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Protein / target

Gamma-aminobutyric acid type B receptor subunit 2

Encoded byGABBR2O75899Homo sapiensSwiss-Prot
Clinically validated
Therapeutic maturity
2
Approved medicines
Open Targets target-level
View by indication →
30
Clinical trials
Small-molecule tractable
Druggability
Approved Drug

Protein at a glance

Biological role

Transmembrane signaling receptor

Strongest disease association

Developmental and epileptic encephalopathy, 59

Via encoding gene GABBR2 · Genetic evidence · score 0.84

Therapeutic position

Established drug target

Small molecules

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 overview

Component of a heterodimeric G protein-coupled receptor for GABA, formed by GABBR1 and GABBR2.

View complete UniProt function annotation

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.

Inhibitory neurotransmissionUniProt · GOLipid & lipoprotein metabolismUniProtG protein-coupled signallingUniProt · GO
View supporting evidence

Inhibitory neurotransmission

  • ·Component of a heterodimeric G protein-coupled receptor for GABA, formed by GABBR1 and G…
  • ·synaptic transmission, GABAergic

Lipid & lipoprotein metabolism

  • ·Component of a heterodimeric G protein-coupled receptor for GABA, formed by GABBR1 and G…

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
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.

Approved medicines with mapped indications

1 medicine · 6 areas

Approved therapies targeting this protein, grouped by what they are approved to treat — the disease-first view of the medicines below. Relationships come from the canonical approved-indication graph (ChEMBL phase-4), the same source as the drug cards.

Brain Injuries1 medicine
Brain Injuries, Traumatic1 medicine
Cerebral Palsy1 medicine
Multiple Sclerosis1 medicine
Muscle Spasticity1 medicine
Spinal Cord Injuries1 medicine

2 medicines meet Open Targets' target-level approved-medicine definition; the 1 shown here are those on this page with a canonical approved disease indication in the graph. Approved indications from ChEMBL (phase-4), via the canonical drug→disease graph.

Drugs targeting this protein

2

How approved and investigational drugs engage this protein — mechanism and action type, direct vs complex targeting, and how broadly each acts across other targets. A drug-first view (the section above groups the approved ones disease-first); direct binders with few recorded targets are listed first.

Baclofen
ApprovedAgonist

GABA-B receptor agonist

Indicated for Brain Injuries, Brain Injuries, Traumatic, Cerebral Palsy, Multiple Sclerosis

Acts on a complex — shared with GABBR1 · 1 of 2 recorded protein targets — narrow recorded profile

Arbaclofen
Phase 3Agonist

GABA-B receptor agonist

Acts on a complex — shared with GABBR1 · 1 of 2 recorded protein targets — narrow recorded profile

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

Translational evidence

Open Targets 26

Why this target matters therapeutically, strongest evidence first. Disease associations are gene-level (via the gene that encodes this protein) and open into the full confidence synthesis; the development universe, tractability and safety annotations are target-level, from Open Targets.

Strongest disease associations · via encoding gene GABBR2

Gene-level evidence surfaced through the gene GABBR2that encodes this protein — not a direct protein–disease relationship. Ranked by Forefront's causal-directness weighting, so genetically- and clinically-evidenced diseases lead over ones that merely share the literature.

Developmental and epileptic encephalopathy, 59
0.87Well supported

Genetic evidence dominant · Open Targets 0.73

Neurodevelopmental disorder with poor language and loss of hand skills
0.85Well supported

Genetic evidence dominant · Open Targets 0.60

atypical Rett syndrome
0.77Well supported

Genetic evidence dominant · Open Targets 0.60

View evidence synthesis (3)
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

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

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 per-type scores above show the calculation.

Show all associations
Developmental and epileptic encephalopathy, 590.73
Neurodevelopmental disorder with poor language and loss of hand skills0.60
atypical Rett syndrome0.60

Drug development

7 compounds recorded · 2 approved · 5 in clinical development

Open Targets' development universe — every compound recorded against the target at any stage, not all approved medicines. Distinct from the 2 drugs that target this protein in Forefront's canonical graph (1 with a mapped approved indication, shown above): these count different sets and are not a subset relation.

View all recorded compounds (7)
ARBACLOFEN PLACARBILPhase 3
SGS-742Phase 2
BACLOFENApproval
LESOGABERANPhase 2
ARBACLOFENPhase 3
OXYBATEPhase 3
SODIUM OXYBATEApproval

Open Targets known-drugs universe. Drug name and highest clinical stage only — the disease relationship is NOT read from this slice (it carries trial-context noise); approved indications come from the canonical graph above.

Tractability

Small moleculesStrong

Approved Drug and Structure with Ligand support this modality.

AntibodiesEmerging

Feasibility evidence (uniprot loc high conf and go cc high conf) — no clinical-stage drug of this modality recorded.

Protein degradersEmerging

Feasibility evidence (database ubiquitination and half-life data) — no clinical-stage drug of this modality recorded.

View underlying tractability evidence (11)
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

Raw Open Targets tractability assessment buckets, by modality.

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. Ranked by active status, then clinical phase and recency, and spread across the targeting drugs.

View all trials (26)

ACTIVE_NOT_RECRUITING · via Baclofen · NCT05921604

RECRUITING · via Baclofen · NCT07560878

TERMINATED · via Baclofen · NCT03720717

COMPLETED · via Baclofen · NCT03860662

UNKNOWN · via Baclofen · NCT03293017

SUSPENDED · via Baclofen · NCT02529514

TERMINATED · via Baclofen · NCT04251819

COMPLETED · via Baclofen · NCT02099006

ClinicalTrials.gov via the drug-target graph.

What's happening now

4

Recent therapeutic activity around this target — regulatory actions, clinical trials and safety signals for a drug that targets this protein, plus publications where such a drug is a genuine subject. Every item is reached indirectly through the drug, not the protein itself; incidental mentions (a paper that merely measures a drug) and press items are excluded.

  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.