{"gene":"CNTNAP2","run_date":"2026-06-09T22:57:18","timeline":{"discoveries":[{"year":2003,"finding":"Caspr2's conserved intracellular juxtamembrane GNP motif binds proteins 4.1R and 4.1B; 4.1B co-immunoprecipitates with Caspr2 from brain homogenates and colocalizes with Caspr2 at juxtaparanodal regions of myelinated axons, linking Caspr2 to the actin-based cytoskeleton.","method":"Co-immunoprecipitation from brain homogenates, pull-down binding assays, immunostaining of developing CNS and PNS","journal":"The European journal of neuroscience","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP from brain tissue plus direct binding assay and developmental colocalization, replicated in multiple myelinated fiber preparations","pmids":["12542678"],"is_preprint":false},{"year":2009,"finding":"Caspr2 is targeted to the axonal surface through PKC-dependent, dynamin-mediated endocytosis from the somatodendritic compartment. A short sequence within the 4.1B-binding domain containing a PKC substrate motif (Thr1292) is required; point mutation of Thr1292 or PKC inhibition prevents somatodendritic internalization, establishing polarized axonal expression.","method":"HA-tagged Caspr2 constructs in hippocampal neurons, dominant-negative Dynamin-1, Dynasore treatment, PKC inhibitor, site-directed mutagenesis (T1292A)","journal":"Journal of cell science","confidence":"High","confidence_rationale":"Tier 1 / Moderate — mutagenesis of specific residue combined with pharmacological inhibition and dominant-negative approach in neuronal culture, single lab but multiple orthogonal methods","pmids":["19706678"],"is_preprint":false},{"year":2010,"finding":"Interaction of Caspr2 with protein 4.1B (via 4.1-binding sequence) is required for accumulation of Caspr2 and Kv1 channels at the juxtaparanodal region; transgenic Caspr2 lacking the 4.1-binding domain fails to cluster at juxtaparanodes, and Caspr2 and Kv1 channels are absent from juxtaparanodes in 4.1B-null mice.","method":"Transgenic rescue of Caspr2-null mice with Caspr2-d4.1 mutant, 4.1B knockout mice, immunofluorescence","journal":"The Journal of neuroscience","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vivo mutagenesis rescue experiment combined with knockout validation, clear mechanistic assignment","pmids":["20164332"],"is_preprint":false},{"year":2011,"finding":"Cntnap2 knockout mice display neuronal migration abnormalities, reduced number of interneurons, and abnormal neuronal network activity before seizure onset, demonstrating CNTNAP2 is required for normal cortical interneuron placement and brain network development.","method":"Cntnap2 constitutive knockout mouse model, neuropathological analysis, electrophysiology, behavioral testing","journal":"Cell","confidence":"High","confidence_rationale":"Tier 2 / Strong — defined cellular phenotypes in constitutive KO with multiple orthogonal readouts (histology, physiology, behavior), widely replicated landmark study","pmids":["21962519"],"is_preprint":false},{"year":2012,"finding":"Caspr2 autoantibodies from patients with encephalitis and peripheral nerve hyperexcitability target Caspr2 protein; immunoabsorption with Caspr2 abolishes reactivity, and antibodies are absent in tissues from Caspr2-null mice, confirming Caspr2 as the pathological autoantigen.","method":"Immunoprecipitation and mass spectrometry antigen identification, cell-based assay with Caspr2-expressing cells, immunoabsorption, comparative immunostaining of wild-type vs. Caspr2-null mouse tissues","journal":"Annals of neurology","confidence":"High","confidence_rationale":"Tier 1 / Strong — mass spectrometry antigen identification plus orthogonal confirmation with null-mouse tissues and immunoabsorption","pmids":["21387375"],"is_preprint":false},{"year":2012,"finding":"CNTNAP2 is a direct transcriptional target of FOXP2; FOXP2 binds the CNTNAP2 promoter and regulates its expression, placing CNTNAP2 downstream of FOXP2 in a language-related gene-regulatory pathway.","method":"Lentiviral FoxP2 knockdown in zebra finch Area X (in vivo), luciferase promoter assays (in vitro), quantitative RT-PCR showing reduced CNTNAP2 expression upon FoxP2 knockdown","journal":"Genes, brain, and behavior","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo knockdown plus in vitro promoter binding, single lab, avian ortholog but consistent with mammalian FOXP2-CNTNAP2 axis","pmids":["28488276"],"is_preprint":false},{"year":2012,"finding":"Several autism-associated CNTNAP2 missense mutations (e.g., D1129H) cause retention of CASPR2 in the endoplasmic reticulum, activate ER chaperones (BiP/Grp78, Calnexin, ERp57) and the ATF6 branch of the unfolded protein response, and promote proteasomal degradation; a frameshift mutation (1253*) produces a secreted soluble protein, losing membrane-tethered function.","method":"Immunofluorescence confocal microscopy, biochemical fractionation, Western blot in HEK-293 cells and hippocampal neurons","journal":"Human molecular genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple mutants examined with orthogonal imaging and biochemistry, single lab","pmids":["22872700"],"is_preprint":false},{"year":2014,"finding":"Both Caspr and Caspr2 are required for the organization of the axolemma at the mesaxonal internodal line: in single mutants Kv1 channels cluster along the inner mesaxon and below Schmidt-Lanterman incisures, but in Caspr/Caspr2 double knockout mice these channels form dispersed aggregates, revealing compensatory roles. Double deletion also widens nodes of Ranvier.","method":"Caspr/Caspr2 double-knockout mouse generation, immunofluorescence, electron microscopy","journal":"The Journal of neuroscience","confidence":"High","confidence_rationale":"Tier 1 / Strong — genetic epistasis via double knockout with electron microscopy and immunofluorescence, rigorous mechanistic assignment of compensatory functions","pmids":["25378149"],"is_preprint":false},{"year":2015,"finding":"CNTNAP2 is present in dendritic spines and is required for normal spine density and synaptic localization of GluA1 AMPA receptor subunits; Cntnap2 knockout neurons show reduced spine density, reduced spine GluA1 levels, and large cytoplasmic GluA1 aggregates, indicating a role for CNTNAP2 in GluA1 trafficking.","method":"Structured illumination super-resolution microscopy, immunofluorescence, Western blot in Cntnap2 KO cultured neurons and brain slices","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 2 / Moderate — super-resolution imaging plus biochemistry in KO neurons, clear trafficking phenotype with multiple readouts","pmids":["25918374"],"is_preprint":false},{"year":2015,"finding":"New dendritic spines in Cntnap2 knockout mice form at normal rates but fail to stabilize in vivo, indicating a specific role for CNTNAP2 in new spine stabilization rather than spine formation or elimination.","method":"In vivo two-photon microscopy for longitudinal spine imaging in Cntnap2 KO mice","journal":"PloS one","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — direct in vivo spine imaging with clear phenotype, single lab, single method","pmids":["25951243"],"is_preprint":false},{"year":2015,"finding":"Interaction proteomics of Caspr2 identifies its binding partners including CNTN2 (TAG-1), Kv1 channel subunits (KCNAs), ADAM family members (ADAM22, ADAM23, ADAM11), LGI family proteins, and MAGUKs (DLGs, MPPs). Caspr2 is enriched in lipid rafts and synaptic membranes but depleted from the postsynaptic density. A short isoform lacking most extracellular domains still associates with ADAM22, LGI1, and Kv1.","method":"Affinity purification-mass spectrometry (interaction proteomics), subcellular fractionation, Western blot","journal":"Biochimica et biophysica acta","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — mass spectrometry interactome with biochemical fractionation, single lab","pmids":["25707359"],"is_preprint":false},{"year":2015,"finding":"Cntnap2 is expressed throughout all primary sensory organs and multiple sensory brain regions; Cntnap2 knockout mice exhibit abnormal olfactory responses and lack novelty preference, linking Caspr2 expression in sensory circuits to sensory behavior.","method":"Caspr2:tau-LacZ knock-in reporter line, X-gal staining for circuit mapping, olfaction-based behavioral tests","journal":"Molecular and cellular neurosciences","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic reporter plus knockout behavioral phenotype, single lab","pmids":["26647347"],"is_preprint":false},{"year":2016,"finding":"Electron microscopy reveals that CNTNAP2 has a three-lobed architecture (large, medium, small lobes) distinct from neurexin-1α; domain assignment places F58C, L1, L2 in the large lobe, FBG and L3 in the middle lobe, and L4 in the small lobe. CNTNAP2 and CNTN2 ectodomains bind directly with low nanomolar affinity.","method":"Electron microscopy with epitope labeling, domain-deletion fragment binding assays, solid-phase binding assay","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Moderate — electron microscopy structure with domain mapping and quantitative binding assay, single lab but multiple orthogonal methods","pmids":["27621318"],"is_preprint":false},{"year":2016,"finding":"4.1B is required for the proper targeting of Caspr2 to juxtaparanodes early during myelination; in 4.1B KO DRG-Schwann cell myelinating cultures, Caspr2 fails to target correctly while paranodal junctions (stability of Caspr at paranodes) are unaffected.","method":"Myelinating DRG neuron-Schwann cell co-cultures from 4.1B KO mice, adenoviral Caspr-GFP, FRAP","journal":"Glia","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vitro myelination model with KO validation and live imaging, single lab","pmids":["26840208"],"is_preprint":false},{"year":2018,"finding":"CNTNAP2 stabilizes interneuron dendritic arbors through direct interaction of its C-terminus with CASK; yeast two-hybrid screening, proximity ligation assay, and super-resolution microscopy (SIM/STED) demonstrate CNTNAP2-CASK interaction at the membrane. Loss of Cntnap2 causes interneuron-specific dendritic simplification (not excitatory neuron), reduced cortical membrane CASK, and this phenotype is rescued by CASK expression.","method":"Yeast two-hybrid, biochemical co-IP, proximity ligation assay, SIM and STED super-resolution microscopy, shRNA knockdown, phenotype rescue","journal":"Molecular psychiatry","confidence":"High","confidence_rationale":"Tier 1 / Strong — yeast two-hybrid plus PLA plus super-resolution imaging plus rescue, multiple orthogonal methods in single study","pmids":["29610457"],"is_preprint":false},{"year":2018,"finding":"Either immune-mediated (patient autoantibody passive transfer) or genetic (Cntnap2-/-) ablation of CASPR2 enhances excitability of dorsal root ganglion neurons in a cell-autonomous manner through downregulation of Kv1 channel expression at the soma membrane, causing pain hypersensitivity. Human CASPR2 autoantibodies are peripherally restricted when injected into mice.","method":"Passive transfer of human autoantibodies into mice, Cntnap2 KO mice, DRG neuron electrophysiology, Kv1 immunostaining and Western blot","journal":"Neuron","confidence":"High","confidence_rationale":"Tier 1 / Strong — passive transfer model plus genetic KO with cell-autonomous electrophysiology and molecular mechanism (Kv1 regulation), two orthogonal genetic/immune approaches","pmids":["29429934"],"is_preprint":false},{"year":2018,"finding":"Caspr2 autoantibodies inhibit the interaction of Caspr2 with contactin-2 (nanomolar affinity interaction confirmed by solid-phase assay) but do not cause internalization of surface Caspr2 from primary hippocampal neurons or HEK cells.","method":"Solid-phase binding assay quantifying Caspr2-contactin-2 interaction, cell-surface biotinylation and Western blot of HEK cells, living neuron immunofluorescence","journal":"Annals of neurology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — quantitative binding assay plus surface biotinylation in two cell systems, single lab; negative result (no internalization) explicitly confirmed","pmids":["29244234"],"is_preprint":false},{"year":2018,"finding":"Human ASD-associated CNTNAP2 missense variants (e.g., I869T, G731S) impair Contactin2/TAG-1 binding and fail to rescue axonal growth deficits in Cntnap2 heterozygous cortical neurons; variant R1119H is retained in ER and exerts a dominant-negative effect on axon growth via oligomerization with wild-type Caspr2. Loss of one Cntnap2 allele is sufficient to reduce axon growth in a dose-dependent manner.","method":"Cortical neuron cultures from mouse embryos, axon growth measurements, co-immunoprecipitation for oligomerization, binding assays for Contactin2, immunofluorescence for ER retention","journal":"Human molecular genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple variant analyses with binding assay and dominant-negative co-IP, single lab","pmids":["29788201"],"is_preprint":false},{"year":2018,"finding":"Mouse and human ASD CNTNAP2 missense mutations cell-autonomously impair the physiology of parvalbumin-positive (PV+) fast-spiking cortical interneurons in a transplantation assay; Cntnap2 null constitutive mutants have reduced PV+ CINs but normal total MGE-derived CIN numbers. Somatostatin+ CINs show no phenotype.","method":"MGE cell transplantation assay (cell-autonomous testing), constitutive Cntnap2 null mice, whole-cell patch clamp, immunofluorescence","journal":"Cerebral cortex","confidence":"High","confidence_rationale":"Tier 1 / Strong — cell transplantation assay directly tests cell autonomy, combined with in vivo knockout and electrophysiology, multiple ASD variant alleles tested","pmids":["29028946"],"is_preprint":false},{"year":2019,"finding":"CNTNAP2 loss causes dramatic reduction in excitatory and inhibitory synaptic inputs onto L2/3 pyramidal neurons of medial prefrontal cortex, along with reduced spines and synapses despite normal dendritic complexity and intrinsic excitability; in vivo mPFC recordings show increased inhibitory neuron activity and disrupted phase-locking to delta/theta oscillations.","method":"Laser-scanning photostimulation, whole-cell recordings, electron microscopy, in vivo LFP and unit recording in Cntnap2 KO mice","journal":"Cell reports","confidence":"High","confidence_rationale":"Tier 1 / Strong — multiple orthogonal methods (EM, in vitro and in vivo electrophysiology, photostimulation) in single study with clear mechanistic circuit phenotype","pmids":["31141683"],"is_preprint":false},{"year":2019,"finding":"Caspr2 loss of function (genetic knockdown or knockout) decreases synaptic AMPA receptor expression and amplitude of AMPA receptor-mediated currents in cortex, blocks synaptic scaling in vitro, and impairs experience-dependent homeostatic synaptic plasticity in vivo; patient CASPR2 antibodies decrease dendritic Caspr2 levels and synaptic AMPA receptor trafficking.","method":"In vitro shRNA knockdown, Cntnap2 KO, in vivo visual cortex monocular deprivation, whole-cell recordings, immunofluorescence; patient antibody application to neurons","journal":"Cerebral cortex","confidence":"High","confidence_rationale":"Tier 1 / Strong — genetic and antibody-mediated loss of function with electrophysiology and in vivo homeostatic plasticity assay, multiple orthogonal methods","pmids":["30843029"],"is_preprint":false},{"year":2019,"finding":"CNTNAP2, CASK, and GluA1 form a tripartite complex in interneurons (confirmed by SIM super-resolution microscopy and biochemical co-IP in mouse brain); individual knockdown of either CNTNAP2 or CASK similarly alters GluA1 levels and localization in interneurons.","method":"Co-immunoprecipitation from mouse brain, structured illumination microscopy, shRNA knockdown","journal":"Neuroscience letters","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal biochemistry plus super-resolution colocalization plus functional knockdown, single lab","pmids":["30779956"],"is_preprint":false},{"year":2019,"finding":"Hyperactive Akt-mTOR signaling is present in the hippocampus and DRG of Cntnap2-/- mice; pharmacological inhibition with Akt inhibitor (LY294002) or mTOR inhibitor (rapamycin) rescues social deficits and pain hypersensitivity, and reduces DRG neuronal hyperexcitability.","method":"RNA sequencing followed by biochemical validation (Western blot for phospho-Akt/mTOR), pharmacological rescue in Cntnap2 KO mice, patch-clamp electrophysiology of DRG neurons","journal":"Scientific reports / Neuropharmacology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — RNA-seq plus biochemical validation plus pharmacological rescue with electrophysiology, single lab across two papers","pmids":["30816216","31874168"],"is_preprint":false},{"year":2019,"finding":"Anti-CASPR2 patient antibodies alter Caspr2 distribution at the cell membrane (promoting cluster formation), impede CASPR2/TAG-1 interaction, and introduction of Caspr2 into HEK cells induces increased Kv1.2 surface expression; patient antibodies increase Kv1.2 expression in both HEK and hippocampal neuron models.","method":"Cell-based assays (HEK cells expressing Caspr2), primary hippocampal neuron cultures, immunofluorescence, domain-deletion constructs identifying CASPR2-TAG1 interaction domains","journal":"Journal of autoimmunity","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple cell systems with domain mapping, single lab","pmids":["31176559"],"is_preprint":false},{"year":2022,"finding":"Patient IgG infused into mouse cerebroventricular system causes reversible memory impairment, reduces surface CASPR2 clusters, decreases CASPR2/TAG-1 colocalization (super-resolution STED), selectively internalizes CASPR2 (not TAG-1) in cultured neurons, and decreases hippocampal Kv1.1 and GluA1 levels; all effects reverse upon IgG removal.","method":"Intracerebroventricular IgG infusion in mice, STED super-resolution microscopy, confocal quantification of Kv1.1 and GluA1, behavioral memory testing, cultured neuron internalization assay","journal":"Annals of neurology","confidence":"High","confidence_rationale":"Tier 1 / Strong — passive transfer model with STED imaging, behavioral readout, molecular endpoint quantification, and reversibility control — multiple orthogonal approaches in single study","pmids":["35253937"],"is_preprint":false},{"year":2023,"finding":"CNTNAP2 is cleaved by γ-secretase to produce a CNTNAP2 intracellular domain (CICD); viral delivery of CICD to the medial prefrontal cortex of Cntnap2-/- mice rescues social and repetitive behavior deficits. CICD promotes nuclear translocation of CASK to regulate transcription of Necdin; Necdin deficiency reduces social interaction, and Necdin viral expression in mPFC rescues social preference in Cntnap2-/- mice.","method":"Biochemical γ-secretase cleavage assay, viral delivery of CICD/Necdin, behavioral rescue in Cntnap2 KO mice, nuclear fractionation showing CASK translocation","journal":"Signal transduction and targeted therapy","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — biochemical cleavage identification plus in vivo viral rescue with downstream pathway (CASK nuclear translocation, Necdin transcription), single lab","pmids":["37271769"],"is_preprint":false},{"year":2024,"finding":"CNTNAP2 undergoes sequential proteolytic processing: furin cleavage, then ADAM10/17-dependent α-secretase cleavage at residues I79 (ADAM10) and L96 (ADAM17) generating fragment C79, which is required for subsequent γ-secretase cleavage to produce CICD. ASD-associated CNTNAP2 mutations impair α-cleavage; inhibiting α-cleavage in Cntnap2-I1254T knock-in mice produces autism-like social and repetitive behaviors. Exogenous C79 rescues these phenotypes in both knock-in and knockout mice.","method":"In vitro cleavage assays with ADAM10/17, γ-secretase inhibitors, mass spectrometry of cleavage sites, Cntnap2-I1254T knock-in mouse generation, behavioral phenotyping, viral C79 delivery","journal":"Signal transduction and targeted therapy","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro biochemical cleavage mapping with site identification plus two in vivo mouse models (KI and KO) with rescue, multiple orthogonal approaches","pmids":["38424048"],"is_preprint":false}],"current_model":"CNTNAP2 encodes Caspr2, a large multidomain neurexin-superfamily transmembrane cell adhesion molecule that undergoes sequential proteolytic processing (furin → ADAM10/17 α-secretase → γ-secretase) to generate a bioactive intracellular domain (CICD) that translocates to the nucleus via CASK to regulate transcription; at the membrane, Caspr2 clusters Kv1 potassium channels at juxtaparanodes of myelinated axons through direct binding to TAG-1/contactin-2 and anchoring to the actin cytoskeleton via protein 4.1B (requiring PKC-dependent somatodendritic endocytosis for axonal polarization); at excitatory and inhibitory synapses it regulates GluA1 AMPA receptor trafficking and homeostatic synaptic plasticity through a tripartite complex with CASK, stabilizes new dendritic spines and interneuron dendritic arbors through CASK interaction, and controls PV+ cortical interneuron physiology in a cell-autonomous manner, with loss of function causing hyperactive Akt-mTOR signaling, reduced prefrontal synaptic connectivity, disrupted cortical oscillations, and pain hypersensitivity via Kv1 downregulation in DRG neurons."},"narrative":{"mechanistic_narrative":"CNTNAP2 encodes Caspr2, a neurexin-superfamily transmembrane cell adhesion molecule that organizes the axonal membrane and regulates cortical circuit development and synaptic function [PMID:21962519, PMID:25378149]. At myelinated axons, Caspr2 clusters Kv1 potassium channels at juxtaparanodes by binding contactin-2/TAG-1 (CNTN2) through its ectodomain with low-nanomolar affinity [PMID:27621318, PMID:29244234] and by anchoring to the actin cytoskeleton via its intracellular GNP motif binding to protein 4.1B [PMID:12542678, PMID:20164332]; this juxtaparanodal targeting requires 4.1B early in myelination and PKC-dependent somatodendritic endocytosis (via Thr1292) to achieve polarized axonal expression [PMID:19706678, PMID:26840208]. Caspr2 and the related Caspr act compensatorily to organize the internodal axolemma and node geometry [PMID:25378149]. At synapses, Caspr2 localizes to dendritic spines and stabilizes newly formed spines, controls GluA1 AMPA-receptor trafficking, and mediates homeostatic synaptic scaling, acting through a tripartite Caspr2–CASK–GluA1 complex [PMID:25918374, PMID:25951243, PMID:30843029, PMID:30779956]; through direct C-terminal binding to CASK it also stabilizes interneuron dendritic arbors [PMID:29610457]. Cntnap2 loss reduces cortical interneurons, disrupts neuronal migration and network activity, cell-autonomously impairs parvalbumin-positive fast-spiking interneurons, and reduces prefrontal synaptic connectivity with disrupted oscillatory phase-locking [PMID:21962519, PMID:29028946, PMID:31141683]. Caspr2 is sequentially processed by furin, ADAM10/17 α-secretase, and γ-secretase to liberate an intracellular domain (CICD) that drives CASK nuclear translocation to regulate Necdin transcription, and exogenous cleavage fragments rescue social and repetitive behaviors in mutant mice [PMID:37271769, PMID:38424048]. CNTNAP2 lies downstream of FOXP2 in a language-related gene-regulatory pathway [PMID:28488276], and its loss causes hyperactive Akt-mTOR signaling whose pharmacological inhibition rescues social and pain phenotypes [PMID:30816216, PMID:31874168]. Caspr2 is the pathological autoantigen in autoimmune encephalitis and peripheral nerve hyperexcitability, where patient antibodies impair the Caspr2–TAG-1 interaction, alter Kv1 and GluA1 levels, and cause reversible memory impairment and pain hypersensitivity via Kv1 downregulation in DRG neurons [PMID:21387375, PMID:29429934, PMID:35253937].","teleology":[{"year":2003,"claim":"Established how Caspr2 is physically linked to the cytoskeleton, identifying the intracellular GNP motif as the binding site for protein 4.1B at juxtaparanodes.","evidence":"Co-IP from brain homogenates, pull-down binding assays, and developmental immunostaining of CNS/PNS","pmids":["12542678"],"confidence":"High","gaps":["Did not show functional consequence of disrupting the interaction in vivo","Role of 4.1R versus 4.1B not resolved"]},{"year":2009,"claim":"Resolved how Caspr2 achieves polarized axonal localization, showing PKC-dependent dynamin-mediated endocytosis from the somatodendritic compartment requires Thr1292.","evidence":"HA-tagged constructs, dominant-negative dynamin, Dynasore, PKC inhibition and T1292A mutagenesis in hippocampal neurons","pmids":["19706678"],"confidence":"High","gaps":["The PKC isoform responsible was not identified","Whether this mechanism operates in vivo not tested"]},{"year":2010,"claim":"Demonstrated that the 4.1B interaction is functionally required for clustering of both Caspr2 and Kv1 channels at juxtaparanodes in vivo.","evidence":"Transgenic rescue of Caspr2-null mice with a 4.1-binding-deficient mutant plus 4.1B knockout mice and immunofluorescence","pmids":["20164332"],"confidence":"High","gaps":["Mechanism connecting 4.1B to Kv1 retention not detailed","Did not address synaptic roles"]},{"year":2011,"claim":"Defined the developmental requirement for CNTNAP2 in cortex, showing it is needed for interneuron placement and normal network activity prior to seizure onset.","evidence":"Constitutive Cntnap2 knockout mouse with neuropathology, electrophysiology, and behavior","pmids":["21962519"],"confidence":"High","gaps":["Did not establish cell-autonomy of the interneuron phenotype","Molecular pathway downstream of loss unresolved"]},{"year":2012,"claim":"Identified Caspr2 as the pathological autoantigen in encephalitis and peripheral nerve hyperexcitability, linking the molecule to autoimmune disease.","evidence":"IP-mass spectrometry antigen identification, cell-based assay, immunoabsorption, and comparison to Caspr2-null mouse tissues","pmids":["21387375"],"confidence":"High","gaps":["Did not establish how antibodies alter Caspr2 function","Epitope mapping not performed"]},{"year":2012,"claim":"Placed CNTNAP2 in a language gene-regulatory network as a direct transcriptional target of FOXP2.","evidence":"Lentiviral FoxP2 knockdown in zebra finch Area X, luciferase promoter assays, and qRT-PCR","pmids":["28488276"],"confidence":"Medium","gaps":["Avian ortholog; mammalian regulation inferred","Direct promoter occupancy in human cells not shown"]},{"year":2012,"claim":"Showed that ASD-associated missense mutations cause ER retention and UPR activation, defining a loss-of-membrane-function mechanism for disease variants.","evidence":"Immunofluorescence, fractionation, and Western blot of mutant constructs in HEK-293 cells and neurons","pmids":["22872700"],"confidence":"Medium","gaps":["Did not test variants in vivo","Quantitative impact on Kv1 clustering not measured"]},{"year":2014,"claim":"Revealed compensatory roles of Caspr and Caspr2 in organizing the internodal axolemma and node geometry through genetic epistasis.","evidence":"Caspr/Caspr2 double-knockout mice with immunofluorescence and electron microscopy","pmids":["25378149"],"confidence":"High","gaps":["Molecular basis of compensation not defined","Functional electrophysiological consequence not measured"]},{"year":2015,"claim":"Extended Caspr2 function to synapses, showing it is required for spine density, spine stabilization, and GluA1 AMPA-receptor trafficking.","evidence":"Super-resolution microscopy, in vivo two-photon spine imaging, and biochemistry in Cntnap2 KO neurons and brain","pmids":["25918374","25951243"],"confidence":"High","gaps":["Molecular mechanism of GluA1 trafficking control not yet identified","Adaptor linking Caspr2 to AMPA receptors unresolved at this stage"]},{"year":2015,"claim":"Mapped the Caspr2 interactome and subcellular partitioning, identifying CNTN2, Kv1 subunits, ADAM/LGI proteins, and MAGUKs as partners.","evidence":"Affinity purification-mass spectrometry, subcellular fractionation, and Western blot","pmids":["25707359"],"confidence":"Medium","gaps":["Direct versus indirect interactions not distinguished for all partners","Functional relevance of ADAM22/LGI1 association not tested"]},{"year":2016,"claim":"Determined the three-lobed architecture of Caspr2 and confirmed direct low-nanomolar binding of its ectodomain to CNTN2.","evidence":"Electron microscopy with epitope labeling, domain-deletion fragment binding, and solid-phase binding assays","pmids":["27621318"],"confidence":"High","gaps":["Atomic-resolution structure of the complex not determined","Stoichiometry in the membrane context unresolved"]},{"year":2018,"claim":"Identified CASK as the C-terminal partner stabilizing interneuron dendritic arbors, with a rescuable, interneuron-specific loss phenotype.","evidence":"Yeast two-hybrid, co-IP, proximity ligation assay, SIM/STED imaging, shRNA knockdown and rescue","pmids":["29610457"],"confidence":"High","gaps":["Why the requirement is interneuron-specific not explained","Link between CASK at membrane and arbor maintenance not mechanistically detailed"]},{"year":2018,"claim":"Established cell-autonomous Caspr2 functions: in DRG neurons loss causes Kv1 downregulation and pain hypersensitivity, and in cortex it selectively impairs PV+ fast-spiking interneurons.","evidence":"Patient antibody passive transfer, Cntnap2 KO, MGE transplantation assay, and patch-clamp electrophysiology","pmids":["29429934","29028946"],"confidence":"High","gaps":["Mechanism linking Caspr2 loss to reduced Kv1 expression at soma not fully defined","Why PV+ but not SST+ interneurons are affected unresolved"]},{"year":2018,"claim":"Showed that ASD variants impair CNTN2 binding and axon growth, with R1119H acting dominant-negatively, and that single-allele loss is sufficient.","evidence":"Cortical neuron axon growth assays, co-IP for oligomerization, binding assays, and ER-retention imaging","pmids":["29788201"],"confidence":"Medium","gaps":["In vivo consequence of dominant-negative effect not tested","Single-lab variant set"]},{"year":2018,"claim":"Characterized how patient autoantibodies act, showing they block the Caspr2–TAG-1 interaction without internalizing surface Caspr2.","evidence":"Solid-phase binding, surface biotinylation in HEK and neurons, and live-neuron immunofluorescence","pmids":["29244234"],"confidence":"Medium","gaps":["Discrepancy with later reports of internalization not reconciled here","Functional electrophysiological readout absent"]},{"year":2019,"claim":"Defined the prefrontal circuit consequences of CNTNAP2 loss, including reduced excitatory and inhibitory inputs and disrupted oscillatory phase-locking.","evidence":"Laser-scanning photostimulation, whole-cell and in vivo recordings, and electron microscopy in Cntnap2 KO mice","pmids":["31141683"],"confidence":"High","gaps":["Cellular mechanism of synapse loss not identified","Relationship to interneuron phenotype not directly linked"]},{"year":2019,"claim":"Demonstrated a role in homeostatic synaptic plasticity, with loss blocking synaptic scaling and reducing AMPA-receptor currents, replicated by patient antibodies.","evidence":"shRNA knockdown, Cntnap2 KO, in vivo monocular deprivation, whole-cell recordings, and antibody application","pmids":["30843029"],"confidence":"High","gaps":["Molecular signaling driving scaling defect not resolved","Link to CASK complex not established in this study"]},{"year":2019,"claim":"Assembled the synaptic mechanism into a tripartite Caspr2–CASK–GluA1 complex regulating AMPA-receptor levels in interneurons.","evidence":"Co-IP from mouse brain, SIM super-resolution microscopy, and shRNA knockdown","pmids":["30779956"],"confidence":"Medium","gaps":["Stoichiometry and direct GluA1 contact not resolved","Whether complex operates in excitatory neurons unclear"]},{"year":2019,"claim":"Identified hyperactive Akt-mTOR signaling as a downstream consequence of CNTNAP2 loss that is pharmacologically rescuable.","evidence":"RNA-seq, phospho-Western validation, and Akt/mTOR inhibitor rescue of social deficits and pain in Cntnap2 KO mice","pmids":["30816216","31874168"],"confidence":"Medium","gaps":["Mechanistic link from Caspr2 loss to Akt-mTOR activation not defined","Cell types driving the signaling change not pinpointed"]},{"year":2022,"claim":"Showed that intracerebral patient IgG causes reversible memory impairment via internalization of CASPR2 and reduction of Kv1.1 and GluA1, establishing antibody pathogenicity in vivo.","evidence":"Intracerebroventricular IgG infusion, STED microscopy, molecular quantification, behavioral testing, and reversibility controls","pmids":["35253937"],"confidence":"High","gaps":["Apparent contradiction with earlier no-internalization report not reconciled","Epitope-specific differences in antibody effect not defined"]},{"year":2023,"claim":"Established a nuclear signaling arm in which γ-secretase-generated CICD drives CASK nuclear translocation to regulate Necdin transcription, rescuing behavior in mutants.","evidence":"γ-secretase cleavage assay, viral CICD/Necdin delivery, behavioral rescue, and nuclear fractionation in Cntnap2 KO mice","pmids":["37271769"],"confidence":"Medium","gaps":["Direct CASK-dependent occupancy at the Necdin promoter not shown","Full set of CICD-regulated transcripts unknown"]},{"year":2024,"claim":"Defined the full sequential proteolytic cascade (furin → ADAM10/17 → γ-secretase) and showed ASD mutations impair α-cleavage, with the C79 fragment rescuing autism-like behaviors.","evidence":"In vitro ADAM/γ-secretase cleavage assays with mass-spectrometry site mapping, Cntnap2-I1254T knock-in and KO mice, behavioral phenotyping, and viral C79 delivery","pmids":["38424048"],"confidence":"High","gaps":["How α-cleavage is regulated physiologically not defined","Relationship between C79 rescue and CICD transcriptional arm not integrated"]},{"year":null,"claim":"The mechanistic link connecting Caspr2 loss of function to hyperactive Akt-mTOR signaling and to the integration of its proteolytic/nuclear signaling arm with its membrane adhesion functions remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No direct signaling chain from Caspr2 to Akt-mTOR identified","Relative contributions of membrane adhesion versus CICD transcription to phenotypes not partitioned","Atomic structure of 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correlation in contactin-associated protein-like 2 (CNTNAP-2) developmental disorder.","date":"2023","source":"Human genetics","url":"https://pubmed.ncbi.nlm.nih.gov/37183190","citation_count":19,"is_preprint":false},{"pmid":"24726720","id":"PMC_24726720","title":"Caspr2 antibody limbic encephalitis is associated with Hashimoto thyroiditis and thymoma.","date":"2014","source":"Journal of the neurological sciences","url":"https://pubmed.ncbi.nlm.nih.gov/24726720","citation_count":19,"is_preprint":false},{"pmid":"28284582","id":"PMC_28284582","title":"The association of CNTNAP2 rs7794745 gene polymorphism and autism in Iranian population.","date":"2017","source":"Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia","url":"https://pubmed.ncbi.nlm.nih.gov/28284582","citation_count":18,"is_preprint":false},{"pmid":"35106542","id":"PMC_35106542","title":"Hyperexcitable and immature-like neuronal activity in the auditory cortex of adult rats lacking the language-linked CNTNAP2 gene.","date":"2022","source":"Cerebral cortex (New York, N.Y. : 1991)","url":"https://pubmed.ncbi.nlm.nih.gov/35106542","citation_count":18,"is_preprint":false},{"pmid":"28370195","id":"PMC_28370195","title":"Axonal domain disorganization in Caspr1 and Caspr2 mutant myelinated axons affects neuromuscular junction integrity, leading to muscle atrophy.","date":"2017","source":"Journal of neuroscience research","url":"https://pubmed.ncbi.nlm.nih.gov/28370195","citation_count":18,"is_preprint":false},{"pmid":"30779956","id":"PMC_30779956","title":"The CNTNAP2-CASK complex modulates GluA1 subcellular distribution in interneurons.","date":"2019","source":"Neuroscience letters","url":"https://pubmed.ncbi.nlm.nih.gov/30779956","citation_count":17,"is_preprint":false},{"pmid":"22133810","id":"PMC_22133810","title":"Cntnap2 expression in the cerebellum of Foxp2(R552H) mice, with a mutation related to speech-language disorder.","date":"2011","source":"Neuroscience 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homogenates, pull-down binding assays, immunostaining of developing CNS and PNS\",\n      \"journal\": \"The European journal of neuroscience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP from brain tissue plus direct binding assay and developmental colocalization, replicated in multiple myelinated fiber preparations\",\n      \"pmids\": [\"12542678\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"Caspr2 is targeted to the axonal surface through PKC-dependent, dynamin-mediated endocytosis from the somatodendritic compartment. A short sequence within the 4.1B-binding domain containing a PKC substrate motif (Thr1292) is required; point mutation of Thr1292 or PKC inhibition prevents somatodendritic internalization, establishing polarized axonal expression.\",\n      \"method\": \"HA-tagged Caspr2 constructs in hippocampal neurons, dominant-negative Dynamin-1, Dynasore treatment, PKC inhibitor, site-directed mutagenesis (T1292A)\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — mutagenesis of specific residue combined with pharmacological inhibition and dominant-negative approach in neuronal culture, single lab but multiple orthogonal methods\",\n      \"pmids\": [\"19706678\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"Interaction of Caspr2 with protein 4.1B (via 4.1-binding sequence) is required for accumulation of Caspr2 and Kv1 channels at the juxtaparanodal region; transgenic Caspr2 lacking the 4.1-binding domain fails to cluster at juxtaparanodes, and Caspr2 and Kv1 channels are absent from juxtaparanodes in 4.1B-null mice.\",\n      \"method\": \"Transgenic rescue of Caspr2-null mice with Caspr2-d4.1 mutant, 4.1B knockout mice, immunofluorescence\",\n      \"journal\": \"The Journal of neuroscience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vivo mutagenesis rescue experiment combined with knockout validation, clear mechanistic assignment\",\n      \"pmids\": [\"20164332\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"Cntnap2 knockout mice display neuronal migration abnormalities, reduced number of interneurons, and abnormal neuronal network activity before seizure onset, demonstrating CNTNAP2 is required for normal cortical interneuron placement and brain network development.\",\n      \"method\": \"Cntnap2 constitutive knockout mouse model, neuropathological analysis, electrophysiology, behavioral testing\",\n      \"journal\": \"Cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — defined cellular phenotypes in constitutive KO with multiple orthogonal readouts (histology, physiology, behavior), widely replicated landmark study\",\n      \"pmids\": [\"21962519\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Caspr2 autoantibodies from patients with encephalitis and peripheral nerve hyperexcitability target Caspr2 protein; immunoabsorption with Caspr2 abolishes reactivity, and antibodies are absent in tissues from Caspr2-null mice, confirming Caspr2 as the pathological autoantigen.\",\n      \"method\": \"Immunoprecipitation and mass spectrometry antigen identification, cell-based assay with Caspr2-expressing cells, immunoabsorption, comparative immunostaining of wild-type vs. Caspr2-null mouse tissues\",\n      \"journal\": \"Annals of neurology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — mass spectrometry antigen identification plus orthogonal confirmation with null-mouse tissues and immunoabsorption\",\n      \"pmids\": [\"21387375\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"CNTNAP2 is a direct transcriptional target of FOXP2; FOXP2 binds the CNTNAP2 promoter and regulates its expression, placing CNTNAP2 downstream of FOXP2 in a language-related gene-regulatory pathway.\",\n      \"method\": \"Lentiviral FoxP2 knockdown in zebra finch Area X (in vivo), luciferase promoter assays (in vitro), quantitative RT-PCR showing reduced CNTNAP2 expression upon FoxP2 knockdown\",\n      \"journal\": \"Genes, brain, and behavior\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo knockdown plus in vitro promoter binding, single lab, avian ortholog but consistent with mammalian FOXP2-CNTNAP2 axis\",\n      \"pmids\": [\"28488276\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Several autism-associated CNTNAP2 missense mutations (e.g., D1129H) cause retention of CASPR2 in the endoplasmic reticulum, activate ER chaperones (BiP/Grp78, Calnexin, ERp57) and the ATF6 branch of the unfolded protein response, and promote proteasomal degradation; a frameshift mutation (1253*) produces a secreted soluble protein, losing membrane-tethered function.\",\n      \"method\": \"Immunofluorescence confocal microscopy, biochemical fractionation, Western blot in HEK-293 cells and hippocampal neurons\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple mutants examined with orthogonal imaging and biochemistry, single lab\",\n      \"pmids\": [\"22872700\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Both Caspr and Caspr2 are required for the organization of the axolemma at the mesaxonal internodal line: in single mutants Kv1 channels cluster along the inner mesaxon and below Schmidt-Lanterman incisures, but in Caspr/Caspr2 double knockout mice these channels form dispersed aggregates, revealing compensatory roles. Double deletion also widens nodes of Ranvier.\",\n      \"method\": \"Caspr/Caspr2 double-knockout mouse generation, immunofluorescence, electron microscopy\",\n      \"journal\": \"The Journal of neuroscience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — genetic epistasis via double knockout with electron microscopy and immunofluorescence, rigorous mechanistic assignment of compensatory functions\",\n      \"pmids\": [\"25378149\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"CNTNAP2 is present in dendritic spines and is required for normal spine density and synaptic localization of GluA1 AMPA receptor subunits; Cntnap2 knockout neurons show reduced spine density, reduced spine GluA1 levels, and large cytoplasmic GluA1 aggregates, indicating a role for CNTNAP2 in GluA1 trafficking.\",\n      \"method\": \"Structured illumination super-resolution microscopy, immunofluorescence, Western blot in Cntnap2 KO cultured neurons and brain slices\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — super-resolution imaging plus biochemistry in KO neurons, clear trafficking phenotype with multiple readouts\",\n      \"pmids\": [\"25918374\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"New dendritic spines in Cntnap2 knockout mice form at normal rates but fail to stabilize in vivo, indicating a specific role for CNTNAP2 in new spine stabilization rather than spine formation or elimination.\",\n      \"method\": \"In vivo two-photon microscopy for longitudinal spine imaging in Cntnap2 KO mice\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — direct in vivo spine imaging with clear phenotype, single lab, single method\",\n      \"pmids\": [\"25951243\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Interaction proteomics of Caspr2 identifies its binding partners including CNTN2 (TAG-1), Kv1 channel subunits (KCNAs), ADAM family members (ADAM22, ADAM23, ADAM11), LGI family proteins, and MAGUKs (DLGs, MPPs). Caspr2 is enriched in lipid rafts and synaptic membranes but depleted from the postsynaptic density. A short isoform lacking most extracellular domains still associates with ADAM22, LGI1, and Kv1.\",\n      \"method\": \"Affinity purification-mass spectrometry (interaction proteomics), subcellular fractionation, Western blot\",\n      \"journal\": \"Biochimica et biophysica acta\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — mass spectrometry interactome with biochemical fractionation, single lab\",\n      \"pmids\": [\"25707359\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Cntnap2 is expressed throughout all primary sensory organs and multiple sensory brain regions; Cntnap2 knockout mice exhibit abnormal olfactory responses and lack novelty preference, linking Caspr2 expression in sensory circuits to sensory behavior.\",\n      \"method\": \"Caspr2:tau-LacZ knock-in reporter line, X-gal staining for circuit mapping, olfaction-based behavioral tests\",\n      \"journal\": \"Molecular and cellular neurosciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic reporter plus knockout behavioral phenotype, single lab\",\n      \"pmids\": [\"26647347\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Electron microscopy reveals that CNTNAP2 has a three-lobed architecture (large, medium, small lobes) distinct from neurexin-1α; domain assignment places F58C, L1, L2 in the large lobe, FBG and L3 in the middle lobe, and L4 in the small lobe. CNTNAP2 and CNTN2 ectodomains bind directly with low nanomolar affinity.\",\n      \"method\": \"Electron microscopy with epitope labeling, domain-deletion fragment binding assays, solid-phase binding assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — electron microscopy structure with domain mapping and quantitative binding assay, single lab but multiple orthogonal methods\",\n      \"pmids\": [\"27621318\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"4.1B is required for the proper targeting of Caspr2 to juxtaparanodes early during myelination; in 4.1B KO DRG-Schwann cell myelinating cultures, Caspr2 fails to target correctly while paranodal junctions (stability of Caspr at paranodes) are unaffected.\",\n      \"method\": \"Myelinating DRG neuron-Schwann cell co-cultures from 4.1B KO mice, adenoviral Caspr-GFP, FRAP\",\n      \"journal\": \"Glia\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vitro myelination model with KO validation and live imaging, single lab\",\n      \"pmids\": [\"26840208\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"CNTNAP2 stabilizes interneuron dendritic arbors through direct interaction of its C-terminus with CASK; yeast two-hybrid screening, proximity ligation assay, and super-resolution microscopy (SIM/STED) demonstrate CNTNAP2-CASK interaction at the membrane. Loss of Cntnap2 causes interneuron-specific dendritic simplification (not excitatory neuron), reduced cortical membrane CASK, and this phenotype is rescued by CASK expression.\",\n      \"method\": \"Yeast two-hybrid, biochemical co-IP, proximity ligation assay, SIM and STED super-resolution microscopy, shRNA knockdown, phenotype rescue\",\n      \"journal\": \"Molecular psychiatry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — yeast two-hybrid plus PLA plus super-resolution imaging plus rescue, multiple orthogonal methods in single study\",\n      \"pmids\": [\"29610457\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"Either immune-mediated (patient autoantibody passive transfer) or genetic (Cntnap2-/-) ablation of CASPR2 enhances excitability of dorsal root ganglion neurons in a cell-autonomous manner through downregulation of Kv1 channel expression at the soma membrane, causing pain hypersensitivity. Human CASPR2 autoantibodies are peripherally restricted when injected into mice.\",\n      \"method\": \"Passive transfer of human autoantibodies into mice, Cntnap2 KO mice, DRG neuron electrophysiology, Kv1 immunostaining and Western blot\",\n      \"journal\": \"Neuron\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — passive transfer model plus genetic KO with cell-autonomous electrophysiology and molecular mechanism (Kv1 regulation), two orthogonal genetic/immune approaches\",\n      \"pmids\": [\"29429934\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"Caspr2 autoantibodies inhibit the interaction of Caspr2 with contactin-2 (nanomolar affinity interaction confirmed by solid-phase assay) but do not cause internalization of surface Caspr2 from primary hippocampal neurons or HEK cells.\",\n      \"method\": \"Solid-phase binding assay quantifying Caspr2-contactin-2 interaction, cell-surface biotinylation and Western blot of HEK cells, living neuron immunofluorescence\",\n      \"journal\": \"Annals of neurology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — quantitative binding assay plus surface biotinylation in two cell systems, single lab; negative result (no internalization) explicitly confirmed\",\n      \"pmids\": [\"29244234\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"Human ASD-associated CNTNAP2 missense variants (e.g., I869T, G731S) impair Contactin2/TAG-1 binding and fail to rescue axonal growth deficits in Cntnap2 heterozygous cortical neurons; variant R1119H is retained in ER and exerts a dominant-negative effect on axon growth via oligomerization with wild-type Caspr2. Loss of one Cntnap2 allele is sufficient to reduce axon growth in a dose-dependent manner.\",\n      \"method\": \"Cortical neuron cultures from mouse embryos, axon growth measurements, co-immunoprecipitation for oligomerization, binding assays for Contactin2, immunofluorescence for ER retention\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple variant analyses with binding assay and dominant-negative co-IP, single lab\",\n      \"pmids\": [\"29788201\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"Mouse and human ASD CNTNAP2 missense mutations cell-autonomously impair the physiology of parvalbumin-positive (PV+) fast-spiking cortical interneurons in a transplantation assay; Cntnap2 null constitutive mutants have reduced PV+ CINs but normal total MGE-derived CIN numbers. Somatostatin+ CINs show no phenotype.\",\n      \"method\": \"MGE cell transplantation assay (cell-autonomous testing), constitutive Cntnap2 null mice, whole-cell patch clamp, immunofluorescence\",\n      \"journal\": \"Cerebral cortex\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — cell transplantation assay directly tests cell autonomy, combined with in vivo knockout and electrophysiology, multiple ASD variant alleles tested\",\n      \"pmids\": [\"29028946\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"CNTNAP2 loss causes dramatic reduction in excitatory and inhibitory synaptic inputs onto L2/3 pyramidal neurons of medial prefrontal cortex, along with reduced spines and synapses despite normal dendritic complexity and intrinsic excitability; in vivo mPFC recordings show increased inhibitory neuron activity and disrupted phase-locking to delta/theta oscillations.\",\n      \"method\": \"Laser-scanning photostimulation, whole-cell recordings, electron microscopy, in vivo LFP and unit recording in Cntnap2 KO mice\",\n      \"journal\": \"Cell reports\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — multiple orthogonal methods (EM, in vitro and in vivo electrophysiology, photostimulation) in single study with clear mechanistic circuit phenotype\",\n      \"pmids\": [\"31141683\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"Caspr2 loss of function (genetic knockdown or knockout) decreases synaptic AMPA receptor expression and amplitude of AMPA receptor-mediated currents in cortex, blocks synaptic scaling in vitro, and impairs experience-dependent homeostatic synaptic plasticity in vivo; patient CASPR2 antibodies decrease dendritic Caspr2 levels and synaptic AMPA receptor trafficking.\",\n      \"method\": \"In vitro shRNA knockdown, Cntnap2 KO, in vivo visual cortex monocular deprivation, whole-cell recordings, immunofluorescence; patient antibody application to neurons\",\n      \"journal\": \"Cerebral cortex\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — genetic and antibody-mediated loss of function with electrophysiology and in vivo homeostatic plasticity assay, multiple orthogonal methods\",\n      \"pmids\": [\"30843029\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"CNTNAP2, CASK, and GluA1 form a tripartite complex in interneurons (confirmed by SIM super-resolution microscopy and biochemical co-IP in mouse brain); individual knockdown of either CNTNAP2 or CASK similarly alters GluA1 levels and localization in interneurons.\",\n      \"method\": \"Co-immunoprecipitation from mouse brain, structured illumination microscopy, shRNA knockdown\",\n      \"journal\": \"Neuroscience letters\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal biochemistry plus super-resolution colocalization plus functional knockdown, single lab\",\n      \"pmids\": [\"30779956\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"Hyperactive Akt-mTOR signaling is present in the hippocampus and DRG of Cntnap2-/- mice; pharmacological inhibition with Akt inhibitor (LY294002) or mTOR inhibitor (rapamycin) rescues social deficits and pain hypersensitivity, and reduces DRG neuronal hyperexcitability.\",\n      \"method\": \"RNA sequencing followed by biochemical validation (Western blot for phospho-Akt/mTOR), pharmacological rescue in Cntnap2 KO mice, patch-clamp electrophysiology of DRG neurons\",\n      \"journal\": \"Scientific reports / Neuropharmacology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — RNA-seq plus biochemical validation plus pharmacological rescue with electrophysiology, single lab across two papers\",\n      \"pmids\": [\"30816216\", \"31874168\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"Anti-CASPR2 patient antibodies alter Caspr2 distribution at the cell membrane (promoting cluster formation), impede CASPR2/TAG-1 interaction, and introduction of Caspr2 into HEK cells induces increased Kv1.2 surface expression; patient antibodies increase Kv1.2 expression in both HEK and hippocampal neuron models.\",\n      \"method\": \"Cell-based assays (HEK cells expressing Caspr2), primary hippocampal neuron cultures, immunofluorescence, domain-deletion constructs identifying CASPR2-TAG1 interaction domains\",\n      \"journal\": \"Journal of autoimmunity\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple cell systems with domain mapping, single lab\",\n      \"pmids\": [\"31176559\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Patient IgG infused into mouse cerebroventricular system causes reversible memory impairment, reduces surface CASPR2 clusters, decreases CASPR2/TAG-1 colocalization (super-resolution STED), selectively internalizes CASPR2 (not TAG-1) in cultured neurons, and decreases hippocampal Kv1.1 and GluA1 levels; all effects reverse upon IgG removal.\",\n      \"method\": \"Intracerebroventricular IgG infusion in mice, STED super-resolution microscopy, confocal quantification of Kv1.1 and GluA1, behavioral memory testing, cultured neuron internalization assay\",\n      \"journal\": \"Annals of neurology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — passive transfer model with STED imaging, behavioral readout, molecular endpoint quantification, and reversibility control — multiple orthogonal approaches in single study\",\n      \"pmids\": [\"35253937\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"CNTNAP2 is cleaved by γ-secretase to produce a CNTNAP2 intracellular domain (CICD); viral delivery of CICD to the medial prefrontal cortex of Cntnap2-/- mice rescues social and repetitive behavior deficits. CICD promotes nuclear translocation of CASK to regulate transcription of Necdin; Necdin deficiency reduces social interaction, and Necdin viral expression in mPFC rescues social preference in Cntnap2-/- mice.\",\n      \"method\": \"Biochemical γ-secretase cleavage assay, viral delivery of CICD/Necdin, behavioral rescue in Cntnap2 KO mice, nuclear fractionation showing CASK translocation\",\n      \"journal\": \"Signal transduction and targeted therapy\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — biochemical cleavage identification plus in vivo viral rescue with downstream pathway (CASK nuclear translocation, Necdin transcription), single lab\",\n      \"pmids\": [\"37271769\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"CNTNAP2 undergoes sequential proteolytic processing: furin cleavage, then ADAM10/17-dependent α-secretase cleavage at residues I79 (ADAM10) and L96 (ADAM17) generating fragment C79, which is required for subsequent γ-secretase cleavage to produce CICD. ASD-associated CNTNAP2 mutations impair α-cleavage; inhibiting α-cleavage in Cntnap2-I1254T knock-in mice produces autism-like social and repetitive behaviors. Exogenous C79 rescues these phenotypes in both knock-in and knockout mice.\",\n      \"method\": \"In vitro cleavage assays with ADAM10/17, γ-secretase inhibitors, mass spectrometry of cleavage sites, Cntnap2-I1254T knock-in mouse generation, behavioral phenotyping, viral C79 delivery\",\n      \"journal\": \"Signal transduction and targeted therapy\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro biochemical cleavage mapping with site identification plus two in vivo mouse models (KI and KO) with rescue, multiple orthogonal approaches\",\n      \"pmids\": [\"38424048\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"CNTNAP2 encodes Caspr2, a large multidomain neurexin-superfamily transmembrane cell adhesion molecule that undergoes sequential proteolytic processing (furin → ADAM10/17 α-secretase → γ-secretase) to generate a bioactive intracellular domain (CICD) that translocates to the nucleus via CASK to regulate transcription; at the membrane, Caspr2 clusters Kv1 potassium channels at juxtaparanodes of myelinated axons through direct binding to TAG-1/contactin-2 and anchoring to the actin cytoskeleton via protein 4.1B (requiring PKC-dependent somatodendritic endocytosis for axonal polarization); at excitatory and inhibitory synapses it regulates GluA1 AMPA receptor trafficking and homeostatic synaptic plasticity through a tripartite complex with CASK, stabilizes new dendritic spines and interneuron dendritic arbors through CASK interaction, and controls PV+ cortical interneuron physiology in a cell-autonomous manner, with loss of function causing hyperactive Akt-mTOR signaling, reduced prefrontal synaptic connectivity, disrupted cortical oscillations, and pain hypersensitivity via Kv1 downregulation in DRG neurons.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"CNTNAP2 encodes Caspr2, a neurexin-superfamily transmembrane cell adhesion molecule that organizes the axonal membrane and regulates cortical circuit development and synaptic function [#3, #7]. At myelinated axons, Caspr2 clusters Kv1 potassium channels at juxtaparanodes by binding contactin-2/TAG-1 (CNTN2) through its ectodomain with low-nanomolar affinity [#12, #16] and by anchoring to the actin cytoskeleton via its intracellular GNP motif binding to protein 4.1B [#0, #2]; this juxtaparanodal targeting requires 4.1B early in myelination and PKC-dependent somatodendritic endocytosis (via Thr1292) to achieve polarized axonal expression [#1, #13]. Caspr2 and the related Caspr act compensatorily to organize the internodal axolemma and node geometry [#7]. At synapses, Caspr2 localizes to dendritic spines and stabilizes newly formed spines, controls GluA1 AMPA-receptor trafficking, and mediates homeostatic synaptic scaling, acting through a tripartite Caspr2–CASK–GluA1 complex [#8, #9, #20, #21]; through direct C-terminal binding to CASK it also stabilizes interneuron dendritic arbors [#14]. Cntnap2 loss reduces cortical interneurons, disrupts neuronal migration and network activity, cell-autonomously impairs parvalbumin-positive fast-spiking interneurons, and reduces prefrontal synaptic connectivity with disrupted oscillatory phase-locking [#3, #18, #19]. Caspr2 is sequentially processed by furin, ADAM10/17 α-secretase, and γ-secretase to liberate an intracellular domain (CICD) that drives CASK nuclear translocation to regulate Necdin transcription, and exogenous cleavage fragments rescue social and repetitive behaviors in mutant mice [#25, #26]. CNTNAP2 lies downstream of FOXP2 in a language-related gene-regulatory pathway [#5], and its loss causes hyperactive Akt-mTOR signaling whose pharmacological inhibition rescues social and pain phenotypes [#22]. Caspr2 is the pathological autoantigen in autoimmune encephalitis and peripheral nerve hyperexcitability, where patient antibodies impair the Caspr2–TAG-1 interaction, alter Kv1 and GluA1 levels, and cause reversible memory impairment and pain hypersensitivity via Kv1 downregulation in DRG neurons [#4, #15, #24].\",\n  \"teleology\": [\n    {\n      \"year\": 2003,\n      \"claim\": \"Established how Caspr2 is physically linked to the cytoskeleton, identifying the intracellular GNP motif as the binding site for protein 4.1B at juxtaparanodes.\",\n      \"evidence\": \"Co-IP from brain homogenates, pull-down binding assays, and developmental immunostaining of CNS/PNS\",\n      \"pmids\": [\"12542678\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not show functional consequence of disrupting the interaction in vivo\", \"Role of 4.1R versus 4.1B not resolved\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Resolved how Caspr2 achieves polarized axonal localization, showing PKC-dependent dynamin-mediated endocytosis from the somatodendritic compartment requires Thr1292.\",\n      \"evidence\": \"HA-tagged constructs, dominant-negative dynamin, Dynasore, PKC inhibition and T1292A mutagenesis in hippocampal neurons\",\n      \"pmids\": [\"19706678\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"The PKC isoform responsible was not identified\", \"Whether this mechanism operates in vivo not tested\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Demonstrated that the 4.1B interaction is functionally required for clustering of both Caspr2 and Kv1 channels at juxtaparanodes in vivo.\",\n      \"evidence\": \"Transgenic rescue of Caspr2-null mice with a 4.1-binding-deficient mutant plus 4.1B knockout mice and immunofluorescence\",\n      \"pmids\": [\"20164332\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism connecting 4.1B to Kv1 retention not detailed\", \"Did not address synaptic roles\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Defined the developmental requirement for CNTNAP2 in cortex, showing it is needed for interneuron placement and normal network activity prior to seizure onset.\",\n      \"evidence\": \"Constitutive Cntnap2 knockout mouse with neuropathology, electrophysiology, and behavior\",\n      \"pmids\": [\"21962519\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not establish cell-autonomy of the interneuron phenotype\", \"Molecular pathway downstream of loss unresolved\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Identified Caspr2 as the pathological autoantigen in encephalitis and peripheral nerve hyperexcitability, linking the molecule to autoimmune disease.\",\n      \"evidence\": \"IP-mass spectrometry antigen identification, cell-based assay, immunoabsorption, and comparison to Caspr2-null mouse tissues\",\n      \"pmids\": [\"21387375\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not establish how antibodies alter Caspr2 function\", \"Epitope mapping not performed\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Placed CNTNAP2 in a language gene-regulatory network as a direct transcriptional target of FOXP2.\",\n      \"evidence\": \"Lentiviral FoxP2 knockdown in zebra finch Area X, luciferase promoter assays, and qRT-PCR\",\n      \"pmids\": [\"28488276\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Avian ortholog; mammalian regulation inferred\", \"Direct promoter occupancy in human cells not shown\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Showed that ASD-associated missense mutations cause ER retention and UPR activation, defining a loss-of-membrane-function mechanism for disease variants.\",\n      \"evidence\": \"Immunofluorescence, fractionation, and Western blot of mutant constructs in HEK-293 cells and neurons\",\n      \"pmids\": [\"22872700\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Did not test variants in vivo\", \"Quantitative impact on Kv1 clustering not measured\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Revealed compensatory roles of Caspr and Caspr2 in organizing the internodal axolemma and node geometry through genetic epistasis.\",\n      \"evidence\": \"Caspr/Caspr2 double-knockout mice with immunofluorescence and electron microscopy\",\n      \"pmids\": [\"25378149\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular basis of compensation not defined\", \"Functional electrophysiological consequence not measured\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Extended Caspr2 function to synapses, showing it is required for spine density, spine stabilization, and GluA1 AMPA-receptor trafficking.\",\n      \"evidence\": \"Super-resolution microscopy, in vivo two-photon spine imaging, and biochemistry in Cntnap2 KO neurons and brain\",\n      \"pmids\": [\"25918374\", \"25951243\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular mechanism of GluA1 trafficking control not yet identified\", \"Adaptor linking Caspr2 to AMPA receptors unresolved at this stage\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Mapped the Caspr2 interactome and subcellular partitioning, identifying CNTN2, Kv1 subunits, ADAM/LGI proteins, and MAGUKs as partners.\",\n      \"evidence\": \"Affinity purification-mass spectrometry, subcellular fractionation, and Western blot\",\n      \"pmids\": [\"25707359\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct versus indirect interactions not distinguished for all partners\", \"Functional relevance of ADAM22/LGI1 association not tested\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Determined the three-lobed architecture of Caspr2 and confirmed direct low-nanomolar binding of its ectodomain to CNTN2.\",\n      \"evidence\": \"Electron microscopy with epitope labeling, domain-deletion fragment binding, and solid-phase binding assays\",\n      \"pmids\": [\"27621318\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Atomic-resolution structure of the complex not determined\", \"Stoichiometry in the membrane context unresolved\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Identified CASK as the C-terminal partner stabilizing interneuron dendritic arbors, with a rescuable, interneuron-specific loss phenotype.\",\n      \"evidence\": \"Yeast two-hybrid, co-IP, proximity ligation assay, SIM/STED imaging, shRNA knockdown and rescue\",\n      \"pmids\": [\"29610457\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Why the requirement is interneuron-specific not explained\", \"Link between CASK at membrane and arbor maintenance not mechanistically detailed\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Established cell-autonomous Caspr2 functions: in DRG neurons loss causes Kv1 downregulation and pain hypersensitivity, and in cortex it selectively impairs PV+ fast-spiking interneurons.\",\n      \"evidence\": \"Patient antibody passive transfer, Cntnap2 KO, MGE transplantation assay, and patch-clamp electrophysiology\",\n      \"pmids\": [\"29429934\", \"29028946\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism linking Caspr2 loss to reduced Kv1 expression at soma not fully defined\", \"Why PV+ but not SST+ interneurons are affected unresolved\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Showed that ASD variants impair CNTN2 binding and axon growth, with R1119H acting dominant-negatively, and that single-allele loss is sufficient.\",\n      \"evidence\": \"Cortical neuron axon growth assays, co-IP for oligomerization, binding assays, and ER-retention imaging\",\n      \"pmids\": [\"29788201\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"In vivo consequence of dominant-negative effect not tested\", \"Single-lab variant set\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Characterized how patient autoantibodies act, showing they block the Caspr2–TAG-1 interaction without internalizing surface Caspr2.\",\n      \"evidence\": \"Solid-phase binding, surface biotinylation in HEK and neurons, and live-neuron immunofluorescence\",\n      \"pmids\": [\"29244234\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Discrepancy with later reports of internalization not reconciled here\", \"Functional electrophysiological readout absent\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Defined the prefrontal circuit consequences of CNTNAP2 loss, including reduced excitatory and inhibitory inputs and disrupted oscillatory phase-locking.\",\n      \"evidence\": \"Laser-scanning photostimulation, whole-cell and in vivo recordings, and electron microscopy in Cntnap2 KO mice\",\n      \"pmids\": [\"31141683\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Cellular mechanism of synapse loss not identified\", \"Relationship to interneuron phenotype not directly linked\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Demonstrated a role in homeostatic synaptic plasticity, with loss blocking synaptic scaling and reducing AMPA-receptor currents, replicated by patient antibodies.\",\n      \"evidence\": \"shRNA knockdown, Cntnap2 KO, in vivo monocular deprivation, whole-cell recordings, and antibody application\",\n      \"pmids\": [\"30843029\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular signaling driving scaling defect not resolved\", \"Link to CASK complex not established in this study\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Assembled the synaptic mechanism into a tripartite Caspr2–CASK–GluA1 complex regulating AMPA-receptor levels in interneurons.\",\n      \"evidence\": \"Co-IP from mouse brain, SIM super-resolution microscopy, and shRNA knockdown\",\n      \"pmids\": [\"30779956\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Stoichiometry and direct GluA1 contact not resolved\", \"Whether complex operates in excitatory neurons unclear\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Identified hyperactive Akt-mTOR signaling as a downstream consequence of CNTNAP2 loss that is pharmacologically rescuable.\",\n      \"evidence\": \"RNA-seq, phospho-Western validation, and Akt/mTOR inhibitor rescue of social deficits and pain in Cntnap2 KO mice\",\n      \"pmids\": [\"30816216\", \"31874168\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanistic link from Caspr2 loss to Akt-mTOR activation not defined\", \"Cell types driving the signaling change not pinpointed\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Showed that intracerebral patient IgG causes reversible memory impairment via internalization of CASPR2 and reduction of Kv1.1 and GluA1, establishing antibody pathogenicity in vivo.\",\n      \"evidence\": \"Intracerebroventricular IgG infusion, STED microscopy, molecular quantification, behavioral testing, and reversibility controls\",\n      \"pmids\": [\"35253937\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Apparent contradiction with earlier no-internalization report not reconciled\", \"Epitope-specific differences in antibody effect not defined\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Established a nuclear signaling arm in which γ-secretase-generated CICD drives CASK nuclear translocation to regulate Necdin transcription, rescuing behavior in mutants.\",\n      \"evidence\": \"γ-secretase cleavage assay, viral CICD/Necdin delivery, behavioral rescue, and nuclear fractionation in Cntnap2 KO mice\",\n      \"pmids\": [\"37271769\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct CASK-dependent occupancy at the Necdin promoter not shown\", \"Full set of CICD-regulated transcripts unknown\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Defined the full sequential proteolytic cascade (furin → ADAM10/17 → γ-secretase) and showed ASD mutations impair α-cleavage, with the C79 fragment rescuing autism-like behaviors.\",\n      \"evidence\": \"In vitro ADAM/γ-secretase cleavage assays with mass-spectrometry site mapping, Cntnap2-I1254T knock-in and KO mice, behavioral phenotyping, and viral C79 delivery\",\n      \"pmids\": [\"38424048\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How α-cleavage is regulated physiologically not defined\", \"Relationship between C79 rescue and CICD transcriptional arm not integrated\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The mechanistic link connecting Caspr2 loss of function to hyperactive Akt-mTOR signaling and to the integration of its proteolytic/nuclear signaling arm with its membrane adhesion functions remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No direct signaling chain from Caspr2 to Akt-mTOR identified\", \"Relative contributions of membrane adhesion versus CICD transcription to phenotypes not partitioned\", \"Atomic structure of Caspr2-CNTN2 complex undetermined\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0098631\", \"supporting_discovery_ids\": [12, 16, 0]},\n      {\"term_id\": \"GO:0008092\", \"supporting_discovery_ids\": [0, 2]},\n      {\"term_id\": \"GO:0060089\", \"supporting_discovery_ids\": [2, 15]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [2, 10, 16]},\n      {\"term_id\": \"GO:0005856\", \"supporting_discovery_ids\": [0, 2]},\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [25]},\n      {\"term_id\": \"GO:0005783\", \"supporting_discovery_ids\": [6, 17]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-112316\", \"supporting_discovery_ids\": [3, 7, 19, 20]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [3, 17, 18]},\n      {\"term_id\": \"R-HSA-392499\", \"supporting_discovery_ids\": [25, 26]},\n      {\"term_id\": \"R-HSA-1643685\", \"supporting_discovery_ids\": [4, 15, 24]}\n    ],\n    \"complexes\": [\n      \"Caspr2-CASK-GluA1 tripartite complex\",\n      \"juxtaparanodal Caspr2-Kv1-CNTN2 complex\"\n    ],\n    \"partners\": [\n      \"CNTN2\",\n      \"EPB41L3\",\n      \"CASK\",\n      \"KCNA1\",\n      \"ADAM22\",\n      \"LGI1\",\n      \"FOXP2\",\n      \"GRIA1\"\n    ],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":8,"faith_total":8,"faith_pct":100.0}}