PSMA6 (Proteasome Subunit Alpha 6) is a component of the 20S proteasome core particle that plays essential roles in protein degradation and has been implicated in neurodegenerative diseases.
The Allen Brain Atlas provides gene expression data for PSMA6:
- Human Brain Expression: Searchable expression data across brain regions
- Cell Type Specificity: Expression patterns in different neuronal populations
- View Expression Data
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Gene: [PSMA6](/genes/psma6)
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UniProt ID: [P60900](https://www.uniprot.org/uniprot/P60900)
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PDB ID: [5MX5](https://www.rcsb.org/structure/5MX5)
Molecular Weight: ~27.7 kDa (246 amino acids)
Subcellular Localization: Cytoplasm, nucleus
Protein Family: Proteasome alpha subunit family
Associated Diseases: [Alzheimer's Disease](/diseases/alzheimers-disease), [Parkinson's Disease](/diseases/parkinsons-disease), [ALS](/diseases/amyotrophic-lateral-sclerosis), Proteasomeopathies
PSMA6 is a member of the proteasome alpha subunit family that forms the 20S proteasome core particle. Encoded by the PSMA6 gene, this 246-amino acid protein is one of seven alpha subunits that comprise the outer rings of the 20S proteasome. The proteasome is responsible for ubiquitin-dependent and ubiquitin-independent protein degradation, playing critical roles in cellular protein homeostasis.
PSMA6 has the characteristic alpha subunit fold:
¶ Domain Organization
- N-terminal domain (residues 1-50): Propeptide, cleaved during assembly
- Core domain (residues 50-200): Proteolytic activity support
- C-terminal domain (residues 200-246): Assembly and interaction
- α-helical fold with conserved active site region
- Forms heptameric alpha ring
- N-terminal threonine catalytic site
- Interaction sites for regulatory particles
| Subunit Ring |
Composition |
Function |
| Alpha ring (outer) |
PSMA1-7 |
Substrate entry gate |
| Beta ring (inner) |
PSMB1-7 |
Proteolytic activity |
PSMA6 is essential for proteasome function:
- Formation of 20S proteasome core particle [^7]
- Recognition of ubiquitinated substrates
- ATP-independent protein degradation
- Regulation of cell cycle proteins
- Removal of oxidized proteins
- MHC class I antigen processing
- Regulation of transcription factors
- Quality control for protein folding
- High expression in neurons
- Critical for synaptic protein turnover
- Role in learning and memory
- Protects against proteotoxic stress
- Altered proteasome activity in AD brain [^8]
- PSMA6 in amyloid-β degradation
- Impaired proteasome function in AD
- Role in tau clearance
- Proteasome dysfunction in PD [^9]
- α-Synuclein degradation via proteasome
- Role in LRRK2 pathogenesis
- PINK1/Parkin-mediated mitophagy connection
- Proteasome activators under investigation
- Proteasome modulators for neuroprotection
- Enhancement of proteasome activity
- Combination with autophagy enhancers
- Proteasome activity assays
- Fluorescent proteasome substrates
- Cryo-EM structures of proteasome