ATP7B Protein - Copper-transporting ATPase 2

ATP7B Protein (Wilson Disease ATPase)

Overview

Atp7B Protein Copper Transporting Atpase 2 plays an important role in the study of neurodegenerative diseases. This page provides comprehensive information about this topic, including its mechanisms, significance in disease processes, and therapeutic implications.

Introduction

ATP7B (Copper-Transporting ATPase 2) is a critical copper-transporting P-type ATPase encoded by the [ATP7B gene](/genes/atp7b) on chromosome 13q14.3. It plays an essential role in copper homeostasis, primarily in hepatocytes but also in [neurons](/entities/neurons) and other tissues. Mutations in ATP7B cause Wilson's disease (WD), a autosomal recessive disorder characterized by toxic copper accumulation in the liver, brain, and cornea. Understanding ATP7B function is crucial for neurodegenerative disease research, as copper dysregulation is implicated in [Alzheimer's disease](/diseases/alzheimers-disease), [Parkinson's disease](/diseases/parkinsons-disease), and other neurodegenerative conditions. [@wilson2014]

ATP7B Protein (Wilson Disease ATPase)

Overview

Atp7B Protein Copper Transporting Atpase 2 plays an important role in the study of neurodegenerative diseases. This page provides comprehensive information about this topic, including its mechanisms, significance in disease processes, and therapeutic implications.

Introduction

ATP7B (Copper-Transporting ATPase 2) is a critical copper-transporting P-type ATPase encoded by the [ATP7B gene](/genes/atp7b) on chromosome 13q14.3. It plays an essential role in copper homeostasis, primarily in hepatocytes but also in [neurons](/entities/neurons) and other tissues. Mutations in ATP7B cause Wilson's disease (WD), a autosomal recessive disorder characterized by toxic copper accumulation in the liver, brain, and cornea. Understanding ATP7B function is crucial for neurodegenerative disease research, as copper dysregulation is implicated in [Alzheimer's disease](/diseases/alzheimers-disease), [Parkinson's disease](/diseases/parkinsons-disease), and other neurodegenerative conditions. [@wilson2014]

<div class="infobox infobox-protein"> [@copper2016]
<table> [@atpb2013]
<tr><th colspan="2" style="background:#e8f4f8; text-align:center; font-size:1.1em;">Copper-transporting ATPase 2</th></tr> [@ceruloplasmin2017]
<tr><td><strong>Protein Name</strong></td><td>Copper-transporting ATPase 2 (Wilson disease protein)</td></tr> [@gene2019]
<tr><td><strong>Gene</strong></td><td>[ATP7B](/genes/ATP7B)</td></tr>
<tr><td><strong>UniProt ID</strong></td><td>[P35602](https://www.uniprot.org/uniprot/P35602)</td></tr>
<tr><td><strong>PDB IDs</td><td>2RCI, 3O0T, 4BMG</td></tr>
<tr><td><strong>Molecular Weight</strong></td><td>165 kDa (1465 amino acids)</td></tr>
<tr><td><strong>Subcellular Localization</strong></td><td>Trans-Golgi network, cytoplasmic vesicles, canalicular membrane</td></tr>
<tr><td><strong>Protein Family</strong></td><td>P-type ATPase (copper-transporting) family</td></tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/alzheimer" style="color:#ef9a9a">ALZHEIMER</a>, <a href="/wiki/alzheimer's-disease" style="color:#ef9a9a">ALZHEIMER'S DISEASE</a>, <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></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">20 edges</a></td>
</tr>
</table>
</div>

Structure

ATP7B is a P-type ATPase with complex domain architecture:

Domain Organization

| Domain | Position | Function |
|--------|----------|----------|
| N-terminal metal-binding domain (MBD) | 1-333 | 6 copper-binding sites (MXHCX5C motifs) |
| Phosphorylation domain | 648-790 | ATP phosphorylation site (DKTGTLT) |
| ATP-binding domain (P-domain) | 900-1050 | Nucleotide binding |
| Actuator domain (A-domain) | 1100-1250 | Conformational changes |
| Transmembrane domain | 1048-1465 | 8 helices forming channel |

Conformational States

Copper Binding

Each MBD can bind one Cu⁺ ion via:

• Methionine residues in MXHCX5C motif
• Cys residues in CXXC motifs
• Cooperative binding enhances affinity

Normal Function

Hepatic Function

In hepatocytes, ATP7B performs critical functions:

Neuronal Function

In neurons, ATP7B maintains copper homeostasis:

• Neuroprotection — Prevents copper-induced oxidative damage
• Enzyme cofactor — Supplies copper for copper-dependent enzymes
• Synaptic modulation — Regulates copper in synaptic vesicles
• Neurotransmitter synthesis — Supports dopamine β-hydroxylase

Copper Trafficking Pathway

Copper uptake (CTR1) → Chaperone delivery → ATP7A/ATP7B →
→ Ceruloplasmin (secretion) OR Biliary excretion (ATP7B)

Role in Neurodegenerative Diseases

Wilson's Disease

ATP7B mutations cause Wilson's disease with estimated prevalence of 1:30,000:

Hepatic manifestations:

• Chronic hepatitis
• Cirrhosis (micronodular)
• Acute liver failure (especially in children)
• Elevated transaminases

• Tremor (resting, postural, intention)
• Dysarthria and dysphagia
• Dystonia (especially facial, limb)
• Choreaathetosis
• Parkinsonism
• Ataxia

• Depression and anxiety
• Personality changes
• Psychosis
• Cognitive impairment

• Kayser-Fleischer rings (corneal copper)
• Hemolytic anemia
• Renal dysfunction
• Arthritis

Alzheimer's Disease

ATP7B connections to AD include:

• Copper homeostasis — Altered in AD brain
• Amyloid processing — Copper affects [Aβ](/proteins/amyloid-beta) generation
• Oxidative stress — Copper dysregulation increases [ROS](/entities/reactive-oxygen-species)
• Ceruloplasmin — Acute phase reactant, inflammatory marker

Parkinson's Disease

• Iron-copper interaction — Both metals accumulate in PD substantia nigra
• Ceruloplasmin — Reduced ferroxidase activity in PD
• ATP7B expression — Altered in PD models
• Oxidative stress — Copper catalyzes Fenton reactions

Other Neurodegenerative Conditions

• Menkes disease — Related disorder from ATP7A mutations
• Amyotrophic lateral sclerosis — Copper dysregulation
• Huntington's disease — Altered metal metabolism

Therapeutic Approaches

Wilson's Disease Treatments

| Approach | Mechanism | Examples |
|----------|-----------|----------|
| Chelation therapy | Bind and excrete copper | Penicillamine, Trientine |
| Zinc salts | Block intestinal copper absorption | Zinc acetate, Zinc sulfate |
| Dietary restriction | Reduce copper intake | Low-copper diet |
| Liver transplantation | Replace defective protein | Orthotopic liver transplant |

Emerging Therapies

• Gene therapy — AAV-ATP7B delivery
• Protein replacement — Recombinant ATP7B
• Copper chaperone modulators — Targeted approaches
• Small molecule correctors — Rescue mutant protein function

Clinical Assessment

Diagnostic Tests

| Test | Finding | Significance |
|------|---------|---------------|
| Ceruloplasmin | Low (<20 mg/dL) | Sensitivity 85% |
| 24-hour urinary copper | Elevated (>100 μg) | Highly specific |
| Serum copper | Variable | Not diagnostic alone |
| Liver copper | Elevated (>250 μg/g) | Gold standard |
| MRI brain | T2 hyperintensities | Basal ganglia, thalamus |

Genotype-Phenotype Correlations

• H1069Q — Most common, later onset, neurological presentation
• R778L — Common in East Asians, hepatic presentation
• Null mutations — Early onset, severe phenotype

Overview

Atp7B Protein Copper Transporting Atpase 2 plays an important role in the study of neurodegenerative diseases. This page provides comprehensive information about this topic, including its mechanisms, significance in disease processes, and therapeutic implications.

Background

The study of Atp7B Protein Copper Transporting Atpase 2 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.

External Links

• [PubMed](https://pubmed.ncbi.nlm.nih.gov/) - Biomedical literature
• [Alzheimer's Disease Neuroimaging Initiative](https://adni.loni.usc.edu/) - Research data
• [Allen Brain Atlas](https://brain-map.org/) - Brain gene expression data

See Also

• [ATP7B Gene](/entities/atp7b-gene)
• [ATP7A Protein](/proteins/atp7a-protein)
• [Wilson's Disease](/diseases/wilsons-disease)
• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Parkinson's Disease](/diseases/parkinsons-disease)
• [Copper Metabolism](/mechanisms/metal-homeostasis)
• [Ceruloplasmin](/proteins/ceruloplasmin)
• [Oxidative Stress](/mechanisms/oxidative-stress)

References