{"gene":"TSPAN12","run_date":"2026-06-10T10:51:56","timeline":{"discoveries":[{"year":2009,"finding":"TSPAN12 is expressed in the retinal vasculature and loss of Tspan12 phenocopies defects seen in Fzd4, Lrp5, and Norrin mutant mice. Overexpressed TSPAN12 associates with the Norrin-receptor complex and significantly increases Norrin/β-catenin but not Wnt/β-catenin signaling. Tspan12 siRNA abolishes transcriptional responses to Norrin but not Wnt3A in retinal endothelial cells. Signaling defects caused by Norrin or FZD4 mutations predicted to impair receptor multimerization are rescued by TSPAN12 overexpression, indicating that Norrin multimers and TSPAN12 cooperatively promote multimerization of FZD4 and associated proteins.","method":"Mouse knockout (phenocopy), genetic interaction studies, Co-IP, siRNA knockdown, reporter assays (luciferase), overexpression rescue experiments","journal":"Cell","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods (KO phenocopy, genetic epistasis, Co-IP, siRNA, reporter assay, rescue experiments) in a single rigorous study","pmids":["19837033"],"is_preprint":false},{"year":2017,"finding":"TSPAN12 is an essential component of the NDP (Norrin) receptor complex and interacts with FZD4 and NDP via its extracellular loops, acting as a co-receptor that enhances FZD4 ligand selectivity for NDP. FEVR-linked mutations in TSPAN12 prevent its incorporation into the NDP receptor complex. TSPAN12 alleviates defects of FZD4 M105V, a mutation that destabilizes the NDP/FZD4 interaction, both in vitro and in Xenopus embryos.","method":"Co-IP (interaction with FZD4 and NDP via extracellular loops), FEVR mutation analysis, in vitro signaling assays, Xenopus embryo rescue experiments","journal":"Cell reports","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP, FEVR mutation functional analysis, in vivo Xenopus rescue, multiple orthogonal methods","pmids":["28658627"],"is_preprint":false},{"year":2018,"finding":"TSPAN12 functions specifically in endothelial cells to promote vascular morphogenesis and blood-retina barrier (BRB) formation in developing mice and BRB maintenance in adult mice. Early endothelial-specific loss of TSPAN12 causes lack of intraretinal capillaries and increased VE-cadherin expression (consistent with premature vascular quiescence). Late loss of TSPAN12 strongly impairs BRB maintenance without affecting vascular morphogenesis, pericyte coverage, or perfusion. Long-term BRB defects associate with immunoglobulin extravasation, complement deposition, cystoid edema, and impaired b-wave in electroretinograms.","method":"Conditional endothelial-specific knockout (loxP/Cdh5-CreERT2), confocal microscopy, RNA-seq, histopathology, electroretinogram","journal":"Arteriosclerosis, thrombosis, and vascular biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — cell-type-specific conditional KO with multiple orthogonal phenotypic readouts and transcriptomic analysis","pmids":["30354230"],"is_preprint":false},{"year":2013,"finding":"TSPAN12 ablation from human MDA-MB-231 cells caused diminished association between FZD4 and its co-receptor LRP5, leading to substantially enhanced proteasomal degradation of β-catenin and altered expression of canonical Wnt pathway components (LRP5, Naked 1/2, DVL2, DVL3, Axin 1, GSK3β). This resulted in decreased primary tumor xenograft growth, increased tumor apoptosis, and markedly enhanced tumor-endothelial interactions and metastasis to mouse lungs.","method":"siRNA/shRNA knockdown, Co-IP (FZD4-LRP5 association), western blot (β-catenin degradation), xenograft tumor models, gene expression analysis","journal":"Cellular and molecular life sciences : CMLS","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP showing FZD4-LRP5 dissociation, proteasomal degradation assay, in vivo xenograft, single lab with multiple methods","pmids":["23955570"],"is_preprint":false},{"year":2014,"finding":"TSPAN12 expression in p53-depleted lung fibroblasts (cancer-associated fibroblasts) is required for contact-mediated cancer cell invasion and proliferation. TSPAN12 in fibroblasts transduces β-catenin signaling upon cancer cell contact, leading to secretion of CXCL6, which promotes cancer cell invasion. TSPAN12 knockdown in p53-depleted fibroblasts inhibited CXCL6 secretion, cancer cell invasion in vitro, and tumor growth in vivo.","method":"siRNA knockdown, co-culture invasion assays, DNA chip/microarray, xenograft tumor model, CXCL6 secretion measurement","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — loss-of-function with specific pathway readout (β-catenin/CXCL6), in vitro and in vivo validation, single lab","pmids":["25512506"],"is_preprint":false},{"year":2017,"finding":"An anti-Tspan12 antibody inhibits the interaction between Tspan12 and Frizzled-4, effectively modulates β-catenin levels and target genes in vascular endothelial cells, and inhibits endothelial cell migration and tube formation. Tspan12/β-catenin signaling is activated in response to acute and chronic stress in retinal neovascular disease models (OIR and VLDLR KO mice). Intravitreal application of the anti-Tspan12 antibody showed therapeutic effects in both models.","method":"Phage display antibody generation, Co-IP (Tspan12-FZD4 interaction disruption), in vitro endothelial cell assays, in vivo OIR and VLDLR KO mouse models, western blot (β-catenin)","journal":"Circulation","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — antibody-mediated disruption of Tspan12-FZD4 interaction with mechanistic downstream readout, in vitro and in vivo validation, single lab","pmids":["28356444"],"is_preprint":false},{"year":2021,"finding":"In endothelial cells, TSPAN12 gene silencing increases endothelial cell permeability and dysregulates genes associated with extracellular matrix pathways. Endothelial cell-fibroblast crosstalk upon TSPAN12 loss induces extracellular matrix changes relevant to esophageal remodeling. IL-13 reduces TSPAN12 expression in endothelial cells, whereas anti-IL-13 therapy increases TSPAN12 expression.","method":"siRNA gene silencing, permeability assays, RNA sequencing, endothelial cell-fibroblast co-culture, cytokine treatment","journal":"Gastroenterology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — loss-of-function with specific cellular phenotype (permeability, ECM gene expression), co-culture crosstalk experiment, single lab","pmids":["34687736"],"is_preprint":false},{"year":2021,"finding":"The E3 ubiquitin ligase RNF152 interacts with TSPAN12 and targets it for ubiquitination and proteasomal degradation, thereby inhibiting TSPAN12-dependent CXCL6 expression and HCC progression.","method":"Co-immunoprecipitation (RNF152-TSPAN12 interaction), in vivo ubiquitination assay, RNAi knockdown, cell proliferation/invasion assays, xenograft tumor model","journal":"Cancer cell international","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP and in vivo ubiquitination assay establish direct PTM relationship, single lab with multiple orthogonal methods","pmids":["33602225"],"is_preprint":false},{"year":2022,"finding":"Novel TSPAN12 missense variants show compromised interactions with binding partners in the Norrin/β-catenin pathway by co-immunoprecipitation, and exhibit abnormal subcellular trafficking by immunofluorescence and subcellular protein extraction. Overexpression of TSPAN12 enhanced Norrin/β-catenin signaling by strengthening the binding affinity of mutant Norrin with FZD4 or LRP5.","method":"Co-immunoprecipitation (variant interaction analysis), immunofluorescence (subcellular trafficking), subcellular protein fractionation, luciferase reporter assay, western blot","journal":"Clinical genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal methods (Co-IP, localization, reporter assay), single lab","pmids":["36453149"],"is_preprint":false},{"year":2022,"finding":"TSPAN12 is a negative regulator of aldosterone production in adrenocortical cells. Gene silencing of TSPAN12 in human adrenocortical cells (HAC15) demonstrated its inverse effect on aldosterone secretion under basal and angiotensin II-stimulated conditions. Angiotensin II stimulation caused increased TSPAN12 expression that was ablated by nifedipine or calmodulin inhibitor W-7.","method":"siRNA gene silencing, aldosterone secretion measurement, angiotensin II stimulation, pharmacological inhibition (nifedipine, W-7), pig adrenal model","journal":"Hypertension (Dallas, Tex. : 1979)","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — loss-of-function with specific quantitative phenotype (aldosterone secretion), pharmacological dissection, in vitro and in vivo (pig) corroboration, single lab","pmids":["36458545"],"is_preprint":false},{"year":2022,"finding":"TSPAN12 frameshift variant c.533dupC (p.D179Rfs*6) causes degradation of the entire TSPAN12 protein, which fails to activate Norrin/β-catenin signaling, establishing that protein integrity is required for pathway activation.","method":"Immunocytochemistry, western blot, qPCR, luciferase reporter assay","journal":"Molecular genetics & genomic medicine","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, functional assays on one variant without structural or binding partner validation","pmids":["35417085"],"is_preprint":false},{"year":2026,"finding":"Cryo-EM structure of the Norrin-Tspan12 large extracellular loop (LEL) complex at 3.78 Å resolution reveals that a Norrin dimer binds two Tspan12 molecules, defining the Norrin-Tspan12 interface. Tspan12 binds directly to Norrin without enhancing the binding affinity between Norrin and FZD4, supporting a model in which Norrin, FZD4, LRP5/6, and Tspan12 form a quaternary signaling complex.","method":"Cryo-EM structure determination (3.78 Å), binding affinity measurements, structural analysis of interface","journal":"Structure (London, England : 1993)","confidence":"High","confidence_rationale":"Tier 1 / Strong — cryo-EM structure with functional validation of binding interface, rigorous structural methodology","pmids":["42155446"],"is_preprint":false},{"year":2025,"finding":"Cryo-EM structure of Tspan12 in complex with FZD4 at 3.4 Å resolution reveals that FZD4 and Tspan12 form a direct complex in the absence of Norrin. The transmembrane domain of Tspan12 forms a tightly packed four-helix bundle that interacts with TM2 of FZD4 to promote trafficking of Tspan12 to the cell surface. The C-D helices of Tspan12, which mediate Norrin binding, remain exposed while Tspan12 is in complex with FZD4, facilitating higher-affinity Norrin binding. Cell-based assays indicate Tspan12 and FZD4 remain associated after Norrin recognition, establishing Tspan12 as a core component of the active FZD4-Norrin-LRP5/6 signaling complex.","method":"Cryo-EM structure (3.4 Å), cell-based signaling assays, cell surface trafficking assays","journal":"bioRxiv","confidence":"High","confidence_rationale":"Tier 1 / Strong — cryo-EM structure with domain-level mechanistic resolution plus orthogonal cell-based functional validation","pmids":["bio_10.1101_2025.09.25.678640"],"is_preprint":true},{"year":2025,"finding":"Tspan12 KO mice develop cystoid edema due to BRB dysfunction mediated by loss of basal β-catenin-dependent Norrin/FZD4 signaling. Activation of β-catenin-dependent signaling by a FZD4/LRP5 agonist antibody achieves complete resolution of cystoid edema in this model, establishing that Tspan12 maintains BRB function through Norrin/FZD4/β-catenin signaling.","method":"Tspan12 KO mouse model (genetic), FZD4/LRP5 agonist antibody rescue, BRB function assays, ERG, cystoid edema quantification, compound mutant analysis (Tspan12 KO; C1qa KO)","journal":"bioRxiv","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic KO with rescue experiment establishing pathway position, multiple phenotypic readouts, preprint not yet peer-reviewed","pmids":["bio_10.1101_2025.07.22.666172"],"is_preprint":true},{"year":2012,"finding":"Homozygous (biallelic) TSPAN12 mutations cause more severe FEVR/retinal dysplasia than heterozygous mutations in the same family, establishing a dose-dependent relationship between TSPAN12 function and Norrin-β-catenin pathway activity in retinal vascular development.","method":"Genetic mutation analysis (Sanger sequencing), reverse transcriptase PCR (splicing verification), phenotype-genotype correlation in family members","journal":"Investigative ophthalmology & visual science","confidence":"Low","confidence_rationale":"Tier 3 / Moderate — genetic dosage-phenotype correlation across multiple families, but no direct biochemical mechanism established","pmids":["22427576"],"is_preprint":false},{"year":2019,"finding":"TSPAN12 overexpression in ovarian cancer cells (OVCAR3, SKOV3) accelerated proliferation and colony formation, while knockdown in A2780 and SKOV3 cells decreased proliferation. Western blot showed that cyclins (A2, D1, E2) and CDKs (CDK2, CDK4) are regulated downstream of TSPAN12, placing TSPAN12 upstream of cell cycle control machinery.","method":"Overexpression and siRNA knockdown, proliferation and colony formation assays, western blot (cyclin and CDK expression)","journal":"Molecules and cells","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, single cell line context, no direct binding or structural evidence for cyclins as direct TSPAN12 substrates","pmids":["31362470"],"is_preprint":false}],"current_model":"TSPAN12 is a tetraspanin co-receptor that forms a pre-formed complex with FZD4 via transmembrane domain interactions (promoting FZD4 cell-surface trafficking), then recruits Norrin dimers through its large extracellular loop to assemble a quaternary Norrin-FZD4-LRP5/6-TSPAN12 signaling complex that selectively amplifies Norrin/β-catenin signaling (but not Wnt/β-catenin signaling); in retinal endothelial cells this pathway is required for vascular morphogenesis, blood-retina barrier formation and maintenance, and loss of TSPAN12 causes familial exudative vitreoretinopathy. Beyond the retina, TSPAN12 stabilizes FZD4-LRP5 association to support β-catenin signaling in cancer contexts, is subject to ubiquitin-proteasomal degradation by E3 ligase RNF152, and acts as a negative regulator of aldosterone secretion in adrenocortical cells."},"narrative":{"mechanistic_narrative":"TSPAN12 is a tetraspanin co-receptor that selectively amplifies Norrin/β-catenin signaling and is essential for retinal vascular morphogenesis and blood-retina barrier (BRB) formation and maintenance [PMID:19837033, PMID:30354230]. It functions as a dedicated component of the Norrin (NDP) receptor complex: TSPAN12 forms a direct transmembrane complex with FZD4 in the absence of ligand—its four-helix transmembrane bundle packs against FZD4 TM2 to promote cell-surface trafficking—while leaving its Norrin-binding C–D helices exposed [PMID:bio_10.1101_2025.09.25.678640]. Through its large extracellular loop it then engages Norrin, with a Norrin dimer binding two TSPAN12 molecules, assembling a quaternary Norrin-FZD4-LRP5/6-TSPAN12 signaling complex [PMID:42155446]. By promoting receptor multimerization and ligand selectivity, TSPAN12 enhances Norrin/β-catenin but not Wnt/β-catenin transcriptional output, and can rescue signaling defects of Norrin and FZD4 mutations that destabilize the complex [PMID:19837033, PMID:28658627]. Loss of endothelial TSPAN12 causes BRB breakdown with immunoglobulin extravasation, complement deposition, cystoid edema, and impaired electroretinogram b-waves, and BRB dysfunction is reversed by direct FZD4/LRP5 agonism, placing TSPAN12 upstream of basal β-catenin signaling [PMID:30354230, PMID:bio_10.1101_2025.07.22.666172]. FEVR-linked TSPAN12 mutations act by preventing incorporation into the receptor complex or by disrupting trafficking, defining TSPAN12 as a causative gene for familial exudative vitreoretinopathy [PMID:28658627, PMID:36453149]. Beyond the retina, TSPAN12 stabilizes FZD4-LRP5 association to sustain β-catenin signaling in cancer cells and stromal fibroblasts, where it drives CXCL6 secretion and tumor progression, is degraded by the E3 ligase RNF152, and acts as a negative regulator of aldosterone secretion in adrenocortical cells [PMID:23955570, PMID:25512506, PMID:33602225, PMID:36458545].","teleology":[{"year":2009,"claim":"Established TSPAN12 as a Norrin-pathway co-receptor by showing it specifically amplifies Norrin/β-catenin signaling and that its loss phenocopies Fzd4/Lrp5/Norrin mutants, answering whether tetraspanins participate in this receptor system.","evidence":"Mouse KO phenocopy, genetic epistasis, Co-IP, siRNA, luciferase reporters and overexpression rescue in retinal endothelial cells","pmids":["19837033"],"confidence":"High","gaps":["Molecular basis of ligand selectivity (Norrin vs Wnt) not resolved","Direct binding interfaces undefined","Mechanism of receptor multimerization inferred, not structurally shown"]},{"year":2017,"claim":"Localized TSPAN12 function to its extracellular loops and showed it enhances FZD4 selectivity for Norrin, explaining how disease mutations and FZD4-destabilizing variants impair signaling.","evidence":"Reciprocal Co-IP, FEVR mutation analysis, in vitro signaling and Xenopus embryo rescue of FZD4 M105V","pmids":["28658627"],"confidence":"High","gaps":["Stoichiometry of the receptor complex unresolved","No structural detail of the extracellular-loop interactions"]},{"year":2018,"claim":"Separated developmental from maintenance roles by endothelial-specific conditional deletion, showing TSPAN12 is required both for retinal vascular morphogenesis and for ongoing BRB integrity in adults.","evidence":"Cdh5-CreERT2 conditional KO with confocal imaging, RNA-seq, histopathology and electroretinogram","pmids":["30354230"],"confidence":"High","gaps":["Molecular link between β-catenin output and barrier gene programs not defined","Whether maintenance defect is fully cell-autonomous unclear"]},{"year":2013,"claim":"Extended TSPAN12 function to cancer by showing it stabilizes the FZD4-LRP5 association to protect β-catenin from degradation and influence tumor growth and metastasis.","evidence":"siRNA/shRNA, Co-IP of FZD4-LRP5, β-catenin degradation western blots, xenograft models in MDA-MB-231 cells","pmids":["23955570"],"confidence":"Medium","gaps":["Whether Norrin is the relevant ligand in this context untested","Single cell-line context","Direct vs indirect effect on FZD4-LRP5 not dissected structurally"]},{"year":2014,"claim":"Showed a stromal role in which fibroblast TSPAN12 transduces contact-induced β-catenin signaling to drive CXCL6 secretion and cancer cell invasion, broadening the pathway's tissue contexts.","evidence":"siRNA knockdown, co-culture invasion assays, microarray, CXCL6 measurement and xenografts in p53-depleted fibroblasts","pmids":["25512506"],"confidence":"Medium","gaps":["Receptor complex composition in fibroblasts unconfirmed","Identity of activating signal upon cancer-cell contact unknown"]},{"year":2017,"claim":"Demonstrated that disrupting the TSPAN12-FZD4 interaction is therapeutically actionable, validating the interaction as the functional node in pathological retinal neovascularization.","evidence":"Phage-display anti-Tspan12 antibody, Co-IP disruption, endothelial assays, and OIR and VLDLR-KO mouse models","pmids":["28356444"],"confidence":"Medium","gaps":["Precise epitope and mechanism of disruption not mapped","Single antibody, single lab"]},{"year":2021,"claim":"Identified RNF152 as an E3 ligase that ubiquitinates TSPAN12 for proteasomal degradation, defining a post-translational control point limiting TSPAN12-driven CXCL6 expression.","evidence":"Co-IP, in vivo ubiquitination assay, RNAi, proliferation/invasion assays and xenografts in HCC","pmids":["33602225"],"confidence":"Medium","gaps":["Ubiquitination sites on TSPAN12 not mapped","Regulation of RNF152 activity unknown","Single lab"]},{"year":2021,"claim":"Linked endothelial TSPAN12 loss to increased permeability and ECM dysregulation in a non-retinal tissue and placed TSPAN12 downstream of IL-13 signaling.","evidence":"siRNA silencing, permeability assays, RNA-seq, endothelial-fibroblast co-culture and cytokine treatment","pmids":["34687736"],"confidence":"Medium","gaps":["Mechanism connecting TSPAN12 to ECM genes undefined","Whether β-catenin mediates this effect not tested directly"]},{"year":2022,"claim":"Defined a non-vascular endocrine role, showing TSPAN12 negatively regulates aldosterone secretion and is induced by angiotensin II via calcium/calmodulin signaling.","evidence":"siRNA silencing, aldosterone measurement, angiotensin II stimulation with nifedipine/W-7 inhibition in HAC15 cells and pig adrenal","pmids":["36458545"],"confidence":"Medium","gaps":["Molecular mechanism of aldosterone suppression unknown","Whether β-catenin/Norrin signaling is involved untested"]},{"year":2022,"claim":"Showed that disease-associated missense variants act by impairing binding-partner interactions and subcellular trafficking, connecting genotype to a defined molecular defect in the Norrin pathway.","evidence":"Co-IP variant analysis, immunofluorescence trafficking, subcellular fractionation and luciferase reporters","pmids":["36453149"],"confidence":"Medium","gaps":["Trafficking defect mechanism not resolved at structural level","Single lab"]},{"year":2026,"claim":"Resolved the Norrin-TSPAN12 interface by cryo-EM, showing a Norrin dimer bridges two TSPAN12 large extracellular loops and that TSPAN12 binds Norrin directly without raising Norrin-FZD4 affinity, supporting a quaternary complex model.","evidence":"Cryo-EM of the Norrin-TSPAN12 LEL complex at 3.78 Å with binding-affinity measurements","pmids":["42155446"],"confidence":"High","gaps":["Full assembly with FZD4 and LRP5/6 not captured in one structure","Dynamics of complex assembly in cells not addressed"]},{"year":2025,"claim":"Cryo-EM of the TSPAN12-FZD4 complex established that the two form a direct pre-ligand complex via a TSPAN12 four-helix transmembrane bundle packing against FZD4 TM2, promoting surface trafficking while leaving the Norrin-binding helices exposed.","evidence":"Cryo-EM at 3.4 Å (preprint) with cell-based signaling and surface-trafficking assays","pmids":["bio_10.1101_2025.09.25.678640"],"confidence":"High","gaps":["Not yet peer-reviewed","LRP5/6 engagement geometry within the active complex not shown"]},{"year":2025,"claim":"Demonstrated in Tspan12 KO mice that cystoid edema arises from loss of basal Norrin/FZD4/β-catenin signaling and is fully reversed by a FZD4/LRP5 agonist antibody, positioning TSPAN12 as an amplifier upstream of a pharmacologically restorable node.","evidence":"Tspan12 KO mice (preprint), FZD4/LRP5 agonist rescue, BRB assays, ERG and Tspan12;C1qa compound mutants","pmids":["bio_10.1101_2025.07.22.666172"],"confidence":"Medium","gaps":["Not yet peer-reviewed","Role of complement in edema only partially dissected"]},{"year":null,"claim":"How TSPAN12's distinct context-specific roles (retinal barrier amplification, cancer β-catenin stabilization, ECM/permeability control, and aldosterone suppression) are mechanistically unified or distinguished remains unresolved.","evidence":"","pmids":[],"confidence":"Low","gaps":["Whether non-retinal roles use the same quaternary complex is untested","Tissue-specific ligand/partner repertoire of TSPAN12 undefined","Mechanism of aldosterone regulation and ECM control not connected to Norrin signaling"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0038024","term_label":"cargo receptor activity","supporting_discovery_ids":[0,1,11,12]},{"term_id":"GO:0060089","term_label":"molecular transducer activity","supporting_discovery_ids":[0,1]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[3,5]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[0,12]}],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[0,1,11]},{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[2,13]},{"term_id":"R-HSA-1643685","term_label":"Disease","supporting_discovery_ids":[1,8,14]}],"complexes":["Norrin-FZD4-LRP5/6-TSPAN12 receptor complex"],"partners":["FZD4","NDP","LRP5","RNF152"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"O95859","full_name":"Tetraspanin-12","aliases":["Tetraspan NET-2","Transmembrane 4 superfamily member 12"],"length_aa":305,"mass_kda":35.4,"function":"Regulator of cell surface receptor signal transduction. Plays a central role in retinal vascularization by regulating norrin (NDP) signal transduction. Acts in concert with norrin (NDP) to promote FZD4 multimerization and subsequent activation of FZD4, leading to promote accumulation of beta-catenin (CTNNB1) and stimulate LEF/TCF-mediated transcriptional programs. Suprisingly, it only activates the norrin (NDP)-dependent activation of FZD4, while it does not activate the Wnt-dependent activation of FZD4, suggesting the existence of a Wnt-independent signaling that also promote accumulation the beta-catenin (CTNNB1) (By similarity). Acts as a regulator of membrane proteinases such as ADAM10 and MMP14/MT1-MMP. Activates ADAM10-dependent cleavage activity of amyloid precursor protein (APP). Activates MMP14/MT1-MMP-dependent cleavage activity","subcellular_location":"Cell membrane","url":"https://www.uniprot.org/uniprotkb/O95859/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/TSPAN12","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/TSPAN12","total_profiled":1310},"omim":[{"mim_id":"613310","title":"EXUDATIVE VITREORETINOPATHY 5; EVR5","url":"https://www.omim.org/entry/613310"},{"mim_id":"613138","title":"TETRASPANIN 12; TSPAN12","url":"https://www.omim.org/entry/613138"},{"mim_id":"605750","title":"EXUDATIVE VITREORETINOPATHY 3; EVR3","url":"https://www.omim.org/entry/605750"},{"mim_id":"601813","title":"EXUDATIVE VITREORETINOPATHY 4; EVR4","url":"https://www.omim.org/entry/601813"},{"mim_id":"305390","title":"EXUDATIVE VITREORETINOPATHY 2, X-LINKED; EVR2","url":"https://www.omim.org/entry/305390"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Microtubules","reliability":"Approved"},{"location":"Vesicles","reliability":"Additional"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"kidney","ntpm":85.5}],"url":"https://www.proteinatlas.org/search/TSPAN12"},"hgnc":{"alias_symbol":["NET-2"],"prev_symbol":["TM4SF12"]},"alphafold":{"accession":"O95859","domains":[{"cath_id":"-","chopping":"1-46_57-120_225-252","consensus_level":"medium","plddt":87.6849,"start":1,"end":252},{"cath_id":"1.10.1450.10","chopping":"125-210","consensus_level":"high","plddt":90.2494,"start":125,"end":210}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/O95859","model_url":"https://alphafold.ebi.ac.uk/files/AF-O95859-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-O95859-F1-predicted_aligned_error_v6.png","plddt_mean":80.31},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=TSPAN12","jax_strain_url":"https://www.jax.org/strain/search?query=TSPAN12"},"sequence":{"accession":"O95859","fasta_url":"https://rest.uniprot.org/uniprotkb/O95859.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/O95859/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/O95859"}},"corpus_meta":[{"pmid":"19837033","id":"PMC_19837033","title":"TSPAN12 regulates retinal vascular development by promoting Norrin- but not Wnt-induced FZD4/beta-catenin signaling.","date":"2009","source":"Cell","url":"https://pubmed.ncbi.nlm.nih.gov/19837033","citation_count":329,"is_preprint":false},{"pmid":"20159111","id":"PMC_20159111","title":"Next-generation sequencing of a 40 Mb linkage interval reveals TSPAN12 mutations in patients with familial exudative vitreoretinopathy.","date":"2010","source":"American journal of human genetics","url":"https://pubmed.ncbi.nlm.nih.gov/20159111","citation_count":176,"is_preprint":false},{"pmid":"20159112","id":"PMC_20159112","title":"Mutations in TSPAN12 cause autosomal-dominant familial exudative vitreoretinopathy.","date":"2010","source":"American journal of human genetics","url":"https://pubmed.ncbi.nlm.nih.gov/20159112","citation_count":157,"is_preprint":false},{"pmid":"32041891","id":"PMC_32041891","title":"miR-196b-5p-mediated downregulation of TSPAN12 and GATA6 promotes tumor progression in non-small cell lung cancer.","date":"2020","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/32041891","citation_count":147,"is_preprint":false},{"pmid":"28658627","id":"PMC_28658627","title":"TSPAN12 Is a Norrin Co-receptor that Amplifies Frizzled4 Ligand Selectivity and Signaling.","date":"2017","source":"Cell reports","url":"https://pubmed.ncbi.nlm.nih.gov/28658627","citation_count":79,"is_preprint":false},{"pmid":"25512506","id":"PMC_25512506","title":"TSPAN12 is a critical factor for cancer-fibroblast cell contact-mediated cancer invasion.","date":"2014","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/25512506","citation_count":65,"is_preprint":false},{"pmid":"22427576","id":"PMC_22427576","title":"Recessive mutations in TSPAN12 cause retinal dysplasia and severe familial exudative vitreoretinopathy (FEVR).","date":"2012","source":"Investigative ophthalmology & visual science","url":"https://pubmed.ncbi.nlm.nih.gov/22427576","citation_count":62,"is_preprint":false},{"pmid":"28494495","id":"PMC_28494495","title":"Mutations in LRP5,FZD4, TSPAN12, NDP, ZNF408, or KIF11 Genes Account for 38.7% of Chinese Patients With Familial Exudative Vitreoretinopathy.","date":"2017","source":"Investigative ophthalmology & visual science","url":"https://pubmed.ncbi.nlm.nih.gov/28494495","citation_count":58,"is_preprint":false},{"pmid":"23955570","id":"PMC_23955570","title":"Tetraspanin TSPAN12 regulates tumor growth and metastasis and inhibits β-catenin degradation.","date":"2013","source":"Cellular and molecular life sciences : CMLS","url":"https://pubmed.ncbi.nlm.nih.gov/23955570","citation_count":49,"is_preprint":false},{"pmid":"26244290","id":"PMC_26244290","title":"Molecular Characterization of FZD4, LRP5, and TSPAN12 in Familial Exudative Vitreoretinopathy.","date":"2015","source":"Investigative ophthalmology & visual science","url":"https://pubmed.ncbi.nlm.nih.gov/26244290","citation_count":49,"is_preprint":false},{"pmid":"34687736","id":"PMC_34687736","title":"Loss of Endothelial TSPAN12 Promotes Fibrostenotic Eosinophilic Esophagitis via Endothelial Cell-Fibroblast Crosstalk.","date":"2021","source":"Gastroenterology","url":"https://pubmed.ncbi.nlm.nih.gov/34687736","citation_count":44,"is_preprint":false},{"pmid":"30354230","id":"PMC_30354230","title":"Endothelial Cell-Specific Inactivation of TSPAN12 (Tetraspanin 12) Reveals Pathological Consequences of Barrier Defects in an Otherwise Intact Vasculature.","date":"2018","source":"Arteriosclerosis, thrombosis, and vascular biology","url":"https://pubmed.ncbi.nlm.nih.gov/30354230","citation_count":43,"is_preprint":false},{"pmid":"29181528","id":"PMC_29181528","title":"Mutation Spectrum of the LRP5, NDP, and TSPAN12 Genes in Chinese Patients With Familial Exudative Vitreoretinopathy.","date":"2017","source":"Investigative ophthalmology & visual science","url":"https://pubmed.ncbi.nlm.nih.gov/29181528","citation_count":34,"is_preprint":false},{"pmid":"21552475","id":"PMC_21552475","title":"Novel TSPAN12 mutations in patients with familial exudative vitreoretinopathy and their associated phenotypes.","date":"2011","source":"Molecular vision","url":"https://pubmed.ncbi.nlm.nih.gov/21552475","citation_count":34,"is_preprint":false},{"pmid":"27316669","id":"PMC_27316669","title":"Mutation spectrum of the FZD-4, TSPAN12 AND ZNF408 genes in Indian FEVR patients.","date":"2016","source":"BMC ophthalmology","url":"https://pubmed.ncbi.nlm.nih.gov/27316669","citation_count":31,"is_preprint":false},{"pmid":"21334594","id":"PMC_21334594","title":"Mutations in the TSPAN12 gene in Japanese patients with familial exudative vitreoretinopathy.","date":"2011","source":"American journal of ophthalmology","url":"https://pubmed.ncbi.nlm.nih.gov/21334594","citation_count":29,"is_preprint":false},{"pmid":"28302484","id":"PMC_28302484","title":"TSPAN12 promotes chemoresistance and proliferation of SCLC under the regulation of miR-495.","date":"2017","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/28302484","citation_count":26,"is_preprint":false},{"pmid":"28356444","id":"PMC_28356444","title":"Antibody-Mediated Inhibition of Tspan12 Ameliorates Vasoproliferative Retinopathy Through Suppression of β-Catenin Signaling.","date":"2017","source":"Circulation","url":"https://pubmed.ncbi.nlm.nih.gov/28356444","citation_count":24,"is_preprint":false},{"pmid":"21626674","id":"PMC_21626674","title":"Submicroscopic deletion in 7q31 encompassing CADPS2 and TSPAN12 in a child with autism spectrum disorder and PHPV.","date":"2011","source":"American journal of medical genetics. Part A","url":"https://pubmed.ncbi.nlm.nih.gov/21626674","citation_count":24,"is_preprint":false},{"pmid":"38374407","id":"PMC_38374407","title":"METTL3-mediated m6A modification of lncRNA TSPAN12 promotes metastasis of hepatocellular carcinoma through SENP1-depentent deSUMOylation of EIF3I.","date":"2024","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/38374407","citation_count":19,"is_preprint":false},{"pmid":"25250762","id":"PMC_25250762","title":"Novel mutation in TSPAN12 leads to autosomal recessive inheritance of congenital vitreoretinal disease with intra-familial phenotypic variability.","date":"2014","source":"American journal of medical genetics. Part A","url":"https://pubmed.ncbi.nlm.nih.gov/25250762","citation_count":19,"is_preprint":false},{"pmid":"25352738","id":"PMC_25352738","title":"Novel mutations in the TSPAN12 gene in Chinese patients with familial exudative vitreoretinopathy.","date":"2014","source":"Molecular vision","url":"https://pubmed.ncbi.nlm.nih.gov/25352738","citation_count":18,"is_preprint":false},{"pmid":"23834558","id":"PMC_23834558","title":"Familial exudative vitreoretinopathy caused by a homozygous mutation in TSPAN12 in a cystic fibrosis infant.","date":"2013","source":"Ophthalmic genetics","url":"https://pubmed.ncbi.nlm.nih.gov/23834558","citation_count":16,"is_preprint":false},{"pmid":"28002565","id":"PMC_28002565","title":"Large Deletions of TSPAN12 Cause Familial Exudative Vitreoretinopathy (FEVR).","date":"2016","source":"Investigative ophthalmology & visual science","url":"https://pubmed.ncbi.nlm.nih.gov/28002565","citation_count":14,"is_preprint":false},{"pmid":"28211206","id":"PMC_28211206","title":"Variable Familial Exudative Vitreoretinopathy in a family harbouring variants in both FZD4 and TSPAN12.","date":"2017","source":"Acta ophthalmologica","url":"https://pubmed.ncbi.nlm.nih.gov/28211206","citation_count":14,"is_preprint":false},{"pmid":"28337310","id":"PMC_28337310","title":"Upregulation of TSPAN12 is associated with the colorectal cancer growth and metastasis.","date":"2017","source":"American journal of translational research","url":"https://pubmed.ncbi.nlm.nih.gov/28337310","citation_count":12,"is_preprint":false},{"pmid":"33602225","id":"PMC_33602225","title":"Ring finger protein 152-dependent degradation of TSPAN12 suppresses hepatocellular carcinoma progression.","date":"2021","source":"Cancer cell international","url":"https://pubmed.ncbi.nlm.nih.gov/33602225","citation_count":11,"is_preprint":false},{"pmid":"32222644","id":"PMC_32222644","title":"RNA sequencing reveals the long noncoding RNA and mRNA profiles and identifies long non-coding RNA TSPAN12 as a potential microvascular invasion-related biomarker in hepatocellular carcinoma.","date":"2020","source":"Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie","url":"https://pubmed.ncbi.nlm.nih.gov/32222644","citation_count":11,"is_preprint":false},{"pmid":"28982955","id":"PMC_28982955","title":"Mutation spectrum of NDP, FZD4 and TSPAN12 genes in Indian patients with retinopathy of prematurity.","date":"2017","source":"The British journal of ophthalmology","url":"https://pubmed.ncbi.nlm.nih.gov/28982955","citation_count":10,"is_preprint":false},{"pmid":"31452356","id":"PMC_31452356","title":"A start codon mutation of the TSPAN12 gene in Chinese families causes clinical heterogeneous familial exudative vitreoretinopathy.","date":"2019","source":"Molecular genetics & genomic medicine","url":"https://pubmed.ncbi.nlm.nih.gov/31452356","citation_count":10,"is_preprint":false},{"pmid":"33907885","id":"PMC_33907885","title":"Pathogenic variants and associated phenotypic spectrum of TSPAN12 based on data from a large cohort.","date":"2021","source":"Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie","url":"https://pubmed.ncbi.nlm.nih.gov/33907885","citation_count":9,"is_preprint":false},{"pmid":"31362470","id":"PMC_31362470","title":"TSPAN12 Precedes Tumor Proliferation by Cell Cycle Control in Ovarian Cancer.","date":"2019","source":"Molecules and cells","url":"https://pubmed.ncbi.nlm.nih.gov/31362470","citation_count":9,"is_preprint":false},{"pmid":"27007396","id":"PMC_27007396","title":"Simultaneous Novel Mutations of LRP5 and TSPAN12 in a Case of Familial Exudative Vitreoretinopathy.","date":"2016","source":"Journal of pediatric ophthalmology and strabismus","url":"https://pubmed.ncbi.nlm.nih.gov/27007396","citation_count":9,"is_preprint":false},{"pmid":"29535534","id":"PMC_29535534","title":"TSPAN12 is overexpressed in NSCLC via p53 inhibition and promotes NSCLC cell growth in vitro and in vivo.","date":"2018","source":"OncoTargets and therapy","url":"https://pubmed.ncbi.nlm.nih.gov/29535534","citation_count":8,"is_preprint":false},{"pmid":"35150239","id":"PMC_35150239","title":"RF-Net 2: fast inference of virus reassortment and hybridization networks.","date":"2022","source":"Bioinformatics (Oxford, England)","url":"https://pubmed.ncbi.nlm.nih.gov/35150239","citation_count":7,"is_preprint":false},{"pmid":"31114654","id":"PMC_31114654","title":"Detection of FZD4, LRP5 and TSPAN12 Genes Variants in Malay Premature Babies with Retinopathy of Prematurity.","date":"2019","source":"Journal of ophthalmic & vision research","url":"https://pubmed.ncbi.nlm.nih.gov/31114654","citation_count":6,"is_preprint":false},{"pmid":"35277167","id":"PMC_35277167","title":"Whole exome sequencing revealed 14 variants in NDP, FZD4, LRP5, and TSPAN12 genes for 20 families with familial exudative vitreoretinopathy.","date":"2022","source":"BMC medical genomics","url":"https://pubmed.ncbi.nlm.nih.gov/35277167","citation_count":6,"is_preprint":false},{"pmid":"12510019","id":"PMC_12510019","title":"Effect of reactive cell density on net [2-14C]acetate uptake into rat brain: labeling of clusters containing GFAP+- and lectin+-immunoreactive cells.","date":"2003","source":"Neurochemistry international","url":"https://pubmed.ncbi.nlm.nih.gov/12510019","citation_count":6,"is_preprint":false},{"pmid":"36453149","id":"PMC_36453149","title":"A comprehensive functional analysis on the pathogenesis of novel TSPAN12 and NDP variants in familial exudative vitreoretinopathy.","date":"2022","source":"Clinical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/36453149","citation_count":5,"is_preprint":false},{"pmid":"34077673","id":"PMC_34077673","title":"Whole-Exome Sequencing Reveals Novel TSPAN12 Variants in Autosomal Dominant Familial Exudative Vitreoretinopathy.","date":"2021","source":"Genetic testing and molecular biomarkers","url":"https://pubmed.ncbi.nlm.nih.gov/34077673","citation_count":5,"is_preprint":false},{"pmid":"38424652","id":"PMC_38424652","title":"Mutations in TSPAN12 gene causing familial exudative vitreoretinopathy.","date":"2024","source":"Human genomics","url":"https://pubmed.ncbi.nlm.nih.gov/38424652","citation_count":4,"is_preprint":false},{"pmid":"31755339","id":"PMC_31755339","title":"Asymptomatic adults in a single family with familial exudative vitreoretinopathy and TSPAN12 variant.","date":"2019","source":"Ophthalmic genetics","url":"https://pubmed.ncbi.nlm.nih.gov/31755339","citation_count":4,"is_preprint":false},{"pmid":"36458545","id":"PMC_36458545","title":"TSPAN12 (Tetraspanin 12) Is a Novel Negative Regulator of Aldosterone Production in Adrenal Physiology and Aldosterone-Producing Adenomas.","date":"2022","source":"Hypertension (Dallas, Tex. : 1979)","url":"https://pubmed.ncbi.nlm.nih.gov/36458545","citation_count":3,"is_preprint":false},{"pmid":"31009104","id":"PMC_31009104","title":"Genetic variants of TSPAN12 gene in patients with retinopathy of prematurity.","date":"2019","source":"Journal of cellular biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/31009104","citation_count":3,"is_preprint":false},{"pmid":"34151585","id":"PMC_34151585","title":"A novel variant in the TSPAN12 gene-presenting as unilateral myopia, pediatric cataract, and heterochromia in a patient with familial exudative vitreoretinopathy.","date":"2021","source":"European journal of ophthalmology","url":"https://pubmed.ncbi.nlm.nih.gov/34151585","citation_count":3,"is_preprint":false},{"pmid":"37451565","id":"PMC_37451565","title":"Five novel dysfunctional variants in the TSPAN12 gene in familial exudative vitreoretinopathy.","date":"2023","source":"Experimental eye research","url":"https://pubmed.ncbi.nlm.nih.gov/37451565","citation_count":2,"is_preprint":false},{"pmid":"35417085","id":"PMC_35417085","title":"A novel frameshift variant in the TSPAN12 gene causes autosomal dominant FEVR.","date":"2022","source":"Molecular genetics & genomic medicine","url":"https://pubmed.ncbi.nlm.nih.gov/35417085","citation_count":2,"is_preprint":false},{"pmid":"34738848","id":"PMC_34738848","title":"A novel stop codon mutation of TSPAN12 gene in Chinese patients with familial exudative vitreoretinopathy.","date":"2021","source":"Ophthalmic genetics","url":"https://pubmed.ncbi.nlm.nih.gov/34738848","citation_count":1,"is_preprint":false},{"pmid":"37252707","id":"PMC_37252707","title":"Identification of Five Novel Variants in the TSPAN12 Gene in Chinese Families With Familial Exudative Vitreoretinopathy.","date":"2023","source":"Translational vision science & technology","url":"https://pubmed.ncbi.nlm.nih.gov/37252707","citation_count":1,"is_preprint":false},{"pmid":"34445920","id":"PMC_34445920","title":"Novel mutation in TSPAN12 associated with familial exudative vitreoretinopathy in a Chinese pedigree.","date":"2021","source":"Ophthalmic genetics","url":"https://pubmed.ncbi.nlm.nih.gov/34445920","citation_count":1,"is_preprint":false},{"pmid":"31513438","id":"PMC_31513438","title":"Whole-Exome Sequencing Analysis Identified Novel Mutations in the TSPAN12 Gene in Chinese Families with Familial Exudative Vitreoretinopathy.","date":"2019","source":"Genetic testing and molecular biomarkers","url":"https://pubmed.ncbi.nlm.nih.gov/31513438","citation_count":1,"is_preprint":false},{"pmid":"11670992","id":"PMC_11670992","title":"Microporous Montmorillonites Expanded with Alumina Clusters and M[(&mgr;-OH)Cu(&mgr;-OCH(2)CH(2)NEt(2))](6)(ClO(4))(3), (M = Al, Ga, and Fe), or Cr[(&mgr;-OCH(3))(&mgr;-OCH(2)CH(2)NEt(2))CuCl](3) Complexes.","date":"1999","source":"Inorganic chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/11670992","citation_count":1,"is_preprint":false},{"pmid":"42155446","id":"PMC_42155446","title":"Structural basis of the interaction between Norrin-Tspan12.","date":"2026","source":"Structure (London, England : 1993)","url":"https://pubmed.ncbi.nlm.nih.gov/42155446","citation_count":0,"is_preprint":false},{"pmid":"38111929","id":"PMC_38111929","title":"De novel heterozygous copy number deletion on 7q31.31-7q31.32 involving TSPAN12 gene with familial exudative vitreoretinopathy in a Chinese family.","date":"2023","source":"International journal of ophthalmology","url":"https://pubmed.ncbi.nlm.nih.gov/38111929","citation_count":0,"is_preprint":false},{"pmid":"41265400","id":"PMC_41265400","title":"A novel TSPAN12 mutation causing retinitis pigmentosa-like appearance of familial exudative vitreoretinopathy.","date":"2025","source":"Ophthalmic genetics","url":"https://pubmed.ncbi.nlm.nih.gov/41265400","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.09.25.678640","title":"Structural basis for regulation of Frizzled-4 signaling by the co-receptor Tetraspanin-12","date":"2025-09-25","source":"bioRxiv","url":"https://doi.org/10.1101/2025.09.25.678640","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.07.22.666172","title":"C1q limits cystoid edema by maintaining basal beta-catenin-dependent signaling and blood-retina barrier function","date":"2025-07-26","source":"bioRxiv","url":"https://doi.org/10.1101/2025.07.22.666172","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2024.11.15.623746","title":"Putative Role of Norrin in Neuroretinal Differentiation Revealed by bulk and scRNA Sequencing of Human Retinal Organoids","date":"2024-11-15","source":"bioRxiv","url":"https://doi.org/10.1101/2024.11.15.623746","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":31644,"output_tokens":4731,"usd":0.082948,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":12850,"output_tokens":4561,"usd":0.089137,"stage2_stop_reason":"end_turn"},"total_usd":0.172085,"stage1_batch_id":"msgbatch_017qqVz33Ga63SCDwzb35XPb","stage2_batch_id":"msgbatch_01Scr2Ei9x4HJMiRGxwrmvLK","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2009,\n      \"finding\": \"TSPAN12 is expressed in the retinal vasculature and loss of Tspan12 phenocopies defects seen in Fzd4, Lrp5, and Norrin mutant mice. Overexpressed TSPAN12 associates with the Norrin-receptor complex and significantly increases Norrin/β-catenin but not Wnt/β-catenin signaling. Tspan12 siRNA abolishes transcriptional responses to Norrin but not Wnt3A in retinal endothelial cells. Signaling defects caused by Norrin or FZD4 mutations predicted to impair receptor multimerization are rescued by TSPAN12 overexpression, indicating that Norrin multimers and TSPAN12 cooperatively promote multimerization of FZD4 and associated proteins.\",\n      \"method\": \"Mouse knockout (phenocopy), genetic interaction studies, Co-IP, siRNA knockdown, reporter assays (luciferase), overexpression rescue experiments\",\n      \"journal\": \"Cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods (KO phenocopy, genetic epistasis, Co-IP, siRNA, reporter assay, rescue experiments) in a single rigorous study\",\n      \"pmids\": [\"19837033\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"TSPAN12 is an essential component of the NDP (Norrin) receptor complex and interacts with FZD4 and NDP via its extracellular loops, acting as a co-receptor that enhances FZD4 ligand selectivity for NDP. FEVR-linked mutations in TSPAN12 prevent its incorporation into the NDP receptor complex. TSPAN12 alleviates defects of FZD4 M105V, a mutation that destabilizes the NDP/FZD4 interaction, both in vitro and in Xenopus embryos.\",\n      \"method\": \"Co-IP (interaction with FZD4 and NDP via extracellular loops), FEVR mutation analysis, in vitro signaling assays, Xenopus embryo rescue experiments\",\n      \"journal\": \"Cell reports\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP, FEVR mutation functional analysis, in vivo Xenopus rescue, multiple orthogonal methods\",\n      \"pmids\": [\"28658627\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"TSPAN12 functions specifically in endothelial cells to promote vascular morphogenesis and blood-retina barrier (BRB) formation in developing mice and BRB maintenance in adult mice. Early endothelial-specific loss of TSPAN12 causes lack of intraretinal capillaries and increased VE-cadherin expression (consistent with premature vascular quiescence). Late loss of TSPAN12 strongly impairs BRB maintenance without affecting vascular morphogenesis, pericyte coverage, or perfusion. Long-term BRB defects associate with immunoglobulin extravasation, complement deposition, cystoid edema, and impaired b-wave in electroretinograms.\",\n      \"method\": \"Conditional endothelial-specific knockout (loxP/Cdh5-CreERT2), confocal microscopy, RNA-seq, histopathology, electroretinogram\",\n      \"journal\": \"Arteriosclerosis, thrombosis, and vascular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — cell-type-specific conditional KO with multiple orthogonal phenotypic readouts and transcriptomic analysis\",\n      \"pmids\": [\"30354230\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"TSPAN12 ablation from human MDA-MB-231 cells caused diminished association between FZD4 and its co-receptor LRP5, leading to substantially enhanced proteasomal degradation of β-catenin and altered expression of canonical Wnt pathway components (LRP5, Naked 1/2, DVL2, DVL3, Axin 1, GSK3β). This resulted in decreased primary tumor xenograft growth, increased tumor apoptosis, and markedly enhanced tumor-endothelial interactions and metastasis to mouse lungs.\",\n      \"method\": \"siRNA/shRNA knockdown, Co-IP (FZD4-LRP5 association), western blot (β-catenin degradation), xenograft tumor models, gene expression analysis\",\n      \"journal\": \"Cellular and molecular life sciences : CMLS\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP showing FZD4-LRP5 dissociation, proteasomal degradation assay, in vivo xenograft, single lab with multiple methods\",\n      \"pmids\": [\"23955570\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"TSPAN12 expression in p53-depleted lung fibroblasts (cancer-associated fibroblasts) is required for contact-mediated cancer cell invasion and proliferation. TSPAN12 in fibroblasts transduces β-catenin signaling upon cancer cell contact, leading to secretion of CXCL6, which promotes cancer cell invasion. TSPAN12 knockdown in p53-depleted fibroblasts inhibited CXCL6 secretion, cancer cell invasion in vitro, and tumor growth in vivo.\",\n      \"method\": \"siRNA knockdown, co-culture invasion assays, DNA chip/microarray, xenograft tumor model, CXCL6 secretion measurement\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — loss-of-function with specific pathway readout (β-catenin/CXCL6), in vitro and in vivo validation, single lab\",\n      \"pmids\": [\"25512506\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"An anti-Tspan12 antibody inhibits the interaction between Tspan12 and Frizzled-4, effectively modulates β-catenin levels and target genes in vascular endothelial cells, and inhibits endothelial cell migration and tube formation. Tspan12/β-catenin signaling is activated in response to acute and chronic stress in retinal neovascular disease models (OIR and VLDLR KO mice). Intravitreal application of the anti-Tspan12 antibody showed therapeutic effects in both models.\",\n      \"method\": \"Phage display antibody generation, Co-IP (Tspan12-FZD4 interaction disruption), in vitro endothelial cell assays, in vivo OIR and VLDLR KO mouse models, western blot (β-catenin)\",\n      \"journal\": \"Circulation\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — antibody-mediated disruption of Tspan12-FZD4 interaction with mechanistic downstream readout, in vitro and in vivo validation, single lab\",\n      \"pmids\": [\"28356444\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"In endothelial cells, TSPAN12 gene silencing increases endothelial cell permeability and dysregulates genes associated with extracellular matrix pathways. Endothelial cell-fibroblast crosstalk upon TSPAN12 loss induces extracellular matrix changes relevant to esophageal remodeling. IL-13 reduces TSPAN12 expression in endothelial cells, whereas anti-IL-13 therapy increases TSPAN12 expression.\",\n      \"method\": \"siRNA gene silencing, permeability assays, RNA sequencing, endothelial cell-fibroblast co-culture, cytokine treatment\",\n      \"journal\": \"Gastroenterology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — loss-of-function with specific cellular phenotype (permeability, ECM gene expression), co-culture crosstalk experiment, single lab\",\n      \"pmids\": [\"34687736\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"The E3 ubiquitin ligase RNF152 interacts with TSPAN12 and targets it for ubiquitination and proteasomal degradation, thereby inhibiting TSPAN12-dependent CXCL6 expression and HCC progression.\",\n      \"method\": \"Co-immunoprecipitation (RNF152-TSPAN12 interaction), in vivo ubiquitination assay, RNAi knockdown, cell proliferation/invasion assays, xenograft tumor model\",\n      \"journal\": \"Cancer cell international\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP and in vivo ubiquitination assay establish direct PTM relationship, single lab with multiple orthogonal methods\",\n      \"pmids\": [\"33602225\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Novel TSPAN12 missense variants show compromised interactions with binding partners in the Norrin/β-catenin pathway by co-immunoprecipitation, and exhibit abnormal subcellular trafficking by immunofluorescence and subcellular protein extraction. Overexpression of TSPAN12 enhanced Norrin/β-catenin signaling by strengthening the binding affinity of mutant Norrin with FZD4 or LRP5.\",\n      \"method\": \"Co-immunoprecipitation (variant interaction analysis), immunofluorescence (subcellular trafficking), subcellular protein fractionation, luciferase reporter assay, western blot\",\n      \"journal\": \"Clinical genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal methods (Co-IP, localization, reporter assay), single lab\",\n      \"pmids\": [\"36453149\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"TSPAN12 is a negative regulator of aldosterone production in adrenocortical cells. Gene silencing of TSPAN12 in human adrenocortical cells (HAC15) demonstrated its inverse effect on aldosterone secretion under basal and angiotensin II-stimulated conditions. Angiotensin II stimulation caused increased TSPAN12 expression that was ablated by nifedipine or calmodulin inhibitor W-7.\",\n      \"method\": \"siRNA gene silencing, aldosterone secretion measurement, angiotensin II stimulation, pharmacological inhibition (nifedipine, W-7), pig adrenal model\",\n      \"journal\": \"Hypertension (Dallas, Tex. : 1979)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — loss-of-function with specific quantitative phenotype (aldosterone secretion), pharmacological dissection, in vitro and in vivo (pig) corroboration, single lab\",\n      \"pmids\": [\"36458545\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"TSPAN12 frameshift variant c.533dupC (p.D179Rfs*6) causes degradation of the entire TSPAN12 protein, which fails to activate Norrin/β-catenin signaling, establishing that protein integrity is required for pathway activation.\",\n      \"method\": \"Immunocytochemistry, western blot, qPCR, luciferase reporter assay\",\n      \"journal\": \"Molecular genetics & genomic medicine\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, functional assays on one variant without structural or binding partner validation\",\n      \"pmids\": [\"35417085\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"Cryo-EM structure of the Norrin-Tspan12 large extracellular loop (LEL) complex at 3.78 Å resolution reveals that a Norrin dimer binds two Tspan12 molecules, defining the Norrin-Tspan12 interface. Tspan12 binds directly to Norrin without enhancing the binding affinity between Norrin and FZD4, supporting a model in which Norrin, FZD4, LRP5/6, and Tspan12 form a quaternary signaling complex.\",\n      \"method\": \"Cryo-EM structure determination (3.78 Å), binding affinity measurements, structural analysis of interface\",\n      \"journal\": \"Structure (London, England : 1993)\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — cryo-EM structure with functional validation of binding interface, rigorous structural methodology\",\n      \"pmids\": [\"42155446\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Cryo-EM structure of Tspan12 in complex with FZD4 at 3.4 Å resolution reveals that FZD4 and Tspan12 form a direct complex in the absence of Norrin. The transmembrane domain of Tspan12 forms a tightly packed four-helix bundle that interacts with TM2 of FZD4 to promote trafficking of Tspan12 to the cell surface. The C-D helices of Tspan12, which mediate Norrin binding, remain exposed while Tspan12 is in complex with FZD4, facilitating higher-affinity Norrin binding. Cell-based assays indicate Tspan12 and FZD4 remain associated after Norrin recognition, establishing Tspan12 as a core component of the active FZD4-Norrin-LRP5/6 signaling complex.\",\n      \"method\": \"Cryo-EM structure (3.4 Å), cell-based signaling assays, cell surface trafficking assays\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — cryo-EM structure with domain-level mechanistic resolution plus orthogonal cell-based functional validation\",\n      \"pmids\": [\"bio_10.1101_2025.09.25.678640\"],\n      \"is_preprint\": true\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Tspan12 KO mice develop cystoid edema due to BRB dysfunction mediated by loss of basal β-catenin-dependent Norrin/FZD4 signaling. Activation of β-catenin-dependent signaling by a FZD4/LRP5 agonist antibody achieves complete resolution of cystoid edema in this model, establishing that Tspan12 maintains BRB function through Norrin/FZD4/β-catenin signaling.\",\n      \"method\": \"Tspan12 KO mouse model (genetic), FZD4/LRP5 agonist antibody rescue, BRB function assays, ERG, cystoid edema quantification, compound mutant analysis (Tspan12 KO; C1qa KO)\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic KO with rescue experiment establishing pathway position, multiple phenotypic readouts, preprint not yet peer-reviewed\",\n      \"pmids\": [\"bio_10.1101_2025.07.22.666172\"],\n      \"is_preprint\": true\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Homozygous (biallelic) TSPAN12 mutations cause more severe FEVR/retinal dysplasia than heterozygous mutations in the same family, establishing a dose-dependent relationship between TSPAN12 function and Norrin-β-catenin pathway activity in retinal vascular development.\",\n      \"method\": \"Genetic mutation analysis (Sanger sequencing), reverse transcriptase PCR (splicing verification), phenotype-genotype correlation in family members\",\n      \"journal\": \"Investigative ophthalmology & visual science\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — genetic dosage-phenotype correlation across multiple families, but no direct biochemical mechanism established\",\n      \"pmids\": [\"22427576\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"TSPAN12 overexpression in ovarian cancer cells (OVCAR3, SKOV3) accelerated proliferation and colony formation, while knockdown in A2780 and SKOV3 cells decreased proliferation. Western blot showed that cyclins (A2, D1, E2) and CDKs (CDK2, CDK4) are regulated downstream of TSPAN12, placing TSPAN12 upstream of cell cycle control machinery.\",\n      \"method\": \"Overexpression and siRNA knockdown, proliferation and colony formation assays, western blot (cyclin and CDK expression)\",\n      \"journal\": \"Molecules and cells\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, single cell line context, no direct binding or structural evidence for cyclins as direct TSPAN12 substrates\",\n      \"pmids\": [\"31362470\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"TSPAN12 is a tetraspanin co-receptor that forms a pre-formed complex with FZD4 via transmembrane domain interactions (promoting FZD4 cell-surface trafficking), then recruits Norrin dimers through its large extracellular loop to assemble a quaternary Norrin-FZD4-LRP5/6-TSPAN12 signaling complex that selectively amplifies Norrin/β-catenin signaling (but not Wnt/β-catenin signaling); in retinal endothelial cells this pathway is required for vascular morphogenesis, blood-retina barrier formation and maintenance, and loss of TSPAN12 causes familial exudative vitreoretinopathy. Beyond the retina, TSPAN12 stabilizes FZD4-LRP5 association to support β-catenin signaling in cancer contexts, is subject to ubiquitin-proteasomal degradation by E3 ligase RNF152, and acts as a negative regulator of aldosterone secretion in adrenocortical cells.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"TSPAN12 is a tetraspanin co-receptor that selectively amplifies Norrin/\\u03b2-catenin signaling and is essential for retinal vascular morphogenesis and blood-retina barrier (BRB) formation and maintenance [#0, #2]. It functions as a dedicated component of the Norrin (NDP) receptor complex: TSPAN12 forms a direct transmembrane complex with FZD4 in the absence of ligand\\u2014its four-helix transmembrane bundle packs against FZD4 TM2 to promote cell-surface trafficking\\u2014while leaving its Norrin-binding C\\u2013D helices exposed [#12]. Through its large extracellular loop it then engages Norrin, with a Norrin dimer binding two TSPAN12 molecules, assembling a quaternary Norrin-FZD4-LRP5/6-TSPAN12 signaling complex [#11]. By promoting receptor multimerization and ligand selectivity, TSPAN12 enhances Norrin/\\u03b2-catenin but not Wnt/\\u03b2-catenin transcriptional output, and can rescue signaling defects of Norrin and FZD4 mutations that destabilize the complex [#0, #1]. Loss of endothelial TSPAN12 causes BRB breakdown with immunoglobulin extravasation, complement deposition, cystoid edema, and impaired electroretinogram b-waves, and BRB dysfunction is reversed by direct FZD4/LRP5 agonism, placing TSPAN12 upstream of basal \\u03b2-catenin signaling [#2, #13]. FEVR-linked TSPAN12 mutations act by preventing incorporation into the receptor complex or by disrupting trafficking, defining TSPAN12 as a causative gene for familial exudative vitreoretinopathy [#1, #8]. Beyond the retina, TSPAN12 stabilizes FZD4-LRP5 association to sustain \\u03b2-catenin signaling in cancer cells and stromal fibroblasts, where it drives CXCL6 secretion and tumor progression, is degraded by the E3 ligase RNF152, and acts as a negative regulator of aldosterone secretion in adrenocortical cells [#3, #4, #7, #9].\",\n  \"teleology\": [\n    {\n      \"year\": 2009,\n      \"claim\": \"Established TSPAN12 as a Norrin-pathway co-receptor by showing it specifically amplifies Norrin/\\u03b2-catenin signaling and that its loss phenocopies Fzd4/Lrp5/Norrin mutants, answering whether tetraspanins participate in this receptor system.\",\n      \"evidence\": \"Mouse KO phenocopy, genetic epistasis, Co-IP, siRNA, luciferase reporters and overexpression rescue in retinal endothelial cells\",\n      \"pmids\": [\"19837033\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular basis of ligand selectivity (Norrin vs Wnt) not resolved\", \"Direct binding interfaces undefined\", \"Mechanism of receptor multimerization inferred, not structurally shown\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Localized TSPAN12 function to its extracellular loops and showed it enhances FZD4 selectivity for Norrin, explaining how disease mutations and FZD4-destabilizing variants impair signaling.\",\n      \"evidence\": \"Reciprocal Co-IP, FEVR mutation analysis, in vitro signaling and Xenopus embryo rescue of FZD4 M105V\",\n      \"pmids\": [\"28658627\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Stoichiometry of the receptor complex unresolved\", \"No structural detail of the extracellular-loop interactions\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Separated developmental from maintenance roles by endothelial-specific conditional deletion, showing TSPAN12 is required both for retinal vascular morphogenesis and for ongoing BRB integrity in adults.\",\n      \"evidence\": \"Cdh5-CreERT2 conditional KO with confocal imaging, RNA-seq, histopathology and electroretinogram\",\n      \"pmids\": [\"30354230\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular link between \\u03b2-catenin output and barrier gene programs not defined\", \"Whether maintenance defect is fully cell-autonomous unclear\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Extended TSPAN12 function to cancer by showing it stabilizes the FZD4-LRP5 association to protect \\u03b2-catenin from degradation and influence tumor growth and metastasis.\",\n      \"evidence\": \"siRNA/shRNA, Co-IP of FZD4-LRP5, \\u03b2-catenin degradation western blots, xenograft models in MDA-MB-231 cells\",\n      \"pmids\": [\"23955570\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether Norrin is the relevant ligand in this context untested\", \"Single cell-line context\", \"Direct vs indirect effect on FZD4-LRP5 not dissected structurally\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Showed a stromal role in which fibroblast TSPAN12 transduces contact-induced \\u03b2-catenin signaling to drive CXCL6 secretion and cancer cell invasion, broadening the pathway's tissue contexts.\",\n      \"evidence\": \"siRNA knockdown, co-culture invasion assays, microarray, CXCL6 measurement and xenografts in p53-depleted fibroblasts\",\n      \"pmids\": [\"25512506\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Receptor complex composition in fibroblasts unconfirmed\", \"Identity of activating signal upon cancer-cell contact unknown\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Demonstrated that disrupting the TSPAN12-FZD4 interaction is therapeutically actionable, validating the interaction as the functional node in pathological retinal neovascularization.\",\n      \"evidence\": \"Phage-display anti-Tspan12 antibody, Co-IP disruption, endothelial assays, and OIR and VLDLR-KO mouse models\",\n      \"pmids\": [\"28356444\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Precise epitope and mechanism of disruption not mapped\", \"Single antibody, single lab\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Identified RNF152 as an E3 ligase that ubiquitinates TSPAN12 for proteasomal degradation, defining a post-translational control point limiting TSPAN12-driven CXCL6 expression.\",\n      \"evidence\": \"Co-IP, in vivo ubiquitination assay, RNAi, proliferation/invasion assays and xenografts in HCC\",\n      \"pmids\": [\"33602225\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Ubiquitination sites on TSPAN12 not mapped\", \"Regulation of RNF152 activity unknown\", \"Single lab\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Linked endothelial TSPAN12 loss to increased permeability and ECM dysregulation in a non-retinal tissue and placed TSPAN12 downstream of IL-13 signaling.\",\n      \"evidence\": \"siRNA silencing, permeability assays, RNA-seq, endothelial-fibroblast co-culture and cytokine treatment\",\n      \"pmids\": [\"34687736\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism connecting TSPAN12 to ECM genes undefined\", \"Whether \\u03b2-catenin mediates this effect not tested directly\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Defined a non-vascular endocrine role, showing TSPAN12 negatively regulates aldosterone secretion and is induced by angiotensin II via calcium/calmodulin signaling.\",\n      \"evidence\": \"siRNA silencing, aldosterone measurement, angiotensin II stimulation with nifedipine/W-7 inhibition in HAC15 cells and pig adrenal\",\n      \"pmids\": [\"36458545\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Molecular mechanism of aldosterone suppression unknown\", \"Whether \\u03b2-catenin/Norrin signaling is involved untested\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Showed that disease-associated missense variants act by impairing binding-partner interactions and subcellular trafficking, connecting genotype to a defined molecular defect in the Norrin pathway.\",\n      \"evidence\": \"Co-IP variant analysis, immunofluorescence trafficking, subcellular fractionation and luciferase reporters\",\n      \"pmids\": [\"36453149\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Trafficking defect mechanism not resolved at structural level\", \"Single lab\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Resolved the Norrin-TSPAN12 interface by cryo-EM, showing a Norrin dimer bridges two TSPAN12 large extracellular loops and that TSPAN12 binds Norrin directly without raising Norrin-FZD4 affinity, supporting a quaternary complex model.\",\n      \"evidence\": \"Cryo-EM of the Norrin-TSPAN12 LEL complex at 3.78 \\u00c5 with binding-affinity measurements\",\n      \"pmids\": [\"42155446\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Full assembly with FZD4 and LRP5/6 not captured in one structure\", \"Dynamics of complex assembly in cells not addressed\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Cryo-EM of the TSPAN12-FZD4 complex established that the two form a direct pre-ligand complex via a TSPAN12 four-helix transmembrane bundle packing against FZD4 TM2, promoting surface trafficking while leaving the Norrin-binding helices exposed.\",\n      \"evidence\": \"Cryo-EM at 3.4 \\u00c5 (preprint) with cell-based signaling and surface-trafficking assays\",\n      \"pmids\": [\"bio_10.1101_2025.09.25.678640\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Not yet peer-reviewed\", \"LRP5/6 engagement geometry within the active complex not shown\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Demonstrated in Tspan12 KO mice that cystoid edema arises from loss of basal Norrin/FZD4/\\u03b2-catenin signaling and is fully reversed by a FZD4/LRP5 agonist antibody, positioning TSPAN12 as an amplifier upstream of a pharmacologically restorable node.\",\n      \"evidence\": \"Tspan12 KO mice (preprint), FZD4/LRP5 agonist rescue, BRB assays, ERG and Tspan12;C1qa compound mutants\",\n      \"pmids\": [\"bio_10.1101_2025.07.22.666172\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Not yet peer-reviewed\", \"Role of complement in edema only partially dissected\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How TSPAN12's distinct context-specific roles (retinal barrier amplification, cancer \\u03b2-catenin stabilization, ECM/permeability control, and aldosterone suppression) are mechanistically unified or distinguished remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Whether non-retinal roles use the same quaternary complex is untested\", \"Tissue-specific ligand/partner repertoire of TSPAN12 undefined\", \"Mechanism of aldosterone regulation and ECM control not connected to Norrin signaling\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0038024\", \"supporting_discovery_ids\": [0, 1, 11, 12]},\n      {\"term_id\": \"GO:0060089\", \"supporting_discovery_ids\": [0, 1]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [3, 5]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [0, 12]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [0, 1, 11]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [2, 13]},\n      {\"term_id\": \"R-HSA-1643685\", \"supporting_discovery_ids\": [1, 8, 14]}\n    ],\n    \"complexes\": [\"Norrin-FZD4-LRP5/6-TSPAN12 receptor complex\"],\n    \"partners\": [\"FZD4\", \"NDP\", \"LRP5\", \"RNF152\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":6,"faith_pct":83.33333333333333}}