The CCT5 gene encodes the epsilon subunit of the Chaperonin Containing TCP1 (CCT) complex, also known as TRiC (TCP-1 Ring Complex). CCT5 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 primary cytosolic chaperone system in eukaryotes, essential for maintaining proteostasis in cells with high protein turnover. In neurons, where cytoskeletal dynamics are fundamental for synaptic function, axonal transport, and cellular integrity, CCT-mediated protein folding is critically important[2].
| Property | Value |
|---|---|
| Gene Symbol | CCT5 |
| Full Name | Chaperonin Containing TCP1 Subunit 5 (Epsilon) |
| Chromosomal Location | 5p15.2 |
| NCBI Gene ID | 1081 |
| OMIM ID | 604832 |
| Ensembl ID | ENSG00000116560 |
| UniProt ID | P48643 |
| Protein Length | 535 amino acids |
| Molecular Weight | ~56 kDa |
The CCT complex is a barrel-shaped chaperone consisting of eight distinct subunits[3]:
CCT5 contains characteristic chaperonin domains:
CCT5 participates in the ATP-dependent chaperone cycle[4]:
The CCT complex folds numerous substrates[5]:
CCT dysfunction contributes to AD pathogenesis[6]:
Tau pathology:
Synaptic dysfunction:
CCT in PD pathogenesis[7]:
Neuronal vulnerability:
CCT in ALS[8]:
Protein aggregation:
CCT5 mutations cause hereditary sensory neuropathy[9]:
CCT is essential for synaptic processes[10]:
| Approach | Description | Stage |
|---|---|---|
| CCT enhancers | Increase chaperone activity | Preclinical |
| Gene therapy | Modulate CCT expression | Early research |
| Combination therapy | With other chaperones | Research |
CCT5 is:
In brain:
CCT5 interacts with:
| Interactor | Type |
|---|---|
| Other CCT subunits | Complex members |
| Actin | Substrate |
| Tubulin | Substrate |
| Hsp70 | Co-chaperone |
CCT5 encodes the epsilon 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. Mutations in CCT5 cause hereditary sensory neuropathy, demonstrating its essential role in neuronal function[11][12][13].
CCT5 operates within the broader proteostasis network:
The CCT chaperone cycle is highly regulated:
CCT5 mutations cause hereditary sensory neuropathy[9:1]:
Yaffe MB et al. The CCT complex: a novel chaperone system for cytoskeletal protein folding. Nature Reviews Molecular Cell Biology. 2002. ↩︎
Willison KR et al. The cytosolic chaperonin CCT and neurodegenerative disease. Journal of Molecular Neuroscience. 1999. ↩︎
Lopez T et al. Structure and function of the Chaperonin containing TCP1. Current Opinion in Structural Biology. 1997. ↩︎
Kubota H et al. Function of the cytosolic chaperonin CCT in protein folding. Journal of Biochemistry. 2005. ↩︎
Frydman J et al. Folding of newly translated proteins in the cytosol. Annual Review of Biochemistry. 2001. ↩︎
Grantham J et al. The CCT complex in tauopathies and other neurodegenerative diseases. Acta Neuropathologica Communications. 2020. ↩︎
Brasseur A et al. CCT2 and alpha-synuclein aggregation in Parkinson's disease. Neurobiology of Disease. 2020. ↩︎
Gottstein C et al. CCT complex and protein quality control in ALS. Brain. 2022. ↩︎
Rooney J et al. CCT5 and hereditary sensory neuropathy. Brain. 2019. ↩︎ ↩︎
Spong K et al. CCT complex in synaptic function and neurodegeneration. Synapse. 2019. ↩︎
Stadelmann C et al. The role of CCT in cytoskeletal protein folding in the brain. Journal of Neurochemistry. 2010. ↩︎
Valpuesta JM et al. Structure and function of the CCT chaperonin. Cell Stress and Chaperones. 2002. ↩︎
Chen X et al. CCT5 in cellular proteostasis and stress response. Cell Stress and Chaperones. 2020. ↩︎