{"gene":"ARHGEF9","run_date":"2026-06-09T22:02:44","timeline":{"discoveries":[{"year":2009,"finding":"The pleckstrin homology (PH) domain of collybistin (ARHGEF9) binds phosphatidylinositol-3-phosphate (PI3P/PtdIns-3-P), not phosphatidylinositol 3,4,5-trisphosphate (PIP3) as previously suggested. Expression of truncated collybistin proteins lacking the PH domain in cultured neurons interferes with synaptic localization of endogenous gephyrin and GABA-A receptors, establishing a role for the PH domain in membrane trafficking of gephyrin and selected GABA-A receptor subtypes.","method":"Lipid-binding assay (PI3P vs PIP3 binding), expression of truncated collybistin in cultured neurons with immunocytochemical readout of gephyrin and GABA-A receptor localization","journal":"Human mutation","confidence":"High","confidence_rationale":"Tier 1-2 / Moderate — direct lipid-binding biochemical assay combined with neuronal expression experiment showing functional consequence on gephyrin/GABA-A receptor synaptic clustering","pmids":["18615734"],"is_preprint":false},{"year":2016,"finding":"The missense mutation R338W in the PH domain of collybistin (ARHGEF9) disrupts PI3P binding and abolishes the ability of collybistin to translocate EGFP-gephyrin to submembrane microaggregates in an in vitro clustering assay. Molecular modeling indicates the R338W substitution causes steric clashes with adjacent residues (K363 and N335) and disrupts local PH domain folding.","method":"PI3P-binding assay with recombinant CB2SH3-(R338W), in vitro gephyrin clustering assay in transfected cells, molecular modeling","journal":"Frontiers in molecular neuroscience","confidence":"High","confidence_rationale":"Tier 1-2 / Moderate — reconstituted lipid-binding assay plus functional clustering assay with mutant protein and structural modeling, single lab but multiple orthogonal methods","pmids":["26834553"],"is_preprint":false},{"year":2015,"finding":"ARHGEF9 (as the Cdc42-specific GEF collybistin) functions downstream of IQGAP1 and Cdc42 in a signaling pathway that regulates eukaryotic cell migration. LAI-1-dependent inhibition of cell migration required ARHGEF9 but not other modulators of Cdc42, RhoA, Rac1, or Ran GTPase; depletion of ARHGEF9 phenocopied Cdc42 inactivation in this context.","method":"siRNA knockdown of ARHGEF9 and other GEFs/GTPases in migration assay, Cdc42 activity measurement, IQGAP1 localization by immunofluorescence","journal":"PLoS pathogens","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic/RNAi epistasis with defined cellular phenotype (migration index), multiple GEF/GTPase controls tested, single lab","pmids":["26633832"],"is_preprint":false},{"year":2020,"finding":"Two ARHGEF9 missense variants (p.I294T and p.R357I) disrupt collybistin-mediated accumulation of gephyrin in submembrane microclusters in vitro. A splicing variant (c.381+3A>G) produces aberrant transcripts leading to a truncated protein product.","method":"In vitro gephyrin clustering assay with transfected cells expressing missense variants; transcriptional/splicing analysis of the splice-site variant","journal":"Journal of molecular neuroscience","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional clustering assay with mutant proteins plus splicing analysis, single lab, two orthogonal approaches","pmids":["31942680"],"is_preprint":false},{"year":2022,"finding":"Collybistin (ARHGEF9) directly interacts with the α2 subunit of GABA-A receptors via a binding motif in its large intracellular loop; disruption of this interaction (Gabra2-1 knock-in mutation replacing the Cb-binding motif with the gephyrin-binding motif from α1) causes strong downregulation of Cb expression particularly at CCK basket cell inhibitory synapses. The Gabra2-1 mice phenocopy ARHGEF9 patient features including deficits in working/recognition memory, hyperactivity, anxiety, reduced social preference, spontaneous seizures, and EEG abnormalities including sleep disturbance.","method":"Knock-in mouse model (Gabra2-1), immunohistochemistry, electrophysiology, EEG, behavioral assays","journal":"Molecular psychiatry","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic knock-in model with multiple orthogonal readouts (molecular, electrophysiological, behavioral, EEG), direct binding motif manipulation establishing mechanism","pmids":["35169261"],"is_preprint":false},{"year":2024,"finding":"In a mouse model carrying a patient-derived ARHGEF9 variant associated with severe disease, collybistin (ARHGEF9) is required for proper organization of the postsynaptic density of inhibitory synapses at the axon initial segment (AIS). Loss of function causes aggregation of postsynaptic proteins, loss of functional inhibitory synapses at the AIS, altered axo-axonic synaptic inhibition, and disrupted action potential generation.","method":"Patient-derived variant knock-in mouse model, immunofluorescence of AIS postsynaptic protein aggregation, electrophysiology (axo-axonic inhibition, action potential recording), in vivo seizure monitoring","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 2 / Moderate — mouse model with patient-derived variant, multiple orthogonal methods (morphology, electrophysiology, seizure phenotype) establishing AIS-specific mechanistic role","pmids":["39374387"],"is_preprint":false},{"year":2025,"finding":"ASD-associated ARHGEF9 variant p.R290C promotes abnormal gephyrin clustering in COS-7 cells and reduces inhibitory synapse density in cultured hippocampal neurons. Variants p.V374F and p.G485S (with p.R290C) induce defective inhibitory synaptic transmission; p.G485S specifically decreases PI3P-binding activity. Conditional knockout of collybistin in medial prefrontal cortex (mPFC) reduces gephyrin phosphorylation levels and impairs ultrasonic vocalization; ASD-associated ARHGEF9 variants fail to rescue impaired GABAergic transmission and reduced gephyrin phosphorylation in mPFC-specific Cb-cKO mice.","method":"Transfection of variants in COS-7 cells (gephyrin clustering assay), primary hippocampal neuron culture (synapse density), whole-cell patch-clamp electrophysiology, PI3P-binding assay, mPFC-specific conditional knockout mouse, proteomics (phosphorylation), ultrasonic vocalization behavioral assay","journal":"Molecular psychiatry","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — multiple orthogonal methods across in vitro and in vivo systems, direct lipid-binding assay, proteomics, electrophysiology, and behavioral readouts in single study","pmids":["41174051"],"is_preprint":false},{"year":2022,"finding":"ARHGEF9/Collybistin is required for melanoma cell shape determination on both soft and stiff substrates and in 3D matrices. Depletion of ARHGEF9 results in loss of tension at focal adhesions, decreased cell-wide contractility, inability to stabilize protrusions, and loss of actin-rich filopodia that normally establish and stabilize adhesions.","method":"Genetic screens with single-cell quantitative morphological analysis, siRNA depletion, traction force microscopy (focal adhesion tension), 3D invasion assay, fluorescence imaging of actin/filopodia","journal":"iScience","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic screen followed by mechanistic validation with multiple morphological and biophysical readouts, single lab","pmids":["36039362"],"is_preprint":false},{"year":2023,"finding":"In the EAE mouse model of multiple sclerosis, inflammation induces region-specific alternative splicing of Arhgef9 (increased inclusion of alternative exon 11a selectively in CA3 and dentate gyrus), coinciding with downregulation of the splicing factor Sam68 that normally represses this splicing event.","method":"Laser microdissection of hippocampal subfields, RT-PCR for exon 11a inclusion, immunohistochemistry for Sam68 and parvalbumin in EAE vs. control mice","journal":"Frontiers in molecular neuroscience","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct measurement of alternative splicing with regional dissection and correlation with Sam68 levels, single lab, mechanistically informative but correlational for Sam68-Arhgef9 link","pmids":["36710925"],"is_preprint":false},{"year":2018,"finding":"ARHGEF9 protein exhibits tissue-dependent and developmental stage-dependent expression in mouse brain (cerebral cortex, hippocampus, cerebellum), and shows partial localization at dendritic spines in cultured hippocampal neurons.","method":"Western blotting across mouse tissues, immunohistochemistry at multiple developmental stages, immunofluorescence in cultured hippocampal neurons with validated polyclonal antibody","journal":"Acta histochemica et cytochemica","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — direct localization by immunofluorescence and IHC with validated antibody, multiple brain regions and developmental stages, but no functional consequence linked to localization","pmids":["30083020"],"is_preprint":false},{"year":2025,"finding":"ARHGEF9 expression increases significantly during skeletal muscle regeneration after injury in mice and co-localizes with actin filaments during C2C12 myoblast differentiation. Inhibition of ARHGEF9 reduces myoblast migration rate, actin filament polymerization, expression of migration-related proteins, and differentiation capacity of C2C12 myoblasts.","method":"Mouse muscle injury model (ARHGEF9 protein expression by Western blot), C2C12 myoblast differentiation assay, siRNA/inhibitor-based knockdown, migration assay, phalloidin staining for actin filaments, Western blot for migration/differentiation markers","journal":"Journal of muscle research and cell motility","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — loss-of-function with defined cellular phenotypes (migration, actin polymerization, differentiation) in muscle context, single lab","pmids":["39992578"],"is_preprint":false},{"year":2022,"finding":"A synonymous ARHGEF9 variant (c.741C>T, p.Cys247Cys) causes abnormal splicing of exon 5 resulting in a 55-bp deletion, demonstrating that synonymous variants in ARHGEF9 can produce loss-of-function via splicing disruption.","method":"RNA splicing analysis (RT-PCR) on patient-derived sample confirming aberrant transcript and 55-bp exon 5 deletion","journal":"Chinese journal of medical genetics","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single patient RNA splicing analysis, no functional reconstitution or cell-based mechanistic assay","pmids":["36184101"],"is_preprint":false}],"current_model":"ARHGEF9 encodes collybistin (Cb), a neuronal Cdc42-specific guanine nucleotide exchange factor that acts as a key organizer of inhibitory postsynaptic densities: its DH domain mediates GEF activity toward Cdc42, its SH3 domain interacts with neuroligin-2, and its PH domain binds PI3P to drive membrane targeting, collectively enabling the submembrane clustering of gephyrin and GABA-A/glycine receptors; loss of Cb function disrupts inhibitory synapses at the axon initial segment, reduces gephyrin phosphorylation, impairs GABAergic transmission, and produces epilepsy, intellectual disability, and behavioral abnormalities in mice and humans, while in non-neuronal contexts Cb regulates actin-driven cell migration and morphology via Cdc42 signaling."},"narrative":{"mechanistic_narrative":"ARHGEF9 encodes collybistin, a neuronal Cdc42-specific guanine nucleotide exchange factor that organizes inhibitory postsynaptic densities by driving submembrane clustering of gephyrin and GABA-A receptors [PMID:18615734, PMID:35169261]. Membrane targeting depends on the PH domain, which binds phosphatidylinositol-3-phosphate (PI3P) rather than PIP3, and PH-domain truncation or PI3P-binding-disrupting mutations abolishes collybistin-mediated translocation of gephyrin and GABA-A receptors to submembrane microaggregates [PMID:18615734, PMID:26834553]. Collybistin directly binds the α2 subunit of GABA-A receptors through a motif in its large intracellular loop, an interaction required to maintain its expression at specific inhibitory synapses [PMID:35169261]. Loss of collybistin function disorganizes inhibitory postsynaptic densities at the axon initial segment, causes aggregation of postsynaptic proteins, reduces gephyrin phosphorylation, and impairs GABAergic transmission, producing seizures, memory and social deficits, and behavioral abnormalities in mouse models that phenocopy ARHGEF9 patient features [PMID:35169261, PMID:39374387, PMID:41174051]. Multiple patient- and ASD-associated missense, synonymous, and splice-site variants act through these mechanisms—disrupting gephyrin clustering, PI3P binding, or producing truncated transcripts—establishing ARHGEF9 dysfunction as a cause of epilepsy, intellectual disability, and autism-spectrum phenotypes [PMID:26834553, PMID:31942680, PMID:41174051]. Outside neurons, collybistin functions downstream of IQGAP1 and Cdc42 to control actin-driven cell migration, focal-adhesion tension, filopodia stabilization, and myoblast differentiation [PMID:26633832, PMID:36039362, PMID:39992578].","teleology":[{"year":2009,"claim":"Established the lipid specificity and membrane-trafficking function of collybistin's PH domain, redefining how it targets gephyrin to synapses.","evidence":"Lipid-binding assay (PI3P vs PIP3) plus expression of PH-domain-truncated collybistin in cultured neurons with gephyrin/GABA-A readout","pmids":["18615734"],"confidence":"High","gaps":["Did not resolve how PI3P generation is regulated at the synapse","No structural detail of the PH-lipid interface"]},{"year":2015,"claim":"Placed collybistin in a non-neuronal IQGAP1-Cdc42 signaling axis controlling cell migration, showing its GEF role extends beyond synapse assembly.","evidence":"siRNA epistasis against multiple GEFs/GTPases with migration assay and Cdc42 activity measurement","pmids":["26633832"],"confidence":"Medium","gaps":["Direct biochemical link between collybistin and IQGAP1 not shown","Whether GEF catalytic activity is required not isolated"]},{"year":2016,"claim":"Demonstrated that a disease-associated PH-domain mutation acts by abolishing PI3P binding and gephyrin clustering, providing a structural mechanism for pathogenicity.","evidence":"PI3P-binding assay with recombinant mutant, in vitro gephyrin clustering assay, and molecular modeling of R338W","pmids":["26834553"],"confidence":"High","gaps":["Modeling not validated by experimental structure","In vivo consequence of R338W not tested"]},{"year":2018,"claim":"Characterized the spatial and developmental expression of collybistin in brain, supporting a synaptic localization consistent with its postsynaptic role.","evidence":"Western blot across tissues, IHC across developmental stages, immunofluorescence in cultured hippocampal neurons","pmids":["30083020"],"confidence":"Medium","gaps":["No functional consequence tied to the observed localization","Dendritic spine localization only partial"]},{"year":2020,"claim":"Extended the variant-to-mechanism link by showing additional patient missense and splice variants impair gephyrin clustering or produce truncated protein.","evidence":"In vitro gephyrin clustering assay with missense variants and splicing analysis of a splice-site variant","pmids":["31942680"],"confidence":"Medium","gaps":["No in vivo modeling of these specific variants","Mechanism of clustering disruption for I294T/R357I not resolved"]},{"year":2022,"claim":"Identified a direct collybistin-GABA-A receptor α2 interaction and showed its disruption causes synapse-specific collybistin downregulation and a patient-like phenotype in mice.","evidence":"Gabra2-1 knock-in mouse, IHC, electrophysiology, EEG, and behavioral assays","pmids":["35169261"],"confidence":"High","gaps":["Binding motif mapped genetically, not by structure","Why CCK basket cell synapses are selectively affected unclear"]},{"year":2022,"claim":"Defined a cell-biological role for collybistin in actin-based mechanics, linking it to focal-adhesion tension, contractility, and filopodia stabilization in melanoma cells.","evidence":"Genetic morphological screen, siRNA depletion, traction force microscopy, 3D invasion assay, actin imaging","pmids":["36039362"],"confidence":"Medium","gaps":["Whether Cdc42 GEF activity mediates these effects not directly tested","Direct cytoskeletal partners not identified"]},{"year":2022,"claim":"Showed that even a synonymous ARHGEF9 variant can cause loss of function through aberrant splicing, broadening the pathogenic variant spectrum.","evidence":"RT-PCR splicing analysis of a single patient-derived sample","pmids":["36184101"],"confidence":"Low","gaps":["Single patient with no functional reconstitution","Protein-level consequence not directly assessed"]},{"year":2023,"claim":"Linked inflammatory neuropathology to region-specific Arhgef9 alternative splicing under Sam68 control, implicating splicing regulation in collybistin function.","evidence":"Laser microdissection, RT-PCR for exon 11a inclusion, IHC for Sam68 in EAE vs control mice","pmids":["36710925"],"confidence":"Medium","gaps":["Sam68-Arhgef9 regulatory link is correlational","Functional impact of exon 11a inclusion on protein activity unknown"]},{"year":2024,"claim":"Localized collybistin's critical role to the axon initial segment, showing loss of function disorganizes axo-axonic inhibitory synapses and disrupts action potential generation.","evidence":"Patient-derived variant knock-in mouse, AIS immunofluorescence, electrophysiology, in vivo seizure monitoring","pmids":["39374387"],"confidence":"High","gaps":["Molecular trigger for protein aggregation at AIS not resolved","Whether AIS defect alone accounts for seizures unclear"]},{"year":2025,"claim":"Integrated ASD-associated variants with mPFC-specific collybistin function, tying loss of function to reduced gephyrin phosphorylation, impaired GABAergic transmission, and altered vocalization.","evidence":"COS-7 clustering and PI3P-binding assays, hippocampal neuron synapse density, patch-clamp, mPFC conditional knockout, phosphoproteomics, ultrasonic vocalization assay","pmids":["41174051"],"confidence":"High","gaps":["Kinase responsible for gephyrin phosphorylation not identified","How distinct variants converge on the same phenotype not mechanistically separated"]},{"year":2025,"claim":"Demonstrated a role for collybistin in skeletal muscle regeneration via actin-dependent myoblast migration and differentiation, extending its cytoskeletal function to a new tissue.","evidence":"Mouse muscle injury model, C2C12 differentiation and migration assays, knockdown, phalloidin staining, marker Western blots","pmids":["39992578"],"confidence":"Medium","gaps":["Cdc42/GEF dependence in muscle not demonstrated","Direct interaction partners in myoblasts not identified"]},{"year":null,"claim":"How collybistin's catalytic GEF activity, PI3P-dependent membrane targeting, and receptor/gephyrin scaffolding are coordinated and regulated to assemble synapse-specific inhibitory densities remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No high-resolution structure of full-length collybistin or its receptor complexes","Kinases/phosphatases controlling gephyrin phosphorylation downstream of collybistin not defined","Mechanism selecting specific inhibitory synapse subtypes unclear"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[2]},{"term_id":"GO:0008289","term_label":"lipid binding","supporting_discovery_ids":[0,1,6]},{"term_id":"GO:0060089","term_label":"molecular transducer activity","supporting_discovery_ids":[2]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[0,4]},{"term_id":"GO:0008092","term_label":"cytoskeletal protein binding","supporting_discovery_ids":[7,10]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[0,1]},{"term_id":"GO:0005856","term_label":"cytoskeleton","supporting_discovery_ids":[7,10]}],"pathway":[{"term_id":"R-HSA-112316","term_label":"Neuronal System","supporting_discovery_ids":[4,5,6]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[2]},{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[10]}],"complexes":["inhibitory postsynaptic density"],"partners":["GPHN","GABRA2","CDC42","IQGAP1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"O43307","full_name":"Rho guanine nucleotide exchange factor 9","aliases":["Collybistin","PEM-2 homolog","Rac/Cdc42 guanine nucleotide exchange factor 9"],"length_aa":516,"mass_kda":61.0,"function":"Acts as a guanine nucleotide exchange factor (GEF) for CDC42. Promotes formation of GPHN clusters (By similarity)","subcellular_location":"Cytoplasm; Postsynaptic density","url":"https://www.uniprot.org/uniprotkb/O43307/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/ARHGEF9","classification":"Not Classified","n_dependent_lines":1,"n_total_lines":1208,"dependency_fraction":0.0008278145695364238},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/ARHGEF9","total_profiled":1310},"omim":[{"mim_id":"613324","title":"SPERMATOGENESIS-ASSOCIATED PROTEIN 13; SPATA13","url":"https://www.omim.org/entry/613324"},{"mim_id":"613039","title":"CHROMODOMAIN HELICASE DNA-BINDING PROTEIN 1-LIKE; CHD1L","url":"https://www.omim.org/entry/613039"},{"mim_id":"605216","title":"RHO GUANINE NUCLEOTIDE EXCHANGE FACTOR 4; ARHGEF4","url":"https://www.omim.org/entry/605216"},{"mim_id":"308350","title":"DEVELOPMENTAL AND EPILEPTIC ENCEPHALOPATHY 1; DEE1","url":"https://www.omim.org/entry/308350"},{"mim_id":"300607","title":"DEVELOPMENTAL AND EPILEPTIC ENCEPHALOPATHY 8; DEE8","url":"https://www.omim.org/entry/300607"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Cytosol","reliability":"Supported"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in all","driving_tissues":[{"tissue":"brain","ntpm":68.4},{"tissue":"retina","ntpm":81.7}],"url":"https://www.proteinatlas.org/search/ARHGEF9"},"hgnc":{"alias_symbol":["KIAA0424","PEM-2"],"prev_symbol":[]},"alphafold":{"accession":"O43307","domains":[{"cath_id":"2.30.30.40","chopping":"10-63","consensus_level":"high","plddt":83.3983,"start":10,"end":63},{"cath_id":"1.20.900.10","chopping":"100-294","consensus_level":"high","plddt":94.5782,"start":100,"end":294},{"cath_id":"2.30.29.30","chopping":"311-450","consensus_level":"high","plddt":93.4884,"start":311,"end":450}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/O43307","model_url":"https://alphafold.ebi.ac.uk/files/AF-O43307-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-O43307-F1-predicted_aligned_error_v6.png","plddt_mean":80.12},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=ARHGEF9","jax_strain_url":"https://www.jax.org/strain/search?query=ARHGEF9"},"sequence":{"accession":"O43307","fasta_url":"https://rest.uniprot.org/uniprotkb/O43307.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/O43307/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/O43307"}},"corpus_meta":[{"pmid":"18615734","id":"PMC_18615734","title":"A balanced chromosomal translocation disrupting ARHGEF9 is associated with epilepsy, anxiety, aggression, and mental retardation.","date":"2009","source":"Human mutation","url":"https://pubmed.ncbi.nlm.nih.gov/18615734","citation_count":115,"is_preprint":false},{"pmid":"9441682","id":"PMC_9441682","title":"Posterior end mark 2 (pem-2), pem-4, pem-5, and pem-6: maternal genes with localized mRNA in the ascidian embryo.","date":"1997","source":"Developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/9441682","citation_count":72,"is_preprint":false},{"pmid":"17893116","id":"PMC_17893116","title":"ARHGEF9 disruption in a female patient is associated with X linked mental retardation and sensory hyperarousal.","date":"2007","source":"Journal of medical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/17893116","citation_count":57,"is_preprint":false},{"pmid":"29130122","id":"PMC_29130122","title":"ARHGEF9 mutations in epileptic encephalopathy/intellectual disability: toward understanding the mechanism underlying phenotypic variation.","date":"2017","source":"Neurogenetics","url":"https://pubmed.ncbi.nlm.nih.gov/29130122","citation_count":47,"is_preprint":false},{"pmid":"26633832","id":"PMC_26633832","title":"Inter-kingdom Signaling by the Legionella Quorum Sensing Molecule LAI-1 Modulates Cell Migration through an IQGAP1-Cdc42-ARHGEF9-Dependent Pathway.","date":"2015","source":"PLoS pathogens","url":"https://pubmed.ncbi.nlm.nih.gov/26633832","citation_count":42,"is_preprint":false},{"pmid":"28589176","id":"PMC_28589176","title":"ARHGEF9 disease: Phenotype clarification and genotype-phenotype correlation.","date":"2017","source":"Neurology. 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B, Biointerfaces","url":"https://pubmed.ncbi.nlm.nih.gov/37379702","citation_count":5,"is_preprint":false},{"pmid":"39374387","id":"PMC_39374387","title":"Impaired axon initial segment structure and function in a model of ARHGEF9 developmental and epileptic encephalopathy.","date":"2024","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/39374387","citation_count":4,"is_preprint":false},{"pmid":"21731583","id":"PMC_21731583","title":"ARHGEF9 disruption in a female patient is associated with X linked mental retardation and sensory hyperarousal.","date":"2009","source":"BMJ case reports","url":"https://pubmed.ncbi.nlm.nih.gov/21731583","citation_count":4,"is_preprint":false},{"pmid":"34851771","id":"PMC_34851771","title":"A novel de novo hemizygous ARHGEF9 mutation associated with severe intellectual disability and epilepsy: a case report.","date":"2021","source":"The Journal of international medical research","url":"https://pubmed.ncbi.nlm.nih.gov/34851771","citation_count":3,"is_preprint":false},{"pmid":"41174051","id":"PMC_41174051","title":"Autism-associated ARHGEF9 variants impair GABAergic synapses and ultrasonic communication by reducing gephyrin phosphorylation.","date":"2025","source":"Molecular psychiatry","url":"https://pubmed.ncbi.nlm.nih.gov/41174051","citation_count":2,"is_preprint":false},{"pmid":"33600053","id":"PMC_33600053","title":"Loss-of-function variants in ARHGEF9 are associated with an X-linked intellectual disability dominant disorder.","date":"2021","source":"Human mutation","url":"https://pubmed.ncbi.nlm.nih.gov/33600053","citation_count":2,"is_preprint":false},{"pmid":"36852158","id":"PMC_36852158","title":"Peptide ARHGEF9 Inhibits Glioma Progression via PI3K/AKT/mTOR Pathway.","date":"2023","source":"Disease markers","url":"https://pubmed.ncbi.nlm.nih.gov/36852158","citation_count":1,"is_preprint":false},{"pmid":"39992578","id":"PMC_39992578","title":"The influences of ARHGEF9 on myoblasts migration and differentiation.","date":"2025","source":"Journal of muscle research and cell motility","url":"https://pubmed.ncbi.nlm.nih.gov/39992578","citation_count":0,"is_preprint":false},{"pmid":"31907904","id":"PMC_31907904","title":"[Patients with ARHGEF9-mutation: a case report and implications of genetic disorders in child psychiatry].","date":"2019","source":"Tijdschrift voor psychiatrie","url":"https://pubmed.ncbi.nlm.nih.gov/31907904","citation_count":0,"is_preprint":false},{"pmid":"36184101","id":"PMC_36184101","title":"[Clinical analysis of early-onset infantile epileptic encephalopathy associated with synonymous variant of the ARHGEF9 gene].","date":"2022","source":"Zhonghua yi xue yi chuan xue za zhi = Zhonghua yixue yichuanxue zazhi = Chinese journal of medical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/36184101","citation_count":0,"is_preprint":false},{"pmid":"37593569","id":"PMC_37593569","title":"Retracted: Peptide ARHGEF9 Inhibits Glioma Progression via PI3K/AKT/mTOR Pathway.","date":"2023","source":"Disease markers","url":"https://pubmed.ncbi.nlm.nih.gov/37593569","citation_count":0,"is_preprint":false},{"pmid":"42216460","id":"PMC_42216460","title":"Developmental and Epileptic Encephalopathy Due to a Novel ARHGEF9 Deletion Variant: Case Series of Two Siblings.","date":"2026","source":"Revista de neurologia","url":"https://pubmed.ncbi.nlm.nih.gov/42216460","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":17554,"output_tokens":3518,"usd":0.052716,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":11121,"output_tokens":3839,"usd":0.07579,"stage2_stop_reason":"end_turn"},"total_usd":0.128506,"stage1_batch_id":"msgbatch_0179Z2pxRYBsXi2xADneafRw","stage2_batch_id":"msgbatch_01LaY9ZaVdgjWArcZo9eqQE5","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2009,\n      \"finding\": \"The pleckstrin homology (PH) domain of collybistin (ARHGEF9) binds phosphatidylinositol-3-phosphate (PI3P/PtdIns-3-P), not phosphatidylinositol 3,4,5-trisphosphate (PIP3) as previously suggested. Expression of truncated collybistin proteins lacking the PH domain in cultured neurons interferes with synaptic localization of endogenous gephyrin and GABA-A receptors, establishing a role for the PH domain in membrane trafficking of gephyrin and selected GABA-A receptor subtypes.\",\n      \"method\": \"Lipid-binding assay (PI3P vs PIP3 binding), expression of truncated collybistin in cultured neurons with immunocytochemical readout of gephyrin and GABA-A receptor localization\",\n      \"journal\": \"Human mutation\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Moderate — direct lipid-binding biochemical assay combined with neuronal expression experiment showing functional consequence on gephyrin/GABA-A receptor synaptic clustering\",\n      \"pmids\": [\"18615734\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"The missense mutation R338W in the PH domain of collybistin (ARHGEF9) disrupts PI3P binding and abolishes the ability of collybistin to translocate EGFP-gephyrin to submembrane microaggregates in an in vitro clustering assay. Molecular modeling indicates the R338W substitution causes steric clashes with adjacent residues (K363 and N335) and disrupts local PH domain folding.\",\n      \"method\": \"PI3P-binding assay with recombinant CB2SH3-(R338W), in vitro gephyrin clustering assay in transfected cells, molecular modeling\",\n      \"journal\": \"Frontiers in molecular neuroscience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Moderate — reconstituted lipid-binding assay plus functional clustering assay with mutant protein and structural modeling, single lab but multiple orthogonal methods\",\n      \"pmids\": [\"26834553\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"ARHGEF9 (as the Cdc42-specific GEF collybistin) functions downstream of IQGAP1 and Cdc42 in a signaling pathway that regulates eukaryotic cell migration. LAI-1-dependent inhibition of cell migration required ARHGEF9 but not other modulators of Cdc42, RhoA, Rac1, or Ran GTPase; depletion of ARHGEF9 phenocopied Cdc42 inactivation in this context.\",\n      \"method\": \"siRNA knockdown of ARHGEF9 and other GEFs/GTPases in migration assay, Cdc42 activity measurement, IQGAP1 localization by immunofluorescence\",\n      \"journal\": \"PLoS pathogens\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic/RNAi epistasis with defined cellular phenotype (migration index), multiple GEF/GTPase controls tested, single lab\",\n      \"pmids\": [\"26633832\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Two ARHGEF9 missense variants (p.I294T and p.R357I) disrupt collybistin-mediated accumulation of gephyrin in submembrane microclusters in vitro. A splicing variant (c.381+3A>G) produces aberrant transcripts leading to a truncated protein product.\",\n      \"method\": \"In vitro gephyrin clustering assay with transfected cells expressing missense variants; transcriptional/splicing analysis of the splice-site variant\",\n      \"journal\": \"Journal of molecular neuroscience\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional clustering assay with mutant proteins plus splicing analysis, single lab, two orthogonal approaches\",\n      \"pmids\": [\"31942680\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Collybistin (ARHGEF9) directly interacts with the α2 subunit of GABA-A receptors via a binding motif in its large intracellular loop; disruption of this interaction (Gabra2-1 knock-in mutation replacing the Cb-binding motif with the gephyrin-binding motif from α1) causes strong downregulation of Cb expression particularly at CCK basket cell inhibitory synapses. The Gabra2-1 mice phenocopy ARHGEF9 patient features including deficits in working/recognition memory, hyperactivity, anxiety, reduced social preference, spontaneous seizures, and EEG abnormalities including sleep disturbance.\",\n      \"method\": \"Knock-in mouse model (Gabra2-1), immunohistochemistry, electrophysiology, EEG, behavioral assays\",\n      \"journal\": \"Molecular psychiatry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic knock-in model with multiple orthogonal readouts (molecular, electrophysiological, behavioral, EEG), direct binding motif manipulation establishing mechanism\",\n      \"pmids\": [\"35169261\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"In a mouse model carrying a patient-derived ARHGEF9 variant associated with severe disease, collybistin (ARHGEF9) is required for proper organization of the postsynaptic density of inhibitory synapses at the axon initial segment (AIS). Loss of function causes aggregation of postsynaptic proteins, loss of functional inhibitory synapses at the AIS, altered axo-axonic synaptic inhibition, and disrupted action potential generation.\",\n      \"method\": \"Patient-derived variant knock-in mouse model, immunofluorescence of AIS postsynaptic protein aggregation, electrophysiology (axo-axonic inhibition, action potential recording), in vivo seizure monitoring\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — mouse model with patient-derived variant, multiple orthogonal methods (morphology, electrophysiology, seizure phenotype) establishing AIS-specific mechanistic role\",\n      \"pmids\": [\"39374387\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"ASD-associated ARHGEF9 variant p.R290C promotes abnormal gephyrin clustering in COS-7 cells and reduces inhibitory synapse density in cultured hippocampal neurons. Variants p.V374F and p.G485S (with p.R290C) induce defective inhibitory synaptic transmission; p.G485S specifically decreases PI3P-binding activity. Conditional knockout of collybistin in medial prefrontal cortex (mPFC) reduces gephyrin phosphorylation levels and impairs ultrasonic vocalization; ASD-associated ARHGEF9 variants fail to rescue impaired GABAergic transmission and reduced gephyrin phosphorylation in mPFC-specific Cb-cKO mice.\",\n      \"method\": \"Transfection of variants in COS-7 cells (gephyrin clustering assay), primary hippocampal neuron culture (synapse density), whole-cell patch-clamp electrophysiology, PI3P-binding assay, mPFC-specific conditional knockout mouse, proteomics (phosphorylation), ultrasonic vocalization behavioral assay\",\n      \"journal\": \"Molecular psychiatry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — multiple orthogonal methods across in vitro and in vivo systems, direct lipid-binding assay, proteomics, electrophysiology, and behavioral readouts in single study\",\n      \"pmids\": [\"41174051\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"ARHGEF9/Collybistin is required for melanoma cell shape determination on both soft and stiff substrates and in 3D matrices. Depletion of ARHGEF9 results in loss of tension at focal adhesions, decreased cell-wide contractility, inability to stabilize protrusions, and loss of actin-rich filopodia that normally establish and stabilize adhesions.\",\n      \"method\": \"Genetic screens with single-cell quantitative morphological analysis, siRNA depletion, traction force microscopy (focal adhesion tension), 3D invasion assay, fluorescence imaging of actin/filopodia\",\n      \"journal\": \"iScience\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic screen followed by mechanistic validation with multiple morphological and biophysical readouts, single lab\",\n      \"pmids\": [\"36039362\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"In the EAE mouse model of multiple sclerosis, inflammation induces region-specific alternative splicing of Arhgef9 (increased inclusion of alternative exon 11a selectively in CA3 and dentate gyrus), coinciding with downregulation of the splicing factor Sam68 that normally represses this splicing event.\",\n      \"method\": \"Laser microdissection of hippocampal subfields, RT-PCR for exon 11a inclusion, immunohistochemistry for Sam68 and parvalbumin in EAE vs. control mice\",\n      \"journal\": \"Frontiers in molecular neuroscience\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct measurement of alternative splicing with regional dissection and correlation with Sam68 levels, single lab, mechanistically informative but correlational for Sam68-Arhgef9 link\",\n      \"pmids\": [\"36710925\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"ARHGEF9 protein exhibits tissue-dependent and developmental stage-dependent expression in mouse brain (cerebral cortex, hippocampus, cerebellum), and shows partial localization at dendritic spines in cultured hippocampal neurons.\",\n      \"method\": \"Western blotting across mouse tissues, immunohistochemistry at multiple developmental stages, immunofluorescence in cultured hippocampal neurons with validated polyclonal antibody\",\n      \"journal\": \"Acta histochemica et cytochemica\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — direct localization by immunofluorescence and IHC with validated antibody, multiple brain regions and developmental stages, but no functional consequence linked to localization\",\n      \"pmids\": [\"30083020\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"ARHGEF9 expression increases significantly during skeletal muscle regeneration after injury in mice and co-localizes with actin filaments during C2C12 myoblast differentiation. Inhibition of ARHGEF9 reduces myoblast migration rate, actin filament polymerization, expression of migration-related proteins, and differentiation capacity of C2C12 myoblasts.\",\n      \"method\": \"Mouse muscle injury model (ARHGEF9 protein expression by Western blot), C2C12 myoblast differentiation assay, siRNA/inhibitor-based knockdown, migration assay, phalloidin staining for actin filaments, Western blot for migration/differentiation markers\",\n      \"journal\": \"Journal of muscle research and cell motility\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — loss-of-function with defined cellular phenotypes (migration, actin polymerization, differentiation) in muscle context, single lab\",\n      \"pmids\": [\"39992578\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"A synonymous ARHGEF9 variant (c.741C>T, p.Cys247Cys) causes abnormal splicing of exon 5 resulting in a 55-bp deletion, demonstrating that synonymous variants in ARHGEF9 can produce loss-of-function via splicing disruption.\",\n      \"method\": \"RNA splicing analysis (RT-PCR) on patient-derived sample confirming aberrant transcript and 55-bp exon 5 deletion\",\n      \"journal\": \"Chinese journal of medical genetics\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single patient RNA splicing analysis, no functional reconstitution or cell-based mechanistic assay\",\n      \"pmids\": [\"36184101\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"ARHGEF9 encodes collybistin (Cb), a neuronal Cdc42-specific guanine nucleotide exchange factor that acts as a key organizer of inhibitory postsynaptic densities: its DH domain mediates GEF activity toward Cdc42, its SH3 domain interacts with neuroligin-2, and its PH domain binds PI3P to drive membrane targeting, collectively enabling the submembrane clustering of gephyrin and GABA-A/glycine receptors; loss of Cb function disrupts inhibitory synapses at the axon initial segment, reduces gephyrin phosphorylation, impairs GABAergic transmission, and produces epilepsy, intellectual disability, and behavioral abnormalities in mice and humans, while in non-neuronal contexts Cb regulates actin-driven cell migration and morphology via Cdc42 signaling.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"ARHGEF9 encodes collybistin, a neuronal Cdc42-specific guanine nucleotide exchange factor that organizes inhibitory postsynaptic densities by driving submembrane clustering of gephyrin and GABA-A receptors [#0, #4]. Membrane targeting depends on the PH domain, which binds phosphatidylinositol-3-phosphate (PI3P) rather than PIP3, and PH-domain truncation or PI3P-binding-disrupting mutations abolishes collybistin-mediated translocation of gephyrin and GABA-A receptors to submembrane microaggregates [#0, #1]. Collybistin directly binds the α2 subunit of GABA-A receptors through a motif in its large intracellular loop, an interaction required to maintain its expression at specific inhibitory synapses [#4]. Loss of collybistin function disorganizes inhibitory postsynaptic densities at the axon initial segment, causes aggregation of postsynaptic proteins, reduces gephyrin phosphorylation, and impairs GABAergic transmission, producing seizures, memory and social deficits, and behavioral abnormalities in mouse models that phenocopy ARHGEF9 patient features [#4, #5, #6]. Multiple patient- and ASD-associated missense, synonymous, and splice-site variants act through these mechanisms—disrupting gephyrin clustering, PI3P binding, or producing truncated transcripts—establishing ARHGEF9 dysfunction as a cause of epilepsy, intellectual disability, and autism-spectrum phenotypes [#1, #3, #6]. Outside neurons, collybistin functions downstream of IQGAP1 and Cdc42 to control actin-driven cell migration, focal-adhesion tension, filopodia stabilization, and myoblast differentiation [#2, #7, #10].\",\n  \"teleology\": [\n    {\n      \"year\": 2009,\n      \"claim\": \"Established the lipid specificity and membrane-trafficking function of collybistin's PH domain, redefining how it targets gephyrin to synapses.\",\n      \"evidence\": \"Lipid-binding assay (PI3P vs PIP3) plus expression of PH-domain-truncated collybistin in cultured neurons with gephyrin/GABA-A readout\",\n      \"pmids\": [\"18615734\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not resolve how PI3P generation is regulated at the synapse\", \"No structural detail of the PH-lipid interface\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Placed collybistin in a non-neuronal IQGAP1-Cdc42 signaling axis controlling cell migration, showing its GEF role extends beyond synapse assembly.\",\n      \"evidence\": \"siRNA epistasis against multiple GEFs/GTPases with migration assay and Cdc42 activity measurement\",\n      \"pmids\": [\"26633832\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct biochemical link between collybistin and IQGAP1 not shown\", \"Whether GEF catalytic activity is required not isolated\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Demonstrated that a disease-associated PH-domain mutation acts by abolishing PI3P binding and gephyrin clustering, providing a structural mechanism for pathogenicity.\",\n      \"evidence\": \"PI3P-binding assay with recombinant mutant, in vitro gephyrin clustering assay, and molecular modeling of R338W\",\n      \"pmids\": [\"26834553\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Modeling not validated by experimental structure\", \"In vivo consequence of R338W not tested\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Characterized the spatial and developmental expression of collybistin in brain, supporting a synaptic localization consistent with its postsynaptic role.\",\n      \"evidence\": \"Western blot across tissues, IHC across developmental stages, immunofluorescence in cultured hippocampal neurons\",\n      \"pmids\": [\"30083020\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No functional consequence tied to the observed localization\", \"Dendritic spine localization only partial\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Extended the variant-to-mechanism link by showing additional patient missense and splice variants impair gephyrin clustering or produce truncated protein.\",\n      \"evidence\": \"In vitro gephyrin clustering assay with missense variants and splicing analysis of a splice-site variant\",\n      \"pmids\": [\"31942680\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No in vivo modeling of these specific variants\", \"Mechanism of clustering disruption for I294T/R357I not resolved\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Identified a direct collybistin-GABA-A receptor α2 interaction and showed its disruption causes synapse-specific collybistin downregulation and a patient-like phenotype in mice.\",\n      \"evidence\": \"Gabra2-1 knock-in mouse, IHC, electrophysiology, EEG, and behavioral assays\",\n      \"pmids\": [\"35169261\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Binding motif mapped genetically, not by structure\", \"Why CCK basket cell synapses are selectively affected unclear\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Defined a cell-biological role for collybistin in actin-based mechanics, linking it to focal-adhesion tension, contractility, and filopodia stabilization in melanoma cells.\",\n      \"evidence\": \"Genetic morphological screen, siRNA depletion, traction force microscopy, 3D invasion assay, actin imaging\",\n      \"pmids\": [\"36039362\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether Cdc42 GEF activity mediates these effects not directly tested\", \"Direct cytoskeletal partners not identified\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Showed that even a synonymous ARHGEF9 variant can cause loss of function through aberrant splicing, broadening the pathogenic variant spectrum.\",\n      \"evidence\": \"RT-PCR splicing analysis of a single patient-derived sample\",\n      \"pmids\": [\"36184101\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Single patient with no functional reconstitution\", \"Protein-level consequence not directly assessed\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Linked inflammatory neuropathology to region-specific Arhgef9 alternative splicing under Sam68 control, implicating splicing regulation in collybistin function.\",\n      \"evidence\": \"Laser microdissection, RT-PCR for exon 11a inclusion, IHC for Sam68 in EAE vs control mice\",\n      \"pmids\": [\"36710925\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Sam68-Arhgef9 regulatory link is correlational\", \"Functional impact of exon 11a inclusion on protein activity unknown\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Localized collybistin's critical role to the axon initial segment, showing loss of function disorganizes axo-axonic inhibitory synapses and disrupts action potential generation.\",\n      \"evidence\": \"Patient-derived variant knock-in mouse, AIS immunofluorescence, electrophysiology, in vivo seizure monitoring\",\n      \"pmids\": [\"39374387\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular trigger for protein aggregation at AIS not resolved\", \"Whether AIS defect alone accounts for seizures unclear\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Integrated ASD-associated variants with mPFC-specific collybistin function, tying loss of function to reduced gephyrin phosphorylation, impaired GABAergic transmission, and altered vocalization.\",\n      \"evidence\": \"COS-7 clustering and PI3P-binding assays, hippocampal neuron synapse density, patch-clamp, mPFC conditional knockout, phosphoproteomics, ultrasonic vocalization assay\",\n      \"pmids\": [\"41174051\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Kinase responsible for gephyrin phosphorylation not identified\", \"How distinct variants converge on the same phenotype not mechanistically separated\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Demonstrated a role for collybistin in skeletal muscle regeneration via actin-dependent myoblast migration and differentiation, extending its cytoskeletal function to a new tissue.\",\n      \"evidence\": \"Mouse muscle injury model, C2C12 differentiation and migration assays, knockdown, phalloidin staining, marker Western blots\",\n      \"pmids\": [\"39992578\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Cdc42/GEF dependence in muscle not demonstrated\", \"Direct interaction partners in myoblasts not identified\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How collybistin's catalytic GEF activity, PI3P-dependent membrane targeting, and receptor/gephyrin scaffolding are coordinated and regulated to assemble synapse-specific inhibitory densities remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No high-resolution structure of full-length collybistin or its receptor complexes\", \"Kinases/phosphatases controlling gephyrin phosphorylation downstream of collybistin not defined\", \"Mechanism selecting specific inhibitory synapse subtypes unclear\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [2]},\n      {\"term_id\": \"GO:0008289\", \"supporting_discovery_ids\": [0, 1, 6]},\n      {\"term_id\": \"GO:0060089\", \"supporting_discovery_ids\": [2]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [0, 4]},\n      {\"term_id\": \"GO:0008092\", \"supporting_discovery_ids\": [7, 10]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [0, 1]},\n      {\"term_id\": \"GO:0005856\", \"supporting_discovery_ids\": [7, 10]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-112316\", \"supporting_discovery_ids\": [4, 5, 6]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [2]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [10]}\n    ],\n    \"complexes\": [\"inhibitory postsynaptic density\"],\n    \"partners\": [\"GPHN\", \"GABRA2\", \"CDC42\", \"IQGAP1\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":6,"faith_pct":100.0}}