{"gene":"TMEM9B","run_date":"2026-04-28T21:42:59","timeline":{"discoveries":[{"year":2008,"finding":"TMEM9B is a glycosylated protein localized to lysosomal membranes and partially to early endosomes, where it acts downstream of RIP1 and upstream of MAPK and IκB kinases at the level of the TAK1 complex to activate NF-κB and MAPK pathways in response to TNF, IL-1β, and TLR ligands, but is not required for apoptotic cell death.","method":"RNAi knockdown, cytokine production assays, subcellular fractionation/localization, epistasis analysis with RIP1/TAK1 complex components","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 — multiple orthogonal methods (RNAi, localization, epistasis), replicated across multiple stimuli and pathways","pmids":["18541524"],"is_preprint":false},{"year":2011,"finding":"TMEM9B knockdown bypasses cellular senescence induced by the p53-p21 and p16-pRB tumour suppressor pathways, placing TMEM9B as a downstream effector of these pathways required for senescence entry.","method":"Loss-of-function RNAi screen in conditionally immortalised human fibroblasts with senescence bypass as phenotypic readout, validated by direct lentiviral shRNAmir silencing","journal":"BMC genomics","confidence":"Medium","confidence_rationale":"Tier 2 — clean KO with defined cellular phenotype, but single lab and limited mechanistic follow-up","pmids":["21740549"],"is_preprint":false},{"year":2024,"finding":"TMEM9B directly interacts with the endosomal Cl⁻/H⁺ antiporters ClC-3 and ClC-4 (but not ClC-1 or ClC-7), and co-expression of TMEM9B dramatically reduces ClC-3 and ClC-4 transporter activity, with TMEM9B also inducing a slow component in ClC-3 activation kinetics.","method":"Co-expression in Xenopus oocytes and HEK cells (electrophysiology), FLIM-FRET to detect direct protein-protein interaction","journal":"Life (Basel, Switzerland)","confidence":"High","confidence_rationale":"Tier 1 — functional reconstitution in two heterologous systems plus direct FRET interaction evidence with specificity controls","pmids":["39202776"],"is_preprint":false},{"year":2025,"finding":"Cryo-EM structures reveal that TMEM9B (and the related TMEM9) directly binds ClC-3, ClC-4, and ClC-5 as accessory β-subunits; TMEM9 inhibits ClC-3 by sealing the cytosolic entrance to the Cl⁻ ion pathway, and phosphatidylinositol 3,5-bisphosphate (PtdIns(3,5)P2) stabilizes the TMEM9/ClC-3 interaction and is required for proper regulation of ClC-3 activity.","method":"Cryo-electron microscopy structure determination, co-immunoprecipitation, electrophysiology, lipid binding assays","journal":"Nature structural & molecular biology","confidence":"High","confidence_rationale":"Tier 1 — atomic-resolution cryo-EM structures with functional validation across multiple methods","pmids":["40670814"],"is_preprint":false},{"year":2025,"finding":"Cross-linking mass spectrometry of purified early endosomes combined with AlphaFold structural predictions and validation in induced neurons confirmed TMEM9B as a subunit of the chloride-proton antiporters CLCN3, CLCN4, and CLCN5 in their native endosomal context.","method":"Crosslinking mass spectrometry of purified early endosomes, AlphaFold structural modeling, validation in induced neurons","journal":"Nature","confidence":"High","confidence_rationale":"Tier 1-2 — native endosomal context crosslinking MS plus structural prediction and neuronal validation, independent of electrophysiology studies","pmids":["40437099"],"is_preprint":false},{"year":2022,"finding":"TMEM9B is a direct target of miR-22-3p, and its inhibition partially rescues the effects of the lncRNA MIR4435-2HG on breast cancer cell proliferation, migration, invasion, and epithelial-mesenchymal transition.","method":"RNA pulldown, dual-luciferase reporter assay, siRNA knockdown with functional rescue assays","journal":"American journal of translational research","confidence":"Medium","confidence_rationale":"Tier 3 — direct interaction validated by luciferase assay and pulldown, but mechanistic pathway placement is limited","pmids":["36105009"],"is_preprint":false}],"current_model":"TMEM9B is a single-span type I transmembrane protein localized to lysosomes and early endosomes that functions as an accessory β-subunit of the endosomal Cl⁻/H⁺ antiporters ClC-3, ClC-4, and ClC-5, directly binding and inhibiting their transport activity (with PtdIns(3,5)P2 stabilizing the interaction), and additionally acts within the TAK1 complex downstream of RIP1 to activate NF-κB and MAPK inflammatory signaling in response to TNF, IL-1β, and TLR ligands, and is required as a downstream effector of the p53-p21/p16-pRB pathways for cellular senescence."},"narrative":{"teleology":[{"year":2008,"claim":"The first functional role for TMEM9B was established: it is a lysosomal/endosomal glycoprotein that activates NF-κB and MAPK inflammatory signaling by operating within the TAK1 complex downstream of RIP1, resolving TMEM9B's position in the innate immune signaling cascade.","evidence":"RNAi knockdown, cytokine assays, subcellular fractionation, and epistasis analysis across TNF, IL-1β, and TLR stimuli in mammalian cells","pmids":["18541524"],"confidence":"High","gaps":["How TMEM9B, as a lysosomal membrane protein, physically engages the cytosolic TAK1 complex is undefined","Whether TMEM9B's signaling role depends on its later-identified ion transporter regulation is unknown","No structural information on TMEM9B's interaction with TAK1 complex components"]},{"year":2011,"claim":"TMEM9B was positioned as an effector of tumor suppressor-driven senescence, showing that its loss bypasses senescence induced by both the p53-p21 and p16-pRB pathways, broadening its function beyond inflammation.","evidence":"Genome-wide RNAi screen for senescence bypass in conditionally immortalized human fibroblasts, validated by lentiviral shRNAmir silencing","pmids":["21740549"],"confidence":"Medium","gaps":["Limited mechanistic follow-up: it is unknown whether TMEM9B promotes senescence via NF-κB/MAPK signaling, lysosomal function, or an independent mechanism","Single-lab finding without independent replication","No rescue experiment with re-expression of TMEM9B reported"]},{"year":2024,"claim":"TMEM9B was identified as a direct binding partner and functional inhibitor of the endosomal ClC-3 and ClC-4 Cl⁻/H⁺ antiporters, establishing a previously unrecognized ion transport regulatory role separate from its signaling functions.","evidence":"Co-expression electrophysiology in Xenopus oocytes and HEK cells, FLIM-FRET for direct interaction, with specificity controls showing no binding to ClC-1 or ClC-7","pmids":["39202776"],"confidence":"High","gaps":["Structural basis of how TMEM9B inhibits transporter currents was not yet resolved","Whether TMEM9B regulation occurs in native endosomal membranes was untested","Physiological consequence of TMEM9B-mediated ClC inhibition in vivo was unknown"]},{"year":2025,"claim":"Cryo-EM structures and native endosomal crosslinking mass spectrometry independently confirmed TMEM9B as a bona fide β-subunit of ClC-3/4/5 in their physiological membrane context, with atomic-resolution detail showing that PtdIns(3,5)P₂ stabilizes the interaction and the related TMEM9 inhibits by occluding the Cl⁻ pathway.","evidence":"Cryo-EM structure determination with lipid binding assays and electrophysiology (Nat. Struct. Mol. Biol.); crosslinking MS of purified early endosomes with AlphaFold modeling and validation in induced neurons (Nature)","pmids":["40670814","40437099"],"confidence":"High","gaps":["Whether TMEM9B occludes the Cl⁻ pathway identically to TMEM9 or uses a distinct inhibitory mechanism is not fully resolved","Physiological consequences of disrupting the TMEM9B–ClC interaction in animal models are unexplored","Relationship between TMEM9B's ion channel regulatory role and its NF-κB/senescence functions remains unconnected"]},{"year":null,"claim":"A central unresolved question is whether TMEM9B's two established roles — endosomal Cl⁻/H⁺ antiporter regulation and inflammatory/senescence signaling — are mechanistically linked, for instance through lysosomal pH or endosomal acidification, or represent independent functions.","evidence":"","pmids":[],"confidence":"Low","gaps":["No study has tested whether TMEM9B's modulation of ClC transporter activity alters endosomal pH sufficiently to affect NF-κB/MAPK signaling","In vivo loss-of-function models (knockout mice) have not been reported","Disease associations from direct genetic evidence are absent"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[2,3]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[0]}],"localization":[{"term_id":"GO:0005764","term_label":"lysosome","supporting_discovery_ids":[0]},{"term_id":"GO:0005768","term_label":"endosome","supporting_discovery_ids":[0,4]}],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[0]},{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[0]},{"term_id":"R-HSA-382551","term_label":"Transport of small molecules","supporting_discovery_ids":[2,3,4]}],"complexes":["ClC-3/TMEM9B complex","ClC-4/TMEM9B complex","ClC-5/TMEM9B complex"],"partners":["CLCN3","CLCN4","CLCN5","TAK1","TMEM9"],"other_free_text":[]},"mechanistic_narrative":"TMEM9B is a glycosylated single-span transmembrane protein that functions as an accessory β-subunit of the endosomal Cl⁻/H⁺ antiporters ClC-3, ClC-4, and ClC-5, directly binding these transporters to inhibit their activity, with PtdIns(3,5)P₂ stabilizing the interaction; cryo-EM structures show the related TMEM9 seals the cytosolic entrance to the Cl⁻ ion pathway, establishing a conserved mechanism of transport regulation [PMID:39202776, PMID:40670814, PMID:40437099]. TMEM9B also operates in inflammatory signaling, acting downstream of RIP1 at the level of the TAK1 complex to activate NF-κB and MAPK pathways in response to TNF, IL-1β, and TLR ligands from its lysosomal/early endosomal localization [PMID:18541524]. Additionally, TMEM9B is required downstream of the p53-p21 and p16-pRB tumor suppressor pathways for entry into cellular senescence [PMID:21740549]."},"prefetch_data":{"uniprot":{"accession":"Q9NQ34","full_name":"Transmembrane protein 9B","aliases":[],"length_aa":198,"mass_kda":22.5,"function":"Enhances production of pro-inflammatory cytokines induced by TNF, IL1B, and TLR ligands. Has a role in TNF activation of both the NF-kappaB and MAPK pathways","subcellular_location":"Lysosome membrane; Early endosome membrane","url":"https://www.uniprot.org/uniprotkb/Q9NQ34/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/TMEM9B","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/TMEM9B","total_profiled":1310},"omim":[{"mim_id":"620293","title":"TMEM9 DOMAIN FAMILY, MEMBER B; TMEM9B","url":"https://www.omim.org/entry/620293"},{"mim_id":"616877","title":"TRANSMEMBRANE PROTEIN 9; TMEM9","url":"https://www.omim.org/entry/616877"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/TMEM9B"},"hgnc":{"alias_symbol":[],"prev_symbol":["C11orf15"]},"alphafold":{"accession":"Q9NQ34","domains":[{"cath_id":"3.10.20","chopping":"39-96","consensus_level":"high","plddt":89.0783,"start":39,"end":96},{"cath_id":"1.20.5","chopping":"98-143","consensus_level":"medium","plddt":76.1604,"start":98,"end":143}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9NQ34","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9NQ34-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9NQ34-F1-predicted_aligned_error_v6.png","plddt_mean":72.38},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=TMEM9B","jax_strain_url":"https://www.jax.org/strain/search?query=TMEM9B"},"sequence":{"accession":"Q9NQ34","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9NQ34.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9NQ34/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9NQ34"}},"corpus_meta":[{"pmid":"18541524","id":"PMC_18541524","title":"The lysosomal transmembrane protein 9B regulates the activity of inflammatory signaling pathways.","date":"2008","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/18541524","citation_count":47,"is_preprint":false},{"pmid":"21740549","id":"PMC_21740549","title":"An RNA interference screen for identifying downstream effectors of the p53 and pRB tumour suppressor pathways involved in senescence.","date":"2011","source":"BMC genomics","url":"https://pubmed.ncbi.nlm.nih.gov/21740549","citation_count":34,"is_preprint":false},{"pmid":"36105009","id":"PMC_36105009","title":"LncRNA MIR4435-2HG promotes proliferation, migration, invasion and epithelial mesenchymal transition via targeting miR-22-3p/TMEM9B in breast cancer.","date":"2022","source":"American journal of translational research","url":"https://pubmed.ncbi.nlm.nih.gov/36105009","citation_count":9,"is_preprint":false},{"pmid":"39202776","id":"PMC_39202776","title":"TMEM9B Regulates Endosomal ClC-3 and ClC-4 Transporters.","date":"2024","source":"Life (Basel, Switzerland)","url":"https://pubmed.ncbi.nlm.nih.gov/39202776","citation_count":7,"is_preprint":false},{"pmid":"40437099","id":"PMC_40437099","title":"EndoMAP.v1 charts the structural landscape of human early endosome complexes.","date":"2025","source":"Nature","url":"https://pubmed.ncbi.nlm.nih.gov/40437099","citation_count":5,"is_preprint":false},{"pmid":"39696495","id":"PMC_39696495","title":"Epigenetic regulation on left atrial function and disease recurrence after catheter ablation in atrial fibrillation.","date":"2024","source":"Clinical epigenetics","url":"https://pubmed.ncbi.nlm.nih.gov/39696495","citation_count":4,"is_preprint":false},{"pmid":"40670814","id":"PMC_40670814","title":"Structural basis of ClC-3 transporter inhibition by TMEM9 and PtdIns(3,5)P2.","date":"2025","source":"Nature structural & molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/40670814","citation_count":3,"is_preprint":false},{"pmid":"38246423","id":"PMC_38246423","title":"Association of GAL-8 promoter methylation levels with coronary plaque inflammation.","date":"2024","source":"International journal of cardiology","url":"https://pubmed.ncbi.nlm.nih.gov/38246423","citation_count":3,"is_preprint":false},{"pmid":"40632859","id":"PMC_40632859","title":"Down-regulation of human-specific lncRNA TMEM9B-AS1 in skeletal muscle of people with type 2 diabetes affects ribosomal biogenesis.","date":"2025","source":"Science advances","url":"https://pubmed.ncbi.nlm.nih.gov/40632859","citation_count":2,"is_preprint":false},{"pmid":"40093093","id":"PMC_40093093","title":"Structural basis of ClC-3 inhibition by TMEM9 and PI(3,5)P2.","date":"2025","source":"bioRxiv : the preprint server for biology","url":"https://pubmed.ncbi.nlm.nih.gov/40093093","citation_count":1,"is_preprint":false},{"pmid":"40356149","id":"PMC_40356149","title":"Cellular uptake and transport mechanism of flaxseed cyclic peptide CLB via clathrin-dependent endocytosis.","date":"2025","source":"Food research international (Ottawa, Ont.)","url":"https://pubmed.ncbi.nlm.nih.gov/40356149","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2024.07.05.602204","title":"Human-specific lncRNA TMEM9B-AS1 is downregulated in skeletal muscle of individuals with type 2 diabetes and regulates ribosomal biogenesis","date":"2024-07-06","source":"bioRxiv","url":"https://doi.org/10.1101/2024.07.05.602204","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.02.28.640562","title":"Structural basis of ClC-3 inhibition by TMEM9 and PI(3,5)P<sub>2</sub>","date":"2025-03-03","source":"bioRxiv","url":"https://doi.org/10.1101/2025.02.28.640562","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":7836,"output_tokens":1575,"usd":0.023567},"stage2":{"model":"claude-opus-4-6","input_tokens":4838,"output_tokens":1912,"usd":0.107985},"total_usd":0.131552,"stage1_batch_id":"msgbatch_01RPbVc9PDH9zQmYK5Hs6srm","stage2_batch_id":"msgbatch_01JVbVLzeKN2yVrsGp3zC8aM","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2008,\n      \"finding\": \"TMEM9B is a glycosylated protein localized to lysosomal membranes and partially to early endosomes, where it acts downstream of RIP1 and upstream of MAPK and IκB kinases at the level of the TAK1 complex to activate NF-κB and MAPK pathways in response to TNF, IL-1β, and TLR ligands, but is not required for apoptotic cell death.\",\n      \"method\": \"RNAi knockdown, cytokine production assays, subcellular fractionation/localization, epistasis analysis with RIP1/TAK1 complex components\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal methods (RNAi, localization, epistasis), replicated across multiple stimuli and pathways\",\n      \"pmids\": [\"18541524\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"TMEM9B knockdown bypasses cellular senescence induced by the p53-p21 and p16-pRB tumour suppressor pathways, placing TMEM9B as a downstream effector of these pathways required for senescence entry.\",\n      \"method\": \"Loss-of-function RNAi screen in conditionally immortalised human fibroblasts with senescence bypass as phenotypic readout, validated by direct lentiviral shRNAmir silencing\",\n      \"journal\": \"BMC genomics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — clean KO with defined cellular phenotype, but single lab and limited mechanistic follow-up\",\n      \"pmids\": [\"21740549\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"TMEM9B directly interacts with the endosomal Cl⁻/H⁺ antiporters ClC-3 and ClC-4 (but not ClC-1 or ClC-7), and co-expression of TMEM9B dramatically reduces ClC-3 and ClC-4 transporter activity, with TMEM9B also inducing a slow component in ClC-3 activation kinetics.\",\n      \"method\": \"Co-expression in Xenopus oocytes and HEK cells (electrophysiology), FLIM-FRET to detect direct protein-protein interaction\",\n      \"journal\": \"Life (Basel, Switzerland)\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — functional reconstitution in two heterologous systems plus direct FRET interaction evidence with specificity controls\",\n      \"pmids\": [\"39202776\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Cryo-EM structures reveal that TMEM9B (and the related TMEM9) directly binds ClC-3, ClC-4, and ClC-5 as accessory β-subunits; TMEM9 inhibits ClC-3 by sealing the cytosolic entrance to the Cl⁻ ion pathway, and phosphatidylinositol 3,5-bisphosphate (PtdIns(3,5)P2) stabilizes the TMEM9/ClC-3 interaction and is required for proper regulation of ClC-3 activity.\",\n      \"method\": \"Cryo-electron microscopy structure determination, co-immunoprecipitation, electrophysiology, lipid binding assays\",\n      \"journal\": \"Nature structural & molecular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — atomic-resolution cryo-EM structures with functional validation across multiple methods\",\n      \"pmids\": [\"40670814\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Cross-linking mass spectrometry of purified early endosomes combined with AlphaFold structural predictions and validation in induced neurons confirmed TMEM9B as a subunit of the chloride-proton antiporters CLCN3, CLCN4, and CLCN5 in their native endosomal context.\",\n      \"method\": \"Crosslinking mass spectrometry of purified early endosomes, AlphaFold structural modeling, validation in induced neurons\",\n      \"journal\": \"Nature\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — native endosomal context crosslinking MS plus structural prediction and neuronal validation, independent of electrophysiology studies\",\n      \"pmids\": [\"40437099\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"TMEM9B is a direct target of miR-22-3p, and its inhibition partially rescues the effects of the lncRNA MIR4435-2HG on breast cancer cell proliferation, migration, invasion, and epithelial-mesenchymal transition.\",\n      \"method\": \"RNA pulldown, dual-luciferase reporter assay, siRNA knockdown with functional rescue assays\",\n      \"journal\": \"American journal of translational research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 — direct interaction validated by luciferase assay and pulldown, but mechanistic pathway placement is limited\",\n      \"pmids\": [\"36105009\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"TMEM9B is a single-span type I transmembrane protein localized to lysosomes and early endosomes that functions as an accessory β-subunit of the endosomal Cl⁻/H⁺ antiporters ClC-3, ClC-4, and ClC-5, directly binding and inhibiting their transport activity (with PtdIns(3,5)P2 stabilizing the interaction), and additionally acts within the TAK1 complex downstream of RIP1 to activate NF-κB and MAPK inflammatory signaling in response to TNF, IL-1β, and TLR ligands, and is required as a downstream effector of the p53-p21/p16-pRB pathways for cellular senescence.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"TMEM9B is a glycosylated single-span transmembrane protein that functions as an accessory β-subunit of the endosomal Cl⁻/H⁺ antiporters ClC-3, ClC-4, and ClC-5, directly binding these transporters to inhibit their activity, with PtdIns(3,5)P₂ stabilizing the interaction; cryo-EM structures show the related TMEM9 seals the cytosolic entrance to the Cl⁻ ion pathway, establishing a conserved mechanism of transport regulation [PMID:39202776, PMID:40670814, PMID:40437099]. TMEM9B also operates in inflammatory signaling, acting downstream of RIP1 at the level of the TAK1 complex to activate NF-κB and MAPK pathways in response to TNF, IL-1β, and TLR ligands from its lysosomal/early endosomal localization [PMID:18541524]. Additionally, TMEM9B is required downstream of the p53-p21 and p16-pRB tumor suppressor pathways for entry into cellular senescence [PMID:21740549].\",\n  \"teleology\": [\n    {\n      \"year\": 2008,\n      \"claim\": \"The first functional role for TMEM9B was established: it is a lysosomal/endosomal glycoprotein that activates NF-κB and MAPK inflammatory signaling by operating within the TAK1 complex downstream of RIP1, resolving TMEM9B's position in the innate immune signaling cascade.\",\n      \"evidence\": \"RNAi knockdown, cytokine assays, subcellular fractionation, and epistasis analysis across TNF, IL-1β, and TLR stimuli in mammalian cells\",\n      \"pmids\": [\"18541524\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"How TMEM9B, as a lysosomal membrane protein, physically engages the cytosolic TAK1 complex is undefined\",\n        \"Whether TMEM9B's signaling role depends on its later-identified ion transporter regulation is unknown\",\n        \"No structural information on TMEM9B's interaction with TAK1 complex components\"\n      ]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"TMEM9B was positioned as an effector of tumor suppressor-driven senescence, showing that its loss bypasses senescence induced by both the p53-p21 and p16-pRB pathways, broadening its function beyond inflammation.\",\n      \"evidence\": \"Genome-wide RNAi screen for senescence bypass in conditionally immortalized human fibroblasts, validated by lentiviral shRNAmir silencing\",\n      \"pmids\": [\"21740549\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Limited mechanistic follow-up: it is unknown whether TMEM9B promotes senescence via NF-κB/MAPK signaling, lysosomal function, or an independent mechanism\",\n        \"Single-lab finding without independent replication\",\n        \"No rescue experiment with re-expression of TMEM9B reported\"\n      ]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"TMEM9B was identified as a direct binding partner and functional inhibitor of the endosomal ClC-3 and ClC-4 Cl⁻/H⁺ antiporters, establishing a previously unrecognized ion transport regulatory role separate from its signaling functions.\",\n      \"evidence\": \"Co-expression electrophysiology in Xenopus oocytes and HEK cells, FLIM-FRET for direct interaction, with specificity controls showing no binding to ClC-1 or ClC-7\",\n      \"pmids\": [\"39202776\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Structural basis of how TMEM9B inhibits transporter currents was not yet resolved\",\n        \"Whether TMEM9B regulation occurs in native endosomal membranes was untested\",\n        \"Physiological consequence of TMEM9B-mediated ClC inhibition in vivo was unknown\"\n      ]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Cryo-EM structures and native endosomal crosslinking mass spectrometry independently confirmed TMEM9B as a bona fide β-subunit of ClC-3/4/5 in their physiological membrane context, with atomic-resolution detail showing that PtdIns(3,5)P₂ stabilizes the interaction and the related TMEM9 inhibits by occluding the Cl⁻ pathway.\",\n      \"evidence\": \"Cryo-EM structure determination with lipid binding assays and electrophysiology (Nat. Struct. Mol. Biol.); crosslinking MS of purified early endosomes with AlphaFold modeling and validation in induced neurons (Nature)\",\n      \"pmids\": [\"40670814\", \"40437099\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Whether TMEM9B occludes the Cl⁻ pathway identically to TMEM9 or uses a distinct inhibitory mechanism is not fully resolved\",\n        \"Physiological consequences of disrupting the TMEM9B–ClC interaction in animal models are unexplored\",\n        \"Relationship between TMEM9B's ion channel regulatory role and its NF-κB/senescence functions remains unconnected\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"A central unresolved question is whether TMEM9B's two established roles — endosomal Cl⁻/H⁺ antiporter regulation and inflammatory/senescence signaling — are mechanistically linked, for instance through lysosomal pH or endosomal acidification, or represent independent functions.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"No study has tested whether TMEM9B's modulation of ClC transporter activity alters endosomal pH sufficiently to affect NF-κB/MAPK signaling\",\n        \"In vivo loss-of-function models (knockout mice) have not been reported\",\n        \"Disease associations from direct genetic evidence are absent\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [2, 3]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005764\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"GO:0005768\", \"supporting_discovery_ids\": [0, 4]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"R-HSA-382551\", \"supporting_discovery_ids\": [2, 3, 4]}\n    ],\n    \"complexes\": [\n      \"ClC-3/TMEM9B complex\",\n      \"ClC-4/TMEM9B complex\",\n      \"ClC-5/TMEM9B complex\"\n    ],\n    \"partners\": [\n      \"CLCN3\",\n      \"CLCN4\",\n      \"CLCN5\",\n      \"TAK1\",\n      \"TMEM9\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```"}