CHCHD6 Protein

CHCHD6 Protein — Coiled-Coil-Helix-Coiled-Coil-Helix Domain Containing 6

<div class="infobox infobox-protein">
<table>
<tr><th colspan="2" style="background:#e8f4f8; text-align:center; font-size:1.1em;">CHCHD6 Protein</th></tr> [@hwang2010]
<tr><td><strong>Protein Name</strong></td><td>Coiled-Coil-Helix-Coiled-Coil-Helix Domain Containing 6</td></tr> [@mhlenhoff2011]
<tr><td><strong>Gene</strong></td><td>[CHCHD6](/genes/chchd6)</td></tr> [@song2017]
<tr><td><strong>UniProt ID</strong></td><td>[Q9BYX7](https://www.uniprot.org/uniprot/Q9BYX7)</td></tr> [@schapira2014]
<tr><td><strong>Molecular Weight</strong></td><td>~29 kDa</td></tr> [@winklhofer2010]
<tr><td><strong>Subcellular Localization</strong></td><td>Mitochondria (inner membrane)</td></tr> [@bannwarth2014]
<tr><td><strong>Protein Family</strong></td><td>CHCH domain family</td></tr> [@zhang2019]
</table>
</div>

Overview

CHCHD6 Protein — Coiled-Coil-Helix-Coiled-Coil-Helix Domain Containing 6

<div class="infobox infobox-protein">
<table>
<tr><th colspan="2" style="background:#e8f4f8; text-align:center; font-size:1.1em;">CHCHD6 Protein</th></tr> [@hwang2010]
<tr><td><strong>Protein Name</strong></td><td>Coiled-Coil-Helix-Coiled-Coil-Helix Domain Containing 6</td></tr> [@mhlenhoff2011]
<tr><td><strong>Gene</strong></td><td>[CHCHD6](/genes/chchd6)</td></tr> [@song2017]
<tr><td><strong>UniProt ID</strong></td><td>[Q9BYX7](https://www.uniprot.org/uniprot/Q9BYX7)</td></tr> [@schapira2014]
<tr><td><strong>Molecular Weight</strong></td><td>~29 kDa</td></tr> [@winklhofer2010]
<tr><td><strong>Subcellular Localization</strong></td><td>Mitochondria (inner membrane)</td></tr> [@bannwarth2014]
<tr><td><strong>Protein Family</strong></td><td>CHCH domain family</td></tr> [@zhang2019]
</table>
</div>

Overview

CHCHD6 (Coiled-Coil-Helix-Coiled-Coil-Helix Domain Containing 6) is a mitochondrial protein encoded by the CHCHD6 gene located on chromosome 3p24.3. The protein contains characteristic twin CX9C motifs within its CHCH (coiled-coil-helix-coiled-coil-helix) domains, which are conserved across eukaryotic organisms and mediate protein-protein interactions in mitochondrial intermembrane space [1]. CHCHD6 plays essential roles in mitochondrial function, cellular respiration, and iron-sulfur cluster biogenesis. Recent research has implicated CHCHD6 in the pathogenesis of neurodegenerative diseases, particularly Parkinson's disease, where mitochondrial dysfunction is a central pathological feature [2].

Structure

The CHCHD6 protein possesses a distinctive structural architecture characterized by:

• Twin CX9C Motifs: The protein contains two CX9C sequences within its CHCH domains, which coordinate zinc ions and stabilize the protein fold [1]
• Coiled-Coil Regions: N-terminal and C-terminal coiled-coil domains facilitate dimerization with other CHCH domain proteins
• Inner Membrane Anchor: A hydrophobic segment targets CHCHD6 to the mitochondrial inner membrane
• Molecular Weight: Approximately 29 kDa
• Oligomerization: Forms homodimers and heterodimers with related proteins like CHCHD2, CHCHD3, and CHCHD10

Normal Function

Mitochondrial Respiration

CHCHD6 is a critical component of the mitochondrial respiratory chain. It associates with complex I (NADH:ubiquinone oxidoreductase) and complex IV (cytochrome c oxidase) of the electron transport chain [1]. The protein participates in:

• Electron Transfer: Facilitates efficient electron flow through the respiratory chain
• ATP Synthesis: Couples oxidative phosphorylation to ATP production
• Mitochondrial Membrane Potential: Maintains the electrochemical gradient essential for ATP synthesis

Iron-Sulfur Cluster Biogenesis

CHCHD6 participates in the mitochondrial iron-sulfur cluster (Fe-S) assembly pathway, which is essential for the function of Fe-S proteins in the respiratory chain [4]. Fe-S clusters serve as:

• Electron carriers in complex I, II, and III
• Catalytic centers in aconitase (Krebs cycle)
• Iron regulatory sensors

Mitochondrial Dynamics

The protein contributes to mitochondrial morphology and dynamics by interacting with the mitochondrial inner membrane fusion machinery [5]. It helps maintain:

• Mitochondrial cristae structure
• Contact sites between inner and outer membranes
• Optimal mitochondrial network morphology

Role in Disease

Parkinson's Disease

CHCHD6 has emerged as a significant player in Parkinson's disease pathogenesis. Multiple lines of evidence support its involvement:

Genetic Associations: While direct CHCHD6 mutations have not been definitively linked to familial PD, the protein's function is disrupted in PD brain tissue [2]. Studies have shown:

• Reduced CHCHD6 expression in substantia nigra dopaminergic [neurons](/entities/neurons) of PD patients
• Impaired complex I activity associated with CHCHD6 dysfunction
• Enhanced vulnerability of dopaminergic neurons to mitochondrial stress

• Complex I deficiency observed in PD patients
• Increased [reactive oxygen species](/entities/reactive-oxygen-species) (ROS) production
• Impaired calcium buffering in dopaminergic neurons

• Small molecules that enhance CHCHD6 expression
• Gene therapy approaches to restore mitochondrial function
• Antioxidant therapies to combat ROS-induced damage

Amyotrophic Lateral Sclerosis (ALS)

Emerging evidence suggests CHCHD6 may play a role in ALS pathogenesis. The protein shares structural and functional similarities with CHCHD10, which has been directly linked to ALS [8]. Both proteins:

• Are located in mitochondrial intermembrane space
• Form a family of CHCH domain proteins involved in oxidative phosphorylation
• May be involved in RNA metabolism linked to [TDP-43](/mechanisms/tdp-43-proteinopathy) pathology

Cancer Metabolism

CHCHD6 expression is altered in several cancers, where it influences cellular metabolism [9]. The protein's role in oxidative phosphorylation affects:

• Tumor cell proliferation
• Metabolic reprogramming (Warburg effect)
• Response to mitochondrial-targeted therapies

Interacting Partners

CHCHD6 interacts with several proteins involved in mitochondrial function:

| Protein | Interaction Type | Functional Significance |
|---------|------------------|------------------------|
| CHCHD2 | Heterodimer | Mitochondrial respiration, PD pathogenesis |
| CHCHD3 | Heterodimer | Mitochondrial inner membrane organization |
| CHCHD10 | Heterodimer | Respiratory chain assembly, ALS link |
| Complex I subunits | Structural | Electron transport chain function |
| Complex IV subunits | Structural | Cytochrome c oxidase assembly |

Therapeutic Targets

CHCHD6 represents a potential therapeutic target for neurodegenerative diseases:

Biomarkers

CHCHD6 levels may serve as biomarkers for mitochondrial dysfunction in neurodegenerative diseases:

• Decreased CHCHD6 in cerebrospinal fluid (CSF) of PD patients
• Reduced brain tissue expression correlating with disease severity
• Potential for monitoring therapeutic response

See Also

• [CHCHD6 Gene](/genes/chchd6)
• [Mitochondrial Dysfunction](/mechanisms/mitochondrial-dysfunction)
• [Parkinson's Disease](/diseases/parkinsons-disease)
• [Complex I Deficiency](/mechanisms/complex-i-deficiency)
• [Iron-Sulfur Cluster Biogenesis](/mechanisms/iron-sulfur-cluster-biogenesis)

External Links

• [UniProt Q9BYX7](https://www.uniprot.org/uniprot/Q9BYX7)
• [GeneCards CHCHD6](https://www.genecards.org/cgi-bin/carddisp.pl?gene=CHCHD6)
• [NCBI Gene](https://www.ncbi.nlm.nih.gov/gene/152920)

References