# MAPK3

Source: https://onco.cc/targets/mapk3/  
OnCo record `mapk3` (Target). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

MAPK3 (Mitogen-activated protein kinase 3) is a protein kinase, an enzyme that switches other proteins on by adding phosphate groups. The public catalogues list it as a drug target, and clinical evidence ties its variants to diagnosis, prognosis or drug response.

## Summary

Serine/threonine kinase which acts as an essential component of the MAP kinase signal transduction pathway. MAPK1/ERK2 and MAPK3/ERK1 are the 2 MAPKs which play an important role in the MAPK/ERK cascade. They participate also in a signalling cascade initiated by activated KIT and KITLG/SCF.

Open Targets scores its association with cancer at 0.63 (direct and indirect evidence; datatypes literature 0.99, affected pathway 0.97, genetic association 0.00, clinical 0.19).

## Fields

- Kind: Target
- Last checked: 2026-09-23
- Also known as: mitogen-activated protein kinase 3; Mitogen-activated protein kinase 3; ERK1; p44mapk; p44erk1; ERK-1; PRKM3
- Tags: cancer-genes-wave
- Symbol: MAPK3
- Class: kinase
- Biology: Serine/threonine kinase which acts as an essential component of the MAP kinase signal transduction pathway. MAPK1/ERK2 and MAPK3/ERK1 are the 2 MAPKs which play an important role in the MAPK/ERK cascade. They participate also in a signalling cascade initiated by activated KIT and KITLG/SCF. Depending on the cellular context, the MAPK/ERK cascade mediates diverse biological functions such as cell growth, adhesion, survival and differentiation through the regulation of transcription, translation, cytoskeletal rearrangements. The MAPK/ERK cascade also plays a role in initiation and regulation of meiosis, mitosis, and postmitotic functions in differentiated cells by phosphorylating a number of transcription factors. About 160 substrates have already been discovered for ERKs. Location: Cytoplasm; Nucleus; Membrane, caveola; Cell junction, focal adhesion (UniProt). Locus 16p11.2 (HGNC).

## 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 0.19. Evidence tier "clinical-evidence" is the strongest of those signals.
- Prevalence not recorded: none of the sources gives a positivity rate.

## Sources

- HGNC HGNC:6877: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:6877
- UniProt P27361: https://www.uniprot.org/uniprotkb/P27361/entry
- NCBI Gene 5595: https://www.ncbi.nlm.nih.gov/gene/5595
- Ensembl ENSG00000102882: https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000102882

## Connected records

- collections: [Open Targets Platform](https://onco.cc/collections/open-targets/)
- pathways: [RAS / RAF / MEK / ERK (MAPK)](https://onco.cc/pathways/ras-mapk/)

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JSON: https://onco.cc/api/v1/entities/mapk3.json