{"gene":"TMEM168","run_date":"2026-06-10T10:51:55","timeline":{"discoveries":[{"year":2017,"finding":"TMEM168 binds extracellular matrix protein osteopontin, as demonstrated by co-immunoprecipitation in COS-7 cells; TMEM168 overexpression enhanced both extracellular and intracellular osteopontin levels in vitro and in vivo in nucleus accumbens of mice.","method":"Co-immunoprecipitation in COS-7 cells; AAV-mediated overexpression in mouse nucleus accumbens with biochemical measurement of osteopontin levels","journal":"Scientific reports","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal Co-IP plus in vivo confirmation, single lab, two orthogonal methods","pmids":["29026117"],"is_preprint":false},{"year":2017,"finding":"Overexpression of TMEM168 in the mouse nucleus accumbens decreased basal extracellular GABA levels and attenuated high-K+-stimulated GABA release without affecting total GABA content, placing TMEM168 as a regulator of GABAergic neurotransmission in the NAc.","method":"AAV-mediated overexpression in mouse nucleus accumbens; microdialysis measurement of extracellular GABA","journal":"PloS one","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct in vivo measurement of GABA release with AAV gain-of-function, single lab","pmids":["29211814"],"is_preprint":false},{"year":2017,"finding":"TMEM168 overexpression in mouse nucleus accumbens suppressed methamphetamine-induced extracellular dopamine elevation, establishing TMEM168 as a modulator of dopaminergic function in the NAc.","method":"AAV-mediated overexpression in mouse nucleus accumbens; in vivo microdialysis measurement of extracellular dopamine","journal":"Scientific reports","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct in vivo neurochemical measurement with AAV gain-of-function, single lab","pmids":["29026117"],"is_preprint":false},{"year":2020,"finding":"TMEM168 localizes to the nuclear membrane in HL-1 cardiomyocytes. A heterozygous R539Q mutation in TMEM168 reduces Nav1.5 (SCN5A) protein expression and Na+ current, through increased Nedd4-2 binding to Nav1.5 and subsequent ubiquitination and degradation of Nav1.5.","method":"Ectopic expression and immunofluorescence for localization; whole-cell patch clamp for Na+ current; co-immunoprecipitation for Nedd4-2/Nav1.5 interaction; knock-in mouse model (Tmem168 R539Q) with ventricular cardiomyocyte electrophysiology; western blot for Nav1.5 protein","journal":"FASEB journal","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — multiple orthogonal methods (electrophysiology, co-IP, knock-in mouse, ubiquitination assay) in a single rigorous study","pmids":["32175648"],"is_preprint":false},{"year":2021,"finding":"The TMEM168 R539Q mutant has higher affinity for αB-crystallin than wild-type TMEM168, causing αB-crystallin to be sequestered from the cell surface to the perinuclear region. This redistribution reduces αB-crystallin's ability to compete with Nedd4-2 for Nav1.5 binding, leading to increased Nav1.5 ubiquitination and proteasomal degradation and reduced Nav1.5 cell-surface expression.","method":"Co-immunoprecipitation of TMEM168 (WT and mutant) with αB-crystallin; αB-crystallin knockdown in HL-1 cardiomyocytes; immunofluorescence for αB-crystallin localization; proteasome inhibitor (MG-132) rescue experiment; western blot for Nav1.5","journal":"Journal of biochemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal methods (Co-IP, KD, proteasome inhibitor rescue, localization), single lab","pmids":["34086898"],"is_preprint":false},{"year":2019,"finding":"siRNA-mediated knockdown of TMEM168 in U87 and U373 GBM cells reduced β-catenin, C-myc, cyclin D1, and survivin expression, induced G0/G1 cell cycle arrest, and promoted apoptosis; the anti-proliferative effect was rescued by LiCl (Wnt/β-catenin activator), placing TMEM168 upstream of the Wnt/β-catenin pathway in GBM cells.","method":"siRNA knockdown in GBM cell lines; cell viability, cell cycle, and apoptosis assays; western blot for Wnt pathway components; LiCl rescue experiment","journal":"Oncology research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — epistasis via pharmacological rescue plus multiple readouts, single lab","pmids":["30940290"],"is_preprint":false}],"current_model":"TMEM168 is a nuclear membrane-localized transmembrane protein that (1) in cardiomyocytes acts as a scaffold modulating Nav1.5 stability by competing for αB-crystallin and Nedd4-2 binding — a mutation (R539Q) linked to Brugada syndrome sequesters αB-crystallin, increases Nedd4-2-mediated ubiquitination and proteasomal degradation of Nav1.5, and reduces Na+ current; (2) in the nucleus accumbens interacts with osteopontin and modulates GABAergic and dopaminergic neurotransmission; and (3) in GBM cells supports proliferation through the Wnt/β-catenin pathway."},"narrative":{"mechanistic_narrative":"TMEM168 is a nuclear membrane-localized transmembrane protein that acts as a scaffold controlling the stability of the cardiac sodium channel Nav1.5 (SCN5A) and that modulates neurotransmission and tumor cell proliferation in other contexts [PMID:32175648, PMID:29211814, PMID:30940290]. In cardiomyocytes it localizes to the nuclear membrane, and a heterozygous R539Q mutation reduces Nav1.5 protein and Na+ current by increasing Nedd4-2 binding to Nav1.5 and promoting its ubiquitination and degradation [PMID:32175648]. Mechanistically, the R539Q mutant binds αB-crystallin with higher affinity than wild-type protein and sequesters it to the perinuclear region, diminishing αB-crystallin's ability to compete with Nedd4-2 for Nav1.5, so that proteasome-dependent Nav1.5 degradation increases and cell-surface channel expression falls [PMID:34086898]. In the nucleus accumbens, TMEM168 binds the matrix protein osteopontin and raises its levels, and its overexpression lowers basal and stimulated GABA release and blunts methamphetamine-induced dopamine elevation [PMID:29026117, PMID:29211814]. In glioblastoma cells, TMEM168 supports proliferation upstream of the Wnt/β-catenin pathway, since its knockdown lowers β-catenin, C-myc, cyclin D1 and survivin, arrests cells in G0/G1 and triggers apoptosis, effects rescued by the Wnt activator LiCl [PMID:30940290]. Beyond these contexts, no unifying molecular activity for TMEM168 has been characterized in the available corpus.","teleology":[{"year":2017,"claim":"Establishing a physical binding partner gave TMEM168 its first molecular handle and tied it to extracellular matrix signaling and dopaminergic function in the brain.","evidence":"Co-immunoprecipitation in COS-7 cells and AAV overexpression in mouse nucleus accumbens with biochemical and in vivo microdialysis readouts","pmids":["29026117"],"confidence":"Medium","gaps":["Direct binding interface and stoichiometry with osteopontin undefined","Mechanism linking osteopontin binding to dopamine modulation unresolved","Gain-of-function only; loss-of-function phenotype untested"]},{"year":2017,"claim":"Linking TMEM168 to GABA release extended its neuromodulatory role beyond dopamine to inhibitory neurotransmission.","evidence":"AAV-mediated overexpression in mouse nucleus accumbens with microdialysis measurement of extracellular GABA","pmids":["29211814"],"confidence":"Medium","gaps":["Molecular mechanism by which TMEM168 suppresses GABA release unknown","Whether the effect is cell-autonomous to GABAergic neurons untested"]},{"year":2019,"claim":"A loss-of-function screen in tumor cells placed TMEM168 upstream of a defined proliferative signaling axis, distinguishing a cancer-relevant role.","evidence":"siRNA knockdown in U87/U373 GBM cells with cell cycle, apoptosis, Wnt-component western blots, and LiCl epistasis rescue","pmids":["30940290"],"confidence":"Medium","gaps":["Direct biochemical link between TMEM168 and Wnt/β-catenin components not identified","Whether effect generalizes beyond GBM lines untested"]},{"year":2020,"claim":"Connecting TMEM168 to Nav1.5 turnover via Nedd4-2 defined a concrete cardiac mechanism and a disease-linked mutation, the strongest mechanistic anchor in the timeline.","evidence":"Immunofluorescence localization, whole-cell patch clamp, co-IP, ubiquitination assay, and Tmem168 R539Q knock-in mouse cardiomyocyte electrophysiology","pmids":["32175648"],"confidence":"High","gaps":["Whether wild-type TMEM168 directly contacts Nav1.5 or Nedd4-2 not shown","Structural basis of nuclear membrane localization unresolved"]},{"year":2021,"claim":"Identifying αB-crystallin sequestration explained how the R539Q mutation shifts the balance toward Nedd4-2-driven Nav1.5 degradation, completing the cardiac mechanistic model.","evidence":"Co-IP of WT/mutant TMEM168 with αB-crystallin, αB-crystallin knockdown, localization imaging, and MG-132 proteasome rescue in HL-1 cardiomyocytes","pmids":["34086898"],"confidence":"Medium","gaps":["Quantitative affinity difference between WT and mutant not measured","Single lab; reciprocal validation of competition model pending"]},{"year":null,"claim":"It remains unknown whether TMEM168's roles in cardiac channel stability, NAc neurotransmission, and GBM proliferation share a common molecular activity or reflect context-specific scaffolding functions.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No unifying biochemical activity or domain function defined across tissues","No structural model of the transmembrane protein"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[3,4]}],"localization":[{"term_id":"GO:0005635","term_label":"nuclear envelope","supporting_discovery_ids":[3]}],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[5]}],"complexes":[],"partners":["SPP1","SCN5A","NEDD4L","CRYAB"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q9H0V1","full_name":"Transmembrane protein 168","aliases":[],"length_aa":697,"mass_kda":79.8,"function":"Plays a key role in maintaining the cardiac electrical stability by modulating cell surface expression of SCN5A (PubMed:32175648). May play a role in the modulation of anxiety behavior by regulating GABAergic neuronal system in the nucleus accumbens (By similarity)","subcellular_location":"Nucleus membrane","url":"https://www.uniprot.org/uniprotkb/Q9H0V1/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/TMEM168","classification":"Not Classified","n_dependent_lines":2,"n_total_lines":1208,"dependency_fraction":0.0016556291390728477},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/TMEM168","total_profiled":1310},"omim":[{"mim_id":"621529","title":"TRANSMEMBRANE PROTEIN 168; TMEM168","url":"https://www.omim.org/entry/621529"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Golgi apparatus","reliability":"Approved"},{"location":"Cytosol","reliability":"Additional"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/TMEM168"},"hgnc":{"alias_symbol":["DKFZp564C012","FLJ13576"],"prev_symbol":[]},"alphafold":{"accession":"Q9H0V1","domains":[{"cath_id":"3.40.50.1460","chopping":"410-627_682-694","consensus_level":"high","plddt":83.5383,"start":410,"end":694}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9H0V1","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9H0V1-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9H0V1-F1-predicted_aligned_error_v6.png","plddt_mean":83.44},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=TMEM168","jax_strain_url":"https://www.jax.org/strain/search?query=TMEM168"},"sequence":{"accession":"Q9H0V1","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9H0V1.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9H0V1/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9H0V1"}},"corpus_meta":[{"pmid":"30940290","id":"PMC_30940290","title":"Inhibition of Proliferation by Knockdown of Transmembrane (TMEM) 168 in Glioblastoma Cells via Suppression of Wnt/β-Catenin Pathway.","date":"2019","source":"Oncology research","url":"https://pubmed.ncbi.nlm.nih.gov/30940290","citation_count":24,"is_preprint":false},{"pmid":"29211814","id":"PMC_29211814","title":"Overexpression of transmembrane protein 168 in the mouse nucleus accumbens induces anxiety and sensorimotor gating deficit.","date":"2017","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/29211814","citation_count":21,"is_preprint":false},{"pmid":"29026117","id":"PMC_29026117","title":"Involvement of the accumbal osteopontin-interacting transmembrane protein 168 in methamphetamine-induced place preference and hyperlocomotion in mice.","date":"2017","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/29026117","citation_count":9,"is_preprint":false},{"pmid":"32175648","id":"PMC_32175648","title":"Identification of transmembrane protein 168 mutation in familial Brugada syndrome.","date":"2020","source":"FASEB journal : official publication of the Federation of American Societies for Experimental Biology","url":"https://pubmed.ncbi.nlm.nih.gov/32175648","citation_count":8,"is_preprint":false},{"pmid":"34086898","id":"PMC_34086898","title":"Transmembrane protein 168 mutation reduces cardiomyocyte cell surface expression of Nav1.5 through αB-crystallin intracellular dynamics.","date":"2021","source":"Journal of biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/34086898","citation_count":3,"is_preprint":false},{"pmid":"32378630","id":"PMC_32378630","title":"[Novel molecules-related drug dependence in mice].","date":"2020","source":"Nihon yakurigaku zasshi. Folia pharmacologica Japonica","url":"https://pubmed.ncbi.nlm.nih.gov/32378630","citation_count":2,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":5353,"output_tokens":1672,"usd":0.02057,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":8492,"output_tokens":2302,"usd":0.050005,"stage2_stop_reason":"end_turn"},"total_usd":0.070575,"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\": 2017,\n      \"finding\": \"TMEM168 binds extracellular matrix protein osteopontin, as demonstrated by co-immunoprecipitation in COS-7 cells; TMEM168 overexpression enhanced both extracellular and intracellular osteopontin levels in vitro and in vivo in nucleus accumbens of mice.\",\n      \"method\": \"Co-immunoprecipitation in COS-7 cells; AAV-mediated overexpression in mouse nucleus accumbens with biochemical measurement of osteopontin levels\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal Co-IP plus in vivo confirmation, single lab, two orthogonal methods\",\n      \"pmids\": [\"29026117\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Overexpression of TMEM168 in the mouse nucleus accumbens decreased basal extracellular GABA levels and attenuated high-K+-stimulated GABA release without affecting total GABA content, placing TMEM168 as a regulator of GABAergic neurotransmission in the NAc.\",\n      \"method\": \"AAV-mediated overexpression in mouse nucleus accumbens; microdialysis measurement of extracellular GABA\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct in vivo measurement of GABA release with AAV gain-of-function, single lab\",\n      \"pmids\": [\"29211814\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"TMEM168 overexpression in mouse nucleus accumbens suppressed methamphetamine-induced extracellular dopamine elevation, establishing TMEM168 as a modulator of dopaminergic function in the NAc.\",\n      \"method\": \"AAV-mediated overexpression in mouse nucleus accumbens; in vivo microdialysis measurement of extracellular dopamine\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct in vivo neurochemical measurement with AAV gain-of-function, single lab\",\n      \"pmids\": [\"29026117\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"TMEM168 localizes to the nuclear membrane in HL-1 cardiomyocytes. A heterozygous R539Q mutation in TMEM168 reduces Nav1.5 (SCN5A) protein expression and Na+ current, through increased Nedd4-2 binding to Nav1.5 and subsequent ubiquitination and degradation of Nav1.5.\",\n      \"method\": \"Ectopic expression and immunofluorescence for localization; whole-cell patch clamp for Na+ current; co-immunoprecipitation for Nedd4-2/Nav1.5 interaction; knock-in mouse model (Tmem168 R539Q) with ventricular cardiomyocyte electrophysiology; western blot for Nav1.5 protein\",\n      \"journal\": \"FASEB journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — multiple orthogonal methods (electrophysiology, co-IP, knock-in mouse, ubiquitination assay) in a single rigorous study\",\n      \"pmids\": [\"32175648\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"The TMEM168 R539Q mutant has higher affinity for αB-crystallin than wild-type TMEM168, causing αB-crystallin to be sequestered from the cell surface to the perinuclear region. This redistribution reduces αB-crystallin's ability to compete with Nedd4-2 for Nav1.5 binding, leading to increased Nav1.5 ubiquitination and proteasomal degradation and reduced Nav1.5 cell-surface expression.\",\n      \"method\": \"Co-immunoprecipitation of TMEM168 (WT and mutant) with αB-crystallin; αB-crystallin knockdown in HL-1 cardiomyocytes; immunofluorescence for αB-crystallin localization; proteasome inhibitor (MG-132) rescue experiment; western blot for Nav1.5\",\n      \"journal\": \"Journal of biochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal methods (Co-IP, KD, proteasome inhibitor rescue, localization), single lab\",\n      \"pmids\": [\"34086898\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"siRNA-mediated knockdown of TMEM168 in U87 and U373 GBM cells reduced β-catenin, C-myc, cyclin D1, and survivin expression, induced G0/G1 cell cycle arrest, and promoted apoptosis; the anti-proliferative effect was rescued by LiCl (Wnt/β-catenin activator), placing TMEM168 upstream of the Wnt/β-catenin pathway in GBM cells.\",\n      \"method\": \"siRNA knockdown in GBM cell lines; cell viability, cell cycle, and apoptosis assays; western blot for Wnt pathway components; LiCl rescue experiment\",\n      \"journal\": \"Oncology research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — epistasis via pharmacological rescue plus multiple readouts, single lab\",\n      \"pmids\": [\"30940290\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"TMEM168 is a nuclear membrane-localized transmembrane protein that (1) in cardiomyocytes acts as a scaffold modulating Nav1.5 stability by competing for αB-crystallin and Nedd4-2 binding — a mutation (R539Q) linked to Brugada syndrome sequesters αB-crystallin, increases Nedd4-2-mediated ubiquitination and proteasomal degradation of Nav1.5, and reduces Na+ current; (2) in the nucleus accumbens interacts with osteopontin and modulates GABAergic and dopaminergic neurotransmission; and (3) in GBM cells supports proliferation through the Wnt/β-catenin pathway.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"TMEM168 is a nuclear membrane-localized transmembrane protein that acts as a scaffold controlling the stability of the cardiac sodium channel Nav1.5 (SCN5A) and that modulates neurotransmission and tumor cell proliferation in other contexts [#3, #1, #5]. In cardiomyocytes it localizes to the nuclear membrane, and a heterozygous R539Q mutation reduces Nav1.5 protein and Na+ current by increasing Nedd4-2 binding to Nav1.5 and promoting its ubiquitination and degradation [#3]. Mechanistically, the R539Q mutant binds αB-crystallin with higher affinity than wild-type protein and sequesters it to the perinuclear region, diminishing αB-crystallin's ability to compete with Nedd4-2 for Nav1.5, so that proteasome-dependent Nav1.5 degradation increases and cell-surface channel expression falls [#4]. In the nucleus accumbens, TMEM168 binds the matrix protein osteopontin and raises its levels, and its overexpression lowers basal and stimulated GABA release and blunts methamphetamine-induced dopamine elevation [#0, #1, #2]. In glioblastoma cells, TMEM168 supports proliferation upstream of the Wnt/β-catenin pathway, since its knockdown lowers β-catenin, C-myc, cyclin D1 and survivin, arrests cells in G0/G1 and triggers apoptosis, effects rescued by the Wnt activator LiCl [#5]. Beyond these contexts, no unifying molecular activity for TMEM168 has been characterized in the available corpus.\",\n  \"teleology\": [\n    {\n      \"year\": 2017,\n      \"claim\": \"Establishing a physical binding partner gave TMEM168 its first molecular handle and tied it to extracellular matrix signaling and dopaminergic function in the brain.\",\n      \"evidence\": \"Co-immunoprecipitation in COS-7 cells and AAV overexpression in mouse nucleus accumbens with biochemical and in vivo microdialysis readouts\",\n      \"pmids\": [\"29026117\"],\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\n        \"Direct binding interface and stoichiometry with osteopontin undefined\",\n        \"Mechanism linking osteopontin binding to dopamine modulation unresolved\",\n        \"Gain-of-function only; loss-of-function phenotype untested\"\n      ]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Linking TMEM168 to GABA release extended its neuromodulatory role beyond dopamine to inhibitory neurotransmission.\",\n      \"evidence\": \"AAV-mediated overexpression in mouse nucleus accumbens with microdialysis measurement of extracellular GABA\",\n      \"pmids\": [\"29211814\"],\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\n        \"Molecular mechanism by which TMEM168 suppresses GABA release unknown\",\n        \"Whether the effect is cell-autonomous to GABAergic neurons untested\"\n      ]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"A loss-of-function screen in tumor cells placed TMEM168 upstream of a defined proliferative signaling axis, distinguishing a cancer-relevant role.\",\n      \"evidence\": \"siRNA knockdown in U87/U373 GBM cells with cell cycle, apoptosis, Wnt-component western blots, and LiCl epistasis rescue\",\n      \"pmids\": [\"30940290\"],\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\n        \"Direct biochemical link between TMEM168 and Wnt/β-catenin components not identified\",\n        \"Whether effect generalizes beyond GBM lines untested\"\n      ]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Connecting TMEM168 to Nav1.5 turnover via Nedd4-2 defined a concrete cardiac mechanism and a disease-linked mutation, the strongest mechanistic anchor in the timeline.\",\n      \"evidence\": \"Immunofluorescence localization, whole-cell patch clamp, co-IP, ubiquitination assay, and Tmem168 R539Q knock-in mouse cardiomyocyte electrophysiology\",\n      \"pmids\": [\"32175648\"],\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\n        \"Whether wild-type TMEM168 directly contacts Nav1.5 or Nedd4-2 not shown\",\n        \"Structural basis of nuclear membrane localization unresolved\"\n      ]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Identifying αB-crystallin sequestration explained how the R539Q mutation shifts the balance toward Nedd4-2-driven Nav1.5 degradation, completing the cardiac mechanistic model.\",\n      \"evidence\": \"Co-IP of WT/mutant TMEM168 with αB-crystallin, αB-crystallin knockdown, localization imaging, and MG-132 proteasome rescue in HL-1 cardiomyocytes\",\n      \"pmids\": [\"34086898\"],\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\n        \"Quantitative affinity difference between WT and mutant not measured\",\n        \"Single lab; reciprocal validation of competition model pending\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"It remains unknown whether TMEM168's roles in cardiac channel stability, NAc neurotransmission, and GBM proliferation share a common molecular activity or reflect context-specific scaffolding functions.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\n        \"No unifying biochemical activity or domain function defined across tissues\",\n        \"No structural model of the transmembrane protein\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [3, 4]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005635\", \"supporting_discovery_ids\": [3]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [5]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"SPP1\", \"SCN5A\", \"NEDD4L\", \"CRYAB\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":5,"faith_pct":100.0}}