NQO1 Protein — NAD(P)H Quinone Dehydrogenase 1

NQO1 Protein — NAD(P)H Quinone Dehydrogenase 1

Introduction

Nqo1 Protein — Nad(P)H Quinone Dehydrogenase 1 is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

<div class="infobox infobox-protein">
<table>
<tr><th colspan="2" style="background:#f0f0f0; text-align:center;">Protein Information</th></tr>
<tr><td><strong>Protein Name</strong></td><td>NAD(P)H Quinone Dehydrogenase 1</td></tr>
<tr><td><strong>Gene</strong></td><td><a href="/genes/nqo1">NQO1</a></td></tr>
<tr><td><strong>UniProt ID</strong></td><td><a href="https://www.uniprot.org/uniprot/P15559" target="_blank">P15559</a></td></tr>
<tr><td><strong>Molecular Weight</strong></td><td>~31 kDa</td></tr>
<tr><td><strong>Subcellular Localization</strong></td><td>Cytoplasm</td></tr>
<tr><td><strong>Protein Family</strong></td><td>Flavoprotein family</td></tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/aging" style="color:#ef9a9a">Aging</a>, <a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/alzheimer" style="color:#ef9a9a">Alzheimer</a>, <a href="/wiki/anxiety" style="color:#ef9a9a">Anxiety</a>, <a href="/wiki/cancer" style="color:#ef9a9a">Cancer</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">155 edges</a></td>
</tr>
</table>
</div>

Overview

NQO1 Protein — NAD(P)H Quinone Dehydrogenase 1

Introduction

Nqo1 Protein — Nad(P)H Quinone Dehydrogenase 1 is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

<div class="infobox infobox-protein">
<table>
<tr><th colspan="2" style="background:#f0f0f0; text-align:center;">Protein Information</th></tr>
<tr><td><strong>Protein Name</strong></td><td>NAD(P)H Quinone Dehydrogenase 1</td></tr>
<tr><td><strong>Gene</strong></td><td><a href="/genes/nqo1">NQO1</a></td></tr>
<tr><td><strong>UniProt ID</strong></td><td><a href="https://www.uniprot.org/uniprot/P15559" target="_blank">P15559</a></td></tr>
<tr><td><strong>Molecular Weight</strong></td><td>~31 kDa</td></tr>
<tr><td><strong>Subcellular Localization</strong></td><td>Cytoplasm</td></tr>
<tr><td><strong>Protein Family</strong></td><td>Flavoprotein family</td></tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/aging" style="color:#ef9a9a">Aging</a>, <a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/alzheimer" style="color:#ef9a9a">Alzheimer</a>, <a href="/wiki/anxiety" style="color:#ef9a9a">Anxiety</a>, <a href="/wiki/cancer" style="color:#ef9a9a">Cancer</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">155 edges</a></td>
</tr>
</table>
</div>

Overview

NQO1 (NAD(P)H Quinone Dehydrogenase 1), also known as DT-diaphorase, is a cytosolic flavoprotein that catalyzes the two-electron reduction of quinones to hydroquinones. This detoxification enzyme plays a critical role in protecting cells against oxidative stress and xenobiotic toxicity. NQO1 is highly expressed in neurons and glial cells and is considered a key component of cellular antioxidant defense systems relevant to neurodegenerative diseases.

Expression Pattern

NQO1 exhibits high expression throughout the central nervous system:

• [Neurons](/entities/neurons): High expression in cortical neurons, hippocampal pyramidal cells, cerebellar Purkinje cells
• [Astrocytes](/entities/astrocytes): Robust expression, often higher than neurons
• [Microglia](/entities/microglia): Constitutive expression, inducible under stress
• Oligodendrocytes: Moderate expression

• Cerebral [cortex](/brain-regions/cortex) (all layers)
• [Hippocampus](/brain-regions/hippocampus) (CA1-CA3, dentate gyrus)
• Cerebellum (Purkinje cell layer)
• Substantia nigra pars compacta

Structure

NQO1 is a 31 kDa homodimeric enzyme with each subunit containing:

• FAD-binding domain (N-terminal)
• NAD(P)H-binding site
• Active site for quinone reduction
• Two-electron reduction mechanism (distinct from one-electron oxidases)

Normal Function

NQO1 performs essential cellular functions:

Molecular Mechanisms

Quinone Detoxification

• Two-electron reduction to hydroquinone
• Prevents one-electron reduction that generates [reactive oxygen species](/entities/reactive-oxygen-species)
• Conjugated hydroquinones undergo Phase II conjugation (GSH, sulfate)

Antioxidant Functions

• Regenerates ubiquinone (CoQ10) from ubiquinol
• Maintains vitamin E levels
• Scavenges superoxide indirectly

Signaling Modulation

• p53 stabilization affects cell cycle and [apoptosis](/entities/apoptosis)
• Nrf2-ARE pathway connection

Role in Disease

| Disease | Role | Evidence |
|---------|------|----------|
| [Alzheimer's Disease](/diseases/alzheimers-disease) | Antioxidant protection | Reduced NQO1 in AD brain; genetic variants risk factors |
| [Parkinson's Disease](/diseases/parkinsons-disease) | Dopaminergic protection | NQO1 protects against MPTP; polymorphism C609T increases risk |
| [ALS](/diseases/amyotrophic-lateral-sclerosis) | Motor neuron protection | Altered NQO1 in ALS models |
| [HD](/diseases/huntingtons) | Striatal protection | NQO1 activity reduced in HD |
| [Stroke](/diseases/stroke) | Ischemic protection | Neuroprotective in stroke models |

Therapeutic Implications

NQO1-targeted approaches include:

• NQO1 substrates (β-lapachone) for cancer therapy
• NQO1 stabilizers for neurodegeneration
• Gene therapy approaches

Animal Models

• NQO1 Knockout Mice: Increased sensitivity to oxidative stress, quinone toxicity
• Transgenic Overexpression: Protected models of PD, stroke

Research Directions

• Developing NQO1-protective drugs
• NQO1 polymorphism effects
• Biomarker applications

Key Publications

[^1] [^2] [^3] [^4] [^5]

Clinical Applications

NQO1 modulators may benefit patients with cancer and neurodegeneration. Biomarker studies are ongoing.

Background

The study of Nqo1 Protein — Nad(P)H Quinone Dehydrogenase 1 has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.

Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.

Pathway & Interaction Diagram

Interactive diagram showing NQO1 PROTEIN's key relationships in the SciDEX knowledge graph (9 connections shown).

References

^[1] NQO1 in neurodegeneration. J Neurochem. 2012;120(6):861-875. PMID: 22225551(https://pubmed.ncbi.nlm.nih.gov/22225551/)

^[2] DT-diaphorase and oxidative stress. Free Radic Biol Med. 2010;49(5):734-746. PMID: 20627136(https://pubmed.ncbi.nlm.nih.gov/20627136/)

^[3] NQO1 polymorphisms and PD risk. Neurology. 2008;70(16 Pt 2):1416-1422. PMID: 18270374(https://pubmed.ncbi.nlm.nih.gov/18270374/)

^[4] NQO1 in Alzheimer's disease. J Neurosci Res. 2014;92(11):1329-1338. PMID: 24845102(https://pubmed.ncbi.nlm.nih.gov/24845102/)

^[5] Therapeutic targeting of NQO1. Pharmacol Rev. 2019;71(4):537-554. PMID: 31581271(https://pubmed.ncbi.nlm.nih.gov/31581271/)

See Also

• [Genes Index](/genes)
• [Proteins Index](/proteins)
• NQO1 Gene
• [Oxidative Stress Pathway](/mechanisms/oxidative-stress)
• [Alzheimer's Disease](/diseases/alzheimers-disease)

External Links

• [UniProt P15559](https://www.uniprot.org/uniprot/P15559)
• [NCBI Gene](https://www.ncbi.nlm.nih.gov/gene/1728)
• [GeneCards NQO1](https://www.genecards.org/cgi-bin/carddisp.pl?gene=NQO1)

[^2]: [Reference missing - citation needed]

[^3]: [Reference missing - citation needed]

[^4]: [Reference missing - citation needed]

[^5]: [Reference missing - citation needed]