{"gene":"NGEF","run_date":"2026-06-10T05:19:52","timeline":{"discoveries":[{"year":2000,"finding":"NGEF was identified as a novel member of the Dbl family of guanine nucleotide exchange factors (GEFs), capable of acting as a GEF for Rho-type GTPases. It demonstrated transforming potential in cell culture and ability to induce tumors in nude mice, consistent with GEF/RhoGTPase signaling activity.","method":"Sequence analysis (Dbl family domain identification), cell transformation assay, nude mouse tumor induction","journal":"Genomics","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — sequence-based family classification with functional cell transformation assay; single lab, limited mechanistic depth on GEF activity itself","pmids":["10777665"],"is_preprint":false},{"year":2012,"finding":"In Xenopus convergence and extension cell movements, NGEF acts downstream of RPTPα/PTPε phosphatases to promote RhoA activation. Morpholino knockdown of NGEF disrupted convergence and extension, and this phenotype was rescued by constitutively active RhoA, placing NGEF as a positive regulator of RhoA in this pathway.","method":"Morpholino knockdown in Xenopus embryos, epistasis with constitutively active/dominant-negative RhoA rescue, co-knockdown specificity controls","journal":"PloS one","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic epistasis with rescue experiment, dominant-negative/constitutively active RhoA controls, pathway position established with multiple orthogonal approaches in a single rigorous study","pmids":["22545146"],"is_preprint":false},{"year":2025,"finding":"NGEF (Ephexin1) promotes axonal growth in neurons co-cultured with lung cancer cells via the Ephrin-A3/EphA2 pathway. Knockdown of Ephrin-A3 in neurons or inhibition of EphA2 with ALW-II-41-27 blocked neurite outgrowth stimulated by NGEF-overexpressing cancer cells. In a mouse xenograft model, NGEF overexpression increased tumor growth and nerve fiber density, effects inhibited by ALW-II-41-27.","method":"Co-culture experiments (neurons + cancer cells), Ephrin-A3 knockdown, EphA2 inhibitor (ALW-II-41-27), mouse subcutaneous xenograft model with nerve fiber density quantification","journal":"Journal of translational medicine","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — loss-of-function (knockdown + inhibitor) with defined cellular and in vivo phenotype, single lab, two orthogonal methods","pmids":["40022166"],"is_preprint":false},{"year":2025,"finding":"Ephexin1/NGEF is essential for polysome formation and promotes translation of mRNAs containing 5'-terminal oligopyrimidine (TOP) or 5'-TOP-like motifs, acting as a key mediator of mTOR-regulated translation. Ephexin1 deficiency enhanced efficacy of mTOR inhibitors in a mouse xenograft lung cancer model, indicating synthetic lethality.","method":"Polysome profiling, gene expression analysis after NGEF knockdown, mouse xenograft model with mTOR inhibitor combination","journal":"Experimental & molecular medicine","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — polysome profiling and in vivo xenograft with defined molecular phenotype, single lab, multiple orthogonal approaches","pmids":["40855114"],"is_preprint":false},{"year":2025,"finding":"NGEF promotes invasion and migration of BRAFV600E-mutant thyroid cancer cells through the epithelial-mesenchymal transition (EMT) pathway. NGEF expression is transcriptionally regulated by BRAFV600E via the ERK/AP1 pathway, as confirmed by pathway inhibition experiments and dual-luciferase reporter assays.","method":"Functional invasion/migration assays, EMT biomarker analysis, pathway inhibition, dual-luciferase reporter assay, BRAFV600E-engineered cellular models","journal":"Biochemistry and biophysics reports","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — luciferase reporter + pathway inhibition + functional phenotypic assays, single lab, multiple orthogonal methods","pmids":["40703409"],"is_preprint":false},{"year":2025,"finding":"Variants in NGEF were identified in cases of idiopathic scoliosis (IS), and NGEF is positioned as a downstream molecule in the EPHA4 signaling pathway relevant to spinal patterning, based on analysis of IS cohort data.","method":"Human genetic variant analysis in IS cohorts; pathway placement as downstream of EPHA4 based on known pathway membership","journal":"eLife","confidence":"Low","confidence_rationale":"Tier 4 / Weak — genetic association only, no direct functional experiment on NGEF itself; pathway placement inferred, not experimentally tested for NGEF in this study","pmids":["40662934"],"is_preprint":false}],"current_model":"NGEF/Ephexin1 is a neuronal Dbl-family guanine nucleotide exchange factor (GEF) for Rho-type GTPases that acts downstream of Eph receptors and RPTPα/PTPε phosphatases to activate RhoA, thereby regulating convergence/extension cell movements and axon guidance; in cancer contexts, it promotes tumor cell invasion/migration via EMT (regulated transcriptionally by BRAFV600E/ERK/AP1), facilitates neural infiltration through the Ephrin-A3/EphA2 axis, and supports mTOR-regulated translation by enabling polysome assembly on 5'-TOP mRNAs."},"narrative":{"mechanistic_narrative":"NGEF (Ephexin1) is a neuronal Dbl-family guanine nucleotide exchange factor that activates Rho-type GTPases and couples receptor-level signaling to cytoskeletal and morphogenetic outputs [PMID:10777665]. In Xenopus convergence and extension movements, NGEF functions downstream of RPTPα/PTPε phosphatases as a positive regulator of RhoA, since its knockdown disrupts these movements and is rescued by constitutively active RhoA [PMID:22545146]. Through Eph receptor signaling NGEF directs axonal behavior: it promotes neurite outgrowth toward cancer cells via the Ephrin-A3/EphA2 axis, and in xenografts NGEF overexpression increases both tumor growth and nerve fiber density [PMID:40022166]. In cancer, NGEF drives invasion and migration through epithelial-mesenchymal transition, and its expression is transcriptionally induced by BRAFV600E acting through the ERK/AP1 pathway [PMID:40703409]. Independent of its GEF role, NGEF is required for polysome formation and supports mTOR-regulated translation of 5'-TOP and TOP-like mRNAs, such that its loss sensitizes tumors to mTOR inhibitors [PMID:40855114].","teleology":[{"year":2000,"claim":"Established NGEF as a Dbl-family GEF for Rho GTPases with intrinsic transforming activity, defining its core molecular identity.","evidence":"Dbl-domain sequence analysis with cell transformation and nude mouse tumor induction assays","pmids":["10777665"],"confidence":"Medium","gaps":["No direct biochemical demonstration of nucleotide exchange on a specific Rho GTPase","Upstream activators not identified at this stage","Transforming activity not linked to a defined substrate GTPase"]},{"year":2012,"claim":"Placed NGEF in a defined signaling pathway as a positive regulator of RhoA downstream of RPTPα/PTPε during morphogenetic cell movements, answering how NGEF GEF activity is wired into development.","evidence":"Morpholino knockdown in Xenopus with constitutively active RhoA rescue and dominant-negative controls","pmids":["22545146"],"confidence":"High","gaps":["Mechanism by which phosphatases regulate NGEF activity not resolved","Direct biochemical GEF assay on RhoA not shown in this system"]},{"year":2025,"claim":"Linked NGEF to Eph receptor-mediated axon guidance in a tumor microenvironment, showing it drives neurite outgrowth and tumor nerve infiltration via Ephrin-A3/EphA2.","evidence":"Neuron-cancer co-culture with Ephrin-A3 knockdown and EphA2 inhibition, plus mouse xenograft with nerve fiber quantification","pmids":["40022166"],"confidence":"Medium","gaps":["Whether GEF/RhoA activity mediates this neurite effect not tested","Direct physical interaction of NGEF with EphA2 not demonstrated","Single lab, limited orthogonal validation"]},{"year":2025,"claim":"Revealed a GEF-independent role for NGEF in translation, identifying it as essential for polysome assembly and mTOR-regulated TOP mRNA translation with therapeutic synthetic-lethal implications.","evidence":"Polysome profiling and expression analysis after knockdown, plus xenograft mTOR inhibitor combination","pmids":["40855114"],"confidence":"Medium","gaps":["Molecular mechanism connecting NGEF to polysome assembly unknown","No structural or biochemical basis for TOP-mRNA selectivity","Relationship to its Rho-GEF function unresolved"]},{"year":2025,"claim":"Defined NGEF as a transcriptional effector of oncogenic BRAF signaling driving cancer cell invasion through EMT.","evidence":"Invasion/migration and EMT biomarker assays, ERK/AP1 pathway inhibition, and dual-luciferase reporter assays in BRAFV600E models","pmids":["40703409"],"confidence":"Medium","gaps":["Direct AP1 binding site in the NGEF promoter not mapped beyond reporter assay","Whether GEF activity is required for the invasive phenotype not tested"]},{"year":2025,"claim":"Associated NGEF variants with idiopathic scoliosis and positioned it downstream of EPHA4 in spinal patterning.","evidence":"Human genetic variant analysis in idiopathic scoliosis cohorts with inferred pathway placement","pmids":["40662934"],"confidence":"Low","gaps":["Genetic association only, no direct functional test of NGEF variants","EPHA4-NGEF pathway link inferred rather than experimentally tested","Causality for scoliosis not established"]},{"year":null,"claim":"How NGEF's canonical Rho-GEF activity mechanistically relates to its distinct translational and Eph-receptor-coupled roles, and which substrate GTPases operate in each context, remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No unifying mechanism connecting GEF, translation, and Eph signaling roles","Direct GTPase substrate specificity not biochemically defined across contexts"]}],"mechanism_profile":{"molecular_activity":[],"localization":[],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[1,2]},{"term_id":"R-HSA-1643685","term_label":"Disease","supporting_discovery_ids":[2,4]}],"complexes":[],"partners":[],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q8N5V2","full_name":"Ephexin-1","aliases":["Eph-interacting exchange protein","Neuronal guanine nucleotide exchange factor"],"length_aa":710,"mass_kda":82.5,"function":"Acts as a guanine nucleotide exchange factor (GEF) which differentially activates the GTPases RHOA, RAC1 and CDC42. Plays a role in axon guidance regulating ephrin-induced growth cone collapse and dendritic spine morphogenesis. Upon activation by ephrin through EPHA4, the GEF activity switches toward RHOA resulting in its activation. Activated RHOA promotes cone retraction at the expense of RAC1- and CDC42-stimulated growth cone extension (By similarity)","subcellular_location":"Cytoplasm; Membrane; Cell projection, growth cone","url":"https://www.uniprot.org/uniprotkb/Q8N5V2/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/NGEF","classification":"Not Classified","n_dependent_lines":1,"n_total_lines":1208,"dependency_fraction":0.0008278145695364238},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/NGEF","total_profiled":1310},"omim":[{"mim_id":"612458","title":"ACTIN-LIKE 6B; ACTL6B","url":"https://www.omim.org/entry/612458"},{"mim_id":"605991","title":"NEURONAL GUANINE NUCLEOTIDE EXCHANGE FACTOR; NGEF","url":"https://www.omim.org/entry/605991"},{"mim_id":"116952","title":"CELL DIVISION CYCLE 42; CDC42","url":"https://www.omim.org/entry/116952"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Plasma membrane","reliability":"Approved"},{"location":"Cytosol","reliability":"Approved"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"adrenal gland","ntpm":54.1},{"tissue":"brain","ntpm":139.7}],"url":"https://www.proteinatlas.org/search/NGEF"},"hgnc":{"alias_symbol":["ARHGEF27"],"prev_symbol":[]},"alphafold":{"accession":"Q8N5V2","domains":[{"cath_id":"1.20.900.10","chopping":"180-202_246-465","consensus_level":"high","plddt":90.6461,"start":180,"end":465},{"cath_id":"2.30.29.30","chopping":"478-503_514-597","consensus_level":"high","plddt":90.0922,"start":478,"end":597},{"cath_id":"2.30.30.40","chopping":"608-704","consensus_level":"high","plddt":80.3248,"start":608,"end":704}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8N5V2","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q8N5V2-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q8N5V2-F1-predicted_aligned_error_v6.png","plddt_mean":71.5},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=NGEF","jax_strain_url":"https://www.jax.org/strain/search?query=NGEF"},"sequence":{"accession":"Q8N5V2","fasta_url":"https://rest.uniprot.org/uniprotkb/Q8N5V2.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q8N5V2/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8N5V2"}},"corpus_meta":[{"pmid":"15733672","id":"PMC_15733672","title":"Candidate downstream regulated genes of HOX group 13 transcription factors with and without monomeric DNA binding capability.","date":"2005","source":"Developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/15733672","citation_count":51,"is_preprint":false},{"pmid":"27793213","id":"PMC_27793213","title":"A panel of four genes accurately differentiates benign from malignant thyroid nodules.","date":"2016","source":"Journal of experimental & clinical cancer research : CR","url":"https://pubmed.ncbi.nlm.nih.gov/27793213","citation_count":37,"is_preprint":false},{"pmid":"22384097","id":"PMC_22384097","title":"3T3 cell lines stably expressing Pax6 or Pax6(5a)--a new tool used for identification of common and isoform specific target genes.","date":"2012","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/22384097","citation_count":29,"is_preprint":false},{"pmid":"10777665","id":"PMC_10777665","title":"Characterization of Ngef, a novel member of the Dbl family of genes expressed predominantly in the caudate nucleus.","date":"2000","source":"Genomics","url":"https://pubmed.ncbi.nlm.nih.gov/10777665","citation_count":26,"is_preprint":false},{"pmid":"21107721","id":"PMC_21107721","title":"Analyses of porcine public SNPs in coding-gene regions by re-sequencing and phenotypic association studies.","date":"2010","source":"Molecular biology reports","url":"https://pubmed.ncbi.nlm.nih.gov/21107721","citation_count":22,"is_preprint":false},{"pmid":"35829701","id":"PMC_35829701","title":"Regulation of the COPII secretory machinery via focal adhesions and extracellular matrix signaling.","date":"2022","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/35829701","citation_count":13,"is_preprint":false},{"pmid":"33613767","id":"PMC_33613767","title":"Identification of Potential BRAF Inhibitor Joint Therapy Targets in PTC based on WGCAN and DCGA.","date":"2021","source":"Journal of Cancer","url":"https://pubmed.ncbi.nlm.nih.gov/33613767","citation_count":11,"is_preprint":false},{"pmid":"22545146","id":"PMC_22545146","title":"Pair-wise regulation of convergence and extension cell movements by four phosphatases via RhoA.","date":"2012","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/22545146","citation_count":9,"is_preprint":false},{"pmid":"36139690","id":"PMC_36139690","title":"Systematic Analysis of Genetic and Pathway Determinants of Eribulin Sensitivity across 100 Human Cancer Cell Lines from the Cancer Cell Line Encyclopedia (CCLE).","date":"2022","source":"Cancers","url":"https://pubmed.ncbi.nlm.nih.gov/36139690","citation_count":8,"is_preprint":false},{"pmid":"39722894","id":"PMC_39722894","title":"Identification of biomarkers and immune microenvironment associated with pterygium through bioinformatics and machine learning.","date":"2024","source":"Frontiers in molecular 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scoliosis.","date":"2025","source":"eLife","url":"https://pubmed.ncbi.nlm.nih.gov/40662934","citation_count":3,"is_preprint":false},{"pmid":"27377345","id":"PMC_27377345","title":"Proinflammatory responses driven by non-gluten factors are masked when they appear associated to gliadins.","date":"2016","source":"Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association","url":"https://pubmed.ncbi.nlm.nih.gov/27377345","citation_count":3,"is_preprint":false},{"pmid":"40022166","id":"PMC_40022166","title":"Neuronal guanine nucleotide exchange factor promotes the axonal growth and cancer cell proliferation via Ephrin-A3/EphA2 axis in lung adenocarcinoma.","date":"2025","source":"Journal of translational medicine","url":"https://pubmed.ncbi.nlm.nih.gov/40022166","citation_count":2,"is_preprint":false},{"pmid":"31498969","id":"PMC_31498969","title":"Association of MAD1L1 polymorphism (rs871925) with prenatal famine exposure 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osteoarthritis.","date":"2026","source":"Ecotoxicology and environmental safety","url":"https://pubmed.ncbi.nlm.nih.gov/42034589","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":12329,"output_tokens":1601,"usd":0.030501,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":8468,"output_tokens":2262,"usd":0.049445,"stage2_stop_reason":"end_turn"},"total_usd":0.079946,"stage1_batch_id":"msgbatch_013a8chtv3AWyTqv4z4sEF4C","stage2_batch_id":"msgbatch_01AHsuW63vinsvuTgzmQ3n62","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2000,\n      \"finding\": \"NGEF was identified as a novel member of the Dbl family of guanine nucleotide exchange factors (GEFs), capable of acting as a GEF for Rho-type GTPases. It demonstrated transforming potential in cell culture and ability to induce tumors in nude mice, consistent with GEF/RhoGTPase signaling activity.\",\n      \"method\": \"Sequence analysis (Dbl family domain identification), cell transformation assay, nude mouse tumor induction\",\n      \"journal\": \"Genomics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — sequence-based family classification with functional cell transformation assay; single lab, limited mechanistic depth on GEF activity itself\",\n      \"pmids\": [\"10777665\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"In Xenopus convergence and extension cell movements, NGEF acts downstream of RPTPα/PTPε phosphatases to promote RhoA activation. Morpholino knockdown of NGEF disrupted convergence and extension, and this phenotype was rescued by constitutively active RhoA, placing NGEF as a positive regulator of RhoA in this pathway.\",\n      \"method\": \"Morpholino knockdown in Xenopus embryos, epistasis with constitutively active/dominant-negative RhoA rescue, co-knockdown specificity controls\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic epistasis with rescue experiment, dominant-negative/constitutively active RhoA controls, pathway position established with multiple orthogonal approaches in a single rigorous study\",\n      \"pmids\": [\"22545146\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"NGEF (Ephexin1) promotes axonal growth in neurons co-cultured with lung cancer cells via the Ephrin-A3/EphA2 pathway. Knockdown of Ephrin-A3 in neurons or inhibition of EphA2 with ALW-II-41-27 blocked neurite outgrowth stimulated by NGEF-overexpressing cancer cells. In a mouse xenograft model, NGEF overexpression increased tumor growth and nerve fiber density, effects inhibited by ALW-II-41-27.\",\n      \"method\": \"Co-culture experiments (neurons + cancer cells), Ephrin-A3 knockdown, EphA2 inhibitor (ALW-II-41-27), mouse subcutaneous xenograft model with nerve fiber density quantification\",\n      \"journal\": \"Journal of translational medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — loss-of-function (knockdown + inhibitor) with defined cellular and in vivo phenotype, single lab, two orthogonal methods\",\n      \"pmids\": [\"40022166\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Ephexin1/NGEF is essential for polysome formation and promotes translation of mRNAs containing 5'-terminal oligopyrimidine (TOP) or 5'-TOP-like motifs, acting as a key mediator of mTOR-regulated translation. Ephexin1 deficiency enhanced efficacy of mTOR inhibitors in a mouse xenograft lung cancer model, indicating synthetic lethality.\",\n      \"method\": \"Polysome profiling, gene expression analysis after NGEF knockdown, mouse xenograft model with mTOR inhibitor combination\",\n      \"journal\": \"Experimental & molecular medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — polysome profiling and in vivo xenograft with defined molecular phenotype, single lab, multiple orthogonal approaches\",\n      \"pmids\": [\"40855114\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"NGEF promotes invasion and migration of BRAFV600E-mutant thyroid cancer cells through the epithelial-mesenchymal transition (EMT) pathway. NGEF expression is transcriptionally regulated by BRAFV600E via the ERK/AP1 pathway, as confirmed by pathway inhibition experiments and dual-luciferase reporter assays.\",\n      \"method\": \"Functional invasion/migration assays, EMT biomarker analysis, pathway inhibition, dual-luciferase reporter assay, BRAFV600E-engineered cellular models\",\n      \"journal\": \"Biochemistry and biophysics reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — luciferase reporter + pathway inhibition + functional phenotypic assays, single lab, multiple orthogonal methods\",\n      \"pmids\": [\"40703409\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Variants in NGEF were identified in cases of idiopathic scoliosis (IS), and NGEF is positioned as a downstream molecule in the EPHA4 signaling pathway relevant to spinal patterning, based on analysis of IS cohort data.\",\n      \"method\": \"Human genetic variant analysis in IS cohorts; pathway placement as downstream of EPHA4 based on known pathway membership\",\n      \"journal\": \"eLife\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 4 / Weak — genetic association only, no direct functional experiment on NGEF itself; pathway placement inferred, not experimentally tested for NGEF in this study\",\n      \"pmids\": [\"40662934\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"NGEF/Ephexin1 is a neuronal Dbl-family guanine nucleotide exchange factor (GEF) for Rho-type GTPases that acts downstream of Eph receptors and RPTPα/PTPε phosphatases to activate RhoA, thereby regulating convergence/extension cell movements and axon guidance; in cancer contexts, it promotes tumor cell invasion/migration via EMT (regulated transcriptionally by BRAFV600E/ERK/AP1), facilitates neural infiltration through the Ephrin-A3/EphA2 axis, and supports mTOR-regulated translation by enabling polysome assembly on 5'-TOP mRNAs.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"NGEF (Ephexin1) is a neuronal Dbl-family guanine nucleotide exchange factor that activates Rho-type GTPases and couples receptor-level signaling to cytoskeletal and morphogenetic outputs [#0]. In Xenopus convergence and extension movements, NGEF functions downstream of RPTPα/PTPε phosphatases as a positive regulator of RhoA, since its knockdown disrupts these movements and is rescued by constitutively active RhoA [#1]. Through Eph receptor signaling NGEF directs axonal behavior: it promotes neurite outgrowth toward cancer cells via the Ephrin-A3/EphA2 axis, and in xenografts NGEF overexpression increases both tumor growth and nerve fiber density [#2]. In cancer, NGEF drives invasion and migration through epithelial-mesenchymal transition, and its expression is transcriptionally induced by BRAFV600E acting through the ERK/AP1 pathway [#4]. Independent of its GEF role, NGEF is required for polysome formation and supports mTOR-regulated translation of 5'-TOP and TOP-like mRNAs, such that its loss sensitizes tumors to mTOR inhibitors [#3].\",\n  \"teleology\": [\n    {\n      \"year\": 2000,\n      \"claim\": \"Established NGEF as a Dbl-family GEF for Rho GTPases with intrinsic transforming activity, defining its core molecular identity.\",\n      \"evidence\": \"Dbl-domain sequence analysis with cell transformation and nude mouse tumor induction assays\",\n      \"pmids\": [\"10777665\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"No direct biochemical demonstration of nucleotide exchange on a specific Rho GTPase\",\n        \"Upstream activators not identified at this stage\",\n        \"Transforming activity not linked to a defined substrate GTPase\"\n      ]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Placed NGEF in a defined signaling pathway as a positive regulator of RhoA downstream of RPTPα/PTPε during morphogenetic cell movements, answering how NGEF GEF activity is wired into development.\",\n      \"evidence\": \"Morpholino knockdown in Xenopus with constitutively active RhoA rescue and dominant-negative controls\",\n      \"pmids\": [\"22545146\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Mechanism by which phosphatases regulate NGEF activity not resolved\",\n        \"Direct biochemical GEF assay on RhoA not shown in this system\"\n      ]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Linked NGEF to Eph receptor-mediated axon guidance in a tumor microenvironment, showing it drives neurite outgrowth and tumor nerve infiltration via Ephrin-A3/EphA2.\",\n      \"evidence\": \"Neuron-cancer co-culture with Ephrin-A3 knockdown and EphA2 inhibition, plus mouse xenograft with nerve fiber quantification\",\n      \"pmids\": [\"40022166\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Whether GEF/RhoA activity mediates this neurite effect not tested\",\n        \"Direct physical interaction of NGEF with EphA2 not demonstrated\",\n        \"Single lab, limited orthogonal validation\"\n      ]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Revealed a GEF-independent role for NGEF in translation, identifying it as essential for polysome assembly and mTOR-regulated TOP mRNA translation with therapeutic synthetic-lethal implications.\",\n      \"evidence\": \"Polysome profiling and expression analysis after knockdown, plus xenograft mTOR inhibitor combination\",\n      \"pmids\": [\"40855114\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Molecular mechanism connecting NGEF to polysome assembly unknown\",\n        \"No structural or biochemical basis for TOP-mRNA selectivity\",\n        \"Relationship to its Rho-GEF function unresolved\"\n      ]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Defined NGEF as a transcriptional effector of oncogenic BRAF signaling driving cancer cell invasion through EMT.\",\n      \"evidence\": \"Invasion/migration and EMT biomarker assays, ERK/AP1 pathway inhibition, and dual-luciferase reporter assays in BRAFV600E models\",\n      \"pmids\": [\"40703409\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Direct AP1 binding site in the NGEF promoter not mapped beyond reporter assay\",\n        \"Whether GEF activity is required for the invasive phenotype not tested\"\n      ]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Associated NGEF variants with idiopathic scoliosis and positioned it downstream of EPHA4 in spinal patterning.\",\n      \"evidence\": \"Human genetic variant analysis in idiopathic scoliosis cohorts with inferred pathway placement\",\n      \"pmids\": [\"40662934\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"Genetic association only, no direct functional test of NGEF variants\",\n        \"EPHA4-NGEF pathway link inferred rather than experimentally tested\",\n        \"Causality for scoliosis not established\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How NGEF's canonical Rho-GEF activity mechanistically relates to its distinct translational and Eph-receptor-coupled roles, and which substrate GTPases operate in each context, remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"No unifying mechanism connecting GEF, translation, and Eph signaling roles\",\n        \"Direct GTPase substrate specificity not biochemically defined across contexts\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0005085\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"localization\": [],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [1, 2]},\n      {\"term_id\": \"R-HSA-1643685\", \"supporting_discovery_ids\": [2, 4]}\n    ],\n    \"complexes\": [],\n    \"partners\": [],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":5,"faith_pct":100.0}}