# Glutathione reductase

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

## TL;DR

Glutathione reductase regenerates the cell's main antioxidant; the nitrosourea carmustine inhibits it as a side action to its DNA cross-linking, which adds to the drug's toxicity as well as its effect.

## Summary

Glutathione reductase converts oxidised glutathione back to its reduced form, maintaining the cell's largest pool of antioxidant. Carmustine (BCNU), the nitrosourea used in glioma and in high-dose conditioning for lymphoma, carbamoylates the enzyme and inactivates it, so cells treated with the drug face oxidative stress as well as DNA cross-links; the effect is thought to contribute to carmustine's lung toxicity. Because tumours with high glutathione levels resist alkylating agents and platinum drugs, the glutathione system as a whole is a target for chemosensitisation.

## Fields

- Kind: Target
- Last checked: 2026-09-04
- Tags: chembl-gap
- Symbol: GSR
- Class: enzyme
- Biology: A dimeric flavoenzyme using NADPH to reduce glutathione disulphide; part of the pentose phosphate and antioxidant network in every cell.
- Where found: All cells, high in liver and red blood cells; Gliomas and lymphomas treated with carmustine

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Glutathione_reductase
- UniProt P00390: GSR: https://www.uniprot.org/uniprotkb/P00390/entry
- HGNC:4623 GSR: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:4623
- ChEMBL target CHEMBL2755: https://www.ebi.ac.uk/chembl/explore/target/CHEMBL2755

## Connected records

- targets: [Thioredoxin reductase 1](https://onco.cc/targets/txnrd1/)
- cancers: [Diffuse large B-cell lymphoma](https://onco.cc/cancers/dlbcl/), [Glioma & glioblastoma](https://onco.cc/cancers/glioblastoma/)
- drugs: [Carmustine](https://onco.cc/drugs/carmustine/)

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