5-HT3A
5-HT receptor subtypes.
- Measurements
- 25
- Compounds
- 17
- Binding constants
- 7
- Median pX
- 9.02
I · Identity
What this target is
Its function as UniProt states it, where in a cell the protein is found, and which cell types and tissues transcribe its gene.
5-hydroxytryptamine receptor 3A
Forms serotonin (5-hydroxytryptamine/5-HT3)-activated cation-selective channel complexes, which when activated cause fast, depolarizing responses in neurons
Quoted from UniProt’s FUNCTION annotation for P46098 (reviewed).
What it acts with
STRING’s highest-confidence human functional partners. The combined score mixes several kinds of evidence, so each channel is shown separately — a partner supported by experiment is a different claim from one supported only by text mining, and for a receptor this is where its coupling appears as evidence rather than as assertion.
Where it sits in the cell
UniProt, curated Postsynaptic cell membrane · Cell membrane
Expression by cell type
Single cell type RNA, the 8 highest of those the Human Protein Atlas reports for this gene. Transcript, not protein, and a cell type rather than a tissue.
- B-cells5.5 nCPM
- Pancreatic acinar cells5.5 nCPM
- Salivary acinar cells2.9 nCPM
- Brain inhibitory neurons2.6 nCPM
- cDC2.4 nCPM
- pDCs2.1 nCPM
- Salivary myoepithelial cells1.9 nCPM
- Submucosal glandular cells1.1 nCPM
Expression by tissue
The tissues this gene is enriched in, by consensus RNA. A tissue absent from this list is one the Atlas does not call specific for this gene, which is not the same as absent from it.
- lymphoid tissue7.5 nTPM
- salivary gland4.8 nTPM
- pancreas2.7 nTPM
- brain2.3 nTPM
- intestine2 nTPM
II · Anatomy
Where the gene is transcribed
The same two atlases the compound plates use, asked about this gene alone. Brain on the left, peripheral and autonomic tissues on the right.
Brain
basal ganglia: drawn as the caudate nucleus, putamen and globus pallidus.
Measured but not drawn — this anatomogram has no outline for them: midbrain 0.1.
Body
Square-root ramp · shared scale across both plates
Shading is transcript level — not affinity, and not affinity combined with expression. Outlined but unshaded organs hold none of HTR3A transcript above the atlas’s detection threshold. Anatomy from EMBL-EBI Anatomogram (Apache License 2.0); regions identified by Uberon (uberon.org), CC BY 3.0.
Brain · 5
- basal ganglia2.3 nTPM
- hippocampal formation1.5 nTPM
- amygdala1.4 nTPM
- cerebral cortex0.9 nTPM
- midbrain0.1 nTPM
Peripheral and autonomic · 11
- salivary gland4.8 nTPM
- pancreas2.7 nTPM
- colon2.0 nTPM
- small intestine1.6 nTPM
- stomach 10.8 nTPM
- smooth muscle0.6 nTPM
- duodenum0.6 nTPM
- spleen0.5 nTPM
- adrenal gland0.3 nTPM
- kidney0.1 nTPM
- urinary bladder0.1 nTPM
Transcript is not protein. These are RNA levels for HTR3A, shaded on √nTPM so that a three-order range stays legible — on a linear ramp every region but the strongest would read as blank, which looks like absence rather than less. A region carrying no shading is one the atlas reports no consensus value for, not one where the gene is silent. And a gene being transcribed somewhere is not evidence that any compound reaches it. Human Protein Atlas, RNA expression, nTPM (normalized transcripts per million), consensus tissue dataset.
III · Ranking
Compounds by strongest binding constant
One bar per compound: its strongest Ki or Kd at this target, expressed as pX. Compounds measured here only by a functional assay do not appear — they are in the table below.
IV · Evidence
Every measurement at this target
Each row links to the ChEMBL assay it came from.
Equilibrium binding constants 7
Ki and Kd — a concentration at equilibrium. Directly comparable across rows at the same target.
| Target | Class | Type | Value (nM) | pX | Organism | Assay |
|---|---|---|---|---|---|---|
| 5-HT3A | Serotonin receptors | Ki | 0.960 | 9.02 | Rattus norvegicus | CHEMBL1006686 |
| 5-HT3A | Serotonin receptors | Ki | 0.960 | 9.02 | Rattus norvegicus | CHEMBL1037804 |
| 5-HT3A | Serotonin receptors | Ki | — no normalized value | — value does not convert to pX | Homo sapiens | CHEMBL5235596 |
| 5-HT3A | Serotonin receptors | Ki | — no normalized value | — value does not convert to pX | Homo sapiens | CHEMBL5235596 |
| 5-HT3A | Serotonin receptors | Ki | — no normalized value | — value does not convert to pX | Homo sapiens | CHEMBL896285 |
| 5-HT3A | Serotonin receptors | Ki | — no normalized value | — value does not convert to pX | Homo sapiens | CHEMBL896285 |
| 5-HT3A | Serotonin receptors | Ki | — no normalized value | — value does not convert to pX | Homo sapiens | CHEMBL2393673 |
Functional readouts 9
IC₅₀, EC₅₀, AC₅₀ and potency. Assay-dependent, and not interchangeable with a binding constant.
| Target | Class | Type | Value (nM) | pX | Organism | Assay |
|---|---|---|---|---|---|---|
| 5-HT3A | Serotonin receptors | AC50 | — no normalized value | — value does not convert to pX | Homo sapiens | CHEMBL5291824 |
| 5-HT3A | Serotonin receptors | AC50 | — no normalized value | — value does not convert to pX | Homo sapiens | CHEMBL5291824 |
| 5-HT3A | Serotonin receptors | AC50 | — no normalized value | — value does not convert to pX | Homo sapiens | CHEMBL5291824 |
| 5-HT3A | Serotonin receptors | AC50 | — no normalized value | — value does not convert to pX | Homo sapiens | CHEMBL5291824 |
| 5-HT3A | Serotonin receptors | AC50 | — no normalized value | — value does not convert to pX | Homo sapiens | CHEMBL5291824 |
| 5-HT3A | Serotonin receptors | AC50 | — no normalized value | — value does not convert to pX | Homo sapiens | CHEMBL5291824 |
| 5-HT3A | Serotonin receptors | AC50 | — no normalized value | — value does not convert to pX | Homo sapiens | CHEMBL5291824 |
| 5-HT3A | Serotonin receptors | AC50 | — no normalized value | — value does not convert to pX | Homo sapiens | CHEMBL5291824 |
| 5-HT3A | Serotonin receptors | AC50 | — no normalized value | — value does not convert to pX | Homo sapiens | CHEMBL5291824 |
Other measurements 9
Everything else ChEMBL recorded for this compound — percentage inhibition, efficacy, half-life, cytotoxicity. Reported in the assay's own units, which is why no value is converted here.
| Target | Class | Type | Value (nM) | pX | Organism | Assay |
|---|---|---|---|---|---|---|
| 5-HT3A | Serotonin receptors | Activity | — no normalized value | — value does not convert to pX | Homo sapiens | CHEMBL5054022 |
| 5-HT3A | Serotonin receptors | Activity | — no normalized value | — value does not convert to pX | Homo sapiens | CHEMBL5054022 |
| 5-HT3A | Serotonin receptors | Activity | — no normalized value | — value does not convert to pX | Homo sapiens | CHEMBL5054022 |
| 5-HT3A | Serotonin receptors | Activity | — no normalized value | — value does not convert to pX | Homo sapiens | CHEMBL5054023 |
| 5-HT3A | Serotonin receptors | Activity | — no normalized value | — value does not convert to pX | Homo sapiens | CHEMBL5054023 |
| 5-HT3A | Serotonin receptors | Activity | — no normalized value | — value does not convert to pX | Homo sapiens | CHEMBL5054023 |
| 5-HT3A | Serotonin receptors | Activity | — no normalized value | — value does not convert to pX | Homo sapiens | CHEMBL5054023 |
| 5-HT3A | Serotonin receptors | Inhibition | — no normalized value | — value does not convert to pX | Homo sapiens | CHEMBL4687656 |
| 5-HT3A | Serotonin receptors | Activity | — no normalized value | — value does not convert to pX | Homo sapiens | CHEMBL5054022 |