PARK7 (DJ-1) Protein

DJ-1 (PARK7) Protein

<div class="infobox infobox-protein">
<table>
<tr><th colspan="2" style="background:#e8f4ea;">DJ-1 (PARK7) — Protein Deglutathionylase</th></tr>
<tr><td><b>Gene</b></td><td>[PARK7](/genes/park7)</td></tr>
<tr><td><b>UniProt ID</b></td><td>[Q99497](https://www.uniprot.org/uniprot/Q99497)</td></tr>
<tr><td><b>PDB Structures</b></td><td>1O62, 1O63, 2RK3, 5D7E</td></tr>
<tr><td><b>Molecular Weight</b></td><td>20,898 Da (189 aa)</td></tr>
<tr><td><b>Subcellular Localization</b></td><td>Cytoplasm, Nucleus, Mitochondria</td></tr>
<tr><td><b>Protein Family</b></td><td>DJ-1/PfpI family</td></tr>
<tr><td><b>EC Number</b></td><td>3.5.1.124</td></tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/ad" style="color:#ef9a9a">AD</a>, <a href="/wiki/als" style="color:#ef9a9a">ALS</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></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">212 edges</a></td>
</tr>
</table>
</div>

Overview

DJ-1 (PARK7) is a multifunctional protein encoded by the [PARK7](/genes/park7) gene, named after the PARK7 locus linked to [Parkinson's disease](/diseases/parkinsons-disease). Originally discovered as an oncogene, DJ-1 has emerged as a critical neuroprotective protein with diverse functions in cellular stress response[@multifunctional2020].

Structure

DJ-1 (PARK7) Protein

<div class="infobox infobox-protein">
<table>
<tr><th colspan="2" style="background:#e8f4ea;">DJ-1 (PARK7) — Protein Deglutathionylase</th></tr>
<tr><td><b>Gene</b></td><td>[PARK7](/genes/park7)</td></tr>
<tr><td><b>UniProt ID</b></td><td>[Q99497](https://www.uniprot.org/uniprot/Q99497)</td></tr>
<tr><td><b>PDB Structures</b></td><td>1O62, 1O63, 2RK3, 5D7E</td></tr>
<tr><td><b>Molecular Weight</b></td><td>20,898 Da (189 aa)</td></tr>
<tr><td><b>Subcellular Localization</b></td><td>Cytoplasm, Nucleus, Mitochondria</td></tr>
<tr><td><b>Protein Family</b></td><td>DJ-1/PfpI family</td></tr>
<tr><td><b>EC Number</b></td><td>3.5.1.124</td></tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/ad" style="color:#ef9a9a">AD</a>, <a href="/wiki/als" style="color:#ef9a9a">ALS</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></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">212 edges</a></td>
</tr>
</table>
</div>

Overview

DJ-1 (PARK7) is a multifunctional protein encoded by the [PARK7](/genes/park7) gene, named after the PARK7 locus linked to [Parkinson's disease](/diseases/parkinsons-disease). Originally discovered as an oncogene, DJ-1 has emerged as a critical neuroprotective protein with diverse functions in cellular stress response[@multifunctional2020].

Structure

DJ-1 adopts a conserved α/β fold characteristic of the DJ-1/PfpI family:

Key Structural Features

• α/β Sandwich: 8 β-strands surrounded by 6 α-helices
• Catalytic Cysteine: Cysteine 106 (C106) — critical for enzymatic activity
• RNA-Binding Domain: C-terminal region involved in RNA binding
• Dimerization Interface: Forms functional homodimers

Post-Translational Modifications

• Oxidation: C106 oxidized to sulfinic/sulfonic acid
• Phosphorylation: Multiple phosphorylation sites (S66, Y127)
• Sumoylation: SUMO conjugation at K6

Normal Function

DJ-1 participates in multiple cellular protective pathways:

1. Antioxidant Defense

• Deglutathionylase: Removes GSH adducts from proteins
• [ROS](/entities/reactive-oxygen-species) Scavenger: Direct antioxidant activity
• Mitochondrial Protector: Maintains mitochondrial integrity

2. Transcriptional Regulation

• p53 Modulation: Represses p53-mediated [apoptosis](/entities/apoptosis)
• Nrf2 Activation: Binds to Keap1, releasing Nrf2 for antioxidant response
• PI3K/Akt Signaling: Enhances cell survival

3. Mitochondrial Function

• Complex I Activity: Maintains mitochondrial respiratory chain
• Mitophagy: Regulates clearance of damaged mitochondria
• Calcium Homeostasis: Modulates mitochondrial calcium signaling

4. RNA Metabolism

• mRNA Stability: Binds to 3'UTR of target mRNAs
• tRNA Processing: Associated with tRNA processing complexes

Role in Parkinson's Disease

Pathogenic Mechanisms

DJ-1 loss-of-function contributes to PD through:

• Impaired antioxidant response
• Elevated ROS accumulation

• Reduced Complex I activity
• Impaired mitophagy

• Failed protection against α-synuclein aggregation
• Altered [autophagy](/entities/autophagy)-lysosome pathway

• Enhanced sensitivity to mitochondrial toxins
• Impaired stress response

PARK7 Mutations

| Mutation | Effect | Phenotype |
|----------|--------|-----------|
| L166P | Misfolding, rapid degradation | Severe PD |
| M26I | Partial loss of function | Early-onset PD |
| E64D | Variable | Typical PD |
| A104T | Reduced activity | Risk factor |

Therapeutic Targeting

DJ-1 represents a promising therapeutic target:

Strategies

Challenges

• [Blood-brain barrier](/entities/blood-brain-barrier) penetration
• Dimer stabilization
• Maintaining enzymatic activity

Expression Pattern

| Tissue | Expression |
|--------|------------|
| Brain (substantia nigra) | Highest |
| Heart | High |
| Liver | Moderate |
| Kidney | Moderate |
| Pancreas | Low |

Interacting Proteins

DJ-1 interacts with numerous proteins:

• Parkin — E3 ubiquitin ligase involved in mitophagy
• PINK1 — Kinase that phosphorylates Parkin
• DJ-1/PARK7 — Homodimer formation
• Hsp70 — Molecular chaperone
• Keap1 — Nrf2 regulator

Research Directions

• Developing DJ-1 activity assays
• Identifying brain-penetrant small molecule activators
• Understanding oxidation-dependent regulation
• Clinical biomarker development

See Also

• [Parkinson's Disease](/diseases/parkinsons-disease)
• PARK7 Gene
• [Alpha-Synuclein](/proteins/alpha-synuclein)
• [Parkin](/genes/parkin)
• [PINK1](/genes/pink1)
• [Mitochondrial Dysfunction](/mechanisms/mitochondrial-dysfunction)
• [Oxidative Stress](/mechanisms/oxidative-stress)