Protein / target

5-hydroxytryptamine receptor 1A

HTR1AP08908Homo sapiensSwiss-Prot
Clinically validated
Therapeutic maturity
17
Approved medicines
30
Clinical trials
Small-molecule tractable
Druggability
Approved Drug

Protein at a glance

Biological role

G protein-coupled serotonin receptor activity

Primary system

Nervous system

Strongest disease association

bipolar disorder

Genetic evidence · score 0.06

Therapeutic maturity

Clinically validated target

17 approved medicines against this target

Druggability

Small molecule

Open Targets tractability · Approved Drug

Clinical development

17 approved · 16 in clinical development

30 linked trials

Derived from structured UniProt, Open Targets and literature data on this page.

Protein profile

UniProt 2026_02

Canonical identity and biological annotation from UniProt.

Function

G protein-coupled receptor for 5-hydroxytryptamine (serotonin) (PubMed:22957663, PubMed:3138543, PubMed:33762731, PubMed:37935376, PubMed:37935377, PubMed:8138923, PubMed:8393041). Also functions as a receptor for various drugs and psychoactive substances (PubMed:22957663, PubMed:3138543, PubMed:33762731, PubMed:38552625, PubMed:8138923, PubMed:8393041). 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:22957663, PubMed:3138543, PubMed:33762731, PubMed:8138923, PubMed:8393041). HTR1A is coupled to G(i)/G(o) G alpha proteins and mediates inhibitory neurotransmission: signaling inhibits adenylate cyclase activity and activates a phosphatidylinositol-calcium second messenger system that regulates the release of Ca(2+) ions from intracellular stores (PubMed:33762731, PubMed:35610220). Beta-arrestin family members regulate signaling by mediating both receptor desensitization and resensitization processes (PubMed:18476671, PubMed:20363322, PubMed:20945968). Plays a role in the regulation of 5-hydroxytryptamine release and in the regulation of dopamine and 5-hydroxytryptamine metabolism (PubMed:18476671, PubMed:20363322, PubMed:20945968). Plays a role in the regulation of dopamine and 5-hydroxytryptamine levels in the brain, and thereby affects neural activity, mood and behavior (PubMed:18476671, PubMed:20363322, PubMed:20945968). Plays a role in the response to anxiogenic stimuli (PubMed:18476671, PubMed:20363322, PubMed:20945968)

Subcellular location

Cell membraneCell projection, dendrite
Domains and Gene Ontology detail (23)

Gene Ontology

  • Cdendrite
  • Cplasma membrane
  • Csynapse
  • FG protein-coupled serotonin receptor activity
  • FGi/o-coupled serotonin receptor activity
  • Fneurotransmitter receptor activity
  • Freceptor-receptor interaction
  • Fserotonin binding
  • Fserotonin receptor activity
  • Padenylate cyclase-inhibiting serotonin receptor signaling pathway
  • Pbehavioral fear response
  • Pchemical synaptic transmission

422 aa · 46 kDa

Biological roles

Reactome v97

What this protein does, drawn together from its UniProt function, Gene Ontology terms and Reactome pathways.

G protein-coupled signallingUniProt · GOSynaptic signallingGOMetabolic enzyme activityGOInhibitory neurotransmissionUniProt
View supporting evidence

G protein-coupled signalling

  • ·G protein-coupled receptor for 5-hydroxytryptamine (serotonin) (PubMed:22957663, PubMed:…
  • ·G protein-coupled serotonin receptor activity
  • ·G protein-coupled receptor signaling pathway
  • ·G protein-coupled receptor signaling pathway, coupled to cyclic nucleotide second messen…

Synaptic signalling

  • ·synapse
  • ·neurotransmitter receptor activity
  • ·chemical synaptic transmission

Metabolic enzyme activity

  • ·regulation of dopamine metabolic process
  • ·serotonin metabolic process

Inhibitory neurotransmission

  • ·G protein-coupled receptor for 5-hydroxytryptamine (serotonin) (PubMed:22957663, PubMed:…
View underlying pathways (1)

Concepts derived from UniProt GO Reactome — each badge above shows which sources supported that role.

Interaction neighbourhood

STRING v12.0

Proteins with the strongest functional or physical association. Node size and line weight reflect STRING confidence; hover or select a partner to inspect one association.

GNB1GNAI1SLC6A4FGFR1GNG2HTR2AHTR1BGALR1MAOAOXTHTR1A

10 strongest partners — larger node and heavier line mean higher confidence

Functional and physical associations from STRING v12.0. Only associations with this protein are drawn — partner-to-partner links are not part of this evidence.

Drugs targeting this protein

1

Whether each drug engages this protein directly or through a complex, and how many other targets are recorded for it. Direct binders with few recorded targets are listed first.

aripiprazole
Narrow target profileApprovedPartial agonist

Serotonin 1a (5-HT1a) receptor partial agonist

Appears in clinical studies involving schizophrenia, major depressive disorder, bipolar disorder, Agitation

Direct interaction with this protein · 1 of 3 recorded protein targets — narrow recorded profile

ChEMBL mechanism, action type and target identity. Open Targets clinical status and indications.

Translational evidence

Open Targets 26

Why this target matters therapeutically — disease associations, drugs in development, tractability and safety, from Open Targets.

Strongest genetic associations

Human genetic evidence — the most direct causal link between this target and a disease.

bipolar disorder0.06

Genetic · overall 0.61

Highest-confidence therapeutic associations

Diseases where a drug acting on this target has already reached clinical development.

schizophrenia1.00

Clinical · overall 0.62

major depressive disorder0.99

Clinical · overall 0.63

anxiety disorder0.99

Clinical · overall 0.61

autism0.98

Clinical · overall 0.60

psychotic disorder0.96

Clinical · overall 0.59

Highest overall evidence

Remaining associations by Open Targets' aggregated evidence score.

Agitation0.58

Clinical

bipolar I disorder0.58

Clinical

depressive disorder0.57

Clinical

Tourette syndrome0.55

Clinical

Show all associations
major depressive disorder0.63
schizophrenia0.62
bipolar disorder0.61
anxiety disorder0.61
autism0.60
psychotic disorder0.59
Agitation0.58
bipolar I disorder0.58
depressive disorder0.57
Tourette syndrome0.55

Open Targets ranks 489 associations for this target and we store the top 10 by aggregated score. The long tail is largely literature co-mention and RNA-expression evidence, not evidence that this target drives those diseases.

Known drugs · 35 total

BEFIRADOLPhase 2

Parkinson disease

DEXFENFLURAMINEApproval

obesity disorder · Obesity

GEPIRONE HYDROCHLORIDEApproval

major depressive disorder

ARIPIPRAZOLEApproval

schizophrenia · major depressive disorder · bipolar disorder

ROBALZOTANPhase 2

anxiety disorder

VORTIOXETINE HYDROBROMIDEApproval

major depressive disorder · depressive disorder

VILAZODONEApproval

major depressive disorder · generalized anxiety disorder · depressive disorder

VORTIOXETINEApproval

major depressive disorder · major depressive disorder · mood disorder

SARIZOTAN HYDROCHLORIDEPhase 2

Parkinson disease · movement disorder

LECOZOTAN HYDROCHLORIDEPhase 2 3

Cognitive impairment · Alzheimer disease

Tractability

SM · Approved DrugSM · Structure with LigandSM · High-Quality LigandSM · Druggable FamilyAB · UniProt loc high confAB · GO CC high confAB · UniProt SigP or TMHMMPR · Database UbiquitinationPR · Small Molecule BinderOC · Approved Drug

Safety liabilities

increased locomotor activitydecreased blood pressuredecreased memorydecreased anxietydecreased body temperatureparesthesiastereotypyincreased heart ratecortisol secretiondecreased/increased locomotor activityincreased memorymethamphetamine psychosis

Clinical trials

30

Trials of drugs that target this protein — reached indirectly through those drugs, so a trial listed here studies the drug, not the protein.

Show remaining trials (24)

COMPLETED · via aripiprazole · NCT00194038

WITHDRAWN · via aripiprazole · NCT05554627

COMPLETED · via aripiprazole · NCT02918370

COMPLETED · via aripiprazole · NCT00685334

COMPLETED · via aripiprazole · NCT00102479

ClinicalTrials.gov via the drug-target graph.

Forefront confidence

Synthesis

Our own weighting of the evidence behind each disease association. Human genetics and clinical evidence count for most; literature co-mention counts for little, because two entities sharing an abstract is not evidence that one drives the other.

major depressive disorderWell supported
0.78
agreement 0.620.93
Clinical86%Literature14%

Open Targets aggregate 0.63 · 2 independent evidence families

schizophreniaWell supported
0.77
agreement 0.620.93
Clinical89%Literature11%

Open Targets aggregate 0.62 · 2 independent evidence families

bipolar disorderWell supported
0.76
agreement 0.660.87
Clinical89%Genetic7%Literature4%

Open Targets aggregate 0.61 · 3 independent evidence families

anxiety disorderWell supported
0.75
agreement 0.590.91
Clinical96%Literature4%

Open Targets aggregate 0.61 · 2 independent evidence families

autismModerately supported
0.74
agreement 0.590.90
Clinical97%Literature3%

Open Targets aggregate 0.60 · 2 independent evidence families

The evidence agreement range shows how closely the independent evidence families agree — it is not a statistical confidence interval, and nothing here is fitted to outcome data. Derived from Open Targets evidence types under Forefront weighting; the underlying per-type scores are shown above so the calculation can be checked.

What's happening now

14

Recent activity around this target, drawn from one canonical event stream. Every item is reached through a drug that targets this protein, so each event is news about that drug rather than about the protein directly.

  1. Product recall2026-05-27

    Recall (Class II): ARIPIPRAZOLE

    fda · safety · fda · via aripiprazole

  2. New publication2024-08-26
    Long-Acting Injectable Antipsychotic Initiation in Child and Adolescent Patients with Psychiatric Disorders.

    Journal of child and adolescent psychopharmacology · 2025 · 4 citations · Europe PMC · via aripiprazole

  3. Safety communication2023-12-18

    Drug Safety Update: Aripiprazole (Abilify and generic brands): risk of pathological gambling

    mhra · safety · mhra · via aripiprazole

  4. New publication2015-12-01
    Cariprazine in acute exacerbation of schizophrenia: a fixed-dose, phase 3, randomized, double-blind, placebo- and active-controlled trial.

    The Journal of clinical psychiatry · 2015 · 124 citations · Europe PMC · via aripiprazole

  5. Regulatory approval2015-11-15

    Approval: Aripiprazole Accord (EMA)

    ema · regulatory · ema · via aripiprazole

  6. Regulatory approval2015-08-20

    Approval: Aripiprazole Sandoz (EMA)

    ema · regulatory · ema · via aripiprazole

  7. Regulatory approval2015-06-30

    Approval: Aripiprazole Mylan Pharma (previously Aripiprazole Pharmathen) (EMA)

    ema · regulatory · ema · via aripiprazole

  8. Regulatory approval2015-06-25

    Approval: Aripiprazole Zentiva (EMA)

    ema · regulatory · ema · via aripiprazole

  9. Regulatory approval2013-11-14

    Approval: Abilify Maintena (EMA)

    ema · regulatory · ema · via aripiprazole

  10. New publication2013-01-03
    Aripiprazole for the treatment of methamphetamine dependence: a randomized, double-blind, placebo-controlled trial.

    Addiction (Abingdon, England) · 2013 · 45 citations · Europe PMC · via aripiprazole

  11. New publication2011-11-29
    Double-blind, randomized, placebo-controlled long-term maintenance study of aripiprazole in children with bipolar disorder.

    The Journal of clinical psychiatry · 2012 · 40 citations · Europe PMC · via aripiprazole

  12. New publication2011-11-01
    An open-label trial of aripiprazole in the treatment of aggression in male adolescents diagnosed with conduct disorder.

    Annals of clinical psychiatry : official journal of the American Academy of Clinical Psychiatrists · 2011 · 4 citations · Europe PMC · via aripiprazole

Objective event titles are shown unmodified; the event kind and significance line are derived from structured fields. Forefront AttentionEvent stream aggregating Europe PMC Regulatory filings ClinicalTrials.gov.