{"gene":"TSPAN18","run_date":"2026-06-10T10:51:56","timeline":{"discoveries":[{"year":2018,"finding":"TSPAN18 interacts with the store-operated Ca2+ channel Orai1 in endothelial cells, and Tspan18-knockdown reduces Orai1 cell surface localization by ~70%, impairing Ca2+ mobilization upon stimulation with thrombin or histamine (55-70% decrease, comparable to Orai1-knockdown). TSPAN18 overexpression in lymphocyte cell lines induces ~20-fold activation of NFAT signaling in an Orai1-dependent manner.","method":"Co-immunoprecipitation (Tspan18-Orai1 interaction), siRNA knockdown with Ca2+ mobilization assay, flow cytometry for surface Orai1, NFAT reporter assay, Tspan18-knockout mouse model (tail-bleed, deep vein thrombosis, ischemia-reperfusion models), bone marrow chimera","journal":"Haematologica","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP, multiple orthogonal functional assays (Ca2+ mobilization, NFAT reporter, surface localization), KO mouse with multiple in vivo phenotypes, single lab but highly rigorous with many convergent methods","pmids":["30573509"],"is_preprint":false},{"year":2018,"finding":"TSPAN18-knockdown in primary human umbilical vein endothelial cells reduces histamine- or thrombin-induced von Willebrand factor (vWF) release by ~90%, and Tspan18-knockout mice show ~45% reduced histamine-induced plasma vWF increase, demonstrating TSPAN18 is required for inflammatory stimulus-induced vWF secretion from endothelial cells.","method":"siRNA knockdown in HUVECs with vWF release assay (ELISA), Tspan18-knockout mouse plasma vWF measurement after histamine stimulation","journal":"Haematologica","confidence":"High","confidence_rationale":"Tier 2 / Strong — loss-of-function in both primary human cells and KO mouse with defined molecular readout (vWF release), multiple orthogonal systems","pmids":["30573509"],"is_preprint":false},{"year":2020,"finding":"TSPAN18 is required for normal Ca2+ signaling in platelets, with Tspan18-knockout mice showing mildly defective platelet aggregation and spreading induced by the collagen receptor GPVI, demonstrating a platelet-intrinsic role for TSPAN18 beyond endothelial cells.","method":"Tspan18-knockout mouse platelet aggregation assay, platelet spreading assay, GPVI stimulation","journal":"Medical microbiology and immunology","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — KO mouse with defined cellular phenotype (platelet aggregation/spreading), single lab reporting new data in a review context","pmids":["32447449"],"is_preprint":false},{"year":2023,"finding":"TSPAN18 directly interacts with STIM1 and competitively inhibits E3 ubiquitin ligase TRIM32-mediated ubiquitination and proteasomal degradation of STIM1, thereby increasing STIM1 protein stability and enhancing STIM1-dependent store-operated Ca2+ entry, which promotes prostate cancer cell migration, invasion, and bone metastasis in vitro and in vivo.","method":"Liquid chromatography-mass spectrometry (TSPAN18 identified as STIM1-binding protein), co-immunoprecipitation (TSPAN18-STIM1 and TRIM32-STIM1 interactions), ubiquitination assay, Ca2+ influx assay, siRNA/overexpression in vitro migration/invasion assays, in vivo bone metastasis mouse model","journal":"Journal of experimental & clinical cancer research : CR","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP plus ubiquitination assay plus in vitro and in vivo functional validation, single lab with multiple orthogonal methods","pmids":["37542345"],"is_preprint":false},{"year":2026,"finding":"The long non-coding RNA LINC00607 epigenetically upregulates TSPAN18 expression in endothelial cells under hypoxia by associating with the chromatin remodeler BRG1 and facilitating BRG1-dependent activation of the TSPAN18 enhancer (marked by increased acetylation and chromatin accessibility). Activation of the LINC00607-TSPAN18 axis enhances store-operated calcium entry and endothelial-monocyte adhesion under hypoxic conditions.","method":"Integrative transcriptomics and chromatin accessibility analysis (ATAC-seq), ChIP-seq for enhancer marks, loss- and gain-of-function experiments for LINC00607, RNA immunoprecipitation (LINC00607-BRG1 association), BRG1 pharmacological inhibition, Ca2+ entry assay, endothelial-monocyte adhesion assay","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple chromatin and functional assays, loss/gain of function, single lab but orthogonal methods; TSPAN18 is downstream effector with functional readout","pmids":["41581880"],"is_preprint":false}],"current_model":"TSPAN18 is a tetraspanin expressed at high levels in endothelial cells that promotes store-operated Ca2+ entry by interacting with and facilitating plasma membrane trafficking/clustering of the Ca2+ channel Orai1; in endothelial cells this drives inflammatory stimulus-induced von Willebrand factor release and thrombo-inflammatory responses, while in prostate cancer cells TSPAN18 protects the Ca2+ sensor STIM1 from TRIM32-mediated ubiquitination and degradation, thereby enhancing STIM1-dependent Ca2+ signaling and bone metastasis; upstream, TSPAN18 expression is epigenetically regulated in endothelial cells by a hypoxia-responsive LINC00607-BRG1 axis."},"narrative":{"mechanistic_narrative":"TSPAN18 is a tetraspanin that promotes store-operated Ca2+ entry and links inflammatory and hypoxic stimuli to endothelial and thrombo-inflammatory responses [PMID:30573509]. In endothelial cells it interacts with the store-operated Ca2+ channel Orai1 and is required for normal Orai1 cell-surface localization, so that its loss markedly impairs thrombin- or histamine-induced Ca2+ mobilization and downstream Orai1-dependent signaling [PMID:30573509]. Through this Ca2+ entry function TSPAN18 is required for inflammatory stimulus-induced von Willebrand factor secretion from endothelial cells [PMID:30573509], and it additionally supports collagen/GPVI-dependent Ca2+ signaling, aggregation, and spreading in platelets [PMID:32447449]. In prostate cancer cells TSPAN18 directly binds the Ca2+ sensor STIM1 and competitively blocks TRIM32-mediated ubiquitination and proteasomal degradation of STIM1, stabilizing STIM1 and enhancing store-operated Ca2+ entry to drive migration, invasion, and bone metastasis [PMID:37542345]. Upstream, TSPAN18 expression is epigenetically induced in endothelial cells under hypoxia by a LINC00607-BRG1 axis that activates the TSPAN18 enhancer, coupling its expression to enhanced Ca2+ entry and endothelial-monocyte adhesion [PMID:41581880].","teleology":[{"year":2018,"claim":"Established TSPAN18 as a molecular partner of the Orai1 store-operated Ca2+ channel and as a determinant of Orai1 surface expression and Ca2+ entry, defining its core mechanism in endothelial cells.","evidence":"Reciprocal Co-IP, siRNA knockdown with Ca2+ mobilization and surface-Orai1 flow cytometry, NFAT reporter assay, and Tspan18-knockout mouse thrombosis/ischemia models","pmids":["30573509"],"confidence":"High","gaps":["Structural basis of the TSPAN18-Orai1 interaction not resolved","Whether TSPAN18 acts as a trafficking chaperone, clustering scaffold, or both is not distinguished","Stoichiometry of the TSPAN18-Orai1 complex unknown"]},{"year":2018,"claim":"Linked TSPAN18-dependent Ca2+ entry to a defined endothelial secretory output, showing it is required for inflammatory stimulus-induced von Willebrand factor release.","evidence":"siRNA knockdown in primary HUVECs with vWF ELISA and plasma vWF measurement in histamine-stimulated Tspan18-knockout mice","pmids":["30573509"],"confidence":"High","gaps":["Quantitative difference between near-complete HUVEC defect and partial mouse phenotype not reconciled","Direct dependence of vWF release on the Orai1 interaction not formally tested"]},{"year":2020,"claim":"Extended TSPAN18 function beyond endothelium by demonstrating a platelet-intrinsic role in GPVI-induced Ca2+ signaling and platelet activation.","evidence":"Tspan18-knockout mouse platelet aggregation and spreading assays under GPVI stimulation","pmids":["32447449"],"confidence":"Medium","gaps":["Whether the platelet defect is mediated by Orai1 as in endothelium not established","Reported as new data within a review context, limiting depth"]},{"year":2023,"claim":"Revealed a second, post-translational mechanism in which TSPAN18 stabilizes the Ca2+ sensor STIM1 by competitively blocking its TRIM32-mediated ubiquitination, expanding its role into cancer-associated Ca2+ signaling.","evidence":"LC-MS interactome, Co-IP of TSPAN18-STIM1 and TRIM32-STIM1, ubiquitination and Ca2+ influx assays, in vitro migration/invasion, and in vivo bone metastasis model","pmids":["37542345"],"confidence":"Medium","gaps":["Relationship between the STIM1-stabilizing and Orai1-trafficking activities not integrated","Whether STIM1 stabilization occurs in endothelium/platelets or is cancer-specific unknown","Single lab; reciprocal independent validation absent"]},{"year":2026,"claim":"Placed TSPAN18 downstream of a hypoxia-responsive epigenetic program, showing LINC00607-BRG1-driven enhancer activation controls its expression and consequent Ca2+ entry and leukocyte adhesion.","evidence":"ATAC-seq, ChIP-seq enhancer marks, LINC00607 loss/gain of function, RIP for LINC00607-BRG1, BRG1 inhibition, Ca2+ entry and endothelial-monocyte adhesion assays","pmids":["41581880"],"confidence":"Medium","gaps":["Direct transcription factors binding the activated TSPAN18 enhancer not identified","Single lab; mechanism of LINC00607 recruitment to the TSPAN18 locus not detailed"]},{"year":null,"claim":"How TSPAN18's two reported activities — facilitating Orai1 surface trafficking and protecting STIM1 from degradation — are mechanistically integrated within a single store-operated Ca2+ entry module remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structural model of TSPAN18 or its channel/sensor complexes","Tissue-specificity of the Orai1 versus STIM1 mechanism untested","Whether both mechanisms operate simultaneously in the same cell unknown"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[0,3]},{"term_id":"GO:0140313","term_label":"molecular sequestering activity","supporting_discovery_ids":[3]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[0]}],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[0,3]},{"term_id":"R-HSA-109582","term_label":"Hemostasis","supporting_discovery_ids":[1,2]},{"term_id":"R-HSA-1643685","term_label":"Disease","supporting_discovery_ids":[3]}],"complexes":[],"partners":["ORAI1","STIM1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q96SJ8","full_name":"Tetraspanin-18","aliases":[],"length_aa":248,"mass_kda":27.7,"function":"Plays a role in the cell surface localization of ORAI1 and may participate in the regulation of Ca(2+) signaling and the VWF release in response to inflammatory stimuli","subcellular_location":"Membrane","url":"https://www.uniprot.org/uniprotkb/Q96SJ8/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/TSPAN18","classification":"Not Classified","n_dependent_lines":3,"n_total_lines":1208,"dependency_fraction":0.0024834437086092716},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/TSPAN18","total_profiled":1310},"omim":[{"mim_id":"619399","title":"TETRASPANIN 18; TSPAN18","url":"https://www.omim.org/entry/619399"},{"mim_id":"611539","title":"FORKHEAD BOX D3; FOXD3","url":"https://www.omim.org/entry/611539"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"heart muscle","ntpm":78.2}],"url":"https://www.proteinatlas.org/search/TSPAN18"},"hgnc":{"alias_symbol":["TSPAN"],"prev_symbol":[]},"alphafold":{"accession":"Q96SJ8","domains":[{"cath_id":"-","chopping":"1-96_223-248","consensus_level":"medium","plddt":91.6146,"start":1,"end":248},{"cath_id":"-","chopping":"113-205","consensus_level":"high","plddt":88.6992,"start":113,"end":205}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q96SJ8","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q96SJ8-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q96SJ8-F1-predicted_aligned_error_v6.png","plddt_mean":90.62},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=TSPAN18","jax_strain_url":"https://www.jax.org/strain/search?query=TSPAN18"},"sequence":{"accession":"Q96SJ8","fasta_url":"https://rest.uniprot.org/uniprotkb/Q96SJ8.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q96SJ8/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q96SJ8"}},"corpus_meta":[{"pmid":"12420314","id":"PMC_12420314","title":"The tetraspanin protein, CD9, is expressed by progenitor cells committed to oligodendrogenesis and is linked to beta1 integrin, CD81, and Tspan-2.","date":"2002","source":"Glia","url":"https://pubmed.ncbi.nlm.nih.gov/12420314","citation_count":63,"is_preprint":false},{"pmid":"17965585","id":"PMC_17965585","title":"Expression and function of transmembrane-4 superfamily (tetraspanin) proteins in osteoclasts: reciprocal roles of Tspan-5 and NET-6 during osteoclastogenesis.","date":"2007","source":"Allergology international : official journal of the Japanese Society of Allergology","url":"https://pubmed.ncbi.nlm.nih.gov/17965585","citation_count":35,"is_preprint":false},{"pmid":"19017553","id":"PMC_19017553","title":"Tspan-1 is a tetraspanin preferentially expressed by mucinous and endometrioid subtypes of human ovarian carcinomas.","date":"2008","source":"Cancer 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research","url":"https://pubmed.ncbi.nlm.nih.gov/15211584","citation_count":26,"is_preprint":false},{"pmid":"20890423","id":"PMC_20890423","title":"Clinicopathological significance of expression of Tspan-1, Jab1 and p27 in human hepatocellular carcinoma.","date":"2010","source":"Journal of Korean medical science","url":"https://pubmed.ncbi.nlm.nih.gov/20890423","citation_count":25,"is_preprint":false},{"pmid":"11472858","id":"PMC_11472858","title":"Pattern of expression of the tetraspanin Tspan-5 during brain development in the mouse.","date":"2001","source":"Mechanisms of development","url":"https://pubmed.ncbi.nlm.nih.gov/11472858","citation_count":24,"is_preprint":false},{"pmid":"38649381","id":"PMC_38649381","title":"Tspan protein family: focusing on the occurrence, progression, and treatment of cancer.","date":"2024","source":"Cell death discovery","url":"https://pubmed.ncbi.nlm.nih.gov/38649381","citation_count":23,"is_preprint":false},{"pmid":"23505562","id":"PMC_23505562","title":"Replication study confirms link between TSPAN18 mutation and schizophrenia in Han Chinese.","date":"2013","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/23505562","citation_count":22,"is_preprint":false},{"pmid":"11043545","id":"PMC_11043545","title":"Mouse Tspan-5, a member of the tetraspanin superfamily, is highly expressed in brain cortical structures.","date":"2000","source":"Neuroreport","url":"https://pubmed.ncbi.nlm.nih.gov/11043545","citation_count":21,"is_preprint":false},{"pmid":"30573509","id":"PMC_30573509","title":"Tspan18 is a novel regulator of the Ca2+ channel Orai1 and von Willebrand factor release in endothelial cells.","date":"2018","source":"Haematologica","url":"https://pubmed.ncbi.nlm.nih.gov/30573509","citation_count":19,"is_preprint":false},{"pmid":"32447449","id":"PMC_32447449","title":"Tspan18 is a novel regulator of thrombo-inflammation.","date":"2020","source":"Medical microbiology and immunology","url":"https://pubmed.ncbi.nlm.nih.gov/32447449","citation_count":16,"is_preprint":false},{"pmid":"21836059","id":"PMC_21836059","title":"Tspan-1 interacts with the thiamine transporter-1 in human intestinal epithelial cells and modulates its stability.","date":"2011","source":"American journal of physiology. Gastrointestinal and liver physiology","url":"https://pubmed.ncbi.nlm.nih.gov/21836059","citation_count":14,"is_preprint":false},{"pmid":"26016498","id":"PMC_26016498","title":"Lack of Association between the TSPAN18 Gene and Schizophrenia Based on New Data from Han Chinese and a Meta-Analysis.","date":"2015","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/26016498","citation_count":9,"is_preprint":false},{"pmid":"27312590","id":"PMC_27312590","title":"GWAS-identified schizophrenia risk SNPs at TSPAN18 are highly diverged between Europeans and East Asians.","date":"2016","source":"American journal of medical genetics. Part B, Neuropsychiatric genetics : the official publication of the International Society of Psychiatric Genetics","url":"https://pubmed.ncbi.nlm.nih.gov/27312590","citation_count":9,"is_preprint":false},{"pmid":"36173052","id":"PMC_36173052","title":"Tetraspanin-enriched Microdomain Containing CD151, CD9, and TSPAN 8 - Potential Mediators of Entry and Exit Mechanisms in Respiratory Viruses Including SARS-CoV-2.","date":"2022","source":"Current pharmaceutical design","url":"https://pubmed.ncbi.nlm.nih.gov/36173052","citation_count":8,"is_preprint":false},{"pmid":"11594770","id":"PMC_11594770","title":"Molecular cloning and characterization of mouse Tspan-3, a novel member of the tetraspanin superfamily, expressed on resting dendritic cells.","date":"2001","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/11594770","citation_count":8,"is_preprint":false},{"pmid":"28927050","id":"PMC_28927050","title":"Expression of Tspan-1 gene in patients with advanced gastric cancer.","date":"2017","source":"Oncology letters","url":"https://pubmed.ncbi.nlm.nih.gov/28927050","citation_count":6,"is_preprint":false},{"pmid":"37749158","id":"PMC_37749158","title":"Angular limb deformity associated with TSPAN18, NRG3 and NOVA2 in Rambouillet rams.","date":"2023","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/37749158","citation_count":6,"is_preprint":false},{"pmid":"27460766","id":"PMC_27460766","title":"Association of NKAPL, TSPAN18, and MPC2 gene variants with schizophrenia based on new data and a meta-analysis in Han Chinese.","date":"2016","source":"Acta neuropsychiatrica","url":"https://pubmed.ncbi.nlm.nih.gov/27460766","citation_count":4,"is_preprint":false},{"pmid":"11092739","id":"PMC_11092739","title":"The molecular characterisation of mouse tspan-3.","date":"2000","source":"DNA sequence : the journal of DNA sequencing and mapping","url":"https://pubmed.ncbi.nlm.nih.gov/11092739","citation_count":3,"is_preprint":false},{"pmid":"25573220","id":"PMC_25573220","title":"[Expression and clinical significance of Tspan 1 and Integrin α6 in human pancreatic ductal adenocarcinoma].","date":"2014","source":"Zhonghua wai ke za zhi [Chinese journal of surgery]","url":"https://pubmed.ncbi.nlm.nih.gov/25573220","citation_count":1,"is_preprint":false},{"pmid":"41581880","id":"PMC_41581880","title":"Long non-coding RNA LINC00607 epigenetically regulates endothelial TSPAN18 to promote hypoxia-induced thromboinflammation.","date":"2026","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/41581880","citation_count":0,"is_preprint":false},{"pmid":"40249952","id":"PMC_40249952","title":"Impact of neonatal family screening in early-onset management of TSPAN 12 positive Familial Exudative Vitreoretinopathy- a case report.","date":"2025","source":"Retinal cases & brief reports","url":"https://pubmed.ncbi.nlm.nih.gov/40249952","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.04.27.650884","title":"Planar cell polarity signaling controls cell division symmetry to promote termination of adult tissue regeneration","date":"2025-04-28","source":"bioRxiv","url":"https://doi.org/10.1101/2025.04.27.650884","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.10.08.680939","title":"Thrombospondin Encapsulated Dense Particles accelerate wound healing and downregulate fibrotic phenotypes","date":"2025-10-08","source":"bioRxiv","url":"https://doi.org/10.1101/2025.10.08.680939","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":15275,"output_tokens":1665,"usd":0.0354,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":8493,"output_tokens":2496,"usd":0.052432,"stage2_stop_reason":"end_turn"},"total_usd":0.087832,"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\": 2018,\n      \"finding\": \"TSPAN18 interacts with the store-operated Ca2+ channel Orai1 in endothelial cells, and Tspan18-knockdown reduces Orai1 cell surface localization by ~70%, impairing Ca2+ mobilization upon stimulation with thrombin or histamine (55-70% decrease, comparable to Orai1-knockdown). TSPAN18 overexpression in lymphocyte cell lines induces ~20-fold activation of NFAT signaling in an Orai1-dependent manner.\",\n      \"method\": \"Co-immunoprecipitation (Tspan18-Orai1 interaction), siRNA knockdown with Ca2+ mobilization assay, flow cytometry for surface Orai1, NFAT reporter assay, Tspan18-knockout mouse model (tail-bleed, deep vein thrombosis, ischemia-reperfusion models), bone marrow chimera\",\n      \"journal\": \"Haematologica\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP, multiple orthogonal functional assays (Ca2+ mobilization, NFAT reporter, surface localization), KO mouse with multiple in vivo phenotypes, single lab but highly rigorous with many convergent methods\",\n      \"pmids\": [\"30573509\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"TSPAN18-knockdown in primary human umbilical vein endothelial cells reduces histamine- or thrombin-induced von Willebrand factor (vWF) release by ~90%, and Tspan18-knockout mice show ~45% reduced histamine-induced plasma vWF increase, demonstrating TSPAN18 is required for inflammatory stimulus-induced vWF secretion from endothelial cells.\",\n      \"method\": \"siRNA knockdown in HUVECs with vWF release assay (ELISA), Tspan18-knockout mouse plasma vWF measurement after histamine stimulation\",\n      \"journal\": \"Haematologica\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — loss-of-function in both primary human cells and KO mouse with defined molecular readout (vWF release), multiple orthogonal systems\",\n      \"pmids\": [\"30573509\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"TSPAN18 is required for normal Ca2+ signaling in platelets, with Tspan18-knockout mice showing mildly defective platelet aggregation and spreading induced by the collagen receptor GPVI, demonstrating a platelet-intrinsic role for TSPAN18 beyond endothelial cells.\",\n      \"method\": \"Tspan18-knockout mouse platelet aggregation assay, platelet spreading assay, GPVI stimulation\",\n      \"journal\": \"Medical microbiology and immunology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — KO mouse with defined cellular phenotype (platelet aggregation/spreading), single lab reporting new data in a review context\",\n      \"pmids\": [\"32447449\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"TSPAN18 directly interacts with STIM1 and competitively inhibits E3 ubiquitin ligase TRIM32-mediated ubiquitination and proteasomal degradation of STIM1, thereby increasing STIM1 protein stability and enhancing STIM1-dependent store-operated Ca2+ entry, which promotes prostate cancer cell migration, invasion, and bone metastasis in vitro and in vivo.\",\n      \"method\": \"Liquid chromatography-mass spectrometry (TSPAN18 identified as STIM1-binding protein), co-immunoprecipitation (TSPAN18-STIM1 and TRIM32-STIM1 interactions), ubiquitination assay, Ca2+ influx assay, siRNA/overexpression in vitro migration/invasion assays, in vivo bone metastasis mouse model\",\n      \"journal\": \"Journal of experimental & clinical cancer research : CR\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP plus ubiquitination assay plus in vitro and in vivo functional validation, single lab with multiple orthogonal methods\",\n      \"pmids\": [\"37542345\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"The long non-coding RNA LINC00607 epigenetically upregulates TSPAN18 expression in endothelial cells under hypoxia by associating with the chromatin remodeler BRG1 and facilitating BRG1-dependent activation of the TSPAN18 enhancer (marked by increased acetylation and chromatin accessibility). Activation of the LINC00607-TSPAN18 axis enhances store-operated calcium entry and endothelial-monocyte adhesion under hypoxic conditions.\",\n      \"method\": \"Integrative transcriptomics and chromatin accessibility analysis (ATAC-seq), ChIP-seq for enhancer marks, loss- and gain-of-function experiments for LINC00607, RNA immunoprecipitation (LINC00607-BRG1 association), BRG1 pharmacological inhibition, Ca2+ entry assay, endothelial-monocyte adhesion assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple chromatin and functional assays, loss/gain of function, single lab but orthogonal methods; TSPAN18 is downstream effector with functional readout\",\n      \"pmids\": [\"41581880\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"TSPAN18 is a tetraspanin expressed at high levels in endothelial cells that promotes store-operated Ca2+ entry by interacting with and facilitating plasma membrane trafficking/clustering of the Ca2+ channel Orai1; in endothelial cells this drives inflammatory stimulus-induced von Willebrand factor release and thrombo-inflammatory responses, while in prostate cancer cells TSPAN18 protects the Ca2+ sensor STIM1 from TRIM32-mediated ubiquitination and degradation, thereby enhancing STIM1-dependent Ca2+ signaling and bone metastasis; upstream, TSPAN18 expression is epigenetically regulated in endothelial cells by a hypoxia-responsive LINC00607-BRG1 axis.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"TSPAN18 is a tetraspanin that promotes store-operated Ca2+ entry and links inflammatory and hypoxic stimuli to endothelial and thrombo-inflammatory responses [#0, #1]. In endothelial cells it interacts with the store-operated Ca2+ channel Orai1 and is required for normal Orai1 cell-surface localization, so that its loss markedly impairs thrombin- or histamine-induced Ca2+ mobilization and downstream Orai1-dependent signaling [#0]. Through this Ca2+ entry function TSPAN18 is required for inflammatory stimulus-induced von Willebrand factor secretion from endothelial cells [#1], and it additionally supports collagen/GPVI-dependent Ca2+ signaling, aggregation, and spreading in platelets [#2]. In prostate cancer cells TSPAN18 directly binds the Ca2+ sensor STIM1 and competitively blocks TRIM32-mediated ubiquitination and proteasomal degradation of STIM1, stabilizing STIM1 and enhancing store-operated Ca2+ entry to drive migration, invasion, and bone metastasis [#3]. Upstream, TSPAN18 expression is epigenetically induced in endothelial cells under hypoxia by a LINC00607-BRG1 axis that activates the TSPAN18 enhancer, coupling its expression to enhanced Ca2+ entry and endothelial-monocyte adhesion [#4].\",\n  \"teleology\": [\n    {\n      \"year\": 2018,\n      \"claim\": \"Established TSPAN18 as a molecular partner of the Orai1 store-operated Ca2+ channel and as a determinant of Orai1 surface expression and Ca2+ entry, defining its core mechanism in endothelial cells.\",\n      \"evidence\": \"Reciprocal Co-IP, siRNA knockdown with Ca2+ mobilization and surface-Orai1 flow cytometry, NFAT reporter assay, and Tspan18-knockout mouse thrombosis/ischemia models\",\n      \"pmids\": [\"30573509\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Structural basis of the TSPAN18-Orai1 interaction not resolved\",\n        \"Whether TSPAN18 acts as a trafficking chaperone, clustering scaffold, or both is not distinguished\",\n        \"Stoichiometry of the TSPAN18-Orai1 complex unknown\"\n      ]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Linked TSPAN18-dependent Ca2+ entry to a defined endothelial secretory output, showing it is required for inflammatory stimulus-induced von Willebrand factor release.\",\n      \"evidence\": \"siRNA knockdown in primary HUVECs with vWF ELISA and plasma vWF measurement in histamine-stimulated Tspan18-knockout mice\",\n      \"pmids\": [\"30573509\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Quantitative difference between near-complete HUVEC defect and partial mouse phenotype not reconciled\",\n        \"Direct dependence of vWF release on the Orai1 interaction not formally tested\"\n      ]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Extended TSPAN18 function beyond endothelium by demonstrating a platelet-intrinsic role in GPVI-induced Ca2+ signaling and platelet activation.\",\n      \"evidence\": \"Tspan18-knockout mouse platelet aggregation and spreading assays under GPVI stimulation\",\n      \"pmids\": [\"32447449\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Whether the platelet defect is mediated by Orai1 as in endothelium not established\",\n        \"Reported as new data within a review context, limiting depth\"\n      ]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Revealed a second, post-translational mechanism in which TSPAN18 stabilizes the Ca2+ sensor STIM1 by competitively blocking its TRIM32-mediated ubiquitination, expanding its role into cancer-associated Ca2+ signaling.\",\n      \"evidence\": \"LC-MS interactome, Co-IP of TSPAN18-STIM1 and TRIM32-STIM1, ubiquitination and Ca2+ influx assays, in vitro migration/invasion, and in vivo bone metastasis model\",\n      \"pmids\": [\"37542345\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Relationship between the STIM1-stabilizing and Orai1-trafficking activities not integrated\",\n        \"Whether STIM1 stabilization occurs in endothelium/platelets or is cancer-specific unknown\",\n        \"Single lab; reciprocal independent validation absent\"\n      ]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Placed TSPAN18 downstream of a hypoxia-responsive epigenetic program, showing LINC00607-BRG1-driven enhancer activation controls its expression and consequent Ca2+ entry and leukocyte adhesion.\",\n      \"evidence\": \"ATAC-seq, ChIP-seq enhancer marks, LINC00607 loss/gain of function, RIP for LINC00607-BRG1, BRG1 inhibition, Ca2+ entry and endothelial-monocyte adhesion assays\",\n      \"pmids\": [\"41581880\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Direct transcription factors binding the activated TSPAN18 enhancer not identified\",\n        \"Single lab; mechanism of LINC00607 recruitment to the TSPAN18 locus not detailed\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How TSPAN18's two reported activities — facilitating Orai1 surface trafficking and protecting STIM1 from degradation — are mechanistically integrated within a single store-operated Ca2+ entry module remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"No structural model of TSPAN18 or its channel/sensor complexes\",\n        \"Tissue-specificity of the Orai1 versus STIM1 mechanism untested\",\n        \"Whether both mechanisms operate simultaneously in the same cell unknown\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [0, 3]},\n      {\"term_id\": \"GO:0140313\", \"supporting_discovery_ids\": [3]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [0, 3]},\n      {\"term_id\": \"R-HSA-109582\", \"supporting_discovery_ids\": [1, 2]},\n      {\"term_id\": \"R-HSA-1643685\", \"supporting_discovery_ids\": [3]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"ORAI1\", \"STIM1\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":5,"faith_pct":100.0}}