Seroatlas · Human Serome Atlas

HRH3

Histamine H3 receptor

Also known as: GPCR97, HRH3_HUMAN

Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene

Protein identityUniProt · HPA

UniProt accession
Q9Y5N1
Gene
HRH3
Ensembl
ENSG00000101180
Chromosome
20
Canonical length
445 aa
Protein class
FDA approved drug targets, G-protein coupled receptors, Predicted membrane proteins

OverviewNCBI Gene

Histamine is a ubiquitous messenger molecule released from mast cells, enterochromaffin-like cells, and neurons. Its various actions are mediated by histamine receptors H1, H2, H3 and H4. This gene encodes one of the histamine receptors (H3) which belongs to the family 1 of G protein-coupled receptors. It is an integral membrane protein and can regulate neurotransmitter release. This receptor can also increase voltage-dependent calcium current in smooth muscles and innervates the blood vessels and the heart in cardiovascular system. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

445 residues, UniProt reviewed canonical sequence.

>Q9Y5N1|HRH3
     1  MERAPPDGPL NASGALAGEA AAAGGARGFS AAWTAVLAAL MALLIVATVL GNALVMLAFV
    61  ADSSLRTQNN FFLLNLAISD FLVGAFCIPL YVPYVLTGRW TFGRGLCKLW LVVDYLLCTS
   121  SAFNIVLISY DRFLSVTRAV SYRAQQGDTR RAVRKMLLVW VLAFLLYGPA ILSWEYLSGG
   181  SSIPEGHCYA EFFYNWYFLI TASTLEFFTP FLSVTFFNLS IYLNIQRRTR LRLDGAREAA
   241  GPEPPPEAQP SPPPPPGCWG CWQKGHGEAM PLHRYGVGEA AVGAEAGEAT LGGGGGGGSV
   301  ASPTSSSGSS SRGTERPRSL KRGSKPSASS ASLEKRMKMV SQSFTQRFRL SRDRKVAKSL
   361  AVIVSIFGLC WAPYTLLMII RAACHGHCVP DYWYETSFWL LWANSAVNPV LYPLCHHSFR
   421  RAFTKLLCPQ KLKIQPHSSL EHCWK

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against HRH3 can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability
Cell surface
Secreted
No
Transmembrane segments
7
Mean surface accessibility (rSASA)
0.41
Highest tissue expression
52 nTPM

Expression across tissuesHPA

Tissue

  • basal ganglia: 52 nTPM
  • cerebellum: 37 nTPM
  • hypothalamus: 35 nTPM
  • cerebral cortex: 26 nTPM
  • amygdala: 13 nTPM
  • hippocampal formation: 10 nTPM

Single-cell type

  • brain inhibitory neurons: 45 nCPM
  • other brain neurons: 30 nCPM
  • retinal ganglion cells: 16 nCPM
  • brain excitatory neurons: 11 nCPM
  • retinal amacrine cells: 7.6 nCPM
  • bergmann glia: 4.3 nCPM

Immune cell

  • basophil: 0 nTPM
  • classical monocyte: 0 nTPM
  • eosinophil: 0 nTPM
  • gdT-cell: 0 nTPM
  • intermediate monocyte: 0 nTPM
  • MAIT T-cell: 0 nTPM

Brain region

  • thalamus: 141 nTPM
  • basal ganglia: 120 nTPM
  • hypothalamus: 81 nTPM
  • midbrain: 70 nTPM
  • amygdala: 59 nTPM
  • cerebral cortex: 57 nTPM

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance)
0.69
gnomAD pLI
0.04
gnomAD missense Z
2.27
DepMap mean gene effect
-0.08
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 3% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of HRH3 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads HRH3 as an antibody target. Whether an autoantibody or antibody against HRH3 could matter depends on whether native HRH3 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

HRH3 is annotated at the cell surface, where native HRH3 is exposed to circulating antibodies and is a prime autoantibody target that could block, deplete, or overstimulate it.

Annotation status

The present source text does not explicitly label HRH3 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/HRH3. Study-independent annotations aggregated from UniProt, Human Protein Atlas, PubMed, IEDB, Pfam, InterPro, Gene Ontology, AlphaFold, gnomAD, DepMap, ClinVar, TCGA. Catalog release seroatlas-reviewed-human-uniprot-20260313.

Seroatlas is the reference for exploring autoantibody and antibody serology at the human-protein level: the autoreactome and human serome, multiplex serology (HuProt, HuScan, VirScan, PhIP-Seq).

© 2026 · Seroatlas, Discover Oregon LLC · Terms of use

Loading the interactive Seroatlas protein explorer...