multiple cancers.
Diabetes and vascular aging
G6PD deficiency accelerates arterial aging in diabetes, implicating reduced NADPH production and increased oxidative stress in vascular complications. This connection underscores the importance of G6PD activity in maintaining vascular health under hyperglycemic conditions.
Neurological disorders and epilepsy
G6PD alleviates epileptic seizures by repressing reactive oxygen species production and promoting STAT1-mediated inhibition of NMDA receptors. This suggests that modulating G6PD activity could influence seizure susceptibility and neuronal excitability.
Infectious diseases
G6PD activity modulates macrophage response to Leishmania major infection, affecting parasite control. During Plasmodium vivax infection, G6PD activity kinetics have implications for early radical malaria treatment, as G6PD deficiency can complicate the use of primaquine.
From glucose-6-phosphate dehydrogenase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does G6PD catalytic activity mediate stress resistance? | G6PD knockout with catalytic-dead rescue (point mutation) |
| How does G6PD lactylation affect cancer phenotypes? | Knock-in of lactylation-deficient G6PD mutants in cancer cell lines |
| What is the role of G6PD in seizure modulation? | Neuron-specific G6PD overexpression or knockout in mouse epilepsy models |
| How does G6PD deficiency affect arterial aging in diabetes? | Endothelial-specific G6PD knockout in diabetic mice |
| Can G6PD activity be targeted in melanoma? | G6PD knockout melanoma cells and xenograft models |
| What are the non-enzymatic functions of G6PD? | Knock-in of enzymatic-dead G6PD variants |
How to Study the glucose-6-phosphate dehydrogenase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| NADPH absorbance assay | G6PD enzymatic activity | Quantifying activity in cell lysates |
| 13C-glucose tracing | Pentose phosphate pathway flux | Metabolic reprogramming studies |
| ROS detection (DCFDA) | Reactive oxygen species levels | Oxidative stress assessment |
| GSH/GSSG ratio | Redox balance | Antioxidant capacity |
| CRISPR knockout screens | Gene dependencies | Identifying G6PD synthetic lethality |
| Western blot | G6PD protein expression | Validating knockout or overexpression |
| Lactylation immunoprecipitation | G6PD lactylation | Post-translational modification studies |
Enzymatic activity assays
G6PD activity is typically measured spectrophotometrically by monitoring NADPH production at 340 nm. This method is used to quantify enzyme kinetics in cell lysates and to assess the impact of genetic variants or inhibitors.
Metabolic flux analysis
Stable isotope tracing with 13C-glucose can measure flux through the pentose phosphate pathway, providing insights into how G6PD activity contributes to NADPH and ribose synthesis.
Redox and oxidative stress measurements
Levels of reactive oxygen species, glutathione, and NADP+/NADPH ratios are used to assess the functional consequences of altered G6PD activity.
CRISPR-based genetic screens
Pooled CRISPR knockout screens can identify genes that modulate G6PD dependency, revealing synthetic lethal interactions and resistance mechanisms.
How CRISPR Can Be Used to Study GO:0004345 glucose-6-phosphate dehydrogenase activity
Knockout
CRISPR knockout of G6PD is used to eliminate enzymatic activity and assess consequences on redox balance, proliferation, and stress responses. Knockout models have revealed increased oxidative stress and metabolic shifts in melanoma cells.
Point Mutation
Point mutations that abolish catalytic activity while preserving protein structure are used to separate enzymatic from non-enzymatic functions of G6PD, as demonstrated by catalytic-dead rescue experiments.
Knock-in
Knock-in of disease-associated G6PD variants or lactylation-deficient mutants allows precise modeling of human phenotypes and post-translational regulation in isogenic backgrounds.
Overexpression
Overexpression of wild-type or mutant G6PD is used to test sufficiency in driving phenotypes such as seizure protection or cancer progression.
How EDITGENE Supports glucose-6-phosphate dehydrogenase activity Research
Researchers studying glucose-6-phosphate dehydrogenase activity-related genes often need to determine whether a candidate gene is causally involved in redox regulation, metabolic reprogramming, or disease phenotypes. EDITGENE provides a comprehensive suite of CRISPR services to enable such causal studies with high precision and reproducibility.
Contact EDITGENE today to design your custom CRISPR model for glucose-6-phosphate dehydrogenase activity research.
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| H6PD Knockout HEK293 Cell Line | EDJ-KQ5983 | Human | 9563 | Details Get a Quote |
| H6PD Knockout A-549 Cell Line | EDJ-KQ30907 | Human | 9563 | Details Get a Quote |
| H6PD Knockout HCT 116 Cell Line | EDJ-KQ30909 | Human | 9563 | Details Get a Quote |
| H6PD Knockout HeLa Cell Line | EDJ-KQ30910 | Human | 9563 | Details Get a Quote |
| G6PD (p.G131V) Point Mutation in HCT 116 Cell Line | EDC03080 | Human | 2539 | Details Get a Quote |
| G6PD (p.V291M) Point Mutation in HCT 116 Cell Line | EDC03076 | Human | 2539 | Details Get a Quote |
| G6PD (p.H32R) Point Mutation in K-562 Cell Line | EDC03149 | Human | 2539 | Details Get a Quote |
| G6PD (p.H32R) Point Mutation in HCT 116 Cell Line | EDC03077 | Human | 2539 | Details Get a Quote |
| G6PD (p.L342F) Point Mutation in HCT 116 Cell Line | EDC03108 | Human | 2539 | Details Get a Quote |
| G6PD (p.L342F) Point Mutation in K-562 Cell Line | EDC03152 | Human | 2539 | Details Get a Quote |
| G6PD (p.R459L) Point Mutation in K-562 Cell Line | EDC03168 | Human | 2539 | Details Get a Quote |
| G6PD (p.R463H) Point Mutation in K-562 Cell Line | EDC03154 | Human | 2539 | Details Get a Quote |
| G6PD (p.G131V) Point Mutation in K-562 Cell Line | EDC03145 | Human | 2539 | Details Get a Quote |
| G6PD Knockout A-549 Cell Line | EDC90419 | Human | 2539 | Details Get a Quote |
| G6PD（p.R459L） Point Mutation in HCT 116 Cell Line | EDC03066 | Human | 2539 | Details Get a Quote |
Frequently Asked Questions About glucose-6-phosphate dehydrogenase activity
What is glucose-6-phosphate dehydrogenase activity?
It is the enzyme activity defined by GO:0004345 that catalyzes the oxidation of D-glucose 6-phosphate to D-glucono-1,5-lactone 6-phosphate while reducing NADP+ to NADPH.
What genes are involved in glucose-6-phosphate dehydrogenase activity?
The primary gene is G6PD, which encodes the enzyme. Other genes such as GSR, GCLC, and NRF2 modulate its downstream effects.
What is the role of G6PD in cancer?
G6PD supports cancer cell proliferation by providing NADPH and ribose-5-phosphate, and its loss increases oxidative stress and glutaminolysis in melanoma cells.
How is G6PD activity regulated?
It is regulated transcriptionally by NRF2 and HIF1A, post-translationally by lactylation, and through feedback inhibition by NADPH.
What diseases are associated with G6PD deficiency?
G6PD deficiency accelerates arterial aging in diabetes and affects malaria treatment; it also modulates macrophage response to Leishmania major.
Can G6PD function independently of its enzymatic activity?
Yes, studies show that G6PD can exert antistress effects independently of its catalytic activity.
What methods are used to measure G6PD activity?
Spectrophotometric NADPH assays, metabolic flux analysis, and redox measurements are commonly used.
How does G6PD affect epilepsy?
G6PD alleviates epileptic seizures by repressing reactive oxygen species and promoting STAT1-mediated NMDA receptor inhibition.
What is the pentose phosphate pathway?
It is a metabolic pathway that generates NADPH and ribose-5-phosphate, with G6PD catalyzing its rate-limiting step.
How can CRISPR help study G6PD?
CRISPR knockout, point mutation, knock-in, and overexpression models allow precise dissection of G6PD function in health and disease.
Conclusion
GO:0004345 glucose-6-phosphate dehydrogenase activity is a central metabolic function that controls NADPH production and redox homeostasis. Its dysregulation is implicated in cancer, diabetes, neurological disorders, and infectious diseases, making it a high-priority target for mechanistic and translational research. Leveraging CRISPR-based models and advanced screening technologies will continue to uncover the full spectrum of G6PD biology and its therapeutic potential.
References
- 1. Jin X et al.. 2022. Glucose-6-phosphate dehydrogenase exerts antistress effects independently of its enzymatic activity.. J Biol Chem 298(12):102587 PMID: 36243112
- 2. Scuteri A et al.. 2024. Glucose-6-phosphate dehydrogenase deficiency accelerates arterial aging in diabetes.. Acta Diabetol 61(1):127-130 PMID: 37741911
- 3. Hu L et al.. 2024. Glucose-6-phosphate dehydrogenase alleviates epileptic seizures by repressing reactive oxygen species production to promote signal transducer and activator of transcription 1-mediated N-methyl-d-aspartic acid receptors inhibition.. Redox Biol 74:103236 PMID: 38875958
- 4. Zhang Y et al.. 2025. The lactylation of glucose-6-phosphate dehydrogenase promotes malignant phenotypes in cancer cell lines.. Mol Biol Rep 52(1):861 PMID: 40900394
- 5. Zamani S et al.. 2019. Glucose-6-phosphate dehydrogenase (G6PD) activity can modulate macrophage response to Leishmania major infection.. Int Immunopharmacol 69:178-183 PMID: 30716588
- 6. Dahuron L et al.. 2024. Kinetics of glucose-6-phosphate dehydrogenase (G6PD) activity during Plasmodium vivax infection: implications for early radical malaria treatment.. Malar J 23(1):140 PMID: 38725027
- 7. Aurora AB et al.. 2022. Loss of glucose 6-phosphate dehydrogenase function increases oxidative stress and glutaminolysis in metastasizing melanoma cells.. Proc Natl Acad Sci U S A 119(6) PMID: 35110412
- 8. Li R et al.. 2020. Exploring the role of glucose‑6‑phosphate dehydrogenase in cancer (Review).. Oncol Rep 44(6):2325-2336 PMID: 33125150
