# GART (trifunctional purine synthesis enzyme)

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

## TL;DR

GART is one of the enzymes that builds purines from scratch; pemetrexed blocks it alongside thymidylate synthase, which is why the drug starves fast-growing lung and mesothelioma cells.

## Summary

The trifunctional protein GART carries three activities of de novo purine synthesis, including glycinamide ribonucleotide formyltransferase, a folate-dependent step. Pemetrexed, once polyglutamated inside cells, inhibits thymidylate synthase most strongly but also GART and dihydrofolate reductase, giving it a multi-targeted antifolate action in non-small cell lung cancer and mesothelioma.

## Fields

- Kind: Target
- Last checked: 2026-09-04
- Symbol: GART
- Class: enzyme
- Biology: A cytosolic enzyme of the purine pathway whose activity rises with proliferation; inhibition depletes purine nucleotides needed for DNA and RNA.
- Where found: Proliferating cells generally; Lung adenocarcinoma and mesothelioma treated with pemetrexed

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Trifunctional_purine_biosynthetic_protein_adenosine-3
- UniProt P22102: GART: https://www.uniprot.org/uniprotkb/P22102/entry
- HGNC:4163 GART: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:4163
- ChEMBL target CHEMBL3972: https://www.ebi.ac.uk/chembl/explore/target/CHEMBL3972

## Connected records

- targets: [Dihydrofolate reductase (DHFR)](https://onco.cc/targets/dhfr/), [Thymidylate synthase (TYMS)](https://onco.cc/targets/tyms/)
- cancers: [Mesothelioma](https://onco.cc/cancers/mesothelioma/), [Non-small-cell lung cancer](https://onco.cc/cancers/nsclc/)
- drugs: [Pemetrexed](https://onco.cc/drugs/pemetrexed/)

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