Protein / target

Gamma-aminobutyric acid type B receptor subunit 2

GABBR2O75899Homo sapiensSwiss-Prot
Clinically validated
Therapeutic maturity
2
Approved medicines
30
Clinical trials
Small-molecule tractable
Druggability
Approved Drug

Protein at a glance

Biological role

Transmembrane signaling receptor activity

Primary system

Nervous system

Strongest disease association

developmental and epileptic encephalopathy, 59

Genetic evidence · score 0.84

Therapeutic maturity

Clinically validated target

2 approved medicines against this target

Druggability

Small molecule

Open Targets tractability · Approved Drug

Clinical development

2 approved · 5 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

Component of a heterodimeric G protein-coupled receptor for GABA, formed by GABBR1 and GABBR2 (PubMed:15617512, PubMed:18165688, PubMed:22660477, PubMed:24305054, PubMed:9872316, PubMed:9872744). Within the heterodimeric GABA receptor, only GABBR1 seems to bind agonists, while GABBR2 mediates coupling to G proteins (PubMed:18165688). Ligand binding causes a conformation change that triggers signaling via guanine nucleotide-binding proteins (G proteins) and modulates the activity of down-stream effectors, such as adenylate cyclase (PubMed:10075644, PubMed:10773016, PubMed:24305054). Signaling inhibits adenylate cyclase, stimulates phospholipase A2, activates potassium channels, inactivates voltage-dependent calcium-channels and modulates inositol phospholipid hydrolysis (PubMed:10075644, PubMed:10773016, PubMed:10906333, PubMed:9872744). Plays a critical role in the fine-tuning of inhibitory synaptic transmission (PubMed:22660477, PubMed:9872744). Pre-synaptic GABA receptor inhibits neurotransmitter release by down-regulating high-voltage activated calcium channels, whereas postsynaptic GABA receptor decreases neuronal excitability by activating a prominent inwardly rectifying potassium (Kir) conductance that underlies the late inhibitory postsynaptic potentials (PubMed:10075644, PubMed:22660477, PubMed:9872316, PubMed:9872744). Not only implicated in synaptic inhibition but also in hippocampal long-term potentiation, slow wave sleep, muscle relaxation and antinociception (Probable)

Subcellular location

Cell membranePostsynaptic cell membrane
Domains and Gene Ontology detail (16)

Gene Ontology

  • Ccytoplasm
  • CG protein-coupled receptor heterodimeric complex
  • CGABA receptor complex
  • Cneuron projection
  • Cplasma membrane
  • Cpostsynaptic membrane
  • FG protein-coupled GABA receptor activity
  • Fprotein heterodimerization activity
  • Ftransmembrane signaling receptor activity
  • Padenylate cyclase-inhibiting G protein-coupled receptor signaling pathway
  • Pchemical synaptic transmission
  • PG protein-coupled receptor signaling pathway

941 aa · 106 kDa

Biological roles

Reactome v97

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

Synaptic signallingUniProt · GOG protein-coupled signallingUniProt · GOInhibitory neurotransmissionUniProt · GO
View supporting evidence

Synaptic signalling

  • ·Component of a heterodimeric G protein-coupled receptor for GABA, formed by GABBR1 and G…
  • ·Postsynaptic cell membrane
  • ·postsynaptic membrane
  • ·chemical synaptic transmission

G protein-coupled signalling

  • ·Component of a heterodimeric G protein-coupled receptor for GABA, formed by GABBR1 and G…
  • ·G protein-coupled receptor heterodimeric complex
  • ·G protein-coupled GABA receptor activity
  • ·adenylate cyclase-inhibiting G protein-coupled receptor signaling pathway

Inhibitory neurotransmission

  • ·Component of a heterodimeric G protein-coupled receptor for GABA, formed by GABBR1 and G…
  • ·synaptic transmission, GABAergic
View underlying pathways (5)

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.

GABBR1GNAI1KCNJ6KCTD16KCNJ3KCNJ9GNG2GNAI3GPR156GNAI2GABBR2

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.

Baclofen
ApprovedAgonist

GABA-B receptor agonist

Appears in clinical studies involving Spasticity, cerebral palsy, multiple sclerosis, Rigidity

Acts on a complex — shared with GABBR1 · 1 of 2 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.

developmental and epileptic encephalopathy, 590.84

Genetic · overall 0.73

Epileptic encephalopathy0.84

Genetic · overall 0.65

neurodevelopmental disorder with poor language and loss of hand skills0.83

Genetic · overall 0.60

atypical Rett syndrome0.73

Genetic · overall 0.60

Highest-confidence therapeutic associations

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

Spasticity0.99

Clinical · overall 0.60

multiple sclerosis0.94

Clinical · overall 0.57

Rigidity0.89

Clinical · overall 0.54

spinal cord injury0.87

Clinical · overall 0.53

cerebral palsy0.84

Clinical · overall 0.51

Highest overall evidence

Remaining associations by Open Targets' aggregated evidence score.

narcolepsy0.51

Clinical

Show all associations
developmental and epileptic encephalopathy, 590.73
Epileptic encephalopathy0.65
Spasticity0.60
neurodevelopmental disorder with poor language and loss of hand skills0.60
atypical Rett syndrome0.60
multiple sclerosis0.57
Rigidity0.54
spinal cord injury0.53
cerebral palsy0.51
narcolepsy0.51

Open Targets ranks 270 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 · 7 total

ARBACLOFEN PLACARBILPhase 3

fragile X syndrome · Spasticity · multiple sclerosis

SGS-742Phase 2

schizophrenia · Alzheimer disease · succinic semialdehyde dehydrogenase deficiency

BACLOFENApproval

Spasticity · cerebral palsy · multiple sclerosis

LESOGABERANPhase 2

gastroesophageal reflux disease

ARBACLOFENPhase 3

fragile X syndrome · autism spectrum disorder · Spasticity

OXYBATEPhase 3

idiopathic hypersomnia · Sleep disturbance · narcolepsy

SODIUM OXYBATEApproval

narcolepsy-cataplexy syndrome · narcolepsy · Cataplexy

Tractability

SM · Approved DrugSM · Structure with LigandSM · High-Quality LigandSM · Druggable FamilyAB · UniProt loc high confAB · GO CC high confAB · UniProt loc med confAB · UniProt SigP or TMHMMPR · Database UbiquitinationPR · Half-life DataPR · Small Molecule Binder

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 Baclofen · NCT00255073

TERMINATED · via Baclofen · NCT03720717

COMPLETED · via Baclofen · NCT00877734

ACTIVE_NOT_RECRUITING · via Baclofen · NCT05921604

COMPLETED · via Baclofen · NCT00373295

COMPLETED · via Baclofen · NCT02099006

COMPLETED · via Baclofen · NCT02998151

RECRUITING · via Baclofen · NCT05935553

COMPLETED · via Baclofen · NCT03860662

COMPLETED · via Baclofen · NCT01266655

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.

developmental and epileptic encephalopathy, 59Well supported
0.87
agreement 0.750.99
Genetic84%Animal model17%Genetic literaturedup

Open Targets aggregate 0.73 · 2 independent evidence families · 1 not counted as duplicate

neurodevelopmental disorder with poor language and loss of hand skillsWell supported
0.85
agreement 0.730.97
Genetic85%Animal model15%Genetic literaturedup

Open Targets aggregate 0.60 · 2 independent evidence families · 1 not counted as duplicate

Epileptic encephalopathyWell supported
0.84
agreement 0.700.98
Genetic99%Literature2%Genetic literaturedup

Open Targets aggregate 0.65 · 2 independent evidence families · 1 not counted as duplicate

atypical Rett syndromeWell supported
0.77
agreement 0.650.89
Genetic82%Animal model17%Literature1%Genetic literaturedup

Open Targets aggregate 0.60 · 3 independent evidence families · 1 not counted as duplicate

SpasticityModerately supported
0.74
agreement 0.580.91
Clinical100%

Open Targets aggregate 0.60 · 1 independent evidence family

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

4

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 publication2022-10-18
    FORWARDS-1: an adaptive, single-blind, placebo-controlled ascending dose study of acute baclofen on safety parameters in opioid dependence during methadone-maintenance treatment-a pharmacokinetic-pharmacodynamic study.

    Trials · 2022 · 2 citations · Europe PMC · via Baclofen

  2. New publication2017-04-25
    Biobehavioral effects of baclofen in anxious alcohol-dependent individuals: a randomized, double-blind, placebo-controlled, laboratory study.

    Translational psychiatry · 2017 · 49 citations · Europe PMC · via Baclofen

  3. New publication2014-04-14
    Prevention and management of chemotherapy-induced peripheral neuropathy in survivors of adult cancers: American Society of Clinical Oncology clinical practice guideline.

    Journal of clinical oncology : official journal of the American Society of Clinical Oncology · 2014 · 831 citations · Europe PMC · via Baclofen

  4. New publication2012-12-19
    A human laboratory pilot study with baclofen in alcoholic individuals.

    Pharmacology, biochemistry, and behavior · 2013 · 60 citations · Europe PMC · via Baclofen

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.