Reactome: A Curated Pathway Database
THIS SITE IS USED FOR CURATION AND TESTING
IT IS NOT STABLE, IS LINKED TO AN INCOMPLETE DATA SET, AND IS NOT MONITORED FOR PERFORMANCE. WE STRONGLY RECOMMEND THE USE OF OUR PUBLIC SITE

Query author contributions in Reactome

Reactome depends on collaboration between our curation team and outside experts to assemble and peer-review its pathway modules. The integration of ORCID within Reactome enables us to meet a key challenge with authoring, curating and reviewing biological information by incentivizing and crediting the external experts that contribute their expertise and time to the Reactome curation process. More information is available at ORCID and Reactome.

If you have an ORCID ID that is not listed on this page, please forward this information to us and we will update your Reactome pathway records.

Name Email address

Details on Person UniProt:P46093 GPR4

Class:IdReferenceGeneProduct:55888
_chainChangeLogchain:1-362 added on Sat February 7 2015
_displayNameUniProt:P46093 GPR4
_timestamp2026-02-20 23:05:58
chainchain:1-362
checksum6C75D97C36204541
commentFUNCTION Proton-sensing G-protein coupled receptor activated by extracellular pH, which is required to monitor pH changes and generate adaptive reactions (PubMed:12955148, PubMed:17462861, PubMed:33478938, PubMed:39753132, PubMed:39799123, PubMed:40211064, PubMed:40215959, PubMed:40215960). Activated by an optimal pH of 6.8-7.2 (PubMed:12955148, PubMed:17462861, PubMed:39753132). Ligand binding causes a conformation change that triggers signaling via guanine nucleotide-binding proteins (G proteins) and modulates the activity of downstream effectors, such as adenylate cyclase (PubMed:39753132, PubMed:40211064, PubMed:40215960). GPR4 is mainly coupled to G(s) G proteins and mediates activation of adenylate cyclase activity (PubMed:12955148, PubMed:17462861, PubMed:20211729, PubMed:22110680, PubMed:39753132, PubMed:40211064, PubMed:40215960). May also couple with G(i), G(q) and G(12)/G(13) G proteins (PubMed:12955148, PubMed:17462861, PubMed:20211729, PubMed:22110680). Acts as a key regulator of respiratory sensitivity to CO2/H(+) in brain retrotrapezoid nucleus neurons: acts by mediating detection of protons generated by the formation of carbonic acid in the blood, an important mechanism to impulse to breathe (By similarity). Also acts as a regulator of acid secretion in the kidney collecting duct by maintaining acid-base homeostasis in the kidney (By similarity). Acidosis-induced GPR4 activation increases paracellular gap formation and permeability of vascular endothelial cells, possibly through the G(12)/G(13)/Rho GTPase signaling pathway (PubMed:32058960).ACTIVITY REGULATION Activated by a network of residues that connects an extracellular-facing cavity to Glu-145, a conserved charged residue buried in the transmembrane core of the receptor (PubMed:39753132). Protonation likely drives conformational changes in extracellular loop 2 (ECL2), which stabilizes movement of transmembrane 3 (TM3) and a series of rearrangements that connect the extracellular-facing cavity to Glu-145, a residue only conserved in proton-sensing G-protein coupled receptors (PubMed:39753132). Inhibited by the antagonist NE52-QQ57, which prevents activation by protons (PubMed:40211064, PubMed:40215960).SUBCELLULAR LOCATION A multitude of proton-sensing residues, which include extracellular histidine residues (His-155, His-165 and His-269) or triad of buried acidic residues (Asp-63, Glu-145 and Asp-282), contribute to activation of the G-protein coupled receptor activity and pH sensitivity.SIMILARITY Belongs to the G-protein coupled receptor 1 family.CAUTION Was originally thought to be a receptor for sphingosylphosphorylcholine and lysophosphatidylcholine (PubMed:11535583). However, this work has been retracted (PubMed:16498716).
descriptionrecommendedName: fullName evidence="19"G-protein coupled receptor 4 shortName evidence="17"hGPR4 alternativeName: fullName evidence="18"G-protein coupled receptor 6C.l shortName evidence="18"GPR6C.l
geneNameGPR4
identifierP46093
isSequenceChangedFALSE
keyword3D-structure
Cell membrane
Disulfide bond
G-protein coupled receptor
Glycoprotein
Membrane
Receptor
Reference proteome
Transducer
Transmembrane
Transmembrane helix
modified[InstanceEdit:9836292] Weiser, Joel, 2023-05-25
[InstanceEdit:9852000] Weiser, Joel, 2023-11-03
[InstanceEdit:9917590] Weiser, Joel, 2024-08-09
[InstanceEdit:9963647] Weiser, Joel, 2025-08-15
[InstanceEdit:9983091] Weiser, Joel, 2026-02-20
nameGPR4
referenceDatabase[ReferenceDatabase:2] UniProt
referenceGene[ReferenceDNASequence:9002372] ENSEMBL:ENSG00000177464 GPR4 [Homo sapiens]
secondaryIdentifierGPR4_HUMAN
A8K3T3
B0M0K1
Q6NWM4
sequenceLength362
species[Species:48887] Homo sapiens
(referenceEntity)[EntityWithAccessionedSequence:444708] GPR4 [plasma membrane] [Homo sapiens]
[Change default viewing format]
No pathways have been reviewed or authored by UniProt:P46093 GPR4 (55888)