Protein / target

D(3) dopamine receptor

DRD3P35462Homo sapiensSwiss-Prot
Clinically validated
Therapeutic maturity
36
Approved medicines
30
Clinical trials
Small-molecule tractable
Druggability
Approved Drug

Protein at a glance

Biological role

Dopamine neurotransmitter receptor activity, coupled via Gi/Go

Primary system

Nervous system

Strongest disease association

schizophrenia

Genetic literature evidence · score 0.30

Therapeutic maturity

Clinically validated target

36 approved medicines against this target

Druggability

Small molecule

Open Targets tractability · Approved Drug

Clinical development

36 approved · 8 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

Dopamine receptor that is primarily expressed in limbic areas of the brain and is involved in the modulation of cognitive, emotional, and endocrine functions (PubMed:39984436). Plays a key role in regulating neuronal signaling pathways associated with motivation, reward, and behavior (PubMed:39984436). Coupled to G(i)/G(o) proteins; activation leads to inhibition of adenylate cyclase and decreased intracellular cAMP levels (PubMed:10578130). Involved in the control of locomotor activity and implicated in several neuropsychiatric disorders, including schizophrenia and substance use disorders (PubMed:39984436). Promotes cell proliferation through MAP kinase signaling (PubMed:19520868). Also involved in autophagy regulation: receptor activation stimulates AMPK, which phosphorylates RPTOR and enhances its interaction with MTOR, thereby inhibiting MTORC1 signaling and its downstream target RPS6KB1. This leads to activation of ULK1 and initiation of the autophagy cascade (PubMed:31538542). Forms heterotetramers with DRD1 to potentiate beta-arrestin recruitment and mediate locomotor activity (By similarity)

Subcellular location

Cell membrane
Domains and Gene Ontology detail (38)

Gene Ontology

  • Cplasma membrane
  • Csynapse
  • Fdopamine neurotransmitter receptor activity, coupled via Gi/Go
  • FG protein-coupled receptor activity
  • Pacid secretion
  • Padenylate cyclase-activating dopamine receptor signaling pathway
  • Padenylate cyclase-inhibiting dopamine receptor signaling pathway
  • Parachidonate secretion
  • Pbehavioral response to cocaine
  • Pcircadian regulation of gene expression
  • Pdopamine metabolic process
  • PG protein-coupled receptor internalization

400 aa · 44 kDa · 2 isoforms

Biological roles

Reactome v97

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

Motor controlUniProt · GOSynaptic signallingGOG protein-coupled signallingGOExcitatory neurotransmissionGOKinase signallingGOImmune signallingGO
View supporting evidence

Motor control

  • ·Dopamine receptor that is primarily expressed in limbic areas of the brain and is involv…
  • ·locomotory behavior

Synaptic signalling

  • ·synapse
  • ·dopamine neurotransmitter receptor activity, coupled via Gi/Go
  • ·negative regulation of synaptic transmission, glutamatergic
  • ·regulation of dopamine uptake involved in synaptic transmission

G protein-coupled signalling

  • ·G protein-coupled receptor activity
  • ·G protein-coupled receptor internalization
  • ·G protein-coupled receptor signaling pathway

Excitatory neurotransmission

  • ·negative regulation of synaptic transmission, glutamatergic

Kinase signalling

  • ·negative regulation of phosphatidylinositol 3-kinase/protein kinase B signal transduction

Immune signalling

  • ·positive regulation of cytokinesis
View underlying pathways (2)

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.

GNB1GNAI1DRD4GNG2GNB3GNB2BDNFGNG7DRD1SLC6A4DRD3

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

2

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.

Levodopa
Narrow target profileApprovedAgonist

Dopamine D3 receptor agonist

Appears in clinical studies involving Parkinson disease, Parkinson disease, injury, restless legs syndrome

Direct interaction with this protein · Only this protein recorded as a target

olanzapine
ApprovedAntagonist

D2-like dopamine receptor antagonist

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

Acts on a complex — shared with DRD2, DRD4 · 1 of 5 recorded protein targets

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.

schizophrenia0.30

Genetic literature · overall 0.67

Highest-confidence therapeutic associations

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

Parkinson disease1.00

Clinical · overall 0.63

bipolar disorder1.00

Clinical · overall 0.61

restless legs syndrome0.98

Clinical · overall 0.60

Agitation0.98

Clinical · overall 0.60

major depressive disorder0.98

Clinical · overall 0.61

Highest overall evidence

Remaining associations by Open Targets' aggregated evidence score.

psychotic disorder0.60

Clinical

bipolar I disorder0.59

Clinical

depressive disorder0.55

Clinical

Tourette syndrome0.54

Clinical

Show all associations
schizophrenia0.67
Parkinson disease0.63
major depressive disorder0.61
bipolar disorder0.61
restless legs syndrome0.60
psychotic disorder0.60
Agitation0.60
bipolar I disorder0.59
depressive disorder0.55
Tourette syndrome0.54

Open Targets ranks 324 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 · 45 total

AMOXAPINEApproval

major depressive disorder

TRIFLUOPERAZINE HYDROCHLORIDEApproval

schizophrenia · anxiety disorder · mental disorder

LOXAPINE SUCCINATEApproval

schizophrenia

THIORIDAZINEApproval

schizophrenia · psychotic disorder · acute myeloid leukemia

PIMOZIDEApproval

Tics · Tourette syndrome · schizophrenia

CHLORPROMAZINEApproval

Nausea and vomiting · schizophrenia · porphyria

ETILEVODOPAPhase 3

Parkinson disease

PERGOLIDE MESYLATEUnknown
TRAZPIROBENPhase 2

gastroparesis · diabetes mellitus · Abnormality of the gastrointestinal tract

ROPINIROLEApproval

Parkinson disease · restless legs syndrome · Parkinson disease

Tractability

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

Safety liabilities

adverse eventscognitive impairmentinsomnianausearole in facilitating drug addiction/dependenceextrapyramidal symptomsSevere akathisiaopioid dependenceFacilitate reward reinforcement

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 Levodopa · NCT07444892

COMPLETED · via Levodopa · NCT00040209

COMPLETED · via Levodopa · NCT00004733

COMPLETED · via olanzapine · NCT00057408

COMPLETED · via Levodopa · NCT01281475

COMPLETED · via Levodopa · NCT04469959

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.

schizophreniaWell supported
0.86
agreement 0.760.96
Clinical59%Genetic literature19%Animal model17%Literature6%Geneticdup

Open Targets aggregate 0.67 · 4 independent evidence families · 1 not counted as duplicate

Parkinson diseaseWell supported
0.78
agreement 0.620.93
Clinical86%Literature14%

Open Targets aggregate 0.63 · 2 independent evidence families

major depressive disorderWell supported
0.76
agreement 0.600.91
Clinical90%Literature11%

Open Targets aggregate 0.61 · 2 independent evidence families

bipolar disorderWell supported
0.75
agreement 0.600.91
Clinical97%Literature3%

Open Targets aggregate 0.61 · 2 independent evidence families

restless legs syndromeModerately supported
0.74
agreement 0.580.90
Clinical98%Literature2%

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

34

Recent activity around this target, drawn from one canonical event stream. Every item is reached through 2 drugs that target this protein, so each event is news about that drug rather than about the protein directly.

  1. Label change2026-07-07

    Label change: LEVODOPA (NDA209184)

    fda · regulatory · fda · via Levodopa

  2. Label change2026-06-24

    Label change: CARBIDOPA AND LEVODOPA (ANDA216505)

    fda · regulatory · fda · via Levodopa

  3. Label change2026-03-31

    Label change: LEVODOPA (NDA209184)

    fda · regulatory · fda · via Levodopa

  4. Withdrawn from market2025-08-12

    Market withdrawal: Olanzapine Apotex (EMA)

    ema · market · ema · via olanzapine

  5. New publication2025-06-09
    The role of L-DOPA in neurological and neurodegenerative complications: a review.

    Molecular and cellular biochemistry · 2025 · 2 citations · Europe PMC · via Levodopa

  6. New publication2024-04-03
    The Gut Microbiota in Parkinson Disease: Interactions with Drugs and Potential for Therapeutic Applications.

    CNS drugs · 2024 · 27 citations · Europe PMC · via Levodopa

  7. New publication2023-12-01
    Hippocampal synaptic failure is an early event in experimental parkinsonism with subtle cognitive deficit.

    Brain : a journal of neurology · 2023 · 19 citations · Europe PMC · via Levodopa

  8. Regulatory approval2022-09-21

    Approval: CARBIDOPA AND LEVODOPA (ANDA216505)

    fda · regulatory · fda · via Levodopa

  9. New publication2021-02-24
    Oral berberine improves brain dopa/dopamine levels to ameliorate Parkinson's disease by regulating gut microbiota.

    Signal transduction and targeted therapy · 2021 · 223 citations · Europe PMC · via Levodopa

  10. Label change2020-08-31

    Label change: LEVODOPA (NDA209184)

    fda · regulatory · fda · via Levodopa

  11. Label change2020-08-31

    Label change: LEVODOPA (NDA209184)

    fda · regulatory · fda · via Levodopa

  12. New publication2020-06-01
    Olanzapine for the Prevention of Postdischarge Nausea and Vomiting after Ambulatory Surgery: A Randomized Controlled Trial.

    Anesthesiology · 2020 · 18 citations · Europe PMC · via olanzapine

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.