GO:0016655 oxidoreductase activity, acting on NAD(P)H, quinone or similar compound as acceptor: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0016655 describes a molecular function: catalysis of a redox reaction in which NADH or NADPH donates electrons to a quinone or a similar acceptor molecule.
• The best-characterized human enzyme carrying this activity is NQO1 (NAD(P)H quinone dehydrogenase 1), a two-electron reductase that detoxifies quinones and prevents one-electron redox cycling.
• NQO1 is a direct transcriptional target of NRF2, placing GO:0016655 at the center of the cellular antioxidant response.
• Loss or inhibition of this activity increases lipid peroxidation and oxidative stress, which can be exploited for cancer therapy.
• NQO1 is overexpressed in several tumors, including NRF2-high pancreatic ductal adenocarcinoma, making it an attractive target for prodrug activation.
• Modulating NRF2/HO1/NQO1 signaling is being explored in non-communicable diseases such as fibromyalgia and other conditions with systemic redox imbalance.
Description
GO:0016655, oxidoreductase activity, acting on NAD(P)H, quinone or similar compound as acceptor, is a molecular function ontology term that captures a specific class of redox reactions. In these reactions, NADH or NADPH serves as the electron donor, and a quinone or a structurally similar molecule acts as the electron acceptor. This activity is essential for maintaining cellular redox balance and for detoxifying reactive quinones that would otherwise participate in harmful redox cycling. The term is therefore central to understanding how cells defend themselves against oxidative stress and how this defense can be harnessed or disrupted in disease. The most extensively studied human enzyme annotated with this activity is NQO1 (NAD(P)H quinone dehydrogenase 1). NQO1 catalyzes a two-electron reduction of quinones, bypassing the formation of semiquinone radicals and thereby preventing the generation of reactive oxygen species. Because NQO1 is a direct transcriptional target of the NRF2 pathway, its expression is tightly coupled to the cellular antioxidant response. This link has made GO:0016655 a focal point in cancer biology, neurodegeneration, and metabolic disease research. For researchers, GO:0016655 provides a precise functional annotation that can be used to interpret gene expression data, design CRISPR screens, and develop targeted therapies. Understanding which genes carry this activity, how they are regulated, and how they contribute to disease is essential for translating redox biology into clinical applications.
oxidoreductase activity, acting on NAD(P)H, quinone or similar compound as acceptor At A Glance
| GO ID | GO:0016655 |
|---|---|
| GO term | oxidoreductase activity, acting on NAD(P)H, quinone or similar compound as acceptor |
| Ontology | molecular_function |
| Synonym | oxidoreductase activity, acting on NADH or NADPH, quinone or similar compound as acceptor |
| Major function | Catalysis of redox reactions using NADH or NADPH as electron donor and quinone or similar compound as acceptor |
| Representative enzyme | NQO1 (NAD(P)H quinone dehydrogenase 1) |
| Cofactors | FAD (flavin adenine dinucleotide) in NQO1 |
| Pathway context | NRF2-mediated antioxidant response |
| Disease relevance | Cancer, oxidative stress-related disorders, systemic redox imbalance |
What Is GO:0016655?
GO:0016655 is defined as the catalysis of an oxidation-reduction (redox) reaction in which NADH or NADPH acts as a hydrogen or electron donor and reduces a quinone or a similar acceptor molecule. In simpler terms, it is the enzyme activity that uses the reducing power of NAD(P)H to convert quinones into less reactive hydroquinones, thereby protecting cells from oxidative damage.
Why Is oxidoreductase activity, acting on NAD(P)H, quinone or similar compound as acceptor Important in Cell Biology?
GO:0016655 is important because it defines a core detoxification and antioxidant mechanism that protects cells from quinone-induced oxidative stress. Enzymes with this activity, particularly NQO1, are critical for maintaining redox homeostasis and are directly regulated by the NRF2 pathway. Dysregulation of this activity contributes to cancer progression, chemoresistance, and non-communicable diseases characterized by systemic redox imbalance. Moreover, the ability to selectively target NQO1 in NRF2-high tumors has opened new avenues for prodrug-based cancer therapy.
• Protects cells from oxidative stress by reducing quinones to hydroquinones.
• Prevents one-electron redox cycling and reactive oxygen species generation.
• Is a direct transcriptional target of NRF2, linking it to the antioxidant response.
• Overexpressed in several cancers, including NRF2-high pancreatic ductal adenocarcinoma.
• Loss of activity increases lipid peroxidation, which can be exploited for cancer treatment.
• Modulating NRF2/HO1/NQO1 axis is explored in fibromyalgia and other redox imbalance conditions.
• Serves as a biomarker for NRF2 pathway activation in tumors.
• Provides a target for prodrug activation strategies in precision oncology.
• Contributes to cellular defense against environmental carcinogens.
• Is a key node in the crosstalk between metabolism and redox signaling.
Molecular Function of GO:0016655
Substrate Binding and Electron Transfer
In simple terms: The enzyme grabs electrons from NADH or NADPH and hands them to a quinone molecule.
Enzymes with GO:0016655 activity, such as NQO1, bind NAD(P)H and a quinone substrate in their active site. The flavin cofactor FAD facilitates the transfer of two electrons from NAD(P)H to the quinone, reducing it to a hydroquinone. This two-electron transfer avoids the formation of semiquinone radicals, which are highly reactive and can generate reactive oxygen species.
Catalytic Mechanism and Cofactor Role
In simple terms: A vitamin-derived molecule inside the enzyme helps move electrons safely.
NQO1 uses FAD as a prosthetic group to accept electrons from NAD(P)H and donate them to the quinone acceptor. The catalytic cycle involves hydride transfer from NAD(P)H to FAD, followed by reduction of the quinone to hydroquinone. This mechanism is highly efficient and prevents the one-electron reduction that would otherwise produce damaging free radicals.
Regulation by NRF2 Pathway
In simple terms: The cell increases production of this enzyme when it senses oxidative danger.
The expression of NQO1, a major enzyme with GO:0016655 activity, is transcriptionally regulated by NRF2. Under oxidative stress, NRF2 translocates to the nucleus and binds antioxidant response elements (AREs) in the NQO1 promoter, increasing its transcription. This feedback loop ensures that the cell can rapidly upregulate quinone detoxification capacity when needed.
Role in Lipid Peroxidation and Ferroptosis
In simple terms: This activity helps stop fats from going rancid inside cells.
By reducing quinones and maintaining redox balance, GO:0016655 activity indirectly protects membrane lipids from peroxidation. Inhibition of NQO1 can sensitize cancer cells to ferroptosis, a form of cell death driven by lipid peroxidation. This connection has made NQO1 a target for inducing ferroptosis in therapy-resistant tumors.
Key Genes Involved in GO:0016655 oxidoreductase activity, acting on NAD(P)H, quinone or similar compound as acceptor
The following genes encode enzymes or regulators directly associated with GO:0016655 activity, based on published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| NQO1 | NAD(P)H quinone dehydrogenase 1; two-electron reductase | Detoxifies quinones, prevents oxidative stress; target in cancer |
| NRF2 (NFE2L2) | Transcription factor regulating antioxidant response | Controls NQO1 expression; frequently altered in cancer |
| KEAP1 | Negative regulator of NRF2 | Mutations lead to constitutive NRF2 activation and NQO1 overexpression |
| HO1 (HMOX1) | Heme oxygenase 1, antioxidant enzyme | Part of NRF2/HO1/NQO1 axis; induced in fibromyalgia |
| NQO2 | Quinone reductase 2, related enzyme | Similar activity but distinct substrate specificity; less studied |
| CBR1 | Carbonyl reductase 1 | Contributes to quinone reduction; overlaps with NQO1 |
| AKR1C1 | Aldo-keto reductase family 1 member C1 | Reduces quinones and participates in detoxification |
| GSTA1 | Glutathione S-transferase A1 | Conjugates quinones with glutathione; complementary to NQO1 |
| SOD1 | Superoxide dismutase 1 | Protects against superoxide; indirect support of redox balance |
| CAT | Catalase | Detoxifies hydrogen peroxide; supports antioxidant network |
| GPX4 | Glutathione peroxidase 4 | Prevents lipid peroxidation; linked to ferroptosis |
| TXN | Thioredoxin | Maintains redox homeostasis; interacts with NRF2 pathway |
| PRDX1 | Peroxiredoxin 1 | Reduces peroxides; part of antioxidant defense |
| GCLC | Glutamate-cysteine ligase catalytic subunit | Synthesizes glutathione; supports NQO1 function |
| GCLM | Glutamate-cysteine ligase modifier subunit | Regulates glutathione synthesis; redox balance |
| SLC7A11 | Cystine/glutamate antiporter | Supplies cysteine for glutathione; impacts ferroptosis |
| FTH1 | Ferritin heavy chain 1 | Iron storage; prevents oxidative stress |
How Is oxidoreductase activity, acting on NAD(P)H, quinone or similar compound as acceptor Regulated?
GO:0016655 activity is primarily regulated at the transcriptional level through the NRF2-KEAP1 pathway. Under basal conditions, KEAP1 targets NRF2 for ubiquitination and degradation. Upon oxidative stress, KEAP1 is modified, allowing NRF2 to stabilize and translocate to the nucleus, where it activates antioxidant response elements (AREs) in target genes including NQO1. This regulation ensures that quinone detoxification capacity is rapidly increased when needed. Additionally, NQO1 activity can be modulated by post-translational modifications and by the availability of NAD(P)H, which is influenced by cellular metabolic state. In fibromyalgia and other conditions with systemic redox imbalance, altered NRF2 signaling affects NQO1 expression, suggesting that this regulatory axis is relevant beyond cancer.
oxidoreductase activity, acting on NAD(P)H, quinone or similar compound as acceptor and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| NQO1 | Pancreatic ductal adenocarcinoma | NQO1-activatable prodrug in NRF2-high PDAC models |
| NQO1 | Oxidative stress-related neurodegeneration | NQO1 knockout neurons treated with quinones |
| NRF2 | Cancer chemoresistance | KEAP1-mutant cancer cell lines with NRF2 activation |
| GPX4 | Ferroptosis sensitivity | GPX4 knockout cells with NQO1 inhibition |
| HMOX1 | Fibromyalgia and redox imbalance | Neuronutritional intervention in fibromyalgia models |
Cancer and Chemoresistance
NQO1, a key enzyme with GO:0016655 activity, is overexpressed in many tumors, often due to constitutive NRF2 activation. In NRF2-high pancreatic ductal adenocarcinoma, NQO1 expression is elevated and can be exploited for selective prodrug activation. Conversely, NQO1 polymorphisms that reduce activity have been associated with increased cancer risk due to impaired quinone detoxification. Targeting NQO1 with inhibitors or prodrugs is an active area of cancer therapy.
Oxidative Stress and Neurodegeneration
Loss of NQO1 activity leads to accumulation of reactive quinones and increased oxidative stress, which is implicated in neurodegenerative diseases. The NRF2/HO1/NQO1 axis is being investigated as a therapeutic target in conditions such as fibromyalgia, where systemic redox imbalance is observed. Enhancing this pathway may protect neurons from oxidative damage.
Lipid Peroxidation and Ferroptosis
GO:0016655 activity indirectly prevents lipid peroxidation by maintaining redox balance. Inhibition of NQO1 can induce ferroptosis, a form of programmed cell death driven by iron-dependent lipid peroxidation. This vulnerability is being explored in cancers that are resistant to conventional therapies.
Systemic Redox Imbalance in Non-Communicable Diseases
Altered NRF2 signaling, which controls NQO1 expression, has been observed in various non-communicable diseases including metabolic disorders and chronic inflammatory conditions. The NRF2/HO1/NQO1 axis is a potential biomarker and therapeutic target in these diseases.
From oxidoreductase activity, acting on NAD(P)H, quinone or similar compound as acceptor-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of NQO1 increase oxidative stress? | NQO1 knockout cell line (e.g., HeLa, A549) |
| Does a specific NQO1 polymorphism affect enzyme activity? | Point mutation knock-in of NQO1 variant (e.g., P187S) |
| Can NQO1 be used to activate a prodrug? | Knock-in of NQO1 into low-expressing cells, then prodrug treatment |
| Where is NQO1 localized in cells? | Tagged knock-in of NQO1 with GFP or FLAG |
| Does NQO1 overexpression protect against ferroptosis? | Overexpression of NQO1 in cancer cell lines |
| What genes work with NQO1 in the antioxidant response? | CRISPR library screening for modifiers of NQO1-dependent survival |
How to Study the oxidoreductase activity, acting on NAD(P)H, quinone or similar compound as acceptor Process
| Method | What It Measures | Typical Application |
|---|---|---|
| NAD(P)H oxidation assay | Enzymatic activity of NQO1 | Confirming GO:0016655 activity in cell lysates |
| RNA-seq | Transcript levels of NQO1 and NRF2 targets | Assessing NRF2 pathway activation in tumors |
| CRISPR knockout screen | Genes required for survival under oxidative stress | Identifying synthetic lethal partners of NQO1 |
| C11-BODIPY staining | Lipid peroxidation | Measuring ferroptosis induction |
| Western blot | Protein expression of NQO1, NRF2, HO1 | Validating pathway activation |
| Immunofluorescence | Subcellular localization of NQO1 | Studying protein trafficking |
| Metabolomics | NAD(P)H/NAD(P)+ ratio and quinone metabolites | Linking metabolism to redox state |
| Prodrug activation assay | Cell viability after prodrug treatment | Testing NQO1-targeted prodrugs |
Enzymatic Activity Assays
Direct measurement of GO:0016655 activity is typically performed using quinone substrates such as menadione or dichlorophenolindophenol (DCPIP) and monitoring NAD(P)H oxidation spectrophotometrically. These assays are used to confirm the function of NQO1 and its variants.
Gene Expression Analysis
RNA-seq and qPCR are used to measure NQO1 and other NRF2 target genes. This is particularly useful in cancer models to assess NRF2 pathway activation and to stratify tumors for NQO1-targeted therapies.
CRISPR Screening
Genome-wide CRISPR knockout screens can identify genes that modulate sensitivity to quinone-induced oxidative stress or NQO1-targeted prodrugs. Such screens have revealed synthetic lethal interactions with NQO1.
Lipid Peroxidation and Ferroptosis Assays
Lipid peroxidation is measured using fluorescent probes like C11-BODIPY, and ferroptosis is assessed by cell viability in the presence of ferroptosis inhibitors. These methods link GO:0016655 activity to ferroptosis sensitivity.
How CRISPR Can Be Used to Study GO:0016655 oxidoreductase activity, acting on NAD(P)H, quinone or similar compound as acceptor
Knockout
CRISPR knockout of NQO1 or other genes with GO:0016655 activity can be used to study their role in oxidative stress resistance and ferroptosis. NQO1 knockout cells show increased sensitivity to quinone-induced toxicity and lipid peroxidation.
Point Mutation
Point mutations in NQO1, such as the common P187S polymorphism, can be introduced using CRISPR to study their impact on enzyme activity and disease susceptibility. This approach helps link specific variants to altered GO:0016655 function.
Knock-in
Knock-in of tagged NQO1 (e.g., GFP or FLAG) allows real-time tracking of protein localization and interaction partners. This is useful for understanding how GO:0016655 enzymes are regulated spatially and temporally.
Overexpression
CRISPR activation (CRISPRa) or lentiviral overexpression of NQO1 can be used to test whether increased GO:0016655 activity protects cells from oxidative stress or ferroptosis. This is relevant for developing antioxidant therapies.
How EDITGENE Supports oxidoreductase activity, acting on NAD(P)H, quinone or similar compound as acceptor Research
Researchers studying oxidoreductase activity, acting on NAD(P)H, quinone or similar compound as acceptor-related genes often need to determine whether a candidate gene is causally involved in redox regulation, disease progression, or therapeutic response. EDITGENE provides a comprehensive suite of CRISPR-based services to enable such investigations, from gene knockout to precise point mutations and library screening.
Contact EDITGENE today to design your custom CRISPR model for oxidoreductase activity, acting on NAD(P)H, quinone or similar compound as acceptor research.
Frequently Asked Questions About oxidoreductase activity, acting on NAD(P)H, quinone or similar compound as acceptor
What is GO:0016655?
GO:0016655 is a Gene Ontology molecular function term for oxidoreductase activity, acting on NAD(P)H, quinone or similar compound as acceptor. It describes enzymes that use NADH or NADPH to reduce quinones.
What genes are involved in oxidoreductase activity, acting on NAD(P)H, quinone or similar compound as acceptor?
The most well-known gene is NQO1, but others include NQO2, CBR1, and AKR1C1. These genes encode enzymes that reduce quinones using NAD(P)H.
How is GO:0016655 related to cancer?
NQO1, a key enzyme with this activity, is overexpressed in many cancers, including NRF2-high pancreatic ductal adenocarcinoma, and is a target for prodrug therapy.
What is the role of NQO1 in oxidative stress?
NQO1 reduces quinones to hydroquinones, preventing the formation of reactive oxygen species and protecting cells from oxidative damage.
How can I study GO:0016655 in the lab?
Common methods include enzymatic activity assays, RNA-seq, CRISPR knockout screens, and lipid peroxidation measurements.
What is the NRF2/HO1/NQO1 axis?
It is a signaling pathway where NRF2 induces the expression of HO1 and NQO1 to combat oxidative stress. It is being studied in fibromyalgia and other diseases.
Can NQO1 be targeted for cancer therapy?
Yes, NQO1-activatable prodrugs are being developed to selectively kill NQO1-overexpressing cancer cells.
What is the connection between GO:0016655 and ferroptosis?
Inhibition of NQO1 can induce ferroptosis, a form of cell death driven by lipid peroxidation, making it a potential therapeutic strategy.
Are there genetic variants in NQO1 that affect activity?
Yes, the P187S polymorphism reduces NQO1 activity and has been associated with increased cancer risk.
How does EDITGENE support research on GO:0016655?
EDITGENE provides CRISPR knockout, point mutation, knock-in, overexpression, and library screening services for genes in this pathway.
Conclusion
GO:0016655, oxidoreductase activity, acting on NAD(P)H, quinone or similar compound as acceptor, is a fundamental molecular function that protects cells from oxidative damage by reducing quinones. The NQO1 enzyme is the prototypical example, and its regulation by NRF2 makes it a critical node in the antioxidant response. Dysregulation of this activity is implicated in cancer, neurodegeneration, and systemic redox imbalance, offering multiple opportunities for therapeutic intervention. Continued research using CRISPR models and advanced screening methods will further elucidate the roles of this activity in health and disease.
References
- 2. Preethi S et al.. 2022. Review on NAD(P)H dehydrogenase quinone 1 (NQO1) pathway.. Mol Biol Rep 49(9):8907-8924 PMID: 35347544
- 4. Antonucci L et al.. 2026. Selective targeting of NRF2-high pancreatic ductal adenocarcinoma with an NQO1-activatable prodrug.. Proc Natl Acad Sci U S A 123(4):e2511733123 PMID: 41564125
- 6. Clemente SM et al.. 2020. Targeting Lipid Peroxidation for Cancer Treatment.. Molecules 25(21) PMID: 33167334
- 7. Jakubowska M et al.. 2025. Altered NRF2 signalling in systemic redox imbalance: Insights from non-communicable diseases.. Redox Biol 87:103891 PMID: 41109135
- 8. Inferrera F et al.. 2025. Neuronutritional enhancement of antioxidant defense system through Nrf2/HO1/NQO1 axis in fibromyalgia.. Neurochem Int 190:106057 PMID: 40997946
