Seroatlas · Human Serome Atlas

HTR3A

5-hydroxytryptamine receptor 3A

Also known as: 5-HT3A, 5-HT3R, 5HT3A_HUMAN, HTR3

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

Protein identityUniProt · HPA

UniProt accession
P46098
Gene
HTR3A
Ensembl
ENSG00000166736
Chromosome
11
Canonical length
478 aa
Protein class
FDA approved drug targets, Predicted membrane proteins, Transporters

OverviewNCBI Gene

The product of this gene belongs to the ligand-gated ion channel receptor superfamily. This gene encodes subunit A of the type 3 receptor for 5-hydroxytryptamine (serotonin), a biogenic hormone that functions as a neurotransmitter, a hormone, and a mitogen. This receptor causes fast, depolarizing responses in neurons after activation. It appears that the heteromeric combination of A and B subunits is necessary to provide the full functional features of this receptor, since either subunit alone results in receptors with very low conductance and response amplitude. Alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

478 residues, UniProt reviewed canonical sequence.

>P46098|HTR3A
     1  MLLWVQQALL ALLLPTLLAQ GEARRSRNTT RPALLRLSDY LLTNYRKGVR PVRDWRKPTT
    61  VSIDVIVYAI LNVDEKNQVL TTYIWYRQYW TDEFLQWNPE DFDNITKLSI PTDSIWVPDI
   121  LINEFVDVGK SPNIPYVYIR HQGEVQNYKP LQVVTACSLD IYNFPFDVQN CSLTFTSWLH
   181  TIQDINISLW RLPEKVKSDR SVFMNQGEWE LLGVLPYFRE FSMESSNYYA EMKFYVVIRR
   241  RPLFYVVSLL LPSIFLMVMD IVGFYLPPNS GERVSFKITL LLGYSVFLII VSDTLPATAI
   301  GTPLIGVYFV VCMALLVISL AETIFIVRLV HKQDLQQPVP AWLRHLVLER IAWLLCLREQ
   361  STSQRPPATS QATKTDDCSA MGNHCSHMGG PQDFEKSPRD RCSPPPPPRE ASLAVCGLLQ
   421  ELSSIRQFLE KRDEIREVAR DWLRVGSVLD KLLFHIYLLA VLAYSITLVM LWSIWQYA

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against HTR3A 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
4
Mean surface accessibility (rSASA)
0.37
Highest tissue expression
7.5 nTPM

Expression across tissuesHPA

Tissue

  • tonsil: 7.5 nTPM
  • lymph node: 6.1 nTPM
  • salivary gland: 4.8 nTPM
  • pancreas: 2.7 nTPM
  • basal ganglia: 2.3 nTPM
  • appendix: 2 nTPM

Single-cell type

  • b-cells: 5.5 nCPM
  • pancreatic acinar cells: 5.5 nCPM
  • salivary acinar cells: 2.9 nCPM
  • brain inhibitory neurons: 2.6 nCPM
  • cdc: 2.4 nCPM
  • pdcs: 2.1 nCPM

Immune cell

  • naive B-cell: 14 nTPM
  • plasmacytoid DC: 12 nTPM
  • memory B-cell: 3.9 nTPM
  • myeloid DC: 0.6 nTPM
  • total PBMC: 0.2 nTPM
  • basophil: 0 nTPM

Brain region

  • basal ganglia: 1.6 nTPM
  • hippocampal formation: 1.6 nTPM
  • cerebral cortex: 1.2 nTPM
  • amygdala: 0.7 nTPM
  • white matter: 0.4 nTPM
  • midbrain: 0.2 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)
1.14
gnomAD pLI
0
gnomAD missense Z
-1.17
DepMap mean gene effect
0.1
DepMap dependency class
none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 2% 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 HTR3A 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 HTR3A as an antibody target. Whether an autoantibody or antibody against HTR3A could matter depends on whether native HTR3A is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

HTR3A is annotated at the cell surface, where native HTR3A 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 HTR3A as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/HTR3A. 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).

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