HSP90AA1 is a human gene whose product aHSA1** (Activator of Hsp90 ATPase 1), also known as Hsp90 co-chaperone AHA1, is a key co-chaperone that stimulates the ATPase activity of Hsp90. It plays a crucial role in regulating the Hsp90 chaperone cycle and thus affects the folding and function of numerous client proteins. Variants in HSP90AA1 have been implicated in Alzheimer's Disease, Parkinson's Disease, Amyotrophic Lateral Sclerosis. This page covers the gene's normal function, disease associations, expression patterns, and key research findings relevant to neurodegeneration.
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Gene Symbol
[^3]
AHSA1
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Full Name
Activator of Hsp90 ATPase 1
Chromosomal Location
14q24.3
NCBI Gene ID
[10598](https://www.ncbi.nlm.nih.gov/gene/10598)
OMIM
[613243](https://www.omim.org/entry/613243)
Ensembl ID
ENSG00000100526
UniProt ID
[Q9BUD6](https://www.uniprot.org/uniprot/Q9BUD6)
Protein
[AHSA1-protein](/proteins/ahsa1-protein)
Associated Diseases
[Alzheimer's Disease](/diseases/alzheimers-disease), [Parkinson's Disease](/diseases/parkinsons-disease), [Amyotrophic Lateral Sclerosis](/diseases/amyotrophic-lateral-sclerosis), Cancer
AHSA1 (Activator of Hsp90 ATPase 1), also known as Hsp90 co-chaperone AHA1, is a key co-chaperone that stimulates the ATPase activity of Hsp90. It plays a crucial role in regulating the Hsp90 chaperone cycle and thus affects the folding and function of numerous client proteins.
AHSA1 has essential co-chaperone functions:
- Hsp90 ATPase activation: Stimulates Hsp90 ATP hydrolysis, accelerating the chaperone cycle
- Client protein loading: Facilitates proper folding of Hsp90 client proteins
- Chaperone complex assembly: Part of the Hsp90 co-chaperone network
- Cellular stress response: Modulates cellular responses to proteotoxic stress
- Signal transduction: Regulates signaling pathways through client protein maturation
AHSA1 interacts with:
AHSA1 is implicated in AD pathogenesis:
- Regulates maturation of tau kinases (e.g., GSK3B, CDK5)
- Modulates Hsp90-mediated clearance of tau aggregates
- Client proteins include tau pathology-related kinases
- Therapeutic potential for targeting Hsp90-AHA1 axis [1]
In PD, AHSA1 plays important roles:
- Regulates LRRK2 (LRRK2) maturation and function
- Modulates alpha-synuclein (SNCA) processing
- Affects autophagy through client protein regulation
- Coordinates with protein homeostasis systems [2]
In ALS:
- Regulates maturation of ALS-associated proteins
- Client proteins include SOD1, TARDBP, FUS
- May affect aggregation of misfolded proteins
- Hsp90 inhibition is being explored as therapy [3]
AHSA1 has significant roles in cancer:
- Essential for oncogenic kinase maturation (e.g., BCR-ABL, EGFR)
- Promotes tumor cell survival
- Resistance to Hsp90 inhibitors
- Therapeutic target in various cancers
AHSA1 is expressed throughout the brain:
- Cerebral cortex: High expression in pyramidal neurons
- Hippocampus: Strong expression in CA1-CA3 regions
- Substantia nigra: Present in dopaminergic neurons
- Cerebellum: Expressed in Purkinje cells
- Glial cells: Detected in astrocytes and microglia
AHSA1 expression is regulated by:
- Stress-responsive transcription factors
- Cellular stress conditions (heat shock, oxidative stress)
- Developmental stage
- Disease states (elevated in cancer, neurodegeneration)
| Variant |
Type |
Effect |
Significance |
| rs2296199 |
Promoter |
Expression modifier |
Cancer association |
| rs3787015 |
3'UTR |
miRNA binding |
mRNA stability |
| rs1243469 |
Coding |
Missense |
Functional impact |
- Hsp90 inhibitors: Geldanamycin derivatives (17-AAG, 17-DMAC)
- AHA1 inhibitors: Direct targeting of AHSA1
- Combination therapies: Hsp90 inhibitors with other agents
- Cancer therapy targeting oncogenic Hsp90 clients
- Neurodegeneration through Hsp90 modulation
- Understanding chaperone biology