# HSP90AA1

Source: https://onco.cc/targets/hsp90aa1/  
OnCo record `hsp90aa1` (Target). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

HSP90AA1 (Heat shock protein HSP 90-alpha) is a gene whose normal job is to hold cell growth in check. The public catalogues list it as a drug target and a tumour suppressor, and clinical evidence ties its variants to diagnosis, prognosis or drug response. Tied to Breast cancer.

## Summary

Molecular chaperone that promotes the maturation, structural maintenance and proper regulation of specific target proteins involved for instance in cell cycle control and signal transduction. Undergoes a functional cycle that is linked to its ATPase activity which is essential for its chaperone activity. This cycle probably induces conformational changes in the client proteins, thereby causing their activation.

Open Targets scores its association with cancer at 0.75 (direct and indirect evidence; datatypes clinical 0.63, affected pathway 0.99, literature 1.00, genetic association 0.00, somatic mutation 0.43, animal model 0.52). IntOGen calls it a driver in 1 cohort (0 activating, 1 loss-of-function), covering Invasive Breast Carcinoma.

## Fields

- Kind: Target
- Last checked: 2026-09-23
- Also known as: heat shock protein 90 alpha family class A member 1; Heat shock protein HSP 90-alpha; Hsp89; Hsp90; FLJ31884; HSP90N; HSPC1; HSPCA; HSPCAL4
- Tags: cancer-genes-wave
- Symbol: HSP90AA1
- Class: tumor-suppressor
- Biology: Molecular chaperone that promotes the maturation, structural maintenance and proper regulation of specific target proteins involved for instance in cell cycle control and signal transduction. Undergoes a functional cycle that is linked to its ATPase activity which is essential for its chaperone activity. This cycle probably induces conformational changes in the client proteins, thereby causing their activation. Interacts dynamically with various co-chaperones that modulate its substrate recognition, ATPase cycle and chaperone function. Engages with a range of client protein classes via its interaction with various co-chaperone proteins or complexes, that act as adapters, simultaneously able to interact with the specific client and the central chaperone itself. Recruitment of ATP and co-chaperone followed by client protein forms a functional chaperone. Location: Nucleus; Cytoplasm; Melanosome; Cell membrane (UniProt). Locus 14q32.31 (HGNC).
- Where found: Breast cancer: IntOGen driver in 1 cohort (BRCA)

## Notes

- Written by scripts/fetch-cancer-genes.ts from CIViC, Open Targets, IntOGen, HGNC and UniProt; the function text is UniProt's, condensed and in UK spelling. Roles: Open Targets known-drug datatype score 0.63; IntOGen calls it a loss-of-function (LoF) driver in 1 cohort. Evidence tier "clinical-evidence" is the strongest of those signals.
- Prevalence not recorded: none of the sources gives a positivity rate.

## Sources

- HGNC HGNC:5253: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:5253
- UniProt P07900: https://www.uniprot.org/uniprotkb/P07900/entry
- NCBI Gene 3320: https://www.ncbi.nlm.nih.gov/gene/3320
- Ensembl ENSG00000080824: https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000080824

## Connected records

- collections: [IntOGen](https://onco.cc/collections/intogen/), [Open Targets Platform](https://onco.cc/collections/open-targets/)
- cancers: [Breast cancer (all types)](https://onco.cc/cancers/breast-cancer/)
- pathways: [Ubiquitin-proteasome system & protein homeostasis](https://onco.cc/pathways/ubiquitin-proteasome-system/)

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JSON: https://onco.cc/api/v1/entities/hsp90aa1.json