{"gene":"GABBR1","run_date":"2026-06-09T23:54:44","timeline":{"discoveries":[{"year":2022,"finding":"Four de novo GABBR1 missense variants (p.Glu368Asp, p.Ala397Val, p.Ala535Thr, p.Gly673Asp) were functionally characterized in transfected HEK293 cells: p.Gly673Asp in TMD3 renders the receptor completely inactive and prevents it from reaching the cell surface; p.Glu368Asp near the orthosteric binding site reduces GABA potency and efficacy; p.Ala397Val and p.Ala535Thr show normal GABA potency but decreased efficacy. All four variants impair GABBR1-mediated signaling, consistent with loss-of-function contributing to neurodevelopmental delay and epilepsy.","method":"In vitro functional characterization (transfected HEK293 cells), active-site mutagenesis analysis, receptor surface expression assays","journal":"American journal of human genetics","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro functional assay with mutagenesis across four independent variants, multiple orthogonal readouts (potency, efficacy, surface expression), single lab but rigorous multi-variant approach","pmids":["36103875"],"is_preprint":false},{"year":2026,"finding":"Functional characterization of seven de novo GABBR1 and GABBR2 missense variants in vitro revealed three distinct mechanisms: (i) increased constitutive activity with decreased GABA efficacy; (ii) significant reduction in GABA potency; and (iii) reduced surface expression resulting in decreased GABA efficacy. These gain- and loss-of-function alterations are associated with autism spectrum disorder, intellectual disability, and/or ADHD.","method":"In vitro functional characterization of de novo variants, receptor surface expression assays, pharmacological characterization (potency/efficacy measurements)","journal":"NPJ genomic medicine","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro functional assays with multiple orthogonal methods (constitutive activity, potency, efficacy, surface expression) across multiple variants in a single rigorous study","pmids":["41803176"],"is_preprint":false},{"year":2021,"finding":"Gabbr1 knockout in mice causes significantly reduced hematopoietic stem/progenitor cell (HSPC) numbers in bone marrow, diminished competitive reconstitution capacity, reduced proliferation under steady-state and stress conditions, and defects in B-cell lineage differentiation. GABBR1 agonist treatment of human cord blood HSPCs ex vivo significantly increased long-term engraftment in immunodeficient mice compared to antagonist or vehicle, demonstrating a direct role for GABBR1 in HSPC proliferation and function.","method":"Constitutive Gabbr1 knockout mouse model, competitive transplantation assay, colony-forming unit assays, in vitro co-culture differentiation, ex vivo GABBR1 agonist/antagonist treatment followed by xenotransplantation, imaging mass spectrometry of bone marrow niche","journal":"Blood","confidence":"High","confidence_rationale":"Tier 2 / Strong — clean KO with defined cellular phenotypes plus rescue with agonist, multiple orthogonal functional readouts across mouse and human HSPCs","pmids":["32881992"],"is_preprint":false},{"year":2015,"finding":"In chronic heart failure (CHF), angiotensin II acting via AT1R in the paraventricular nucleus (PVN) induces HoxD10, which upregulates miR-7b; miR-7b binds the 3'UTR of GABBR1 mRNA (confirmed by luciferase reporter assay with targeted mutagenesis) to suppress GABBR1 translation, reducing GABBR1 protein and causing sympathoexcitation. Antisense miR-7b normalized GABBR1 expression and attenuated CHF symptoms; GABBR1 silencing exaggerated sympathoexcitation.","method":"Luciferase reporter assay with 3'UTR mutagenesis, in vivo PVN infusion of miR-7b/antisense, AT1R knockdown, HoxD10 overexpression/silencing in NG108 cells, coronary artery ligation CHF rat model","journal":"Circulation. Heart failure","confidence":"High","confidence_rationale":"Tier 1 / Moderate — luciferase reporter with mutagenesis confirming direct miR-7b/GABBR1 interaction, corroborated by in vivo loss- and gain-of-function experiments with defined physiological readout","pmids":["26699387"],"is_preprint":false},{"year":2016,"finding":"miR-106a/b, miR-20a/b, and miR-17 of the miR-17-92 cluster directly bind the 3'UTR of GABBR1 (validated by luciferase reporter assay and western blotting), suppressing GABBR1 expression and promoting colorectal cancer cell proliferation and invasion. GABBR1 inhibition mimics miRNA-promoted phenotypes; GABBR1 overexpression blocks miRNA-promoted proliferation and invasion.","method":"Luciferase reporter assay (3'UTR binding), RT-PCR, western blotting, MTT/BrdU proliferation assays, Transwell invasion assays, overexpression/inhibition experiments in HCT116 and HT-29 cells","journal":"Cancer medicine","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — luciferase reporter and western blot confirming miRNA-GABBR1 interaction, with functional rescue experiments, single lab","pmids":["27230463"],"is_preprint":false},{"year":2001,"finding":"Two alternatively spliced cDNA variants of murine GABA(B) receptor 1 (Gabbr1) were identified, predominantly expressed in the CNS, with deduced protein structures highly homologous to rat and human receptors. Alternative splicing occurs at the same position as in human, while the mouse gene has an additional 5' exon. The Gabbr1 gene was mapped to mouse chromosome 17 in a region syntenic to human chromosome 6p21.3.","method":"cDNA cloning, sequence analysis, radiation hybrid mapping, tissue distribution assay","journal":"Cytogenetics and cell genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct cloning and mapping with structural characterization, two orthogonal methods (cDNA cloning + radiation hybrid mapping), single lab","pmids":["11306808"],"is_preprint":false},{"year":2025,"finding":"Global knockout of GABBR1 or GABBR2 produces a similar phenotype (spontaneous epileptiform activity, hyperlocomotor activity, hyperalgesia, impaired memory, premature death) consistent with obligatory heterodimerization of GABBR1 and GABBR2 to form a functional GABA-B receptor. In vitro studies demonstrated that GABBR1 and GABBR2 interactions can alter CaSR (extracellular calcium-sensing receptor) signaling in HEK cells and breast cancer cells, indicating GABBR1 can heterodimerize with non-GABBR2 class C GPCRs.","method":"Global and conditional (CRISPR floxed) knockout mice, in vitro heterodimerization studies in HEK cells","journal":"bioRxiv","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — preprint; genetic KO with defined phenotype confirming functional heterodimerization requirement; CaSR interaction data from in vitro studies cited within abstract","pmids":["bio_10.1101_2025.01.23.634473"],"is_preprint":true},{"year":2026,"finding":"Valerate was identified as a biased ligand that specifically binds GABBR1, upregulates its expression in lung cancer cells, and activates a GABBR1→CXCL13 signaling axis. Mechanistically, valerate-induced GABBR1 upregulation stimulates CXCL13 secretion, which is negatively transcriptionally regulated by NRF2 and its co-factor ATF4, promoting CD8+ T cell infiltration and anti-tumor immunity in NSCLC.","method":"In vitro and in vivo functional assays, single-cell RNA sequencing analysis, GABBR1 overexpression/knockdown, CXCL13 measurement, enrichment analysis identifying ATF4-NRF2 axis","journal":"International journal of biological sciences","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vitro and in vivo experiments with GABBR1 overexpression/knockdown and mechanistic pathway identification, single lab","pmids":["42157924"],"is_preprint":false},{"year":2024,"finding":"In a collagen-induced arthritis mouse model, GABBR1 and p38 MAPK expression were elevated in RA joints relative to healthy joints. Glucocorticoid (dexamethasone) treatment reduced GABBR1 and p38 protein expression in joints and in synovial fluid mononuclear cells ex vivo/in vitro, suggesting GABBR1 modulates p38 MAPK signaling in the joint inflammatory microenvironment.","method":"Collagen-induced arthritis mouse model, immunohistochemistry, western blotting in PB/SF mononuclear cells, dexamethasone treatment in vitro/ex vivo","journal":"Cellular and molecular biology","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single method (western blot/IHC) with pharmacological manipulation, no direct mechanistic dissection of GABBR1-MAPK link, single lab","pmids":["38836679"],"is_preprint":false},{"year":2025,"finding":"In diabetic mouse and AML12 cell models, GABBR1 overexpression or miR-19b-3p knockdown alleviated insulin resistance, liver injury, and inflammation induced by palmitic acid or poly I:C. GABBR1 was shown to mediate targeted regulation of WNT2B by miR-19b-3p, defining a GABBR1/miR-19b-3p/WNT2B axis in hepatic glucose metabolism and injury.","method":"GABBR1 overexpression and knockdown in AML12 cells, miR-19b-3p overexpression/knockdown, diabetic mouse model, CCK-8, ELISA, immunofluorescence, western blot for GLUT4 and IR indices","journal":"Cell cycle","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, single set of methods, indirect evidence for GABBR1-miR-19b-3p-WNT2B pathway without direct binding validation","pmids":["40999757"],"is_preprint":false}],"current_model":"GABBR1 encodes the obligatory GABA-B receptor subunit 1 that heterodimerizes with GABBR2 to form a functional metabotropic GABA receptor; loss-of-function variants (including de novo missense mutations affecting the orthosteric binding site, transmembrane domain, or surface trafficking) impair GABA potency/efficacy or abolish receptor surface expression, leading to neurodevelopmental disorders and epilepsy, while in non-neural contexts GABBR1 regulates hematopoietic stem cell proliferation, is post-transcriptionally suppressed by miR-7b (via an ANG II/AT1R/HoxD10 pathway) or by miR-17-92 cluster members binding its 3'UTR, and can interact with class C GPCRs such as CaSR to modulate downstream signaling."},"narrative":{"mechanistic_narrative":"GABBR1 is the obligatory subunit 1 of the metabotropic GABA-B receptor, which heterodimerizes with GABBR2 to form a functional class C GPCR whose loss produces spontaneous epileptiform activity, hyperalgesia, impaired memory, and premature death [PMID:bio_10.1101_2025.01.23.634473]. De novo missense variants stratify the receptor's functional anatomy: substitutions in transmembrane domain 3 (p.Gly673Asp) abolish surface expression and signaling, variants near the orthosteric site (p.Glu368Asp) reduce GABA potency and efficacy, and others selectively lower efficacy or raise constitutive activity, with these loss- and gain-of-function alterations causing neurodevelopmental delay, epilepsy, autism spectrum disorder, intellectual disability, and ADHD [PMID:36103875, PMID:41803176]. Beyond the nervous system, GABBR1 is required for hematopoietic stem/progenitor cell proliferation, reconstitution capacity, and B-cell differentiation, and agonist stimulation of human cord-blood HSPCs enhances long-term engraftment [PMID:32881992]. GABBR1 is repressed post-transcriptionally through direct binding of microRNAs to its 3'UTR—miR-7b acting downstream of an angiotensin II/AT1R/HoxD10 axis to drive sympathoexcitation in heart failure [PMID:26699387], and miR-17-92 cluster members (miR-106a/b, miR-20a/b, miR-17) to promote colorectal cancer proliferation and invasion [PMID:27230463]. GABBR1 can also heterodimerize with the non-GABBR2 class C GPCR CaSR to alter its signaling [PMID:bio_10.1101_2025.01.23.634473].","teleology":[{"year":2001,"claim":"Established the molecular identity and CNS-predominant expression of the murine receptor, providing the gene structure and splice variants needed to study GABBR1 function.","evidence":"cDNA cloning, sequence analysis, and radiation hybrid mapping of mouse Gabbr1","pmids":["11306808"],"confidence":"Medium","gaps":["Did not establish a functional receptor assay","No partner subunit or signaling readout defined"]},{"year":2015,"claim":"Answered how GABBR1 is post-transcriptionally controlled in disease by showing direct miR-7b targeting of its 3'UTR within an Ang II/AT1R/HoxD10 cascade drives sympathoexcitation in heart failure.","evidence":"Luciferase reporter with 3'UTR mutagenesis plus in vivo PVN infusion and AT1R/HoxD10 manipulation in a CHF rat model","pmids":["26699387"],"confidence":"High","gaps":["Mechanism is upstream regulation, not receptor signaling per se","Does not address GABBR1's downstream effectors in PVN neurons"]},{"year":2016,"claim":"Showed GABBR1 acts as a functional tumor suppressor in colorectal cancer, repressed by direct miR-17-92 cluster binding to its 3'UTR.","evidence":"Luciferase reporter, western blotting, and proliferation/invasion rescue in HCT116 and HT-29 cells","pmids":["27230463"],"confidence":"Medium","gaps":["Single lab","Downstream signaling linking GABBR1 to proliferation/invasion not defined"]},{"year":2021,"claim":"Defined a non-neural role for GABBR1 by demonstrating it is required for hematopoietic stem/progenitor cell proliferation and engraftment, with agonist stimulation enhancing human HSPC function.","evidence":"Constitutive Gabbr1 knockout mice, competitive transplantation, and ex vivo agonist/antagonist treatment of human cord-blood HSPCs followed by xenotransplantation","pmids":["32881992"],"confidence":"High","gaps":["Intracellular signaling pathway in HSPCs not resolved","Whether GABBR2 heterodimerization is required in HSPCs untested"]},{"year":2022,"claim":"Mapped the functional consequences of de novo missense variants onto receptor anatomy, distinguishing trafficking-dead, orthosteric, and efficacy-reducing mutations as a mechanistic basis for neurodevelopmental disorders.","evidence":"In vitro functional characterization of four variants in HEK293 cells with potency, efficacy, and surface-expression readouts","pmids":["36103875"],"confidence":"High","gaps":["No in vivo modeling of the variants","Patient genotype-phenotype correlation limited"]},{"year":2024,"claim":"Linked GABBR1 to inflammatory signaling by correlating its expression with p38 MAPK in arthritic joints and showing both decline with glucocorticoid treatment.","evidence":"Collagen-induced arthritis mouse model with IHC, western blot, and dexamethasone treatment of mononuclear cells","pmids":["38836679"],"confidence":"Low","gaps":["No direct mechanistic link between GABBR1 and p38 MAPK","Correlative expression only, single method"]},{"year":2025,"claim":"Confirmed obligatory GABBR1/GABBR2 heterodimerization through matched knockout phenotypes and revealed GABBR1 can heterodimerize with CaSR to modulate its signaling.","evidence":"Global and conditional knockout mice plus in vitro heterodimerization studies in HEK and breast cancer cells (preprint)","pmids":["bio_10.1101_2025.01.23.634473"],"confidence":"Medium","gaps":["Preprint, not peer-reviewed","Functional consequences of CaSR heterodimer in vivo undefined"]},{"year":2025,"claim":"Proposed a hepatic metabolic role via a GABBR1/miR-19b-3p/WNT2B axis alleviating insulin resistance and liver injury.","evidence":"GABBR1 and miR-19b-3p overexpression/knockdown in AML12 cells and a diabetic mouse model","pmids":["40999757"],"confidence":"Low","gaps":["No direct binding validation of the miR-19b-3p/WNT2B regulation","Single lab, indirect pathway evidence"]},{"year":2026,"claim":"Broadened the variant spectrum to include gain-of-function (increased constitutive activity) alongside loss-of-function, expanding the disorder phenotypes to autism, intellectual disability, and ADHD.","evidence":"In vitro functional characterization of seven de novo GABBR1/GABBR2 variants with constitutive activity, potency, efficacy, and surface-expression assays","pmids":["41803176"],"confidence":"High","gaps":["No in vivo correlate of constitutive-activity variants","Mechanism distinguishing gain- vs loss-of-function clinical outcomes unclear"]},{"year":2026,"claim":"Identified valerate as a biased ligand that upregulates GABBR1 to drive a GABBR1→CXCL13 axis promoting anti-tumor CD8+ T-cell immunity in lung cancer.","evidence":"In vitro/in vivo assays, scRNA-seq, GABBR1 overexpression/knockdown, and CXCL13 measurement in NSCLC models","pmids":["42157924"],"confidence":"Medium","gaps":["Direct molecular coupling of GABBR1 to CXCL13 transcription not resolved","Single lab"]},{"year":null,"claim":"The intracellular effector pathways linking GABBR1 activation to its diverse cellular phenotypes (HSPC proliferation, hepatic metabolism, tumor immunity) remain undefined.","evidence":"","pmids":[],"confidence":"Low","gaps":["No unified downstream signaling mechanism across non-neural contexts","Role of GABBR2 vs alternative heterodimer partners in each context untested"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0060089","term_label":"molecular transducer activity","supporting_discovery_ids":[0,1,6]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[0,1]}],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[0,1,6]},{"term_id":"R-HSA-112316","term_label":"Neuronal System","supporting_discovery_ids":[5,6]}],"complexes":["GABA-B receptor (GABBR1–GABBR2 heterodimer)"],"partners":["GABBR2","CASR"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q9UBS5","full_name":"Gamma-aminobutyric acid type B receptor subunit 1","aliases":[],"length_aa":961,"mass_kda":108.3,"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:36103875, 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:10906333, PubMed:24305054, PubMed:9872744). Signaling inhibits adenylate cyclase, stimulates phospholipase A2, activates potassium channels, inactivates voltage-dependent calcium-channels and modulates inositol phospholipid hydrolysis (PubMed:10075644). Calcium is required for high affinity binding to GABA (By similarity). Plays a critical role in the fine-tuning of inhibitory synaptic transmission (PubMed:9844003). 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:9844003, 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). Activated by (-)-baclofen, cgp27492 and blocked by phaclofen (PubMed:24305054, PubMed:9844003, PubMed:9872316) Isoform 1E may regulate the formation of functional GABBR1/GABBR2 heterodimers by competing for GABBR2 binding. This could explain the observation that certain small molecule ligands exhibit differential affinity for central versus peripheral sites","subcellular_location":"Secreted","url":"https://www.uniprot.org/uniprotkb/Q9UBS5/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/GABBR1","classification":"Not Classified","n_dependent_lines":3,"n_total_lines":1208,"dependency_fraction":0.0024834437086092716},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/GABBR1","total_profiled":1310},"omim":[{"mim_id":"620502","title":"NEURODEVELOPMENTAL DISORDER WITH LANGUAGE DELAY AND VARIABLE COGNITIVE ABNORMALITIES; NEDLC","url":"https://www.omim.org/entry/620502"},{"mim_id":"611195","title":"JANUS KINASE AND MICROTUBULE-INTERACTING PROTEIN 1; JAKMIP1","url":"https://www.omim.org/entry/611195"},{"mim_id":"610464","title":"G PROTEIN-COUPLED RECEPTOR 156; GPR156","url":"https://www.omim.org/entry/610464"},{"mim_id":"609327","title":"MICRO RNA 124-1; MIR124-1","url":"https://www.omim.org/entry/609327"},{"mim_id":"608645","title":"DEAFNESS, AUTOSOMAL DOMINANT 31; DFNA31","url":"https://www.omim.org/entry/608645"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Vesicles","reliability":"Approved"},{"location":"Plasma membrane","reliability":"Approved"},{"location":"Primary cilium tip","reliability":"Additional"},{"location":"Basal body","reliability":"Additional"}],"tissue_specificity":"Tissue enriched","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"brain","ntpm":224.4}],"url":"https://www.proteinatlas.org/search/GABBR1"},"hgnc":{"alias_symbol":["hGB1a","GPRC3A"],"prev_symbol":[]},"alphafold":{"accession":"Q9UBS5","domains":[{"cath_id":"2.10.70.10","chopping":"29-97","consensus_level":"high","plddt":82.4271,"start":29,"end":97},{"cath_id":"2.10.70.10","chopping":"101-158","consensus_level":"high","plddt":82.8509,"start":101,"end":158},{"cath_id":"3.40.50.2300","chopping":"187-287_431-521","consensus_level":"high","plddt":91.8152,"start":187,"end":521},{"cath_id":"3.40.50.2300","chopping":"289-428_537-577","consensus_level":"high","plddt":94.8313,"start":289,"end":577},{"cath_id":"1.20.1070.10","chopping":"587-694_705-737_764-861","consensus_level":"high","plddt":89.434,"start":587,"end":861}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9UBS5","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9UBS5-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9UBS5-F1-predicted_aligned_error_v6.png","plddt_mean":84.19},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=GABBR1","jax_strain_url":"https://www.jax.org/strain/search?query=GABBR1"},"sequence":{"accession":"Q9UBS5","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9UBS5.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9UBS5/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9UBS5"}},"corpus_meta":[{"pmid":"32881992","id":"PMC_32881992","title":"The neurotransmitter receptor Gabbr1 regulates proliferation and function of hematopoietic stem and progenitor cells.","date":"2021","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/32881992","citation_count":46,"is_preprint":false},{"pmid":"15685626","id":"PMC_15685626","title":"Evidence for the gamma-amino-butyric acid type B receptor 1 (GABBR1) gene as a susceptibility factor in obsessive-compulsive disorder.","date":"2005","source":"American journal of medical genetics. Part B, Neuropsychiatric genetics : the official publication of the International Society of Psychiatric Genetics","url":"https://pubmed.ncbi.nlm.nih.gov/15685626","citation_count":45,"is_preprint":false},{"pmid":"19763258","id":"PMC_19763258","title":"Association and interaction analyses of GABBR1 and GABBR2 with nicotine dependence in European- and African-American populations.","date":"2009","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/19763258","citation_count":34,"is_preprint":false},{"pmid":"27230463","id":"PMC_27230463","title":"A miRNAs panel promotes the proliferation and invasion of colorectal cancer cells by targeting GABBR1.","date":"2016","source":"Cancer medicine","url":"https://pubmed.ncbi.nlm.nih.gov/27230463","citation_count":31,"is_preprint":false},{"pmid":"29026448","id":"PMC_29026448","title":"Newborn genome-wide DNA methylation in association with pregnancy anxiety reveals a potential role for GABBR1.","date":"2017","source":"Clinical epigenetics","url":"https://pubmed.ncbi.nlm.nih.gov/29026448","citation_count":28,"is_preprint":false},{"pmid":"36103875","id":"PMC_36103875","title":"GABBR1 monoallelic de novo variants linked to neurodevelopmental delay and epilepsy.","date":"2022","source":"American journal of human genetics","url":"https://pubmed.ncbi.nlm.nih.gov/36103875","citation_count":26,"is_preprint":false},{"pmid":"15820424","id":"PMC_15820424","title":"Possible association between the gamma-aminobutyric acid type B receptor 1 (GABBR1) gene and schizophrenia.","date":"2005","source":"European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/15820424","citation_count":25,"is_preprint":false},{"pmid":"23391219","id":"PMC_23391219","title":"GABBR1 has a HERV-W LTR in its regulatory region--a possible implication for schizophrenia.","date":"2013","source":"Biology direct","url":"https://pubmed.ncbi.nlm.nih.gov/23391219","citation_count":21,"is_preprint":false},{"pmid":"21621395","id":"PMC_21621395","title":"GABBR1 gene polymorphism(G1465A)isassociated with temporal lobe epilepsy.","date":"2011","source":"Epilepsy research","url":"https://pubmed.ncbi.nlm.nih.gov/21621395","citation_count":17,"is_preprint":false},{"pmid":"26727527","id":"PMC_26727527","title":"GABBR1 and SLC6A1, Two Genes Involved in Modulation of GABA Synaptic Transmission, Influence Risk for Alcoholism: Results from Three Ethnically Diverse Populations.","date":"2016","source":"Alcoholism, clinical and experimental research","url":"https://pubmed.ncbi.nlm.nih.gov/26727527","citation_count":16,"is_preprint":false},{"pmid":"15799783","id":"PMC_15799783","title":"The GABBR1 locus and the G1465A variant is not associated with temporal lobe epilepsy preceded by febrile seizures.","date":"2005","source":"BMC medical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/15799783","citation_count":16,"is_preprint":false},{"pmid":"18355961","id":"PMC_18355961","title":"Analysis of LGI1 promoter sequence, PDYN and GABBR1 polymorphisms in sporadic and familial lateral temporal lobe epilepsy.","date":"2008","source":"Neuroscience letters","url":"https://pubmed.ncbi.nlm.nih.gov/18355961","citation_count":16,"is_preprint":false},{"pmid":"34448502","id":"PMC_34448502","title":"Adipose-derived stem cell-derived extracellular vesicles inhibit neuroblastoma growth by regulating GABBR1 activity through LINC00622-mediated transcription factor AR.","date":"2021","source":"Journal of leukocyte biology","url":"https://pubmed.ncbi.nlm.nih.gov/34448502","citation_count":14,"is_preprint":false},{"pmid":"26699387","id":"PMC_26699387","title":"Sympathoexcitation in Rats With Chronic Heart Failure Depends on Homeobox D10 and MicroRNA-7b Inhibiting GABBR1 Translation in Paraventricular Nucleus.","date":"2015","source":"Circulation. 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R133C) and GABBR1.","date":"2025","source":"Frontiers in pediatrics","url":"https://pubmed.ncbi.nlm.nih.gov/40612488","citation_count":0,"is_preprint":false},{"pmid":"40999757","id":"PMC_40999757","title":"The GABBR1/miR-19b-3p/WNT2B axis regulates insulin resistance and liver injury in diabetes with viral infection: mechanistic and therapeutic insights.","date":"2025","source":"Cell cycle (Georgetown, Tex.)","url":"https://pubmed.ncbi.nlm.nih.gov/40999757","citation_count":0,"is_preprint":false},{"pmid":"41792070","id":"PMC_41792070","title":"<em>IGHG1, HLA-DOB, </em>and <em>GABBR1</em>: Genetic Insights into Rheumatoid Arthritis Using Mendelian Randomisation and Single-Cell RNA Sequencing.","date":"2026","source":"Journal of the College of Physicians and Surgeons--Pakistan : JCPSP","url":"https://pubmed.ncbi.nlm.nih.gov/41792070","citation_count":0,"is_preprint":false},{"pmid":"42157924","id":"PMC_42157924","title":"Activation of GABBR1 by New Ligand Valerate Transcriptionally Regulates ATF4-NRF2-CXCL13 Axis Mediating CD8+ T Cell Anti-Tumor Immunity.","date":"2026","source":"International journal of biological sciences","url":"https://pubmed.ncbi.nlm.nih.gov/42157924","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.01.23.634473","title":"Development of a floxed  <i>Gabbr2</i>  gene allows for widespread conditional disruption of GABBR2 and recapitulates the phenotype of germline Gabbr2 knockout mice","date":"2025-01-23","source":"bioRxiv","url":"https://doi.org/10.1101/2025.01.23.634473","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.07.03.25330832","title":"Etiological basis for chronic pain genetic variation in brain and dorsal root ganglia cell types","date":"2025-07-03","source":"bioRxiv","url":"https://doi.org/10.1101/2025.07.03.25330832","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.10.22.684048","title":"Genomic signatures associated with convergent funnel-web building behavior in spiders","date":"2025-10-23","source":"bioRxiv","url":"https://doi.org/10.1101/2025.10.22.684048","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":16512,"output_tokens":3230,"usd":0.048993,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":10616,"output_tokens":3303,"usd":0.067827,"stage2_stop_reason":"end_turn"},"total_usd":0.11682,"stage1_batch_id":"msgbatch_01AsR7g8dGTEiEw9U83bJeWn","stage2_batch_id":"msgbatch_01YV5ZyxtFNUZEjxRcpd9jzb","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2022,\n      \"finding\": \"Four de novo GABBR1 missense variants (p.Glu368Asp, p.Ala397Val, p.Ala535Thr, p.Gly673Asp) were functionally characterized in transfected HEK293 cells: p.Gly673Asp in TMD3 renders the receptor completely inactive and prevents it from reaching the cell surface; p.Glu368Asp near the orthosteric binding site reduces GABA potency and efficacy; p.Ala397Val and p.Ala535Thr show normal GABA potency but decreased efficacy. All four variants impair GABBR1-mediated signaling, consistent with loss-of-function contributing to neurodevelopmental delay and epilepsy.\",\n      \"method\": \"In vitro functional characterization (transfected HEK293 cells), active-site mutagenesis analysis, receptor surface expression assays\",\n      \"journal\": \"American journal of human genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro functional assay with mutagenesis across four independent variants, multiple orthogonal readouts (potency, efficacy, surface expression), single lab but rigorous multi-variant approach\",\n      \"pmids\": [\"36103875\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"Functional characterization of seven de novo GABBR1 and GABBR2 missense variants in vitro revealed three distinct mechanisms: (i) increased constitutive activity with decreased GABA efficacy; (ii) significant reduction in GABA potency; and (iii) reduced surface expression resulting in decreased GABA efficacy. These gain- and loss-of-function alterations are associated with autism spectrum disorder, intellectual disability, and/or ADHD.\",\n      \"method\": \"In vitro functional characterization of de novo variants, receptor surface expression assays, pharmacological characterization (potency/efficacy measurements)\",\n      \"journal\": \"NPJ genomic medicine\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro functional assays with multiple orthogonal methods (constitutive activity, potency, efficacy, surface expression) across multiple variants in a single rigorous study\",\n      \"pmids\": [\"41803176\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"Gabbr1 knockout in mice causes significantly reduced hematopoietic stem/progenitor cell (HSPC) numbers in bone marrow, diminished competitive reconstitution capacity, reduced proliferation under steady-state and stress conditions, and defects in B-cell lineage differentiation. GABBR1 agonist treatment of human cord blood HSPCs ex vivo significantly increased long-term engraftment in immunodeficient mice compared to antagonist or vehicle, demonstrating a direct role for GABBR1 in HSPC proliferation and function.\",\n      \"method\": \"Constitutive Gabbr1 knockout mouse model, competitive transplantation assay, colony-forming unit assays, in vitro co-culture differentiation, ex vivo GABBR1 agonist/antagonist treatment followed by xenotransplantation, imaging mass spectrometry of bone marrow niche\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — clean KO with defined cellular phenotypes plus rescue with agonist, multiple orthogonal functional readouts across mouse and human HSPCs\",\n      \"pmids\": [\"32881992\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"In chronic heart failure (CHF), angiotensin II acting via AT1R in the paraventricular nucleus (PVN) induces HoxD10, which upregulates miR-7b; miR-7b binds the 3'UTR of GABBR1 mRNA (confirmed by luciferase reporter assay with targeted mutagenesis) to suppress GABBR1 translation, reducing GABBR1 protein and causing sympathoexcitation. Antisense miR-7b normalized GABBR1 expression and attenuated CHF symptoms; GABBR1 silencing exaggerated sympathoexcitation.\",\n      \"method\": \"Luciferase reporter assay with 3'UTR mutagenesis, in vivo PVN infusion of miR-7b/antisense, AT1R knockdown, HoxD10 overexpression/silencing in NG108 cells, coronary artery ligation CHF rat model\",\n      \"journal\": \"Circulation. Heart failure\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — luciferase reporter with mutagenesis confirming direct miR-7b/GABBR1 interaction, corroborated by in vivo loss- and gain-of-function experiments with defined physiological readout\",\n      \"pmids\": [\"26699387\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"miR-106a/b, miR-20a/b, and miR-17 of the miR-17-92 cluster directly bind the 3'UTR of GABBR1 (validated by luciferase reporter assay and western blotting), suppressing GABBR1 expression and promoting colorectal cancer cell proliferation and invasion. GABBR1 inhibition mimics miRNA-promoted phenotypes; GABBR1 overexpression blocks miRNA-promoted proliferation and invasion.\",\n      \"method\": \"Luciferase reporter assay (3'UTR binding), RT-PCR, western blotting, MTT/BrdU proliferation assays, Transwell invasion assays, overexpression/inhibition experiments in HCT116 and HT-29 cells\",\n      \"journal\": \"Cancer medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — luciferase reporter and western blot confirming miRNA-GABBR1 interaction, with functional rescue experiments, single lab\",\n      \"pmids\": [\"27230463\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"Two alternatively spliced cDNA variants of murine GABA(B) receptor 1 (Gabbr1) were identified, predominantly expressed in the CNS, with deduced protein structures highly homologous to rat and human receptors. Alternative splicing occurs at the same position as in human, while the mouse gene has an additional 5' exon. The Gabbr1 gene was mapped to mouse chromosome 17 in a region syntenic to human chromosome 6p21.3.\",\n      \"method\": \"cDNA cloning, sequence analysis, radiation hybrid mapping, tissue distribution assay\",\n      \"journal\": \"Cytogenetics and cell genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct cloning and mapping with structural characterization, two orthogonal methods (cDNA cloning + radiation hybrid mapping), single lab\",\n      \"pmids\": [\"11306808\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Global knockout of GABBR1 or GABBR2 produces a similar phenotype (spontaneous epileptiform activity, hyperlocomotor activity, hyperalgesia, impaired memory, premature death) consistent with obligatory heterodimerization of GABBR1 and GABBR2 to form a functional GABA-B receptor. In vitro studies demonstrated that GABBR1 and GABBR2 interactions can alter CaSR (extracellular calcium-sensing receptor) signaling in HEK cells and breast cancer cells, indicating GABBR1 can heterodimerize with non-GABBR2 class C GPCRs.\",\n      \"method\": \"Global and conditional (CRISPR floxed) knockout mice, in vitro heterodimerization studies in HEK cells\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — preprint; genetic KO with defined phenotype confirming functional heterodimerization requirement; CaSR interaction data from in vitro studies cited within abstract\",\n      \"pmids\": [\"bio_10.1101_2025.01.23.634473\"],\n      \"is_preprint\": true\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"Valerate was identified as a biased ligand that specifically binds GABBR1, upregulates its expression in lung cancer cells, and activates a GABBR1→CXCL13 signaling axis. Mechanistically, valerate-induced GABBR1 upregulation stimulates CXCL13 secretion, which is negatively transcriptionally regulated by NRF2 and its co-factor ATF4, promoting CD8+ T cell infiltration and anti-tumor immunity in NSCLC.\",\n      \"method\": \"In vitro and in vivo functional assays, single-cell RNA sequencing analysis, GABBR1 overexpression/knockdown, CXCL13 measurement, enrichment analysis identifying ATF4-NRF2 axis\",\n      \"journal\": \"International journal of biological sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vitro and in vivo experiments with GABBR1 overexpression/knockdown and mechanistic pathway identification, single lab\",\n      \"pmids\": [\"42157924\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"In a collagen-induced arthritis mouse model, GABBR1 and p38 MAPK expression were elevated in RA joints relative to healthy joints. Glucocorticoid (dexamethasone) treatment reduced GABBR1 and p38 protein expression in joints and in synovial fluid mononuclear cells ex vivo/in vitro, suggesting GABBR1 modulates p38 MAPK signaling in the joint inflammatory microenvironment.\",\n      \"method\": \"Collagen-induced arthritis mouse model, immunohistochemistry, western blotting in PB/SF mononuclear cells, dexamethasone treatment in vitro/ex vivo\",\n      \"journal\": \"Cellular and molecular biology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single method (western blot/IHC) with pharmacological manipulation, no direct mechanistic dissection of GABBR1-MAPK link, single lab\",\n      \"pmids\": [\"38836679\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"In diabetic mouse and AML12 cell models, GABBR1 overexpression or miR-19b-3p knockdown alleviated insulin resistance, liver injury, and inflammation induced by palmitic acid or poly I:C. GABBR1 was shown to mediate targeted regulation of WNT2B by miR-19b-3p, defining a GABBR1/miR-19b-3p/WNT2B axis in hepatic glucose metabolism and injury.\",\n      \"method\": \"GABBR1 overexpression and knockdown in AML12 cells, miR-19b-3p overexpression/knockdown, diabetic mouse model, CCK-8, ELISA, immunofluorescence, western blot for GLUT4 and IR indices\",\n      \"journal\": \"Cell cycle\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, single set of methods, indirect evidence for GABBR1-miR-19b-3p-WNT2B pathway without direct binding validation\",\n      \"pmids\": [\"40999757\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"GABBR1 encodes the obligatory GABA-B receptor subunit 1 that heterodimerizes with GABBR2 to form a functional metabotropic GABA receptor; loss-of-function variants (including de novo missense mutations affecting the orthosteric binding site, transmembrane domain, or surface trafficking) impair GABA potency/efficacy or abolish receptor surface expression, leading to neurodevelopmental disorders and epilepsy, while in non-neural contexts GABBR1 regulates hematopoietic stem cell proliferation, is post-transcriptionally suppressed by miR-7b (via an ANG II/AT1R/HoxD10 pathway) or by miR-17-92 cluster members binding its 3'UTR, and can interact with class C GPCRs such as CaSR to modulate downstream signaling.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"GABBR1 is the obligatory subunit 1 of the metabotropic GABA-B receptor, which heterodimerizes with GABBR2 to form a functional class C GPCR whose loss produces spontaneous epileptiform activity, hyperalgesia, impaired memory, and premature death [#6]. De novo missense variants stratify the receptor's functional anatomy: substitutions in transmembrane domain 3 (p.Gly673Asp) abolish surface expression and signaling, variants near the orthosteric site (p.Glu368Asp) reduce GABA potency and efficacy, and others selectively lower efficacy or raise constitutive activity, with these loss- and gain-of-function alterations causing neurodevelopmental delay, epilepsy, autism spectrum disorder, intellectual disability, and ADHD [#0, #1]. Beyond the nervous system, GABBR1 is required for hematopoietic stem/progenitor cell proliferation, reconstitution capacity, and B-cell differentiation, and agonist stimulation of human cord-blood HSPCs enhances long-term engraftment [#2]. GABBR1 is repressed post-transcriptionally through direct binding of microRNAs to its 3'UTR—miR-7b acting downstream of an angiotensin II/AT1R/HoxD10 axis to drive sympathoexcitation in heart failure [#3], and miR-17-92 cluster members (miR-106a/b, miR-20a/b, miR-17) to promote colorectal cancer proliferation and invasion [#4]. GABBR1 can also heterodimerize with the non-GABBR2 class C GPCR CaSR to alter its signaling [#6].\",\n  \"teleology\": [\n    {\n      \"year\": 2001,\n      \"claim\": \"Established the molecular identity and CNS-predominant expression of the murine receptor, providing the gene structure and splice variants needed to study GABBR1 function.\",\n      \"evidence\": \"cDNA cloning, sequence analysis, and radiation hybrid mapping of mouse Gabbr1\",\n      \"pmids\": [\"11306808\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Did not establish a functional receptor assay\", \"No partner subunit or signaling readout defined\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Answered how GABBR1 is post-transcriptionally controlled in disease by showing direct miR-7b targeting of its 3'UTR within an Ang II/AT1R/HoxD10 cascade drives sympathoexcitation in heart failure.\",\n      \"evidence\": \"Luciferase reporter with 3'UTR mutagenesis plus in vivo PVN infusion and AT1R/HoxD10 manipulation in a CHF rat model\",\n      \"pmids\": [\"26699387\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism is upstream regulation, not receptor signaling per se\", \"Does not address GABBR1's downstream effectors in PVN neurons\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Showed GABBR1 acts as a functional tumor suppressor in colorectal cancer, repressed by direct miR-17-92 cluster binding to its 3'UTR.\",\n      \"evidence\": \"Luciferase reporter, western blotting, and proliferation/invasion rescue in HCT116 and HT-29 cells\",\n      \"pmids\": [\"27230463\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab\", \"Downstream signaling linking GABBR1 to proliferation/invasion not defined\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Defined a non-neural role for GABBR1 by demonstrating it is required for hematopoietic stem/progenitor cell proliferation and engraftment, with agonist stimulation enhancing human HSPC function.\",\n      \"evidence\": \"Constitutive Gabbr1 knockout mice, competitive transplantation, and ex vivo agonist/antagonist treatment of human cord-blood HSPCs followed by xenotransplantation\",\n      \"pmids\": [\"32881992\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Intracellular signaling pathway in HSPCs not resolved\", \"Whether GABBR2 heterodimerization is required in HSPCs untested\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Mapped the functional consequences of de novo missense variants onto receptor anatomy, distinguishing trafficking-dead, orthosteric, and efficacy-reducing mutations as a mechanistic basis for neurodevelopmental disorders.\",\n      \"evidence\": \"In vitro functional characterization of four variants in HEK293 cells with potency, efficacy, and surface-expression readouts\",\n      \"pmids\": [\"36103875\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"No in vivo modeling of the variants\", \"Patient genotype-phenotype correlation limited\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Linked GABBR1 to inflammatory signaling by correlating its expression with p38 MAPK in arthritic joints and showing both decline with glucocorticoid treatment.\",\n      \"evidence\": \"Collagen-induced arthritis mouse model with IHC, western blot, and dexamethasone treatment of mononuclear cells\",\n      \"pmids\": [\"38836679\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No direct mechanistic link between GABBR1 and p38 MAPK\", \"Correlative expression only, single method\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Confirmed obligatory GABBR1/GABBR2 heterodimerization through matched knockout phenotypes and revealed GABBR1 can heterodimerize with CaSR to modulate its signaling.\",\n      \"evidence\": \"Global and conditional knockout mice plus in vitro heterodimerization studies in HEK and breast cancer cells (preprint)\",\n      \"pmids\": [\"bio_10.1101_2025.01.23.634473\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Preprint, not peer-reviewed\", \"Functional consequences of CaSR heterodimer in vivo undefined\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Proposed a hepatic metabolic role via a GABBR1/miR-19b-3p/WNT2B axis alleviating insulin resistance and liver injury.\",\n      \"evidence\": \"GABBR1 and miR-19b-3p overexpression/knockdown in AML12 cells and a diabetic mouse model\",\n      \"pmids\": [\"40999757\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No direct binding validation of the miR-19b-3p/WNT2B regulation\", \"Single lab, indirect pathway evidence\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Broadened the variant spectrum to include gain-of-function (increased constitutive activity) alongside loss-of-function, expanding the disorder phenotypes to autism, intellectual disability, and ADHD.\",\n      \"evidence\": \"In vitro functional characterization of seven de novo GABBR1/GABBR2 variants with constitutive activity, potency, efficacy, and surface-expression assays\",\n      \"pmids\": [\"41803176\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"No in vivo correlate of constitutive-activity variants\", \"Mechanism distinguishing gain- vs loss-of-function clinical outcomes unclear\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Identified valerate as a biased ligand that upregulates GABBR1 to drive a GABBR1\\u2192CXCL13 axis promoting anti-tumor CD8+ T-cell immunity in lung cancer.\",\n      \"evidence\": \"In vitro/in vivo assays, scRNA-seq, GABBR1 overexpression/knockdown, and CXCL13 measurement in NSCLC models\",\n      \"pmids\": [\"42157924\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct molecular coupling of GABBR1 to CXCL13 transcription not resolved\", \"Single lab\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The intracellular effector pathways linking GABBR1 activation to its diverse cellular phenotypes (HSPC proliferation, hepatic metabolism, tumor immunity) remain undefined.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No unified downstream signaling mechanism across non-neural contexts\", \"Role of GABBR2 vs alternative heterodimer partners in each context untested\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0060089\", \"supporting_discovery_ids\": [0, 1, 6]},\n      {\"term_id\": \"GO:0004930\", \"supporting_discovery_ids\": [0, 1, 6]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [0, 1]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [0, 1, 6]},\n      {\"term_id\": \"R-HSA-112316\", \"supporting_discovery_ids\": [5, 6]}\n    ],\n    \"complexes\": [\"GABA-B receptor (GABBR1\\u2013GABBR2 heterodimer)\"],\n    \"partners\": [\"GABBR2\", \"CaSR\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":3,"faith_total":3,"faith_pct":100.0}}