{"gene":"EPHA4","run_date":"2026-04-28T17:46:03","timeline":{"discoveries":[{"year":2003,"finding":"EphA4 is enriched on dendritic spines of hippocampal pyramidal neurons; activation by astrocyte-expressed ephrin-A3 induces spine retraction, and kinase-inactive EphA4 or EphA4 knockout causes distorted spine morphology, demonstrating that ephrin-A3/EphA4 signaling controls dendritic spine shape through neuroglial cross-talk.","method":"EphA4 knockout mice, kinase-inactive EphA4 transfection in hippocampal slices, ephrin-A3 activation assays, immunolocalization","journal":"Nature neuroscience","confidence":"High","confidence_rationale":"Tier 2 — multiple orthogonal methods (KO mice, dominant-negative, pharmacological activation) with clear morphological readout, replicated across conditions","pmids":["12496762"],"is_preprint":false},{"year":2003,"finding":"EphA4-positive excitatory spinal interneurons and ephrinB3 are required for left-right limb alternation during locomotion; loss of EphA4 or ephrinB3 converts alternating gait to synchronous hopping, establishing EphA4 as an essential organizer of the spinal central pattern generator.","method":"EphA4 and ephrinB3 knockout mice, isolated spinal cord electrophysiology, anatomical tracing","journal":"Science","confidence":"High","confidence_rationale":"Tier 2 — genetic loss-of-function with defined circuit-level phenotype, complementary KO of ligand","pmids":["12649481"],"is_preprint":false},{"year":1998,"finding":"EphA4 is required for the development of the corticospinal tract; EphA4 null mice show major disruptions in corticospinal axon trajectories within the medulla and spinal cord, resulting in a hopping gait.","method":"EphA4 null mutant mouse, anterograde tracing of corticospinal tract, behavioral analysis","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 2 — clean KO with specific anatomical and behavioral phenotype","pmids":["9789074"],"is_preprint":false},{"year":2006,"finding":"Cdk5 is recruited to activated EphA4, undergoes tyrosine phosphorylation and activation, then phosphorylates ephexin1 to enhance RhoA activation, driving ephrin-A1-induced dendritic spine retraction and reduction of mEPSC frequency; blocking Cdk5 or its phosphorylation of ephexin1 abolishes EphA4-dependent spine retraction.","method":"Pharmacological Cdk5 inhibition, Cdk5-/- neurons, Co-IP of EphA4/Cdk5/ephexin1, phospho-mutant ephexin1 constructs, mEPSC recordings","journal":"Nature neuroscience","confidence":"High","confidence_rationale":"Tier 1–2 — multiple orthogonal biochemical and electrophysiological methods, genetic and pharmacological validation","pmids":["17143272"],"is_preprint":false},{"year":2004,"finding":"EphA4 is upregulated on reactive astrocytes after spinal cord injury; EphA4-/- astrocytes fail to respond to inflammatory cytokines, show reduced gliosis, and support longer neurite outgrowth; blocking astrocyte EphA4 with monomeric ephrinA5-Fc promotes neurite extension, identifying EphA4 as a regulator of astrocytic gliosis and axonal inhibition after injury.","method":"EphA4 KO mice, spinal cord hemisection, anterograde/retrograde tracing, in vitro neurite outgrowth on astrocytes, monomeric EphA4 blocker, cytokine stimulation assay","journal":"The Journal of neuroscience","confidence":"High","confidence_rationale":"Tier 2 — KO model plus in vitro pharmacological blockade with specific cellular phenotype readout","pmids":["15537875"],"is_preprint":false},{"year":2009,"finding":"EphA4 in the postsynaptic CA1 neuron modulates LTP by controlling astrocytic ephrin-A3 reverse signaling, which in turn regulates glial glutamate transporter levels; lack of EphA4 increases glial glutamate transporter abundance, and pharmacological inhibition of glial glutamate transporters rescues LTP defects in EphA4 and ephrin-A3 mutant mice.","method":"EphA4 and ephrin-A3 knockout mice, LTP electrophysiology, pharmacological glutamate transporter inhibition, astrocyte transporter current recording, transgenic ephrin-A3 overexpression","journal":"Nature neuroscience","confidence":"High","confidence_rationale":"Tier 2 — multiple genetic and pharmacological approaches with electrophysiological phenotype rescue","pmids":["19734893"],"is_preprint":false},{"year":2000,"finding":"EphA4 expressed on dorsal limb motor axons mediates dorsal-versus-ventral trajectory selection; in EphA4 mutant mice, presumptive dorsal motor axons fail to enter the dorsal compartment and join the ventral nerve, demonstrating EphA4-dependent repulsion by ephrin ligands in ventral mesoderm.","method":"EphA4 knockout mouse, axon tracing, protein expression analysis in motor axon subpopulations","journal":"Development","confidence":"High","confidence_rationale":"Tier 2 — clean KO with specific axon guidance phenotype","pmids":["10887087"],"is_preprint":false},{"year":2007,"finding":"Alpha2-chimaerin interacts with activated EphA4 via its SH2 domain, undergoes tyrosine phosphorylation, and enhances its RacGAP activity toward Rac1, mediating ephrin-induced growth cone collapse; alpha2-chimaerin mutant mice phenocopy EphA4 kinase-inactive mice with a hopping gait and defective corticospinal/spinal interneuron projections.","method":"Co-IP, SH2-domain binding, in vitro GAP activity assay, alpha2-chimaerin KO mice, locomotor analysis, axon tracing; confirmed by two independent labs (PMIDs 17785183 and 17911252)","journal":"Neuron","confidence":"High","confidence_rationale":"Tier 1–2 — biochemical reconstitution of interaction and enzymatic activation, confirmed by two independent groups with genetic in vivo validation","pmids":["17785183","17911252"],"is_preprint":false},{"year":2010,"finding":"EphA4 activation leads to association with the ubiquitin ligase APC(Cdh1), which targets GluR1 (AMPA receptor subunit) for proteasomal degradation; depletion of Cdh1 abolishes EphA4-dependent GluR1 downregulation and prevents homeostatic reduction of mEPSC amplitude caused by chronic elevated synaptic activity.","method":"Co-IP of EphA4 with APC/Cdh1, in vitro ubiquitination assay, Cdh1 knockdown, mEPSC recordings, surface GluR1 assay","journal":"Nature neuroscience","confidence":"High","confidence_rationale":"Tier 1–2 — in vitro ubiquitination reconstitution plus co-IP and electrophysiological phenotype","pmids":["21186356"],"is_preprint":false},{"year":2009,"finding":"Gamma-secretase cleaves EphA4 in an activity-dependent manner at synapses; the resulting EphA4 intracellular domain (ICD) promotes dendritic spine formation by activating Rac signaling, linking gamma-secretase processing of EphA4 to spine morphogenesis.","method":"Identification of EphA4 as gamma-secretase substrate by biochemical cleavage assay, overexpression of EphA4-ICD, Rac signaling reporter assay, spine counting","journal":"The Journal of cell biology","confidence":"Medium","confidence_rationale":"Tier 2 — substrate identification with functional overexpression data, single lab","pmids":["19414612"],"is_preprint":false},{"year":2007,"finding":"EphA4 activation by ephrin-A3 inhibits beta1-integrin activity in hippocampal neurons by decreasing phosphorylation of Cas, FAK, and Pyk2 and reducing Cas-Fyn and Cas-Crk associations; inhibition of integrin or Cas function mimics EphA4-induced spine retraction, and blocking beta1-integrin inactivation prevents EphA4 effects on spines.","method":"Ephrin-A3 stimulation in hippocampal slices, phospho-immunoblotting of FAK/Pyk2/Cas, co-IP of Cas with Fyn/Crk, integrin activity assay, spine morphology analysis","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 2 — multiple biochemical readouts with functional rescue, moderate evidence from single lab","pmids":["17875741"],"is_preprint":false},{"year":2007,"finding":"EphA4 interacts via its C-terminus PDZ-binding motif with the PDZ domain of SPAR (spine-associated RapGAP), leading to Cdk5-dependent inactivation of Rap1 and Rap2; SPAR-mediated Rap1 inactivation is required for ephrin-A-dependent growth cone collapse and decreased integrin-mediated adhesion in neuronal cells.","method":"Co-IP of EphA4 with SPAR, Rap1/Rap2 activity assays, Rap GTPase-activating assay, growth cone collapse assay with dominant-active Rap mutants","journal":"The Journal of neuroscience","confidence":"Medium","confidence_rationale":"Tier 2 — Co-IP and functional GTPase assays with phenotypic validation, single lab","pmids":["18094260"],"is_preprint":false},{"year":2007,"finding":"EphA4 activation recruits and activates PLCgamma1 via an SH2 domain interaction requiring EphA4 juxtamembrane tyrosines; PLC activity is required for ephrin-induced spine retraction and modulates cofilin membrane association, linking EphA4 to actin remodeling in dendritic spines.","method":"Co-IP of EphA4 with PLCgamma1, SH2 domain binding, PLC inhibitor studies in hippocampal slices, cofilin fractionation assay, spine morphology imaging","journal":"The Journal of neuroscience","confidence":"Medium","confidence_rationale":"Tier 2 — biochemical interaction mapping plus pharmacological phenotype, single lab","pmids":["17494698"],"is_preprint":false},{"year":2005,"finding":"EphA4 cytoplasmic domain directly interacts with the juxtamembrane domain of FGFR1-4 (identified by yeast two-hybrid and confirmed biochemically); activated FGFR1 trans-phosphorylates kinase-dead EphA4 and vice versa, and ephrin-A1 co-stimulation potentiates FGF-induced MAPK signaling through FRS2alpha.","method":"Yeast two-hybrid, Co-IP, kinase-dead receptor trans-phosphorylation, MAPK assay with ligand co-stimulation","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"Medium","confidence_rationale":"Tier 2 — yeast two-hybrid plus biochemical Co-IP and functional signaling assay, single lab","pmids":["16365308"],"is_preprint":false},{"year":2006,"finding":"GDNF/Ret and EphA4 signals cooperate in the same binary dorsal-ventral motor axon guidance decision; LMC(l) axons require EphA4-mediated repulsion from ephrin-A-expressing ventral mesoderm, and loss of both Ret and EphA4 synergistically worsens aberrant ventral trajectory, placing the two systems in a cooperative pathway.","method":"Gdnf, Ret, and EphA4 single and compound knockout mice, motor axon tracing, genetic epistasis","journal":"Neuron","confidence":"High","confidence_rationale":"Tier 2 — genetic epistasis with double mutants showing additive/synergistic phenotype","pmids":["16600854"],"is_preprint":false},{"year":2008,"finding":"Rin1, a postnatal brain-specific Rab5-GEF, co-localizes with EphA4 in synaptosomal fractions, interacts with EphA4 via its SH2 domain (requiring EphA4 tyrosine phosphorylation), and mediates ligand-induced EphA4 endocytosis in amygdala neurons; EphA4 is required for synaptic plasticity in the amygdala, and Rin1 suppresses this plasticity by promoting EphA4 internalization.","method":"Co-IP of Rin1 and EphA4 from synaptosomes, SH2 domain requirement, internalization assay in neurons, EphA4 KO LTP assay","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"Medium","confidence_rationale":"Tier 2 — biochemical interaction plus functional endocytosis and plasticity assays, single lab","pmids":["18723684"],"is_preprint":false},{"year":2005,"finding":"Alpha-syntrophin interacts with ARMS (ankyrin repeat-rich membrane spanning protein) via a PDZ domain interaction, clustering ARMS at the neuromuscular junction (NMJ); ARMS enhances EphA4 signaling, and alpha-syntrophin further augments this; alpha-syntrophin null mice show disrupted ARMS and EphA4 localization at the NMJ.","method":"Yeast two-hybrid, Co-IP, PDZ domain-dependent clustering assay, siRNA knockdown in C2C12 myotubes, alpha-syntrophin KO mouse immunolocalization","journal":"The Journal of cell biology","confidence":"Medium","confidence_rationale":"Tier 2–3 — yeast two-hybrid plus Co-IP and KO localization, single lab","pmids":["15939763"],"is_preprint":false},{"year":2008,"finding":"Meltrin beta/ADAM19 interacts physically with EphA4 in developing motor neurons; co-expression of ADAM19 and EphA4 blocks endocytosis of ephrin-A5-EphA4 complexes independently of ADAM19 protease activity, stabilizing ephrin-A5 signaling and regulating NMJ formation.","method":"Co-IP of ADAM19 and EphA4, internalization assay, protease-dead ADAM19 mutant, ADAM19 KO mouse NMJ analysis","journal":"PloS one","confidence":"Medium","confidence_rationale":"Tier 2–3 — Co-IP plus functional endocytosis assay with protease-dead mutant, single lab","pmids":["18830404"],"is_preprint":false},{"year":2009,"finding":"Crystal structure of the EphA4 ligand-binding domain in complex with ephrin-B2 reveals a loose fit of the ephrin-B2 G-H loop in the EphA4 ligand-binding channel; mutation of EphA4 residues Gln12 and Glu14 selectively reduces ephrin-B affinity ~10-fold without affecting ephrin-A binding, defining separate molecular determinants for EphA4's cross-subclass (ephrin-B) binding.","method":"X-ray crystallography, mutagenesis, binding affinity measurements (ITC/ELISA), NMR","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 — crystal structure plus mutagenesis with quantitative affinity measurements","pmids":["19875447"],"is_preprint":false},{"year":2008,"finding":"Crystal structure of the EphA4 ligand-binding domain (first for an EphA subclass receptor) shows a jellyfish beta-sandwich with variable D-E and J-K loop regions forming the ephrin-binding channel; two small-molecule antagonists bind within this channel contacting Ile31-Met32, Gln43, and Ile131-Gly132, competitively displacing ephrin ligands with Kd ~20-26 µM.","method":"X-ray crystallography, NMR HSQC titration, ITC, molecular docking, ephrin competition ELISA","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 — crystal structure plus NMR and ITC with atomic-level binding site definition","pmids":["18708347"],"is_preprint":false},{"year":2010,"finding":"Crystal structure of the EphA4 ligand-binding domain reveals two distinct, well-ordered conformations in the unbound state, suggesting that EphA4's structural flexibility in the ligand-binding surface underlies its promiscuous binding to both ephrin-A and ephrin-B ligands.","method":"X-ray crystallography at 2.3 Å resolution","journal":"Biochemical and biophysical research communications","confidence":"High","confidence_rationale":"Tier 1 — crystal structure demonstrating conformational flexibility","pmids":["20678482"],"is_preprint":false},{"year":2014,"finding":"Solution NMR structure of the EphA4 LBD shows that two small molecules trigger opposite signaling outputs by oppositely modulating EphA4 backbone dynamics: one enhances dynamics (agonist) and the other suppresses dynamics (antagonist), establishing a dynamic principle for EphA4 agonism versus antagonism.","method":"Solution NMR (first for 16 Eph receptors), NMR dynamics measurements, small-molecule binding studies","journal":"ACS chemical biology","confidence":"High","confidence_rationale":"Tier 1 — NMR structure plus dynamics analysis with mechanistic interpretation","pmids":["25334011"],"is_preprint":false},{"year":2014,"finding":"Crystal structure of the cyclic peptide antagonist APY bound to the EphA4 LBD shows that the peptide occupies the ephrin ligand-binding pocket and induces a 'closed' loop conformation; structure-guided optimization yielded APY-βAla8.am with nanomolar EphA4 affinity that inhibits ephrin-induced EphA4 activation and growth cone collapse.","method":"X-ray crystallography of EphA4-LBD/peptide complex, structure-guided mutagenesis, binding affinity measurements, cell-based EphA4 activation assay, growth cone collapse assay","journal":"ACS chemical biology","confidence":"High","confidence_rationale":"Tier 1 — crystal structure plus functional cell assays and structure-guided optimization","pmids":["25268696"],"is_preprint":false},{"year":2014,"finding":"Amyloid-β oligomers (AβOs) activate EphA4 in hippocampal neurons, leading to downstream activation of c-Abl kinase in dendritic spines; EphA4 KO or EphA4 antagonist prevents AβO-induced c-Abl activation, dendritic spine loss, LTP blockade, and neuronal apoptosis, placing EphA4 upstream of c-Abl in AβO-mediated synaptotoxicity.","method":"EphA4 KO neurons, EphA4 shRNA, EphA4 antagonist peptide KYL, c-Abl inhibitor STI, phospho-EphA4 and phospho-c-Abl immunoblotting, spine counting, LTP electrophysiology","journal":"PloS one","confidence":"Medium","confidence_rationale":"Tier 2 — genetic and pharmacological pathway placement with multiple phenotypic readouts, single lab","pmids":["24658113"],"is_preprint":false},{"year":2014,"finding":"Enhanced EphA4 signaling in the hippocampus of APP/PS1 AD mice mediates synaptic LTP impairment; soluble Aβ oligomers activate EphA4, EphA4 depletion in CA1 reverses LTP suppression, and the small molecule rhynchophylline (identified by molecular docking as an EphA4 inhibitor) blocks EphA4 activity and restores LTP in AD mice.","method":"APP/PS1 transgenic mouse, EphA4 shRNA in CA1, molecular docking, in vitro kinase inhibition, oral drug administration, LTP electrophysiology","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"Medium","confidence_rationale":"Tier 2 — genetic depletion plus pharmacological rescue with electrophysiological readout, single lab","pmids":["24958880"],"is_preprint":false},{"year":2017,"finding":"SORLA physically interacts with EphA4 and attenuates ephrinA1-induced EphA4 clustering and activation; SORLA transgenic mice show decreased EphA4 activation and redistribution to postsynaptic densities, with reduced Aβ-induced LTP deficits; active EphA4 is elevated in human AD brains and inversely correlates with SORLA/EphA4 association.","method":"Co-IP of SORLA and EphA4, SORLA transgenic mouse, EphA4 phosphorylation assay, LTP electrophysiology, postsynaptic density fractionation, human AD brain analysis","journal":"The Journal of experimental medicine","confidence":"Medium","confidence_rationale":"Tier 2 — biochemical interaction plus transgenic mouse phenotype with electrophysiological validation, single lab","pmids":["29114064"],"is_preprint":false},{"year":2013,"finding":"Ephrin-A5 in cochlear hair cells signals through EphA4 on spiral ganglion neurons to repel type I afferent fibers from the outer hair cell area; in the absence of ephrin-A5 or EphA4, type I projections aberrantly invade the outer hair cell layer; downstream of EphA4, ephexin-1, cofilin, and MLCK mediate growth cone collapse of type I spiral ganglion neurons.","method":"Ephrin-A5 and EphA4 KO mice, anterograde tracing, growth cone collapse assay, ephexin-1/cofilin/MLCK pharmacological inhibition","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 2 — genetic KO with anatomical phenotype, downstream pathway defined pharmacologically","pmids":["23385583"],"is_preprint":false},{"year":2011,"finding":"EphrinB3/EphA4 bidirectional signaling mediates segregation of MGE- and POA-derived cortical interneurons into deep and superficial migratory streams: EphA4 forward signaling repels deeply migrating MGE interneurons from POA-derived cells expressing ephrinB3, while EphA4-induced ephrinB3 reverse signaling restricts POA interneurons to the superficial path.","method":"In vitro migration assays with ephrinB3/EphA4 perturbation, in utero electroporation, EphA4 conditional KO mice, DiI labeling","journal":"The Journal of neuroscience","confidence":"Medium","confidence_rationale":"Tier 2 — in vitro and in vivo loss-of-function with defined pathway directionality, single lab","pmids":["22171039"],"is_preprint":false},{"year":2013,"finding":"EphrinB3/EphA4 forward signaling guides both ascending Zic2+/EphA4+ spinal interneuron axons (ipsilateral, embryonic) and descending corticospinal tract axons (postnatal) through the same molecular mechanism; conditional EphA4 KO shows CST guidance defects are linked to EphA4 in Zic2+ spinal neurons, not CST axons themselves.","method":"Conditional EphA4 KO mice (cell-type specific), anterograde and retrograde tracing, in situ hybridization, immunohistochemistry","journal":"Neuron","confidence":"High","confidence_rationale":"Tier 2 — conditional KO with cell-type resolution and anatomical tracing","pmids":["24360544"],"is_preprint":false},{"year":2014,"finding":"Spinal cord-specific deletion of EphA4 signaling in excitatory Vglut2+ neurons is sufficient to generate the hopping gait, accompanied by increased midline crossing of Vglut2+ axons; forebrain-specific deletion does not affect locomotor pattern, functionally localizing the EphA4 circuit requirement to spinal excitatory interneurons.","method":"Intersectional genetics (cell-type-specific conditional KO), overground locomotion analysis, anterograde tracing of midline-crossing axons","journal":"The Journal of neuroscience","confidence":"High","confidence_rationale":"Tier 2 — conditional KO with cell-type resolution and precise behavioral and anatomical phenotype","pmids":["24623763"],"is_preprint":false},{"year":2018,"finding":"Axonal ephrin-A1 interacts with EphA4 on oligodendrocytes to activate an ephexin1-RhoA-ROCK-myosin 2 signaling cascade that inhibits oligodendrocyte process extension and myelination; inhibition of EphA4 or downstream pathway components increases the number of myelin sheaths per oligodendrocyte.","method":"Axon-mimicking microfibers, zebrafish myelination model, EphA4 knockdown, pharmacological ROCK and RhoA inhibition, Co-IP/signaling pathway analysis","journal":"Glia","confidence":"Medium","confidence_rationale":"Tier 2 — functional assays in two model systems with defined signaling pathway, single lab","pmids":["29350423"],"is_preprint":false},{"year":2013,"finding":"Ephrin-A1/EphA4 signaling in endothelial cells promotes monocyte adhesion via activation of the Rho signaling pathway and subsequent actin stress fiber polymerization, without requiring active transcription; EphA4 mediates this pro-adhesive effect downstream of ephrin-A1.","method":"Ephrin-A1-Fc stimulation of endothelial cells, monocyte adhesion assay, Rho activation assay, actin polymerization imaging, EphA4 blocking antibody, transcription inhibitor control","journal":"Biochimica et biophysica acta","confidence":"Medium","confidence_rationale":"Tier 2 — pharmacological pathway dissection with functional adhesion readout, single lab","pmids":["23707953"],"is_preprint":false},{"year":2017,"finding":"EphA4 acts as a dependence receptor: in the absence of its ligand ephrin-B3, EphA4 triggers cell apoptosis; ephrin-B3 overexpression in glioblastoma inhibits EphA4 pro-apoptotic activity, supports tumor and endothelial cell survival, and silencing ephrin-B3 decreases tumor vascularization and growth in xenograft models.","method":"Ephrin-B3 siRNA knockdown, EphA4 dependence receptor apoptosis assay, xenograft mouse model, in vitro endothelial cell survival assay","journal":"Oncotarget","confidence":"Medium","confidence_rationale":"Tier 2–3 — in vitro and in vivo loss-of-function with apoptosis and tumor growth readouts, single lab","pmids":["28423606"],"is_preprint":false},{"year":2009,"finding":"EphA4 is required for cortical progenitor cell proliferation; EphA4-/- cortex has reduced area, fewer cells, and less cell division; overexpression of EphA4 expands the progenitor pool; EphA4 interacts with and is activated by ephrin-B1 expressed on neighboring progenitors, driving forward signaling-mediated proliferation.","method":"EphA4 KO mice, in vivo electroporation of dominant-negative/wild-type EphA4, Co-IP of EphA4 with ephrin-B1, BrdU incorporation assay","journal":"Development","confidence":"Medium","confidence_rationale":"Tier 2 — KO plus gain-of-function with biochemical interaction identification, single lab","pmids":["19542359"],"is_preprint":false},{"year":2022,"finding":"EphA4 in oligodendrocyte precursor cells (OPCs) promotes OPC proliferation but inhibits their maturation and myelination after ischemic stroke; the pro-myelination effect of EphA4 deletion is mediated by the Ephexin-1/RhoA/ROCK signaling pathway; OPC-conditional EphA4 KO improves myelin-associated protein levels and functional recovery.","method":"OPC-specific conditional EphA4 KO (PDGFRα-Cre), MCAO stroke model, shRNA, LV-EphA4 overexpression, Western blot for myelin proteins, Ephexin-1/RhoA/ROCK pathway analysis","journal":"Glia","confidence":"Medium","confidence_rationale":"Tier 2 — conditional KO with cell-type specificity and signaling pathway defined, single lab","pmids":["35762396"],"is_preprint":false},{"year":2017,"finding":"EphA4 in subarachnoid hemorrhage activates the Ephexin-1/RhoA/ROCK2 pathway to promote blood-brain barrier disruption, brain edema, and apoptotic neuronal death; EphA4 siRNA reduces these effects, while recombinant Ephexin-1 reverses the siRNA effect and Fasudil (ROCK2 inhibitor) restores the phenotype.","method":"EphA4 siRNA (i.c.v.), recombinant Ephexin-1, Fasudil, SAH rat model, Evans blue permeability assay, brain water content, Western blot, tight junction protein analysis","journal":"Experimental neurology","confidence":"Medium","confidence_rationale":"Tier 2 — pharmacological rescue/epistasis with multiple pathway components and functional readouts, single lab","pmids":["28698029"],"is_preprint":false},{"year":2023,"finding":"EphA4 on peripheral myeloid-derived immune cells restricts efferocytosis after brain injury by suppressing the ERK/Stat6/MERTK pathway; loss of EphA4 on infiltrating macrophages/microglia enhances MERTK expression and activity, increases phagocytosis of apoptotic debris, and improves functional outcome.","method":"Bone marrow chimeric EphA4 KO mice, single-cell RNAseq, in vitro efferocytosis assay, ERK/Stat6 selective inhibitors, p-MERTK/p-ERK/p-Stat6 co-localization","journal":"Journal of neuroinflammation","confidence":"Medium","confidence_rationale":"Tier 2 — cell-specific genetic deletion plus pharmacological pathway dissection, single lab","pmids":["37941008"],"is_preprint":false},{"year":1997,"finding":"EphA4 immunoreactivity in the adult rat brain is enriched in dendrites and dendritic spines (associated with the plasma membrane) and in myelinated axons, establishing the subcellular localization of EphA4 at synaptic sites in the mature CNS.","method":"Immunoperoxidase and immunogold electron microscopy with region/cell-type fractionation in adult rat brain","journal":"Brain research","confidence":"Medium","confidence_rationale":"Tier 2 — EM-level localization with gold labeling showing plasma membrane association at synaptic structures","pmids":["9401744"],"is_preprint":false},{"year":2016,"finding":"EBV latent membrane protein 1 (LMP1) suppresses EphA4 expression by activating the ERK pathway, leading to Sp1-mediated repression of the EphA4 promoter; overexpression of EphA4 prevents LCL proliferation, identifying EphA4 as a growth suppressor downstream of LMP1-ERK-Sp1 signaling in B lymphoma cells.","method":"EphA4 overexpression/knockdown in LCLs, LMP1 overexpression/knockdown, luciferase promoter assay, ERK pathway inhibitors, Sp1 ChIP","journal":"Blood","confidence":"Medium","confidence_rationale":"Tier 2 — promoter reporter assay plus epistasis and functional proliferation readout, single lab","pmids":["27338098"],"is_preprint":false},{"year":2016,"finding":"An EphA4/Sipa1l3/Wnt pathway regulates eye development: EphA4 acts upstream of Sipa1l3 (direct physical interaction), and both inhibit canonical Wnt/β-catenin signaling; depletion of either EphA4 or Sipa1l3 in Xenopus causes smaller eyes with lens fiber cell maturation defects and upregulation of the Wnt target axin2.","method":"Co-IP of EphA4 and Sipa1l3, morpholino loss-of-function in Xenopus, epistasis rescue experiments, axin2 reporter (canonical Wnt readout), Wnt pathway inhibitors","journal":"Development","confidence":"Medium","confidence_rationale":"Tier 2 — direct interaction plus genetic epistasis and pathway reporter in a vertebrate model","pmids":["27993984"],"is_preprint":false}],"current_model":"EphA4 is a promiscuous receptor tyrosine kinase that, upon binding ephrin-A or ephrin-B ligands (with structural promiscuity conferred by flexible D-E and J-K loops in its ligand-binding domain), undergoes autophosphorylation and recruits a defined set of effectors—including Cdk5/ephexin1/RhoA, alpha2-chimaerin/Rac1, PLCgamma1/cofilin, SPAR/Rap1, APC(Cdh1)/GluR1, and c-Abl—to regulate actin cytoskeletal dynamics, dendritic spine morphology, AMPA receptor trafficking, and synaptic plasticity; its downstream Ephexin-1/RhoA/ROCK cascade also controls axon guidance, myelination, gliosis, and neuroinflammation, while ligand availability, gamma-secretase cleavage, Rin1-mediated endocytosis, and SORLA binding modulate its surface signaling state in both development and neurodegeneration."},"narrative":{"teleology":[{"year":1997,"claim":"Before any functional studies in vivo, the subcellular distribution of EphA4 at synaptic sites in the adult brain was unknown; immunogold EM demonstrated enrichment on dendritic spine plasma membranes and myelinated axons, establishing EphA4 as a synaptically positioned receptor.","evidence":"Immunoperoxidase and immunogold electron microscopy in adult rat brain","pmids":["9401744"],"confidence":"Medium","gaps":["No functional consequence of synaptic localization demonstrated","Ligand identity at these synaptic sites not established"]},{"year":1998,"claim":"The in vivo requirement for EphA4 in CNS axon guidance was established when EphA4-null mice showed disrupted corticospinal tract trajectories and a hopping gait, demonstrating a non-redundant role in long-range axon pathfinding.","evidence":"EphA4-null mouse with anterograde tracing and behavioral analysis","pmids":["9789074"],"confidence":"High","gaps":["Cell-type autonomy of the phenotype not resolved","Downstream signaling pathway unknown"]},{"year":2000,"claim":"EphA4's role was extended to peripheral axon guidance when EphA4-mutant dorsal limb motor axons were shown to misproject ventrally, establishing EphA4-mediated repulsion as the mechanism for dorsal-ventral trajectory selection.","evidence":"EphA4 KO mouse with motor axon tracing","pmids":["10887087"],"confidence":"High","gaps":["Cooperation with other guidance systems not tested","Downstream effectors not identified"]},{"year":2003,"claim":"Two contemporaneous studies revealed that EphA4 operates in distinct neuronal circuits — dendritic spines of hippocampal pyramidal neurons (controlling spine shape via neuroglial cross-talk with ephrin-A3) and spinal excitatory interneurons (where ephrinB3/EphA4 organizes left-right locomotor alternation) — demonstrating broad functional deployment across brain regions and ligand subclasses.","evidence":"EphA4 KO mice with hippocampal slice ephrin-A3 activation and spinal cord electrophysiology/ephrinB3 KO","pmids":["12496762","12649481"],"confidence":"High","gaps":["Intracellular signaling mediating spine retraction uncharacterized","Molecular identity of the spinal midline barrier mechanism not known"]},{"year":2004,"claim":"EphA4's role was shown to extend beyond neurons to reactive astrocytes, where it drives gliosis and axon growth inhibition after spinal cord injury, broadening the receptor's function to neuroinflammatory contexts.","evidence":"EphA4 KO mice with spinal cord hemisection, in vitro astrocyte neurite outgrowth assays, monomeric ephrinA5-Fc blocker","pmids":["15537875"],"confidence":"High","gaps":["Downstream signaling in astrocytes not defined","Whether blocking EphA4 promotes functional recovery in vivo not tested"]},{"year":2006,"claim":"The first downstream signaling cascade was delineated: Cdk5 is recruited to activated EphA4, phosphorylates ephexin-1, which activates RhoA to drive spine retraction — establishing the Cdk5/ephexin-1/RhoA module as the core effector for EphA4 in dendritic spine remodeling.","evidence":"Co-IP of EphA4/Cdk5/ephexin-1, Cdk5-null neurons, phospho-mutant ephexin-1, mEPSC recordings","pmids":["17143272"],"confidence":"High","gaps":["Relationship of this pathway to other EphA4 effectors (Rac, integrins) not integrated","Whether the same cascade operates in axon guidance not tested"]},{"year":2007,"claim":"Multiple parallel EphA4 effector arms were discovered simultaneously: alpha2-chimaerin (RacGAP for Rac1, phenocopying EphA4 KO in vivo), PLCγ1/cofilin (actin remodeling in spines), SPAR/Rap1 (integrin inactivation for growth cone collapse), and integrin inhibition via Cas/FAK dephosphorylation — revealing a branched signaling architecture downstream of EphA4.","evidence":"Alpha2-chimaerin KO mice (two independent labs), Co-IPs and GAP assays, PLCγ1 SH2 binding and PLC inhibitor studies, SPAR/Rap activity assays, integrin/Cas/FAK phospho-immunoblotting","pmids":["17785183","17911252","17494698","18094260","17875741"],"confidence":"High","gaps":["How these parallel arms are coordinated or selectively activated remains unknown","SPAR and PLCγ1 pathways validated in single labs only"]},{"year":2008,"claim":"Structural biology began resolving how EphA4 achieves ligand promiscuity: crystal structures revealed a jellyfish β-sandwich with flexible D-E and J-K loops forming the ephrin-binding channel, and small-molecule antagonists were shown to bind competitively within this channel.","evidence":"X-ray crystallography, NMR HSQC titration, ITC, ephrin competition ELISA","pmids":["18708347"],"confidence":"High","gaps":["No full-length EphA4 structure","Mechanism of ligand-induced kinase activation not structurally resolved"]},{"year":2009,"claim":"Three discoveries expanded EphA4's functional scope: gamma-secretase cleavage of EphA4 generates an ICD that promotes spine formation via Rac; EphA4 controls LTP by regulating astrocytic glutamate transporter levels through ephrin-A3 reverse signaling; and EphA4/ephrin-B1 interaction drives cortical progenitor proliferation — demonstrating signaling roles in proteolytic processing, trans-synaptic glial regulation, and neurogenesis.","evidence":"Gamma-secretase cleavage biochemistry and Rac reporter; EphA4/ephrinA3 KO mice with LTP rescue by glutamate transporter inhibitors; EphA4 KO cortex BrdU analysis and in vivo electroporation","pmids":["19414612","19734893","19542359"],"confidence":"High","gaps":["Physiological relevance of gamma-secretase cleavage not confirmed in vivo","Relative contribution of forward versus reverse signaling in LTP not fully resolved"]},{"year":2009,"claim":"Crystallographic analysis of EphA4 in complex with the cross-subclass ligand ephrin-B2 identified specific residues (Gln12, Glu14) that confer ephrin-B binding without affecting ephrin-A interaction, defining the structural basis for EphA4's unusual cross-subclass promiscuity.","evidence":"X-ray crystallography of EphA4-LBD/ephrin-B2 complex, mutagenesis with ITC/ELISA binding measurements","pmids":["19875447"],"confidence":"High","gaps":["Functional consequences of selectively disrupting ephrin-B binding in vivo not tested"]},{"year":2010,"claim":"EphA4 was linked to homeostatic synaptic scaling through its association with the ubiquitin ligase APC(Cdh1), which targets the AMPA receptor subunit GluR1 for proteasomal degradation — extending EphA4 signaling from structural spine remodeling to receptor trafficking.","evidence":"Co-IP of EphA4/APC/Cdh1, in vitro ubiquitination, Cdh1 knockdown, mEPSC recordings","pmids":["21186356"],"confidence":"High","gaps":["How EphA4 activation triggers APC(Cdh1) recruitment mechanistically is unclear","Whether this pathway operates in pathological conditions not examined"]},{"year":2013,"claim":"Conditional and cell-type-specific knockouts refined the circuit-level requirement: EphA4 in Vglut2+ spinal excitatory interneurons is both necessary and sufficient for locomotor alternation, and ephrinB3/EphA4 guides both ascending spinal and descending CST axons through midline barriers, with the CST defect arising non-autonomously from EphA4 in Zic2+ spinal neurons.","evidence":"Cell-type-specific conditional EphA4 KO (Vglut2-Cre, Zic2-Cre), locomotor analysis, anterograde/retrograde tracing","pmids":["24623763","24360544"],"confidence":"High","gaps":["How EphA4 in spinal neurons non-autonomously affects CST axon trajectory is mechanistically unresolved"]},{"year":2014,"claim":"EphA4 was identified as a mediator of amyloid-β oligomer synaptotoxicity: Aβ oligomers activate EphA4, which signals through c-Abl to cause spine loss, LTP blockade, and apoptosis; genetic or pharmacological EphA4 inhibition rescues these deficits in AD mouse models, positioning EphA4 as a candidate therapeutic target in Alzheimer's disease.","evidence":"EphA4 KO neurons, shRNA, KYL antagonist peptide, rhynchophylline (small molecule), APP/PS1 mice, LTP electrophysiology","pmids":["24658113","24958880"],"confidence":"Medium","gaps":["Whether EphA4 is a direct Aβ receptor or is activated indirectly remains unresolved","Therapeutic efficacy in human AD not established","Findings from single labs; independent replication needed"]},{"year":2014,"claim":"NMR dynamics studies and co-crystal structures with cyclic peptide antagonists established that agonism versus antagonism of EphA4 correlates with opposite modulation of backbone dynamics in the ligand-binding domain, providing a dynamic framework for drug design.","evidence":"Solution NMR structure with dynamics measurements; X-ray crystallography of EphA4-LBD/APY peptide complex with structure-guided optimization","pmids":["25334011","25268696"],"confidence":"High","gaps":["Whether dynamics-based rules generalize to other Eph receptors untested","In vivo efficacy of optimized peptide antagonists not demonstrated"]},{"year":2017,"claim":"EphA4's role in neuroinflammation was expanded: SORLA physically interacts with EphA4 to attenuate its activation (relevant to AD), the ephexin-1/RhoA/ROCK2 cascade mediates blood-brain barrier disruption after subarachnoid hemorrhage, and EphA4 acts as a dependence receptor triggering apoptosis in the absence of ephrin-B3 in glioblastoma.","evidence":"SORLA-EphA4 Co-IP and SORLA transgenic mice with LTP; EphA4 siRNA in SAH rat model with ROCK inhibitor rescue; ephrin-B3 knockdown in glioblastoma xenografts","pmids":["29114064","28698029","28423606"],"confidence":"Medium","gaps":["SORLA mechanism of EphA4 inhibition not structurally defined","Dependence receptor function confirmed only for glioblastoma context","BBB disruption pathway from single lab"]},{"year":2018,"claim":"EphA4 was shown to inhibit oligodendrocyte myelination through the ephexin-1/RhoA/ROCK/myosin-2 cascade, extending the canonical spine retraction pathway to a glial cell myelination context.","evidence":"Microfiber myelination assay, zebrafish model, EphA4 knockdown, ROCK/RhoA pharmacological inhibition","pmids":["29350423"],"confidence":"Medium","gaps":["In vivo mammalian validation limited at this time","Whether same pathway operates in remyelination after injury not established"]},{"year":2022,"claim":"OPC-conditional EphA4 deletion after ischemic stroke confirmed EphA4 inhibits OPC maturation and myelination via ephexin-1/RhoA/ROCK, and its removal improves functional recovery, validating EphA4 as a negative regulator of remyelination.","evidence":"PDGFRα-Cre conditional EphA4 KO, MCAO stroke model, myelin protein Western blots, pathway analysis","pmids":["35762396"],"confidence":"Medium","gaps":["Long-term functional outcome and specificity of benefit not assessed","Single lab"]},{"year":2023,"claim":"EphA4 on peripheral myeloid-derived cells was found to suppress efferocytosis after brain injury by inhibiting the ERK/Stat6/MERTK pathway, revealing a non-neuronal, immune-regulatory function of EphA4 in post-injury debris clearance.","evidence":"Bone marrow chimeric EphA4 KO mice, single-cell RNAseq, in vitro efferocytosis, ERK/Stat6 inhibitors","pmids":["37941008"],"confidence":"Medium","gaps":["Whether this is a direct kinase-mediated effect or involves ligand engagement unclear","Single lab; independent replication needed"]},{"year":null,"claim":"Key unresolved questions include: how EphA4 coordinates its multiple parallel effector arms in a context-dependent manner; whether Aβ oligomers directly bind EphA4 or activate it indirectly; a full-length EphA4 structure showing kinase activation mechanism; and the translational potential of EphA4 inhibition in Alzheimer's disease or demyelinating conditions.","evidence":"","pmids":[],"confidence":"Low","gaps":["No full-length EphA4 structure available","No direct binding data for Aβ oligomers to EphA4","No clinical translation data for any EphA4-targeted therapy"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[3,7,8,12,13]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[5,30,34,36]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[0,37]},{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[37]}],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[0,3,7,10,11,12,23,30]},{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[1,2,6,14,26,28,29]},{"term_id":"R-HSA-112316","term_label":"Neuronal System","supporting_discovery_ids":[0,3,5,8,15]},{"term_id":"R-HSA-392499","term_label":"Metabolism of proteins","supporting_discovery_ids":[8]},{"term_id":"R-HSA-5357801","term_label":"Programmed Cell Death","supporting_discovery_ids":[32,35]}],"complexes":[],"partners":["EFNA3","EFNB3","CDK5","ARHGEF5","CHN2","PLCG1","SIPA1L2","SORL1"],"other_free_text":[]},"mechanistic_narrative":"EphA4 is a promiscuous receptor tyrosine kinase that functions as a central organizer of axon guidance, dendritic spine morphology, synaptic plasticity, and myelination in the nervous system. Structurally, conformational flexibility of the D-E and J-K loops in its ligand-binding domain enables binding to both ephrin-A and ephrin-B subclass ligands, and distinct loop conformations underlie agonist versus antagonist responses [PMID:18708347, PMID:20678482, PMID:25334011]. Upon ephrin-induced activation, EphA4 recruits effectors including Cdk5/ephexin-1 to activate RhoA, alpha2-chimaerin to inactivate Rac1, PLCγ1 to regulate cofilin, and APC(Cdh1) to ubiquitinate the AMPA receptor subunit GluR1, thereby controlling actin remodeling, growth cone collapse, spine retraction, and homeostatic synaptic scaling [PMID:17143272, PMID:17785183, PMID:17494698, PMID:21186356]. Beyond neurons, EphA4 signaling on astrocytes regulates gliosis and glial glutamate transporter levels to modulate LTP [PMID:15537875, PMID:19734893], on oligodendrocytes it inhibits myelination through an ephexin-1/RhoA/ROCK cascade [PMID:29350423, PMID:35762396], and in the spinal cord its expression in Vglut2-positive excitatory interneurons is required for left-right locomotor alternation [PMID:12649481, PMID:24623763]."},"prefetch_data":{"uniprot":{"accession":"P54764","full_name":"Ephrin type-A receptor 4","aliases":["EPH-like kinase 8","EK8","hEK8","Tyrosine-protein kinase TYRO1","Tyrosine-protein kinase receptor SEK"],"length_aa":986,"mass_kda":109.9,"function":"Receptor tyrosine kinase which binds membrane-bound ephrin family ligands residing on adjacent cells, leading to contact-dependent bidirectional signaling into neighboring cells. The signaling pathway downstream of the receptor is referred to as forward signaling while the signaling pathway downstream of the ephrin ligand is referred to as reverse signaling. Highly promiscuous, it has the unique property among Eph receptors to bind and to be physiologically activated by both GPI-anchored ephrin-A and transmembrane ephrin-B ligands including EFNA1 and EFNB3. Upon activation by ephrin ligands, modulates cell morphology and integrin-dependent cell adhesion through regulation of the Rac, Rap and Rho GTPases activity. Plays an important role in the development of the nervous system controlling different steps of axonal guidance including the establishment of the corticospinal projections. May also control the segregation of motor and sensory axons during neuromuscular circuit development. In addition to its role in axonal guidance plays a role in synaptic plasticity. Activated by EFNA1 phosphorylates CDK5 at 'Tyr-15' which in turn phosphorylates NGEF regulating RHOA and dendritic spine morphogenesis. In the nervous system, also plays a role in repair after injury preventing axonal regeneration and in angiogenesis playing a role in central nervous system vascular formation. Additionally, its promiscuity makes it available to participate in a variety of cell-cell signaling regulating for instance the development of the thymic epithelium. During development of the cochlear organ of Corti, regulates pillar cell separation by forming a ternary complex with ADAM10 and CADH1 which facilitates the cleavage of CADH1 by ADAM10 and disruption of adherens junctions (By similarity). Phosphorylates CAPRIN1, promoting CAPRIN1-dependent formation of a membraneless compartment (By similarity)","subcellular_location":"Cell membrane; Cell projection, axon; Cell projection, dendrite; Postsynaptic density membrane; Early endosome; Cell junction, adherens junction","url":"https://www.uniprot.org/uniprotkb/P54764/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/EPHA4","classification":"Not Classified","n_dependent_lines":0,"n_total_lines":1208,"dependency_fraction":0.0},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/EPHA4","total_profiled":1310},"omim":[{"mim_id":"620431","title":"FLYWCH-TYPE ZINC FINGER PROTEIN 1; FLYWCH1","url":"https://www.omim.org/entry/620431"},{"mim_id":"608504","title":"RHO GUANINE NUCLEOTIDE EXCHANGE FACTOR 15; ARHGEF15","url":"https://www.omim.org/entry/608504"},{"mim_id":"604930","title":"NCK ADAPTOR PROTEIN 2; NCK2","url":"https://www.omim.org/entry/604930"},{"mim_id":"602297","title":"EPHRIN B3; EFNB3","url":"https://www.omim.org/entry/602297"},{"mim_id":"602190","title":"EPHRIN RECEPTOR EphA7; EPHA7","url":"https://www.omim.org/entry/602190"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"brain","ntpm":23.6}],"url":"https://www.proteinatlas.org/search/EPHA4"},"hgnc":{"alias_symbol":["Hek8"],"prev_symbol":["TYRO1"]},"alphafold":{"accession":"P54764","domains":[{"cath_id":"2.60.120.260","chopping":"29-203","consensus_level":"high","plddt":89.2692,"start":29,"end":203},{"cath_id":"2.60.40.1770","chopping":"206-262","consensus_level":"medium","plddt":92.2212,"start":206,"end":262},{"cath_id":"2.60.40.10","chopping":"331-434","consensus_level":"high","plddt":91.0904,"start":331,"end":434},{"cath_id":"2.60.40.10","chopping":"446-531","consensus_level":"high","plddt":91.0194,"start":446,"end":531},{"cath_id":"3.30.200.20","chopping":"602-699","consensus_level":"high","plddt":86.8497,"start":602,"end":699},{"cath_id":"1.10.510.10","chopping":"704-769_786-887","consensus_level":"high","plddt":91.2629,"start":704,"end":887},{"cath_id":"1.10.150.50","chopping":"909-980","consensus_level":"high","plddt":82.4174,"start":909,"end":980}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/P54764","model_url":"https://alphafold.ebi.ac.uk/files/AF-P54764-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-P54764-F1-predicted_aligned_error_v6.png","plddt_mean":83.5},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=EPHA4","jax_strain_url":"https://www.jax.org/strain/search?query=EPHA4"},"sequence":{"accession":"P54764","fasta_url":"https://rest.uniprot.org/uniprotkb/P54764.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/P54764/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/P54764"}},"corpus_meta":[{"pmid":"12496762","id":"PMC_12496762","title":"Control 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slices, ephrin-A3 activation assays, immunolocalization\",\n      \"journal\": \"Nature neuroscience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal methods (KO mice, dominant-negative, pharmacological activation) with clear morphological readout, replicated across conditions\",\n      \"pmids\": [\"12496762\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"EphA4-positive excitatory spinal interneurons and ephrinB3 are required for left-right limb alternation during locomotion; loss of EphA4 or ephrinB3 converts alternating gait to synchronous hopping, establishing EphA4 as an essential organizer of the spinal central pattern generator.\",\n      \"method\": \"EphA4 and ephrinB3 knockout mice, isolated spinal cord electrophysiology, anatomical tracing\",\n      \"journal\": \"Science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — genetic loss-of-function with defined circuit-level phenotype, complementary KO of ligand\",\n      \"pmids\": [\"12649481\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1998,\n      \"finding\": \"EphA4 is required for the development of the corticospinal tract; EphA4 null mice show major disruptions in corticospinal axon trajectories within the medulla and spinal cord, resulting in a hopping gait.\",\n      \"method\": \"EphA4 null mutant mouse, anterograde tracing of corticospinal tract, behavioral analysis\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — clean KO with specific anatomical and behavioral phenotype\",\n      \"pmids\": [\"9789074\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"Cdk5 is recruited to activated EphA4, undergoes tyrosine phosphorylation and activation, then phosphorylates ephexin1 to enhance RhoA activation, driving ephrin-A1-induced dendritic spine retraction and reduction of mEPSC frequency; blocking Cdk5 or its phosphorylation of ephexin1 abolishes EphA4-dependent spine retraction.\",\n      \"method\": \"Pharmacological Cdk5 inhibition, Cdk5-/- neurons, Co-IP of EphA4/Cdk5/ephexin1, phospho-mutant ephexin1 constructs, mEPSC recordings\",\n      \"journal\": \"Nature neuroscience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 — multiple orthogonal biochemical and electrophysiological methods, genetic and pharmacological validation\",\n      \"pmids\": [\"17143272\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"EphA4 is upregulated on reactive astrocytes after spinal cord injury; EphA4-/- astrocytes fail to respond to inflammatory cytokines, show reduced gliosis, and support longer neurite outgrowth; blocking astrocyte EphA4 with monomeric ephrinA5-Fc promotes neurite extension, identifying EphA4 as a regulator of astrocytic gliosis and axonal inhibition after injury.\",\n      \"method\": \"EphA4 KO mice, spinal cord hemisection, anterograde/retrograde tracing, in vitro neurite outgrowth on astrocytes, monomeric EphA4 blocker, cytokine stimulation assay\",\n      \"journal\": \"The Journal of neuroscience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — KO model plus in vitro pharmacological blockade with specific cellular phenotype readout\",\n      \"pmids\": [\"15537875\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"EphA4 in the postsynaptic CA1 neuron modulates LTP by controlling astrocytic ephrin-A3 reverse signaling, which in turn regulates glial glutamate transporter levels; lack of EphA4 increases glial glutamate transporter abundance, and pharmacological inhibition of glial glutamate transporters rescues LTP defects in EphA4 and ephrin-A3 mutant mice.\",\n      \"method\": \"EphA4 and ephrin-A3 knockout mice, LTP electrophysiology, pharmacological glutamate transporter inhibition, astrocyte transporter current recording, transgenic ephrin-A3 overexpression\",\n      \"journal\": \"Nature neuroscience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple genetic and pharmacological approaches with electrophysiological phenotype rescue\",\n      \"pmids\": [\"19734893\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"EphA4 expressed on dorsal limb motor axons mediates dorsal-versus-ventral trajectory selection; in EphA4 mutant mice, presumptive dorsal motor axons fail to enter the dorsal compartment and join the ventral nerve, demonstrating EphA4-dependent repulsion by ephrin ligands in ventral mesoderm.\",\n      \"method\": \"EphA4 knockout mouse, axon tracing, protein expression analysis in motor axon subpopulations\",\n      \"journal\": \"Development\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — clean KO with specific axon guidance phenotype\",\n      \"pmids\": [\"10887087\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"Alpha2-chimaerin interacts with activated EphA4 via its SH2 domain, undergoes tyrosine phosphorylation, and enhances its RacGAP activity toward Rac1, mediating ephrin-induced growth cone collapse; alpha2-chimaerin mutant mice phenocopy EphA4 kinase-inactive mice with a hopping gait and defective corticospinal/spinal interneuron projections.\",\n      \"method\": \"Co-IP, SH2-domain binding, in vitro GAP activity assay, alpha2-chimaerin KO mice, locomotor analysis, axon tracing; confirmed by two independent labs (PMIDs 17785183 and 17911252)\",\n      \"journal\": \"Neuron\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 — biochemical reconstitution of interaction and enzymatic activation, confirmed by two independent groups with genetic in vivo validation\",\n      \"pmids\": [\"17785183\", \"17911252\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"EphA4 activation leads to association with the ubiquitin ligase APC(Cdh1), which targets GluR1 (AMPA receptor subunit) for proteasomal degradation; depletion of Cdh1 abolishes EphA4-dependent GluR1 downregulation and prevents homeostatic reduction of mEPSC amplitude caused by chronic elevated synaptic activity.\",\n      \"method\": \"Co-IP of EphA4 with APC/Cdh1, in vitro ubiquitination assay, Cdh1 knockdown, mEPSC recordings, surface GluR1 assay\",\n      \"journal\": \"Nature neuroscience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 — in vitro ubiquitination reconstitution plus co-IP and electrophysiological phenotype\",\n      \"pmids\": [\"21186356\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"Gamma-secretase cleaves EphA4 in an activity-dependent manner at synapses; the resulting EphA4 intracellular domain (ICD) promotes dendritic spine formation by activating Rac signaling, linking gamma-secretase processing of EphA4 to spine morphogenesis.\",\n      \"method\": \"Identification of EphA4 as gamma-secretase substrate by biochemical cleavage assay, overexpression of EphA4-ICD, Rac signaling reporter assay, spine counting\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — substrate identification with functional overexpression data, single lab\",\n      \"pmids\": [\"19414612\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"EphA4 activation by ephrin-A3 inhibits beta1-integrin activity in hippocampal neurons by decreasing phosphorylation of Cas, FAK, and Pyk2 and reducing Cas-Fyn and Cas-Crk associations; inhibition of integrin or Cas function mimics EphA4-induced spine retraction, and blocking beta1-integrin inactivation prevents EphA4 effects on spines.\",\n      \"method\": \"Ephrin-A3 stimulation in hippocampal slices, phospho-immunoblotting of FAK/Pyk2/Cas, co-IP of Cas with Fyn/Crk, integrin activity assay, spine morphology analysis\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple biochemical readouts with functional rescue, moderate evidence from single lab\",\n      \"pmids\": [\"17875741\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"EphA4 interacts via its C-terminus PDZ-binding motif with the PDZ domain of SPAR (spine-associated RapGAP), leading to Cdk5-dependent inactivation of Rap1 and Rap2; SPAR-mediated Rap1 inactivation is required for ephrin-A-dependent growth cone collapse and decreased integrin-mediated adhesion in neuronal cells.\",\n      \"method\": \"Co-IP of EphA4 with SPAR, Rap1/Rap2 activity assays, Rap GTPase-activating assay, growth cone collapse assay with dominant-active Rap mutants\",\n      \"journal\": \"The Journal of neuroscience\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — Co-IP and functional GTPase assays with phenotypic validation, single lab\",\n      \"pmids\": [\"18094260\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"EphA4 activation recruits and activates PLCgamma1 via an SH2 domain interaction requiring EphA4 juxtamembrane tyrosines; PLC activity is required for ephrin-induced spine retraction and modulates cofilin membrane association, linking EphA4 to actin remodeling in dendritic spines.\",\n      \"method\": \"Co-IP of EphA4 with PLCgamma1, SH2 domain binding, PLC inhibitor studies in hippocampal slices, cofilin fractionation assay, spine morphology imaging\",\n      \"journal\": \"The Journal of neuroscience\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — biochemical interaction mapping plus pharmacological phenotype, single lab\",\n      \"pmids\": [\"17494698\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"EphA4 cytoplasmic domain directly interacts with the juxtamembrane domain of FGFR1-4 (identified by yeast two-hybrid and confirmed biochemically); activated FGFR1 trans-phosphorylates kinase-dead EphA4 and vice versa, and ephrin-A1 co-stimulation potentiates FGF-induced MAPK signaling through FRS2alpha.\",\n      \"method\": \"Yeast two-hybrid, Co-IP, kinase-dead receptor trans-phosphorylation, MAPK assay with ligand co-stimulation\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — yeast two-hybrid plus biochemical Co-IP and functional signaling assay, single lab\",\n      \"pmids\": [\"16365308\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"GDNF/Ret and EphA4 signals cooperate in the same binary dorsal-ventral motor axon guidance decision; LMC(l) axons require EphA4-mediated repulsion from ephrin-A-expressing ventral mesoderm, and loss of both Ret and EphA4 synergistically worsens aberrant ventral trajectory, placing the two systems in a cooperative pathway.\",\n      \"method\": \"Gdnf, Ret, and EphA4 single and compound knockout mice, motor axon tracing, genetic epistasis\",\n      \"journal\": \"Neuron\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — genetic epistasis with double mutants showing additive/synergistic phenotype\",\n      \"pmids\": [\"16600854\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"Rin1, a postnatal brain-specific Rab5-GEF, co-localizes with EphA4 in synaptosomal fractions, interacts with EphA4 via its SH2 domain (requiring EphA4 tyrosine phosphorylation), and mediates ligand-induced EphA4 endocytosis in amygdala neurons; EphA4 is required for synaptic plasticity in the amygdala, and Rin1 suppresses this plasticity by promoting EphA4 internalization.\",\n      \"method\": \"Co-IP of Rin1 and EphA4 from synaptosomes, SH2 domain requirement, internalization assay in neurons, EphA4 KO LTP assay\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — biochemical interaction plus functional endocytosis and plasticity assays, single lab\",\n      \"pmids\": [\"18723684\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"Alpha-syntrophin interacts with ARMS (ankyrin repeat-rich membrane spanning protein) via a PDZ domain interaction, clustering ARMS at the neuromuscular junction (NMJ); ARMS enhances EphA4 signaling, and alpha-syntrophin further augments this; alpha-syntrophin null mice show disrupted ARMS and EphA4 localization at the NMJ.\",\n      \"method\": \"Yeast two-hybrid, Co-IP, PDZ domain-dependent clustering assay, siRNA knockdown in C2C12 myotubes, alpha-syntrophin KO mouse immunolocalization\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 — yeast two-hybrid plus Co-IP and KO localization, single lab\",\n      \"pmids\": [\"15939763\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"Meltrin beta/ADAM19 interacts physically with EphA4 in developing motor neurons; co-expression of ADAM19 and EphA4 blocks endocytosis of ephrin-A5-EphA4 complexes independently of ADAM19 protease activity, stabilizing ephrin-A5 signaling and regulating NMJ formation.\",\n      \"method\": \"Co-IP of ADAM19 and EphA4, internalization assay, protease-dead ADAM19 mutant, ADAM19 KO mouse NMJ analysis\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 — Co-IP plus functional endocytosis assay with protease-dead mutant, single lab\",\n      \"pmids\": [\"18830404\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"Crystal structure of the EphA4 ligand-binding domain in complex with ephrin-B2 reveals a loose fit of the ephrin-B2 G-H loop in the EphA4 ligand-binding channel; mutation of EphA4 residues Gln12 and Glu14 selectively reduces ephrin-B affinity ~10-fold without affecting ephrin-A binding, defining separate molecular determinants for EphA4's cross-subclass (ephrin-B) binding.\",\n      \"method\": \"X-ray crystallography, mutagenesis, binding affinity measurements (ITC/ELISA), NMR\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — crystal structure plus mutagenesis with quantitative affinity measurements\",\n      \"pmids\": [\"19875447\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"Crystal structure of the EphA4 ligand-binding domain (first for an EphA subclass receptor) shows a jellyfish beta-sandwich with variable D-E and J-K loop regions forming the ephrin-binding channel; two small-molecule antagonists bind within this channel contacting Ile31-Met32, Gln43, and Ile131-Gly132, competitively displacing ephrin ligands with Kd ~20-26 µM.\",\n      \"method\": \"X-ray crystallography, NMR HSQC titration, ITC, molecular docking, ephrin competition ELISA\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — crystal structure plus NMR and ITC with atomic-level binding site definition\",\n      \"pmids\": [\"18708347\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"Crystal structure of the EphA4 ligand-binding domain reveals two distinct, well-ordered conformations in the unbound state, suggesting that EphA4's structural flexibility in the ligand-binding surface underlies its promiscuous binding to both ephrin-A and ephrin-B ligands.\",\n      \"method\": \"X-ray crystallography at 2.3 Å resolution\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — crystal structure demonstrating conformational flexibility\",\n      \"pmids\": [\"20678482\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Solution NMR structure of the EphA4 LBD shows that two small molecules trigger opposite signaling outputs by oppositely modulating EphA4 backbone dynamics: one enhances dynamics (agonist) and the other suppresses dynamics (antagonist), establishing a dynamic principle for EphA4 agonism versus antagonism.\",\n      \"method\": \"Solution NMR (first for 16 Eph receptors), NMR dynamics measurements, small-molecule binding studies\",\n      \"journal\": \"ACS chemical biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — NMR structure plus dynamics analysis with mechanistic interpretation\",\n      \"pmids\": [\"25334011\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Crystal structure of the cyclic peptide antagonist APY bound to the EphA4 LBD shows that the peptide occupies the ephrin ligand-binding pocket and induces a 'closed' loop conformation; structure-guided optimization yielded APY-βAla8.am with nanomolar EphA4 affinity that inhibits ephrin-induced EphA4 activation and growth cone collapse.\",\n      \"method\": \"X-ray crystallography of EphA4-LBD/peptide complex, structure-guided mutagenesis, binding affinity measurements, cell-based EphA4 activation assay, growth cone collapse assay\",\n      \"journal\": \"ACS chemical biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — crystal structure plus functional cell assays and structure-guided optimization\",\n      \"pmids\": [\"25268696\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Amyloid-β oligomers (AβOs) activate EphA4 in hippocampal neurons, leading to downstream activation of c-Abl kinase in dendritic spines; EphA4 KO or EphA4 antagonist prevents AβO-induced c-Abl activation, dendritic spine loss, LTP blockade, and neuronal apoptosis, placing EphA4 upstream of c-Abl in AβO-mediated synaptotoxicity.\",\n      \"method\": \"EphA4 KO neurons, EphA4 shRNA, EphA4 antagonist peptide KYL, c-Abl inhibitor STI, phospho-EphA4 and phospho-c-Abl immunoblotting, spine counting, LTP electrophysiology\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — genetic and pharmacological pathway placement with multiple phenotypic readouts, single lab\",\n      \"pmids\": [\"24658113\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Enhanced EphA4 signaling in the hippocampus of APP/PS1 AD mice mediates synaptic LTP impairment; soluble Aβ oligomers activate EphA4, EphA4 depletion in CA1 reverses LTP suppression, and the small molecule rhynchophylline (identified by molecular docking as an EphA4 inhibitor) blocks EphA4 activity and restores LTP in AD mice.\",\n      \"method\": \"APP/PS1 transgenic mouse, EphA4 shRNA in CA1, molecular docking, in vitro kinase inhibition, oral drug administration, LTP electrophysiology\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — genetic depletion plus pharmacological rescue with electrophysiological readout, single lab\",\n      \"pmids\": [\"24958880\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"SORLA physically interacts with EphA4 and attenuates ephrinA1-induced EphA4 clustering and activation; SORLA transgenic mice show decreased EphA4 activation and redistribution to postsynaptic densities, with reduced Aβ-induced LTP deficits; active EphA4 is elevated in human AD brains and inversely correlates with SORLA/EphA4 association.\",\n      \"method\": \"Co-IP of SORLA and EphA4, SORLA transgenic mouse, EphA4 phosphorylation assay, LTP electrophysiology, postsynaptic density fractionation, human AD brain analysis\",\n      \"journal\": \"The Journal of experimental medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — biochemical interaction plus transgenic mouse phenotype with electrophysiological validation, single lab\",\n      \"pmids\": [\"29114064\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Ephrin-A5 in cochlear hair cells signals through EphA4 on spiral ganglion neurons to repel type I afferent fibers from the outer hair cell area; in the absence of ephrin-A5 or EphA4, type I projections aberrantly invade the outer hair cell layer; downstream of EphA4, ephexin-1, cofilin, and MLCK mediate growth cone collapse of type I spiral ganglion neurons.\",\n      \"method\": \"Ephrin-A5 and EphA4 KO mice, anterograde tracing, growth cone collapse assay, ephexin-1/cofilin/MLCK pharmacological inhibition\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — genetic KO with anatomical phenotype, downstream pathway defined pharmacologically\",\n      \"pmids\": [\"23385583\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"EphrinB3/EphA4 bidirectional signaling mediates segregation of MGE- and POA-derived cortical interneurons into deep and superficial migratory streams: EphA4 forward signaling repels deeply migrating MGE interneurons from POA-derived cells expressing ephrinB3, while EphA4-induced ephrinB3 reverse signaling restricts POA interneurons to the superficial path.\",\n      \"method\": \"In vitro migration assays with ephrinB3/EphA4 perturbation, in utero electroporation, EphA4 conditional KO mice, DiI labeling\",\n      \"journal\": \"The Journal of neuroscience\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — in vitro and in vivo loss-of-function with defined pathway directionality, single lab\",\n      \"pmids\": [\"22171039\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"EphrinB3/EphA4 forward signaling guides both ascending Zic2+/EphA4+ spinal interneuron axons (ipsilateral, embryonic) and descending corticospinal tract axons (postnatal) through the same molecular mechanism; conditional EphA4 KO shows CST guidance defects are linked to EphA4 in Zic2+ spinal neurons, not CST axons themselves.\",\n      \"method\": \"Conditional EphA4 KO mice (cell-type specific), anterograde and retrograde tracing, in situ hybridization, immunohistochemistry\",\n      \"journal\": \"Neuron\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — conditional KO with cell-type resolution and anatomical tracing\",\n      \"pmids\": [\"24360544\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Spinal cord-specific deletion of EphA4 signaling in excitatory Vglut2+ neurons is sufficient to generate the hopping gait, accompanied by increased midline crossing of Vglut2+ axons; forebrain-specific deletion does not affect locomotor pattern, functionally localizing the EphA4 circuit requirement to spinal excitatory interneurons.\",\n      \"method\": \"Intersectional genetics (cell-type-specific conditional KO), overground locomotion analysis, anterograde tracing of midline-crossing axons\",\n      \"journal\": \"The Journal of neuroscience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — conditional KO with cell-type resolution and precise behavioral and anatomical phenotype\",\n      \"pmids\": [\"24623763\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"Axonal ephrin-A1 interacts with EphA4 on oligodendrocytes to activate an ephexin1-RhoA-ROCK-myosin 2 signaling cascade that inhibits oligodendrocyte process extension and myelination; inhibition of EphA4 or downstream pathway components increases the number of myelin sheaths per oligodendrocyte.\",\n      \"method\": \"Axon-mimicking microfibers, zebrafish myelination model, EphA4 knockdown, pharmacological ROCK and RhoA inhibition, Co-IP/signaling pathway analysis\",\n      \"journal\": \"Glia\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — functional assays in two model systems with defined signaling pathway, single lab\",\n      \"pmids\": [\"29350423\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Ephrin-A1/EphA4 signaling in endothelial cells promotes monocyte adhesion via activation of the Rho signaling pathway and subsequent actin stress fiber polymerization, without requiring active transcription; EphA4 mediates this pro-adhesive effect downstream of ephrin-A1.\",\n      \"method\": \"Ephrin-A1-Fc stimulation of endothelial cells, monocyte adhesion assay, Rho activation assay, actin polymerization imaging, EphA4 blocking antibody, transcription inhibitor control\",\n      \"journal\": \"Biochimica et biophysica acta\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — pharmacological pathway dissection with functional adhesion readout, single lab\",\n      \"pmids\": [\"23707953\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"EphA4 acts as a dependence receptor: in the absence of its ligand ephrin-B3, EphA4 triggers cell apoptosis; ephrin-B3 overexpression in glioblastoma inhibits EphA4 pro-apoptotic activity, supports tumor and endothelial cell survival, and silencing ephrin-B3 decreases tumor vascularization and growth in xenograft models.\",\n      \"method\": \"Ephrin-B3 siRNA knockdown, EphA4 dependence receptor apoptosis assay, xenograft mouse model, in vitro endothelial cell survival assay\",\n      \"journal\": \"Oncotarget\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 — in vitro and in vivo loss-of-function with apoptosis and tumor growth readouts, single lab\",\n      \"pmids\": [\"28423606\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"EphA4 is required for cortical progenitor cell proliferation; EphA4-/- cortex has reduced area, fewer cells, and less cell division; overexpression of EphA4 expands the progenitor pool; EphA4 interacts with and is activated by ephrin-B1 expressed on neighboring progenitors, driving forward signaling-mediated proliferation.\",\n      \"method\": \"EphA4 KO mice, in vivo electroporation of dominant-negative/wild-type EphA4, Co-IP of EphA4 with ephrin-B1, BrdU incorporation assay\",\n      \"journal\": \"Development\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — KO plus gain-of-function with biochemical interaction identification, single lab\",\n      \"pmids\": [\"19542359\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"EphA4 in oligodendrocyte precursor cells (OPCs) promotes OPC proliferation but inhibits their maturation and myelination after ischemic stroke; the pro-myelination effect of EphA4 deletion is mediated by the Ephexin-1/RhoA/ROCK signaling pathway; OPC-conditional EphA4 KO improves myelin-associated protein levels and functional recovery.\",\n      \"method\": \"OPC-specific conditional EphA4 KO (PDGFRα-Cre), MCAO stroke model, shRNA, LV-EphA4 overexpression, Western blot for myelin proteins, Ephexin-1/RhoA/ROCK pathway analysis\",\n      \"journal\": \"Glia\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — conditional KO with cell-type specificity and signaling pathway defined, single lab\",\n      \"pmids\": [\"35762396\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"EphA4 in subarachnoid hemorrhage activates the Ephexin-1/RhoA/ROCK2 pathway to promote blood-brain barrier disruption, brain edema, and apoptotic neuronal death; EphA4 siRNA reduces these effects, while recombinant Ephexin-1 reverses the siRNA effect and Fasudil (ROCK2 inhibitor) restores the phenotype.\",\n      \"method\": \"EphA4 siRNA (i.c.v.), recombinant Ephexin-1, Fasudil, SAH rat model, Evans blue permeability assay, brain water content, Western blot, tight junction protein analysis\",\n      \"journal\": \"Experimental neurology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — pharmacological rescue/epistasis with multiple pathway components and functional readouts, single lab\",\n      \"pmids\": [\"28698029\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"EphA4 on peripheral myeloid-derived immune cells restricts efferocytosis after brain injury by suppressing the ERK/Stat6/MERTK pathway; loss of EphA4 on infiltrating macrophages/microglia enhances MERTK expression and activity, increases phagocytosis of apoptotic debris, and improves functional outcome.\",\n      \"method\": \"Bone marrow chimeric EphA4 KO mice, single-cell RNAseq, in vitro efferocytosis assay, ERK/Stat6 selective inhibitors, p-MERTK/p-ERK/p-Stat6 co-localization\",\n      \"journal\": \"Journal of neuroinflammation\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — cell-specific genetic deletion plus pharmacological pathway dissection, single lab\",\n      \"pmids\": [\"37941008\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1997,\n      \"finding\": \"EphA4 immunoreactivity in the adult rat brain is enriched in dendrites and dendritic spines (associated with the plasma membrane) and in myelinated axons, establishing the subcellular localization of EphA4 at synaptic sites in the mature CNS.\",\n      \"method\": \"Immunoperoxidase and immunogold electron microscopy with region/cell-type fractionation in adult rat brain\",\n      \"journal\": \"Brain research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — EM-level localization with gold labeling showing plasma membrane association at synaptic structures\",\n      \"pmids\": [\"9401744\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"EBV latent membrane protein 1 (LMP1) suppresses EphA4 expression by activating the ERK pathway, leading to Sp1-mediated repression of the EphA4 promoter; overexpression of EphA4 prevents LCL proliferation, identifying EphA4 as a growth suppressor downstream of LMP1-ERK-Sp1 signaling in B lymphoma cells.\",\n      \"method\": \"EphA4 overexpression/knockdown in LCLs, LMP1 overexpression/knockdown, luciferase promoter assay, ERK pathway inhibitors, Sp1 ChIP\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — promoter reporter assay plus epistasis and functional proliferation readout, single lab\",\n      \"pmids\": [\"27338098\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"An EphA4/Sipa1l3/Wnt pathway regulates eye development: EphA4 acts upstream of Sipa1l3 (direct physical interaction), and both inhibit canonical Wnt/β-catenin signaling; depletion of either EphA4 or Sipa1l3 in Xenopus causes smaller eyes with lens fiber cell maturation defects and upregulation of the Wnt target axin2.\",\n      \"method\": \"Co-IP of EphA4 and Sipa1l3, morpholino loss-of-function in Xenopus, epistasis rescue experiments, axin2 reporter (canonical Wnt readout), Wnt pathway inhibitors\",\n      \"journal\": \"Development\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — direct interaction plus genetic epistasis and pathway reporter in a vertebrate model\",\n      \"pmids\": [\"27993984\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"EphA4 is a promiscuous receptor tyrosine kinase that, upon binding ephrin-A or ephrin-B ligands (with structural promiscuity conferred by flexible D-E and J-K loops in its ligand-binding domain), undergoes autophosphorylation and recruits a defined set of effectors—including Cdk5/ephexin1/RhoA, alpha2-chimaerin/Rac1, PLCgamma1/cofilin, SPAR/Rap1, APC(Cdh1)/GluR1, and c-Abl—to regulate actin cytoskeletal dynamics, dendritic spine morphology, AMPA receptor trafficking, and synaptic plasticity; its downstream Ephexin-1/RhoA/ROCK cascade also controls axon guidance, myelination, gliosis, and neuroinflammation, while ligand availability, gamma-secretase cleavage, Rin1-mediated endocytosis, and SORLA binding modulate its surface signaling state in both development and neurodegeneration.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"EphA4 is a promiscuous receptor tyrosine kinase that functions as a central organizer of axon guidance, dendritic spine morphology, synaptic plasticity, and myelination in the nervous system. Structurally, conformational flexibility of the D-E and J-K loops in its ligand-binding domain enables binding to both ephrin-A and ephrin-B subclass ligands, and distinct loop conformations underlie agonist versus antagonist responses [PMID:18708347, PMID:20678482, PMID:25334011]. Upon ephrin-induced activation, EphA4 recruits effectors including Cdk5/ephexin-1 to activate RhoA, alpha2-chimaerin to inactivate Rac1, PLCγ1 to regulate cofilin, and APC(Cdh1) to ubiquitinate the AMPA receptor subunit GluR1, thereby controlling actin remodeling, growth cone collapse, spine retraction, and homeostatic synaptic scaling [PMID:17143272, PMID:17785183, PMID:17494698, PMID:21186356]. Beyond neurons, EphA4 signaling on astrocytes regulates gliosis and glial glutamate transporter levels to modulate LTP [PMID:15537875, PMID:19734893], on oligodendrocytes it inhibits myelination through an ephexin-1/RhoA/ROCK cascade [PMID:29350423, PMID:35762396], and in the spinal cord its expression in Vglut2-positive excitatory interneurons is required for left-right locomotor alternation [PMID:12649481, PMID:24623763].\",\n  \"teleology\": [\n    {\n      \"year\": 1997,\n      \"claim\": \"Before any functional studies in vivo, the subcellular distribution of EphA4 at synaptic sites in the adult brain was unknown; immunogold EM demonstrated enrichment on dendritic spine plasma membranes and myelinated axons, establishing EphA4 as a synaptically positioned receptor.\",\n      \"evidence\": \"Immunoperoxidase and immunogold electron microscopy in adult rat brain\",\n      \"pmids\": [\"9401744\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No functional consequence of synaptic localization demonstrated\", \"Ligand identity at these synaptic sites not established\"]\n    },\n    {\n      \"year\": 1998,\n      \"claim\": \"The in vivo requirement for EphA4 in CNS axon guidance was established when EphA4-null mice showed disrupted corticospinal tract trajectories and a hopping gait, demonstrating a non-redundant role in long-range axon pathfinding.\",\n      \"evidence\": \"EphA4-null mouse with anterograde tracing and behavioral analysis\",\n      \"pmids\": [\"9789074\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Cell-type autonomy of the phenotype not resolved\", \"Downstream signaling pathway unknown\"]\n    },\n    {\n      \"year\": 2000,\n      \"claim\": \"EphA4's role was extended to peripheral axon guidance when EphA4-mutant dorsal limb motor axons were shown to misproject ventrally, establishing EphA4-mediated repulsion as the mechanism for dorsal-ventral trajectory selection.\",\n      \"evidence\": \"EphA4 KO mouse with motor axon tracing\",\n      \"pmids\": [\"10887087\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Cooperation with other guidance systems not tested\", \"Downstream effectors not identified\"]\n    },\n    {\n      \"year\": 2003,\n      \"claim\": \"Two contemporaneous studies revealed that EphA4 operates in distinct neuronal circuits — dendritic spines of hippocampal pyramidal neurons (controlling spine shape via neuroglial cross-talk with ephrin-A3) and spinal excitatory interneurons (where ephrinB3/EphA4 organizes left-right locomotor alternation) — demonstrating broad functional deployment across brain regions and ligand subclasses.\",\n      \"evidence\": \"EphA4 KO mice with hippocampal slice ephrin-A3 activation and spinal cord electrophysiology/ephrinB3 KO\",\n      \"pmids\": [\"12496762\", \"12649481\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Intracellular signaling mediating spine retraction uncharacterized\", \"Molecular identity of the spinal midline barrier mechanism not known\"]\n    },\n    {\n      \"year\": 2004,\n      \"claim\": \"EphA4's role was shown to extend beyond neurons to reactive astrocytes, where it drives gliosis and axon growth inhibition after spinal cord injury, broadening the receptor's function to neuroinflammatory contexts.\",\n      \"evidence\": \"EphA4 KO mice with spinal cord hemisection, in vitro astrocyte neurite outgrowth assays, monomeric ephrinA5-Fc blocker\",\n      \"pmids\": [\"15537875\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Downstream signaling in astrocytes not defined\", \"Whether blocking EphA4 promotes functional recovery in vivo not tested\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"The first downstream signaling cascade was delineated: Cdk5 is recruited to activated EphA4, phosphorylates ephexin-1, which activates RhoA to drive spine retraction — establishing the Cdk5/ephexin-1/RhoA module as the core effector for EphA4 in dendritic spine remodeling.\",\n      \"evidence\": \"Co-IP of EphA4/Cdk5/ephexin-1, Cdk5-null neurons, phospho-mutant ephexin-1, mEPSC recordings\",\n      \"pmids\": [\"17143272\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Relationship of this pathway to other EphA4 effectors (Rac, integrins) not integrated\", \"Whether the same cascade operates in axon guidance not tested\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Multiple parallel EphA4 effector arms were discovered simultaneously: alpha2-chimaerin (RacGAP for Rac1, phenocopying EphA4 KO in vivo), PLCγ1/cofilin (actin remodeling in spines), SPAR/Rap1 (integrin inactivation for growth cone collapse), and integrin inhibition via Cas/FAK dephosphorylation — revealing a branched signaling architecture downstream of EphA4.\",\n      \"evidence\": \"Alpha2-chimaerin KO mice (two independent labs), Co-IPs and GAP assays, PLCγ1 SH2 binding and PLC inhibitor studies, SPAR/Rap activity assays, integrin/Cas/FAK phospho-immunoblotting\",\n      \"pmids\": [\"17785183\", \"17911252\", \"17494698\", \"18094260\", \"17875741\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How these parallel arms are coordinated or selectively activated remains unknown\", \"SPAR and PLCγ1 pathways validated in single labs only\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Structural biology began resolving how EphA4 achieves ligand promiscuity: crystal structures revealed a jellyfish β-sandwich with flexible D-E and J-K loops forming the ephrin-binding channel, and small-molecule antagonists were shown to bind competitively within this channel.\",\n      \"evidence\": \"X-ray crystallography, NMR HSQC titration, ITC, ephrin competition ELISA\",\n      \"pmids\": [\"18708347\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"No full-length EphA4 structure\", \"Mechanism of ligand-induced kinase activation not structurally resolved\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Three discoveries expanded EphA4's functional scope: gamma-secretase cleavage of EphA4 generates an ICD that promotes spine formation via Rac; EphA4 controls LTP by regulating astrocytic glutamate transporter levels through ephrin-A3 reverse signaling; and EphA4/ephrin-B1 interaction drives cortical progenitor proliferation — demonstrating signaling roles in proteolytic processing, trans-synaptic glial regulation, and neurogenesis.\",\n      \"evidence\": \"Gamma-secretase cleavage biochemistry and Rac reporter; EphA4/ephrinA3 KO mice with LTP rescue by glutamate transporter inhibitors; EphA4 KO cortex BrdU analysis and in vivo electroporation\",\n      \"pmids\": [\"19414612\", \"19734893\", \"19542359\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Physiological relevance of gamma-secretase cleavage not confirmed in vivo\", \"Relative contribution of forward versus reverse signaling in LTP not fully resolved\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Crystallographic analysis of EphA4 in complex with the cross-subclass ligand ephrin-B2 identified specific residues (Gln12, Glu14) that confer ephrin-B binding without affecting ephrin-A interaction, defining the structural basis for EphA4's unusual cross-subclass promiscuity.\",\n      \"evidence\": \"X-ray crystallography of EphA4-LBD/ephrin-B2 complex, mutagenesis with ITC/ELISA binding measurements\",\n      \"pmids\": [\"19875447\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Functional consequences of selectively disrupting ephrin-B binding in vivo not tested\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"EphA4 was linked to homeostatic synaptic scaling through its association with the ubiquitin ligase APC(Cdh1), which targets the AMPA receptor subunit GluR1 for proteasomal degradation — extending EphA4 signaling from structural spine remodeling to receptor trafficking.\",\n      \"evidence\": \"Co-IP of EphA4/APC/Cdh1, in vitro ubiquitination, Cdh1 knockdown, mEPSC recordings\",\n      \"pmids\": [\"21186356\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How EphA4 activation triggers APC(Cdh1) recruitment mechanistically is unclear\", \"Whether this pathway operates in pathological conditions not examined\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Conditional and cell-type-specific knockouts refined the circuit-level requirement: EphA4 in Vglut2+ spinal excitatory interneurons is both necessary and sufficient for locomotor alternation, and ephrinB3/EphA4 guides both ascending spinal and descending CST axons through midline barriers, with the CST defect arising non-autonomously from EphA4 in Zic2+ spinal neurons.\",\n      \"evidence\": \"Cell-type-specific conditional EphA4 KO (Vglut2-Cre, Zic2-Cre), locomotor analysis, anterograde/retrograde tracing\",\n      \"pmids\": [\"24623763\", \"24360544\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How EphA4 in spinal neurons non-autonomously affects CST axon trajectory is mechanistically unresolved\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"EphA4 was identified as a mediator of amyloid-β oligomer synaptotoxicity: Aβ oligomers activate EphA4, which signals through c-Abl to cause spine loss, LTP blockade, and apoptosis; genetic or pharmacological EphA4 inhibition rescues these deficits in AD mouse models, positioning EphA4 as a candidate therapeutic target in Alzheimer's disease.\",\n      \"evidence\": \"EphA4 KO neurons, shRNA, KYL antagonist peptide, rhynchophylline (small molecule), APP/PS1 mice, LTP electrophysiology\",\n      \"pmids\": [\"24658113\", \"24958880\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether EphA4 is a direct Aβ receptor or is activated indirectly remains unresolved\", \"Therapeutic efficacy in human AD not established\", \"Findings from single labs; independent replication needed\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"NMR dynamics studies and co-crystal structures with cyclic peptide antagonists established that agonism versus antagonism of EphA4 correlates with opposite modulation of backbone dynamics in the ligand-binding domain, providing a dynamic framework for drug design.\",\n      \"evidence\": \"Solution NMR structure with dynamics measurements; X-ray crystallography of EphA4-LBD/APY peptide complex with structure-guided optimization\",\n      \"pmids\": [\"25334011\", \"25268696\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether dynamics-based rules generalize to other Eph receptors untested\", \"In vivo efficacy of optimized peptide antagonists not demonstrated\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"EphA4's role in neuroinflammation was expanded: SORLA physically interacts with EphA4 to attenuate its activation (relevant to AD), the ephexin-1/RhoA/ROCK2 cascade mediates blood-brain barrier disruption after subarachnoid hemorrhage, and EphA4 acts as a dependence receptor triggering apoptosis in the absence of ephrin-B3 in glioblastoma.\",\n      \"evidence\": \"SORLA-EphA4 Co-IP and SORLA transgenic mice with LTP; EphA4 siRNA in SAH rat model with ROCK inhibitor rescue; ephrin-B3 knockdown in glioblastoma xenografts\",\n      \"pmids\": [\"29114064\", \"28698029\", \"28423606\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"SORLA mechanism of EphA4 inhibition not structurally defined\", \"Dependence receptor function confirmed only for glioblastoma context\", \"BBB disruption pathway from single lab\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"EphA4 was shown to inhibit oligodendrocyte myelination through the ephexin-1/RhoA/ROCK/myosin-2 cascade, extending the canonical spine retraction pathway to a glial cell myelination context.\",\n      \"evidence\": \"Microfiber myelination assay, zebrafish model, EphA4 knockdown, ROCK/RhoA pharmacological inhibition\",\n      \"pmids\": [\"29350423\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"In vivo mammalian validation limited at this time\", \"Whether same pathway operates in remyelination after injury not established\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"OPC-conditional EphA4 deletion after ischemic stroke confirmed EphA4 inhibits OPC maturation and myelination via ephexin-1/RhoA/ROCK, and its removal improves functional recovery, validating EphA4 as a negative regulator of remyelination.\",\n      \"evidence\": \"PDGFRα-Cre conditional EphA4 KO, MCAO stroke model, myelin protein Western blots, pathway analysis\",\n      \"pmids\": [\"35762396\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Long-term functional outcome and specificity of benefit not assessed\", \"Single lab\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"EphA4 on peripheral myeloid-derived cells was found to suppress efferocytosis after brain injury by inhibiting the ERK/Stat6/MERTK pathway, revealing a non-neuronal, immune-regulatory function of EphA4 in post-injury debris clearance.\",\n      \"evidence\": \"Bone marrow chimeric EphA4 KO mice, single-cell RNAseq, in vitro efferocytosis, ERK/Stat6 inhibitors\",\n      \"pmids\": [\"37941008\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether this is a direct kinase-mediated effect or involves ligand engagement unclear\", \"Single lab; independent replication needed\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"Key unresolved questions include: how EphA4 coordinates its multiple parallel effector arms in a context-dependent manner; whether Aβ oligomers directly bind EphA4 or activate it indirectly; a full-length EphA4 structure showing kinase activation mechanism; and the translational potential of EphA4 inhibition in Alzheimer's disease or demyelinating conditions.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No full-length EphA4 structure available\", \"No direct binding data for Aβ oligomers to EphA4\", \"No clinical translation data for any EphA4-targeted therapy\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [3, 7, 8, 12, 13]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [5, 30, 34, 36]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [0, 37]},\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [37]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [0, 3, 7, 10, 11, 12, 23, 30]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [1, 2, 6, 14, 26, 28, 29]},\n      {\"term_id\": \"R-HSA-112316\", \"supporting_discovery_ids\": [0, 3, 5, 8, 15]},\n      {\"term_id\": \"R-HSA-392499\", \"supporting_discovery_ids\": [8]},\n      {\"term_id\": \"R-HSA-5357801\", \"supporting_discovery_ids\": [32, 35]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\n      \"EFNA3\",\n      \"EFNB3\",\n      \"CDK5\",\n      \"ARHGEF5\",\n      \"CHN2\",\n      \"PLCG1\",\n      \"SIPA1L2\",\n      \"SORL1\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```"}