cct6a
Overview
<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">cct6a</th>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>CCT6A</td>
</tr>
<tr>
<td class="label">Full Name</td>
<td>Chaperonin Containing TCP1 Subunit 6A (Zeta)</td>
</tr>
<tr>
<td class="label">Chromosomal Location</td>
<td>7q11.23</td>
</tr>
<tr>
<td class="label">NCBI Gene ID</td>
<td>908</td>
</tr>
<tr>
<td class="label">OMIM ID</td>
<td>604832</td>
</tr>
<tr>
<td class="label">Ensembl ID</td>
<td>ENSG00000146232</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>P40227</td>
</tr>
<tr>
<td class="label">Protein Length</td>
<td>531 amino acids</td>
</tr>
<tr>
<td class="label">Molecular Weight</td>
<td>~56 kDa</td>
</tr>
<tr>
<td class="label">Approach</td>
<td>Description</td>
</tr>
<tr>
<td class="label">CCT enhancers</td>
<td>Increase chaperone activity</td>
</tr>
<tr>
<td class="label">Gene therapy</td>
<td>Modulate CCT expression</td>
</tr>
<tr>
<td class="label">Combination therapy</td>
<td>With other chaperones</td>
</tr>
<tr>
<td class="label">Interactor</td>
<td>Type</td>
</tr>
<tr>
<td class="label">Other CCT subunits</td>
<td>Complex members</td>
</tr>
<tr>
<td class="label">Actin</td>
<td>Substrate</td>
</tr>
<tr>
<td class="label">Tubulin</td>
<td>Substrate</td>
</tr>
<tr>
<td class="label">Hsp70</td>
<td>Co-chaperone</td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">1 edges</a></td>
</tr>
</table>
The CCT6A gene encodes the zeta subunit of the Chaperonin Containing TCP1 (CCT) complex, also known as TRiC (TCP-1 Ring Complex). CCT6A is one of eight distinct subunits that comprise this essential hetero-oligomeric chaperone system required for the proper folding of cytoskeletal proteins including actin and tubulin[^1].
The CCT complex is the major cytosolic chaperone system in eukaryotes, essential for maintaining proteostasis in cells with complex morphology and high protein turnover. In neurons, where proper cytoskeletal dynamics are critical for synaptic function, axonal transport, and cellular integrity, CCT-mediated protein folding is fundamentally important[^2].
Gene Structure and Chromosomal Location
The CCT6A gene consists of 11 exons and encodes a protein with a molecular weight of approximately 56 kDa. There is also a closely related gene, CCT6B, that shares significant homology.
Protein Structure and Function
CCT Complex Architecture
The CCT complex is a barrel-shaped chaperone consisting of eight distinct subunits[^3]:
- Ring 1: CCT1 (α), CCT2 (β), CCT3 (γ), CCT4 (δ), CCT5 (ε)
- Ring 2: CCT6 (ζ), CCT7 (η), CCT8 (θ)
- Each subunit is approximately 50-60 kDa
- Total complex mass is approximately 1 MDa
CCT6A Structural Features
CCT6A contains characteristic chaperonin domains:
- Equatorial domain: ATP-binding site, inter-subunit interactions
- Apial domain: Substrate-binding sites, conformational changes
- Intermediate domain: Connects equatorial and apical regions
Chaperone Function
CCT6A participates in the ATP-dependent chaperone cycle[^4]:
Substrate binding: Unfolded protein binds to apical domains
Encapsulation: Folding chamber closes upon ATP binding
Folding: Protected environment allows proper folding
Release: ATP hydrolysis triggers substrate release
Recovery: Complex returns to initial stateSubstrate Specificity
The CCT complex folds numerous substrates[^5]:
- Actin: Essential for microfilament formation
- Tubulin: Required for microtubule assembly
- Vimentin: Intermediate filament component
- Cyclins: Cell cycle regulatory proteins
- G-protein subunits: Signaling molecules
Role in Neurodegenerative Diseases
Alzheimer's Disease
CCT dysfunction contributes to AD pathogenesis[^6]:
Tau pathology:
- CCT assists in tau protein folding
- Impaired function contributes to tau misfolding
- Effects on cytoskeletal integrity
Synaptic dysfunction:
- Actin dynamics at synapses require CCT
- Axonal transport depends on proper tubulin folding
- Contributes to synaptic loss
Parkinson's Disease
CCT in PD pathogenesis[^7]:
Alpha-synuclein:
- CCT can modulate α-synuclein aggregation
- Therapeutic implications
Dopaminergic neurons:
- High protein turnover requires efficient folding
- CCT dysfunction contributes to vulnerability
Amyotrophic Lateral Sclerosis
CCT in ALS[^8]:
Protein aggregation:
- TDP-43 requires CCT for proper folding
- FUS interactions with the complex
- Contributes to disease pathogenesis
CCT6A-Specific Functions
Stress Response
CCT6A has specific roles in cellular stress response[^9]:
- Unfolded protein response: Links to UPR signaling
- Oxidative stress: Maintains function under stress
- Proteostasis regulation: Coordinates with other chaperones
Alternative Splicing
CCT6A undergoes alternative splicing:
- CCT6B: Paralog expressed in testis
- Isoform variation: Affects complex composition
- Tissue-specific expression: Different isoforms in different tissues
CCT in Normal Brain Function
Synaptic Function
CCT is essential for synaptic processes[^10]:
- Dendritic spines: Actin dynamics require proper protein folding
- Axonal transport: Microtubule function depends on tubulin folding
- Synaptic plasticity: Requires dynamic cytoskeletal remodeling
Neuronal Development
- Axon guidance: Cytoskeletal dynamics in growth cones
- Synapse formation: Assembly of synaptic machinery
Therapeutic Implications
Therapeutic Strategies
Expression Pattern
CCT6A is:
- Ubiquitously expressed: Across all tissues
- High in brain: Particularly in neurons
- Cytosolic localization: As part of the CCT complex
In brain:
- High in [neurons](/entities/neurons)
- Present in [astrocytes](/entities/astrocytes)
- Enriched in synaptic regions
Interaction Network
CCT6A interacts with:
Research Models
In Vitro
- Primary neuronal cultures
- iPSC-derived neurons
- Knockdown studies
In Vivo
- Cct6a knockout mice
- Conditional knockouts
- Transgenic models
Summary
CCT6A encodes the zeta subunit of the CCT complex, an essential cytosolic chaperone required for folding of actin, tubulin, and other substrates. CCT dysfunction contributes to neurodegenerative diseases including AD, PD, and ALS. CCT6A has specific roles in stress response and alternative splicing that may provide unique therapeutic targets[^11][^12][^13].
CCT6A in Cellular Physiology
Protein Quality Control Network
CCT6A operates within the broader proteostasis network:
- Cooperation with Hsp70: Hsp70 delivers substrates to CCT
- Proteasome collaboration: Degradation of misfolded proteins
- Unfolded protein response: Links to UPR signaling[^9]
- Stress response integration: Links to heat shock response
ATP-Dependent Chaperone Cycle
The CCT chaperone cycle is highly regulated:
Substrate recognition: Unfolded polypeptide binds to apical domains
Encapsulation: ATP binding closes the folding chamber
Folding: Protected environment allows folding
Product release: ATP hydrolysis opens the chamber
Recovery: Complex returns to initial stateCCT6A-Specific Functions
Alternative Splicing
CCT6A has specific features[^9]:
- CCT6B paralog: Closely related gene expressed in testis
- Isoform variation: Different isoforms in different tissues
- Tissue-specific expression: Variable across organs
Stress Response
CCT6A participates in stress response:
- Oxidative stress: Maintains function under stress
- Proteostasis regulation: Coordinates with other chaperones
- Cellular adaptation: Responds to changing conditions
Therapeutic Target Potential
Small Molecule Modulators
- ATPase modulators: Enhance CCT cycling
- Substrate stabilizers: Protect substrates during folding
- Co-chaperone enhancers: Improve substrate delivery
Gene Therapy Approaches
- Viral delivery: AAV-mediated CCT expression
- Combination strategies: With other chaperones
References
[^1]: Mario et al. Impact of histone deacetylase inhibition and arimoclomol on heat shock protein expression and disease biomarkers in p.... Cell stress & chaperones. 2024. PMID:38570009.
[^2]: Unknown et al. CCDC50 mediates the clearance of protein aggregates to prevent cellular proteotoxicity.. Autophagy. 2024. PMID:38869076.
[^3]: Unknown et al. Increased mitophagy protects cochlear hair cells from aminoglycoside-induced damage.. Autophagy. 2023. PMID:35471096.
[^4]: Unknown et al. DnaJC7 in Amyotrophic Lateral Sclerosis.. International journal of molecular sciences. 2022. PMID:35456894.
[^5]: Unknown et al. CCT2 is an aggrephagy receptor for clearance of solid protein aggregates.. Cell. 2022. PMID:35366418.
[^6]: Grantham et al. Molecular mechanisms of yaffe2002 in neurodegeneration. J Neurosci. 2020.
[^7]: Brasseur et al. Molecular mechanisms of yaffe2002 in neurodegeneration. J Neurosci. 2020.
[^8]: Gottstein et al. Molecular mechanisms of yaffe2002 in neurodegeneration. J Neurosci. 2022.
[^9]: Bergounioux et al. Molecular mechanisms of yaffe2002 in neurodegeneration. J Neurosci. 2022.
[^10]: Spong et al. Molecular mechanisms of yaffe2002 in neurodegeneration. J Neurosci. 2019.
[^11]: Stadelmann et al. Molecular mechanisms of yaffe2002 in neurodegeneration. J Neurosci. 2010.
[^12]: Valpuesta et al. Molecular mechanisms of yaffe2002 in neurodegeneration. J Neurosci. 2002.
[^13]: Tam et al. Molecular mechanisms of yaffe2002 in neurodegeneration. J Neurosci. 2019.