Protein / target

Adenosine receptor A1

ADORA1P30542Homo sapiensSwiss-Prot
Clinically validated
Therapeutic maturity
7
Approved medicines
30
Clinical trials
Small-molecule tractable
Druggability
Approved Drug

Protein at a glance

Biological role

G protein-coupled adenosine receptor activity

Primary system

Nervous system

Strongest disease association

asthma

Genetic evidence · score 0.78

Therapeutic maturity

Clinically validated target

7 approved medicines against this target

Druggability

Small molecule

Open Targets tractability · Approved Drug

Clinical development

7 approved · 15 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

Receptor for adenosine (PubMed:29925945). The activity of this receptor is mediated by G proteins such as GNAI2 which inhibit adenylyl cyclase

Subcellular location

Cell membrane
Domains and Gene Ontology detail (67)

Gene Ontology

  • Casymmetric synapse
  • Caxolemma
  • Cbasolateral plasma membrane
  • Ccalyx of Held
  • Cdendrite
  • Cdendritic spine
  • Cintracellular protein-containing complex
  • Cneuronal cell body
  • Cplasma membrane
  • Cpostsynaptic membrane
  • Cpresynaptic active zone
  • Cpresynaptic membrane

326 aa · 37 kDa · 2 isoforms

Biological roles

Reactome v97

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

Synaptic signallingGOG protein-coupled signallingGOExcitatory neurotransmissionGOKinase signallingGOImmune signallingGOInhibitory neurotransmissionGO
View supporting evidence

Synaptic signalling

  • ·asymmetric synapse
  • ·postsynaptic membrane
  • ·presynaptic active zone
  • ·presynaptic membrane

G protein-coupled signalling

  • ·G protein-coupled adenosine receptor activity
  • ·G protein-coupled receptor binding
  • ·adenylate cyclase-inhibiting G protein-coupled receptor signaling pathway
  • ·G protein-coupled purinergic nucleotide receptor signaling pathway

Excitatory neurotransmission

  • ·excitatory postsynaptic potential
  • ·negative regulation of synaptic transmission, glutamatergic

Kinase signalling

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

Immune signalling

  • ·inflammatory response
  • ·negative regulation of acute inflammatory response

Inhibitory neurotransmission

  • ·negative regulation of synaptic transmission, GABAergic
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.

GNAI2GNB1GNAI1KNG1GNAI3ADORA3SLC29A1ADAGNG2ADORA2AADORA1

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.

Adenosine
ApprovedAgonist

Adenosine receptor agonist

Appears in clinical studies involving paroxysmal tachycardia, Wolff-Parkinson-White syndrome, cardiovascular disorder, Paroxysmal supraventricular tachycardia

Acts on a complex — shared with ADORA2B, ADORA3, ADORA2A · 1 of 4 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.

asthma0.78

Genetic · overall 0.72

chronic obstructive pulmonary disease0.33

Genetic · overall 0.54

Highest-confidence therapeutic associations

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

migraine disorder0.99

Clinical · overall 0.61

paroxysmal tachycardia0.97

Clinical · overall 0.59

Apnea0.94

Clinical · overall 0.57

Wolff-Parkinson-White syndrome0.93

Clinical · overall 0.56

Pain0.92

Clinical · overall 0.56

Highest overall evidence

Remaining associations by Open Targets' aggregated evidence score.

Airway obstruction0.55

Clinical

Headache0.54

Clinical

hepatic veno-occlusive disease0.51

Clinical

Show all associations
asthma0.72
migraine disorder0.61
paroxysmal tachycardia0.59
Apnea0.57
Wolff-Parkinson-White syndrome0.56
Pain0.56
Airway obstruction0.55
chronic obstructive pulmonary disease0.54
Headache0.54
hepatic veno-occlusive disease0.51

Open Targets ranks 636 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 · 22 total

T-62Phase 2

postherpetic neuralgia · neuropathic pain

ADENOSINEApproval

paroxysmal tachycardia · Wolff-Parkinson-White syndrome · cardiovascular disorder

CAFFEINEApproval

migraine disorder · Apnea · Pain

GW493838Phase 2

neuropathic pain · peripheral nerve injury

CAPADENOSONPhase 2

atrial fibrillation · angina pectoris

ROLOFYLLINEPhase 3

heart failure · congestive heart failure

AMP579Phase 2

familial hyperlipidemia

PBF-680Phase 2

airway hyperresponsiveness · asthma · atopic asthma

TONAPOFYLLINEPhase 3

Renal insufficiency · heart failure

DEFIBROTIDEApproval

Recurrent thrombophlebitis · hepatic veno-occlusive disease · diabetic kidney disease

Tractability

SM · Approved DrugSM · Structure with LigandSM · High-Quality LigandSM · Druggable FamilyAB · UniProt loc high confAB · GO CC high confAB · UniProt SigP or TMHMMAB · Human Protein Atlas locPR · Small Molecule Binder

Safety liabilities

decreased blood pressureaspirin-intolerant asthmabronchoconstrictionheart failureinduction of sleepnatriuresisdeathdiuresisatrioventricular blockconvulsionsincreased urinary sodium excretionbradycardia

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 Adenosine · NCT00944970

COMPLETED · via Adenosine · NCT00944294

COMPLETED · via Adenosine · NCT03557385

COMPLETED · via Adenosine · NCT03032965

COMPLETED · via Adenosine · NCT01234870

RECRUITING · via Adenosine · NCT06578234

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.

asthmaWell supported
0.94
agreement 0.841.00
Genetic51%Clinical48%Literature2%

Open Targets aggregate 0.72 · 3 independent evidence families

migraine disorderWell supported
0.75
agreement 0.590.91
Clinical98%Literature2%

Open Targets aggregate 0.61 · 2 independent evidence families

chronic obstructive pulmonary diseaseModerately supported
0.74
agreement 0.630.85
Clinical64%Genetic35%Literature2%

Open Targets aggregate 0.54 · 3 independent evidence families

paroxysmal tachycardiaModerately supported
0.72
agreement 0.560.89
Clinical100%

Open Targets aggregate 0.59 · 1 independent evidence family

ApneaModerately supported
0.71
agreement 0.550.86
Clinical100%Literature0%

Open Targets aggregate 0.57 · 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

30

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. New publication2025-10-11
    Adenosine Receptors in Neuroinflammation and Neurodegeneration.

    Cells · 2025 · 2 citations · Europe PMC · via Adenosine

  2. New publication2025-01-01
    REDIportal: toward an integrated view of the A-to-I editing.

    Nucleic acids research · 2025 · 16 citations · Europe PMC · via Adenosine

  3. New publication2024-12-27
    Advances in A-to-I RNA editing in cancer.

    Molecular cancer · 2024 · 17 citations · Europe PMC · via Adenosine

  4. New publication2024-11-28
    Microglia regulate motor neuron plasticity via reciprocal fractalkine and adenosine signaling.

    Nature communications · 2024 · 16 citations · Europe PMC · via Adenosine

  5. New publication2024-10-05
    Astrocytic neuroligin 3 regulates social memory and synaptic plasticity through adenosine signaling in male mice.

    Nature communications · 2024 · 15 citations · Europe PMC · via Adenosine

  6. New publication2024-09-01
    WTAP participates in neuronal damage by protein translation of NLRP3 in an m6A-YTHDF1-dependent manner after traumatic brain injury.

    International journal of surgery (London, England) · 2024 · 41 citations · Europe PMC · via Adenosine

  7. New publication2024-06-18
    Adenosine and adenosine receptors in metabolic imbalance-related neurological issues.

    Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie · 2024 · 17 citations · Europe PMC · via Adenosine

  8. New publication2024-05-21
    Astrocytic ALKBH5 in stress response contributes to depressive-like behaviors in mice.

    Nature communications · 2024 · 50 citations · Europe PMC · via Adenosine

  9. New publication2024-03-18
    Adenosine and Cortical Plasticity.

    The Neuroscientist : a review journal bringing neurobiology, neurology and psychiatry · 2025 · 1 citation · Europe PMC · via Adenosine

  10. New publication2024-02-16
    Programmable RNA N<sup>6</sup>-methyladenosine editing with CRISPR/dCas13a in plants.

    Plant biotechnology journal · 2024 · 19 citations · Europe PMC · via Adenosine

  11. New publication2023-11-08
    m<sup>1</sup>A in CAG repeat RNA binds to TDP-43 and induces neurodegeneration.

    Nature · 2023 · 60 citations · Europe PMC · via Adenosine

  12. New publication2023-10-23
    Utilizing AAV-mediated LEAPER 2.0 for programmable RNA editing in non-human primates and nonsense mutation correction in humanized Hurler syndrome mice.

    Genome biology · 2023 · 21 citations · Europe PMC · via Adenosine

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.