Protein / target

Alpha-1B adrenergic receptor

ADRA1BP35368Homo sapiensSwiss-Prot
Clinically validated
Therapeutic maturity
54
Approved medicines
30
Clinical trials
Small-molecule tractable
Druggability
Approved Drug

Protein at a glance

Biological role

Alpha1-adrenergic receptor activity

Primary system

Nervous system

Strongest disease association

hypertensive disorder

Clinical evidence · score 0.62

Therapeutic maturity

Clinically validated target

54 approved medicines against this target

Druggability

Small molecule

Open Targets tractability · Approved Drug

Clinical development

54 approved · 3 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

Alpha-1 adrenergic receptors are G protein-coupled receptors for catecholamines that signal through the G(q) family of G proteins, including G(q) and G(11). Upon activation, they stimulate the phosphatidylinositol-calcium second messenger pathway, leading to calcium release from intracellular stores and activation of protein kinase C (By similarity). ADRA1B binds the catecholamine ligands norepinephrine and epinephrine (PubMed:7815325, PubMed:8183249). Can also couple to G(14) and G(16) proteins (By similarity). Nuclear ADRA1B forms heterooligomers with ADRA1A to regulate phenylephrine(PE)-stimulated ERK signaling in cardiac myocytes (PubMed:18802028, PubMed:22120526). At the plasma membrane, ADRA1B interacts with CAVIN4/MURC to regulates ERK activation in cardiomyocytes, contributing to the regulation of cardiac hypertrophy (PubMed:24567387)

Subcellular location

Nucleus membraneCell membraneCytoplasmMembrane, caveola
Domains and Gene Ontology detail (19)

Gene Ontology

  • Ccaveola
  • Ccytoplasm
  • Cnuclear membrane
  • Cnucleus
  • Cplasma membrane
  • Falpha1-adrenergic receptor activity
  • Fprotein heterodimerization activity
  • Padenylate cyclase-activating adrenergic receptor signaling pathway
  • Padenylate cyclase-modulating G protein-coupled receptor signaling pathway
  • Pcell-cell signaling
  • PG protein-coupled receptor signaling pathway
  • Pintracellular signal transduction

520 aa · 57 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 · GOKinase signallingUniProtMuscle contractionGO
View supporting evidence

G protein-coupled signalling

  • ·Alpha-1 adrenergic receptors are G protein-coupled receptors for catecholamines that sig…
  • ·adenylate cyclase-modulating G protein-coupled receptor signaling pathway
  • ·G protein-coupled receptor signaling pathway
  • ·phospholipase C-activating G protein-coupled receptor signaling pathway

Kinase signalling

  • ·Alpha-1 adrenergic receptors are G protein-coupled receptors for catecholamines that sig…

Muscle contraction

  • ·regulation of cardiac muscle contraction
View underlying pathways (3)

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.

GNAQADRA1AADRA1DGNA11GNA12GNA13TBXA2RAGTINPP1GNA15ADRA1B

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.

carvedilol
ApprovedAntagonist

Adrenergic receptor alpha-1 antagonist

Appears in clinical studies involving myocardial infarction, hypertensive disorder, heart failure, congestive heart failure

Acts on a complex — shared with ADRA1A, ADRA1D · 1 of 6 recorded protein targets

Epinephrine
ApprovedAgonist

Adrenergic receptor agonist

Appears in clinical studies involving sudden cardiac arrest, asthma, sinusitis, septic shock

Acts on a complex — shared with ADRA1A, ADRA2A, ADRB2 +5 more · 1 of 9 recorded protein targets — broad pharmacology

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.

Highest-confidence therapeutic associations

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

Nasal congestion1.00

Clinical · overall 0.61

benign prostatic hyperplasia1.00

Clinical · overall 0.61

hypertensive disorder1.00

Clinical · overall 0.62

common cold0.99

Clinical · overall 0.60

myocardial infarction0.99

Clinical · overall 0.60

Highest overall evidence

Remaining associations by Open Targets' aggregated evidence score.

seasonal allergic rhinitis0.60

Clinical

Headache0.60

Clinical

Cough0.60

Clinical

asthma0.60

Clinical

sudden cardiac arrest0.60

Clinical

Show all associations
hypertensive disorder0.62
benign prostatic hyperplasia0.61
Nasal congestion0.61
myocardial infarction0.60
common cold0.60
seasonal allergic rhinitis0.60
Headache0.60
Cough0.60
asthma0.60
sudden cardiac arrest0.60

Open Targets ranks 746 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 · 58 total

TETRAHYDROZOLINE HYDROCHLORIDEUnknown
ALFUZOSIN HYDROCHLORIDEApproval

benign prostatic hyperplasia · lower urinary tract symptom

ERGOLOID MESYLATESApproval

cardiovascular disorder · vascular dementia · fragile X syndrome

BUNAZOSINApproval
EPINEPHRINEApproval

sudden cardiac arrest · asthma · sinusitis

NAPHAZOLINE HYDROCHLORIDEApproval

Nasal congestion · seasonal allergic rhinitis · common cold

ALFUZOSINApproval

benign prostatic hyperplasia · chronic prostatitis · Urinary retention

NOREPINEPHRINEApproval

cardiovascular disorder · Sepsis · major depressive disorder

HYDROXYAMPHETAMINE HYDROBROMIDEApproval

Horner syndrome

TAMSULOSIN HYDROCHLORIDEApproval

benign prostatic hyperplasia · prostate carcinoma · lower urinary tract symptom

Tractability

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

Safety liabilities

convulsionscardiac hypertrophyneurodegenerationdecreased blood pressuredecreased locomotor activityorthostatic hypotension

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 carvedilol · NCT00000294

WITHDRAWN · via carvedilol · NCT04121299

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.

hypertensive disorderWell supported
0.77
agreement 0.610.92
Clinical90%Literature10%

Open Targets aggregate 0.62 · 2 independent evidence families

sudden cardiac arrestWell supported
0.77
agreement 0.630.90
Clinical83%Animal model17%

Open Targets aggregate 0.60 · 2 independent evidence families

benign prostatic hyperplasiaModerately supported
0.75
agreement 0.590.90
Clinical99%Literature1%

Open Targets aggregate 0.61 · 2 independent evidence families

Nasal congestionModerately supported
0.75
agreement 0.580.91
Clinical100%

Open Targets aggregate 0.61 · 1 independent evidence family

myocardial infarctionModerately supported
0.75
agreement 0.590.90
Clinical99%Literature1%

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

16

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 change2026-06-22

    Label change: EPINEPHRINE (NDA204640)

    fda · regulatory · fda · via Epinephrine

  2. Product recall2026-05-14

    Recall (Class III): EPINEPHRINE

    fda · safety · fda · via Epinephrine

  3. Regulatory approval2024-08-22

    Approval: Eurneffy (EMA)

    ema · regulatory · ema · via Epinephrine

  4. New publication2023-11-07
    Impact of norepinephrine on immunity and oxidative metabolism in sepsis.

    Frontiers in immunology · 2023 · 33 citations · Europe PMC · via Epinephrine

  5. New publication2023-09-25
    Multicenter, Prospective, Randomized Controlled Trial of High-Sensitivity Cardiac Troponin I-Guided Combination Angiotensin Receptor Blockade and Beta-Blocker Therapy to Prevent Anthracycline Cardiotoxicity: The Cardiac CARE Trial.

    Circulation · 2023 · 53 citations · Europe PMC · via carvedilol

  6. Label change2023-01-05

    Label change: EPINEPHRINE (NDA204640)

    fda · regulatory · fda · via Epinephrine

  7. Supplemental approval2021-08-17

    Supplemental approval: EPINEPHRINE (NDA204640)

    fda · regulatory · fda · via Epinephrine

  8. New publication2019-10-31
    The effect of topical epinephrine 1:1000 with and without infiltration of 1% lidocaine with epinephrine 1:100,000 on endoscopic surgical field visualization: a double-blind randomized controlled study.

    International forum of allergy & rhinology · 2020 · 6 citations · Europe PMC · via Epinephrine

  9. Indication expanded2019-01-29

    Indication expansion: EPINEPHRINE (NDA204640)

    fda · regulatory · fda · via Epinephrine

  10. New publication2017-08-17
    Pulmonary arterial hypertension treatment with carvedilol for heart failure: a randomized controlled trial.

    JCI insight · 2017 · 74 citations · Europe PMC · via carvedilol

  11. Label change2017-08-09

    Label change: EPINEPHRINE (NDA204640)

    fda · regulatory · fda · via Epinephrine

  12. Label change2016-05-18

    Label change: EPINEPHRINE (NDA204640)

    fda · regulatory · fda · via Epinephrine

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.