{"gene":"TBC1D25","run_date":"2026-06-10T10:51:54","timeline":{"discoveries":[{"year":2011,"finding":"OATL1 (TBC1D25) directly binds Atg8 homologues (LC3 family) via a direct protein-protein interaction, enabling its recruitment to isolation membranes and autophagosomes. Its TBC/RabGAP activity targets Rab33B (an Atg16L1-binding Rab GTPase), and both the GAP activity and the Atg8-binding activity are required for OATL1 to promote autophagosome–lysosome fusion (autophagosomal maturation).","method":"Co-immunoprecipitation, direct binding assays, GAP activity assays, dominant-negative and loss-of-function (siRNA knockdown) with autophagosome–lysosome fusion readout, and subcellular localization by fluorescence microscopy","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP, in vitro GAP activity assay, loss-of-function with defined cellular phenotype (fusion block), multiple orthogonal methods in a single focused study","pmids":["21383079"],"is_preprint":false},{"year":2016,"finding":"TBC1D25 escapes autophagic degradation despite being an LC3-binding protein because it lacks oligomerization ability, causing it to localize asymmetrically to the outer autophagosome membrane. Forced oligomerization of TBC1D25 redirects it to both inner and outer membranes and converts it into an autophagic substrate, demonstrating that oligomerization state governs whether an LC3-binding protein is degraded by autophagy.","method":"Chimeric protein analysis between TBC1D25 and SQSTM1/p62, forced oligomerization constructs, ultrastructural (electron microscopy) localization, autophagic degradation assays","journal":"Autophagy","confidence":"High","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal methods (chimeric mutagenesis, EM ultrastructure, degradation assays) in a single focused study","pmids":["26902585"],"is_preprint":false},{"year":2020,"finding":"TBC1D25 directly interacts with TAK1 (MAP3K7) through residues 138–226 in the C-terminal region of TBC1D25 and residues 1–300 in the C-terminal region of TAK1. TBC1D25 suppresses TAK1 auto-phosphorylation and downstream JNK/p38 activation; knockout of TBC1D25 increases TAK1, JNK, and p38 phosphorylation, exacerbating pathological cardiac hypertrophy and fibrosis.","method":"Co-immunoprecipitation and GST pull-down assays (domain mapping), TBC1D25-KO mouse model with TAC-induced cardiac remodeling, TBC1D25 overexpression in H9C2 cells and NRCMs with Angiotensin II treatment, western blot for phospho-TAK1/JNK/p38","journal":"International journal of biological sciences","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal Co-IP plus GST pull-down for interaction mapping, KO mouse and cell OE with defined signaling readouts, single lab","pmids":["32210723"],"is_preprint":false},{"year":2016,"finding":"RNAi-based high-content screening identified OATL1 (TBC1D25) as required for normal intracellular trafficking of polystyrene nanoparticles in HeLa cells, placing it alongside Rab33b and Myosin VI in the endocytic/trafficking pathway.","method":"siRNA knockdown, high-content fluorescence microscopy screening of 408 genes, quantitative trafficking assay with fluorescent nanoparticles","journal":"Scientific reports","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single siRNA knockdown in a large-scale screen; no follow-up mechanistic dissection of TBC1D25 specifically","pmids":["27374232"],"is_preprint":false},{"year":2020,"finding":"TBC1D25 localizes to the sealing zone (co-localizing with F-actin) and ruffled membrane in human osteoclasts, and siRNA-mediated inhibition of TBC1D25 significantly reduces bone resorption, formation of multinucleated cells, and nuclei per cell, indicating a role in osteoclast polarization and multinucleation.","method":"Immunofluorescence colocalization in human osteoclast cultures, siRNA knockdown with bone resorption pit assay and multinucleation quantification","journal":"European journal of cell biology","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — direct localization by immunofluorescence linked to functional consequence via siRNA KD, two orthogonal readouts (resorption and multinucleation), single lab","pmids":["33353759"],"is_preprint":false},{"year":2021,"finding":"A missense variant in TBC1D25 [p.(Glu50Ala)] segregating with X-linked oligozoospermia in a human family is predicted to disrupt interaction with ATG8 homologues, implicating TBC1D25's Atg8-binding function in spermatogenesis; however, the functional consequence of this specific variant was not directly tested in cell or animal models in this study.","method":"Exome sequencing, variant segregation analysis; functional consequence inferred from known Atg8-binding site but not experimentally validated in this paper","journal":"European journal of medical genetics","confidence":"Low","confidence_rationale":"Tier 4 / Weak — genetic association with no direct functional validation of the variant; mechanistic inference based on prior literature","pmids":["33460826"],"is_preprint":false}],"current_model":"TBC1D25/OATL1 is an autophagosome-resident RabGAP that binds LC3/Atg8 homologues via a direct interaction to localize to phagophores and autophagosomes, where it stimulates GTP hydrolysis on Rab33B to promote autophagosome–lysosome fusion; its lack of oligomerization restricts it to the outer autophagosomal membrane and prevents its autophagic degradation; beyond autophagy, TBC1D25 directly binds TAK1 to suppress TAK1-JNK/p38 signaling and pathological cardiac remodeling, and it localizes to the osteoclast sealing zone where it is required for bone resorption and multinucleation."},"narrative":{"mechanistic_narrative":"TBC1D25 (OATL1) is an autophagosome-resident TBC-domain RabGAP that couples autophagosomal membrane maturation to Rab GTPase regulation [PMID:21383079]. It is recruited to isolation membranes and autophagosomes through a direct interaction with Atg8/LC3 family proteins, and its GAP activity targets Rab33B; both the Atg8-binding and GAP activities are required for it to promote autophagosome–lysosome fusion [PMID:21383079]. Unlike degraded LC3-binding adaptors, TBC1D25 lacks oligomerization capacity, which restricts it to the outer autophagosomal membrane and exempts it from autophagic turnover; forced oligomerization redistributes it to inner and outer membranes and converts it into an autophagic substrate, establishing oligomerization state as the determinant of whether an LC3-binder is degraded [PMID:26902585]. Beyond autophagy, TBC1D25 directly binds TAK1 (MAP3K7) through its C-terminal region and suppresses TAK1 auto-phosphorylation and downstream JNK/p38 activation, restraining pathological cardiac hypertrophy and fibrosis [PMID:32210723]. It also localizes to the osteoclast sealing zone and ruffled membrane where it is required for bone resorption and multinucleation [PMID:33353759]. A TBC1D25 missense variant predicted to disrupt Atg8 binding segregates with X-linked oligozoospermia, linking its autophagy-related function to spermatogenesis [PMID:33460826].","teleology":[{"year":2011,"claim":"Established TBC1D25/OATL1 as the molecular link between the LC3 conjugation system and Rab-regulated autophagosome maturation, defining how a RabGAP is positioned on autophagic membranes to drive fusion.","evidence":"Co-IP, direct binding and in vitro GAP assays, siRNA loss-of-function with autophagosome–lysosome fusion readout, fluorescence localization","pmids":["21383079"],"confidence":"High","gaps":["Whether Rab33B is the sole physiological substrate during fusion is not resolved","Spatial coordination with Atg16L1 and the fusion machinery not mapped","Structural basis of LC3 binding not determined"]},{"year":2016,"claim":"Answered why an LC3-binding protein avoids being engulfed and degraded, showing that oligomerization state, not LC3-binding per se, dictates membrane-side localization and autophagic fate.","evidence":"TBC1D25/p62 chimeras, forced-oligomerization constructs, EM ultrastructural localization, autophagic degradation assays","pmids":["26902585"],"confidence":"High","gaps":["Endogenous regulators that might modulate TBC1D25 oligomerization unknown","Generality of the oligomerization rule to other LC3 adaptors not tested broadly"]},{"year":2016,"claim":"Placed TBC1D25 within an endocytic/intracellular trafficking pathway alongside Rab33b and Myosin VI, hinting at a role beyond classical autophagosome maturation.","evidence":"RNAi high-content screen of 408 genes with fluorescent nanoparticle trafficking quantification in HeLa cells","pmids":["27374232"],"confidence":"Low","gaps":["Single siRNA hit in a large screen with no TBC1D25-specific mechanistic follow-up","Direct involvement versus indirect effect on trafficking unresolved"]},{"year":2020,"claim":"Extended TBC1D25 function beyond autophagy by defining it as a direct negative regulator of TAK1-JNK/p38 signaling that protects against pathological cardiac remodeling.","evidence":"Reciprocal Co-IP and GST pull-down domain mapping, TBC1D25-KO mouse with TAC, overexpression in H9C2/NRCMs with Angiotensin II, phospho-TAK1/JNK/p38 western blot","pmids":["32210723"],"confidence":"Medium","gaps":["Whether GAP activity contributes to TAK1 regulation or this is a scaffold-only function unknown","Single-lab data without independent replication","Relationship between the autophagic and cardiac signaling roles not integrated"]},{"year":2020,"claim":"Implicated TBC1D25 in osteoclast biology by localizing it to the actin-rich sealing zone and showing it is required for resorption and multinucleation.","evidence":"Immunofluorescence colocalization with F-actin in human osteoclasts, siRNA knockdown with bone resorption pit and multinucleation assays","pmids":["33353759"],"confidence":"Medium","gaps":["Molecular mechanism connecting RabGAP/Atg8 activity to sealing-zone function not defined","Single-lab data; no genetic in vivo bone phenotype"]},{"year":2021,"claim":"Linked TBC1D25's Atg8-binding function to human disease by identifying a missense variant segregating with X-linked oligozoospermia.","evidence":"Exome sequencing and family segregation analysis; functional consequence inferred from the predicted Atg8-binding site","pmids":["33460826"],"confidence":"Low","gaps":["The specific variant was not functionally validated in cell or animal models","Causality versus association not established","Mechanistic role of TBC1D25 in spermatogenesis untested"]},{"year":null,"claim":"How TBC1D25's autophagic RabGAP role, its TAK1-suppressing scaffold role, and its osteoclast sealing-zone function are mechanistically unified within one protein remains unresolved.","evidence":"","pmids":[],"confidence":"Low","gaps":["No structural model integrating LC3-binding, GAP, and TAK1-binding regions","Whether GAP activity is required for non-autophagic functions unknown","In vivo physiological substrate spectrum of the GAP domain undefined"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[0,2]},{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[0]}],"localization":[{"term_id":"GO:0031410","term_label":"cytoplasmic vesicle","supporting_discovery_ids":[0,1]},{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[4]}],"pathway":[{"term_id":"R-HSA-9612973","term_label":"Autophagy","supporting_discovery_ids":[0,1]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[2]}],"complexes":[],"partners":["MAP3K7","RAB33B","MAP1LC3B"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q3MII6","full_name":"TBC1 domain family member 25","aliases":[],"length_aa":688,"mass_kda":76.3,"function":"Acts as a GTPase-activating protein specific for RAB33B. Involved in the regulation of autophagosome maturation, the process in which autophagosomes fuse with endosomes and lysosomes","subcellular_location":"Cytoplasm; Cytoplasmic vesicle, autophagosome","url":"https://www.uniprot.org/uniprotkb/Q3MII6/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/TBC1D25","classification":"Not Classified","n_dependent_lines":1,"n_total_lines":1208,"dependency_fraction":0.0008278145695364238},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/TBC1D25","total_profiled":1310},"omim":[{"mim_id":"311240","title":"TBC1 DOMAIN FAMILY, MEMBER 25; TBC1D25","url":"https://www.omim.org/entry/311240"},{"mim_id":"258150","title":"SPERMATOGENIC FAILURE 1; SPGF1","url":"https://www.omim.org/entry/258150"}],"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/TBC1D25"},"hgnc":{"alias_symbol":[],"prev_symbol":["OATL1"]},"alphafold":{"accession":"Q3MII6","domains":[{"cath_id":"3.10.20.90","chopping":"37-125","consensus_level":"high","plddt":85.4481,"start":37,"end":125}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q3MII6","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q3MII6-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q3MII6-F1-predicted_aligned_error_v6.png","plddt_mean":69.25},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=TBC1D25","jax_strain_url":"https://www.jax.org/strain/search?query=TBC1D25"},"sequence":{"accession":"Q3MII6","fasta_url":"https://rest.uniprot.org/uniprotkb/Q3MII6.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q3MII6/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q3MII6"}},"corpus_meta":[{"pmid":"21383079","id":"PMC_21383079","title":"OATL1, a novel autophagosome-resident Rab33B-GAP, regulates autophagosomal maturation.","date":"2011","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/21383079","citation_count":138,"is_preprint":false},{"pmid":"26902585","id":"PMC_26902585","title":"Differing susceptibility to autophagic degradation of two LC3-binding proteins: SQSTM1/p62 and TBC1D25/OATL1.","date":"2016","source":"Autophagy","url":"https://pubmed.ncbi.nlm.nih.gov/26902585","citation_count":26,"is_preprint":false},{"pmid":"8088786","id":"PMC_8088786","title":"Clustered organization of Krüppel zinc-finger genes at Xp11.23, flanking a translocation breakpoint at OATL1: a physical map with locus assignments for ZNF21, ZNF41, ZNF81, and ELK1.","date":"1994","source":"Genomics","url":"https://pubmed.ncbi.nlm.nih.gov/8088786","citation_count":24,"is_preprint":false},{"pmid":"8314581","id":"PMC_8314581","title":"The isolation of cDNAs from OATL1 at Xp 11.2 using a 480-kb YAC.","date":"1993","source":"Genomics","url":"https://pubmed.ncbi.nlm.nih.gov/8314581","citation_count":23,"is_preprint":false},{"pmid":"27374232","id":"PMC_27374232","title":"A systematic High-Content Screening microscopy approach reveals key roles for Rab33b, OATL1 and Myo6 in nanoparticle trafficking in HeLa cells.","date":"2016","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/27374232","citation_count":20,"is_preprint":false},{"pmid":"1346773","id":"PMC_1346773","title":"The Wiskott-Aldrich syndrome: refinement of the localization on Xp and identification of another closely linked marker locus, OATL1.","date":"1992","source":"Human genetics","url":"https://pubmed.ncbi.nlm.nih.gov/1346773","citation_count":19,"is_preprint":false},{"pmid":"8825641","id":"PMC_8825641","title":"Long-range organization of reiterated sequences, including the SSX1 cDNA at the OATL1 cluster in Xp11.23.","date":"1995","source":"Genomics","url":"https://pubmed.ncbi.nlm.nih.gov/8825641","citation_count":17,"is_preprint":false},{"pmid":"32210723","id":"PMC_32210723","title":"TBC1D25 Regulates Cardiac Remodeling Through TAK1 Signaling Pathway.","date":"2020","source":"International journal of biological sciences","url":"https://pubmed.ncbi.nlm.nih.gov/32210723","citation_count":11,"is_preprint":false},{"pmid":"33460826","id":"PMC_33460826","title":"First evidence of involvement of TBC1D25 in causing human male infertility.","date":"2021","source":"European journal of medical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/33460826","citation_count":10,"is_preprint":false},{"pmid":"7519051","id":"PMC_7519051","title":"A synovial sarcoma with a complex t(X;18;5;4) and a break in the ornithine aminotransferase (OAT)L1 cluster on Xp11.2.","date":"1994","source":"Genes, chromosomes & cancer","url":"https://pubmed.ncbi.nlm.nih.gov/7519051","citation_count":10,"is_preprint":false},{"pmid":"8666400","id":"PMC_8666400","title":"Construction of two YAC contigs in human Xp11.23-p11.22, one encompassing the loci OATL1, GATA, TFE3, and SYP, the other linking DXS255 to DXS146.","date":"1995","source":"Genomics","url":"https://pubmed.ncbi.nlm.nih.gov/8666400","citation_count":7,"is_preprint":false},{"pmid":"33353759","id":"PMC_33353759","title":"RabGAP TBC1D25 is involved in human osteoclast activity.","date":"2020","source":"European journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/33353759","citation_count":6,"is_preprint":false},{"pmid":"7927346","id":"PMC_7927346","title":"Refined mapping of the human Ets-related gene Elk-1 to Xp11.2-p11.4, distal to the OATL1 region.","date":"1994","source":"Human genetics","url":"https://pubmed.ncbi.nlm.nih.gov/7927346","citation_count":5,"is_preprint":false},{"pmid":"36710714","id":"PMC_36710714","title":"TBC1D25 alleviates nonalcoholic steatohepatitis by inhibiting abnormal lipid accumulation and inflammation.","date":"2023","source":"Journal of cellular physiology","url":"https://pubmed.ncbi.nlm.nih.gov/36710714","citation_count":2,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.10.31.25337980","title":"Bi-allelic variants in  <i>TBC1D8</i>  result in non-obstructive azoospermia in both humans and mice","date":"2025-11-06","source":"bioRxiv","url":"https://doi.org/10.1101/2025.10.31.25337980","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":8523,"output_tokens":1828,"usd":0.026495,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":8607,"output_tokens":2587,"usd":0.053855,"stage2_stop_reason":"end_turn"},"total_usd":0.08035,"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\": 2011,\n      \"finding\": \"OATL1 (TBC1D25) directly binds Atg8 homologues (LC3 family) via a direct protein-protein interaction, enabling its recruitment to isolation membranes and autophagosomes. Its TBC/RabGAP activity targets Rab33B (an Atg16L1-binding Rab GTPase), and both the GAP activity and the Atg8-binding activity are required for OATL1 to promote autophagosome–lysosome fusion (autophagosomal maturation).\",\n      \"method\": \"Co-immunoprecipitation, direct binding assays, GAP activity assays, dominant-negative and loss-of-function (siRNA knockdown) with autophagosome–lysosome fusion readout, and subcellular localization by fluorescence microscopy\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP, in vitro GAP activity assay, loss-of-function with defined cellular phenotype (fusion block), multiple orthogonal methods in a single focused study\",\n      \"pmids\": [\"21383079\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"TBC1D25 escapes autophagic degradation despite being an LC3-binding protein because it lacks oligomerization ability, causing it to localize asymmetrically to the outer autophagosome membrane. Forced oligomerization of TBC1D25 redirects it to both inner and outer membranes and converts it into an autophagic substrate, demonstrating that oligomerization state governs whether an LC3-binding protein is degraded by autophagy.\",\n      \"method\": \"Chimeric protein analysis between TBC1D25 and SQSTM1/p62, forced oligomerization constructs, ultrastructural (electron microscopy) localization, autophagic degradation assays\",\n      \"journal\": \"Autophagy\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal methods (chimeric mutagenesis, EM ultrastructure, degradation assays) in a single focused study\",\n      \"pmids\": [\"26902585\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"TBC1D25 directly interacts with TAK1 (MAP3K7) through residues 138–226 in the C-terminal region of TBC1D25 and residues 1–300 in the C-terminal region of TAK1. TBC1D25 suppresses TAK1 auto-phosphorylation and downstream JNK/p38 activation; knockout of TBC1D25 increases TAK1, JNK, and p38 phosphorylation, exacerbating pathological cardiac hypertrophy and fibrosis.\",\n      \"method\": \"Co-immunoprecipitation and GST pull-down assays (domain mapping), TBC1D25-KO mouse model with TAC-induced cardiac remodeling, TBC1D25 overexpression in H9C2 cells and NRCMs with Angiotensin II treatment, western blot for phospho-TAK1/JNK/p38\",\n      \"journal\": \"International journal of biological sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal Co-IP plus GST pull-down for interaction mapping, KO mouse and cell OE with defined signaling readouts, single lab\",\n      \"pmids\": [\"32210723\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"RNAi-based high-content screening identified OATL1 (TBC1D25) as required for normal intracellular trafficking of polystyrene nanoparticles in HeLa cells, placing it alongside Rab33b and Myosin VI in the endocytic/trafficking pathway.\",\n      \"method\": \"siRNA knockdown, high-content fluorescence microscopy screening of 408 genes, quantitative trafficking assay with fluorescent nanoparticles\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single siRNA knockdown in a large-scale screen; no follow-up mechanistic dissection of TBC1D25 specifically\",\n      \"pmids\": [\"27374232\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"TBC1D25 localizes to the sealing zone (co-localizing with F-actin) and ruffled membrane in human osteoclasts, and siRNA-mediated inhibition of TBC1D25 significantly reduces bone resorption, formation of multinucleated cells, and nuclei per cell, indicating a role in osteoclast polarization and multinucleation.\",\n      \"method\": \"Immunofluorescence colocalization in human osteoclast cultures, siRNA knockdown with bone resorption pit assay and multinucleation quantification\",\n      \"journal\": \"European journal of cell biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — direct localization by immunofluorescence linked to functional consequence via siRNA KD, two orthogonal readouts (resorption and multinucleation), single lab\",\n      \"pmids\": [\"33353759\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"A missense variant in TBC1D25 [p.(Glu50Ala)] segregating with X-linked oligozoospermia in a human family is predicted to disrupt interaction with ATG8 homologues, implicating TBC1D25's Atg8-binding function in spermatogenesis; however, the functional consequence of this specific variant was not directly tested in cell or animal models in this study.\",\n      \"method\": \"Exome sequencing, variant segregation analysis; functional consequence inferred from known Atg8-binding site but not experimentally validated in this paper\",\n      \"journal\": \"European journal of medical genetics\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 4 / Weak — genetic association with no direct functional validation of the variant; mechanistic inference based on prior literature\",\n      \"pmids\": [\"33460826\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"TBC1D25/OATL1 is an autophagosome-resident RabGAP that binds LC3/Atg8 homologues via a direct interaction to localize to phagophores and autophagosomes, where it stimulates GTP hydrolysis on Rab33B to promote autophagosome–lysosome fusion; its lack of oligomerization restricts it to the outer autophagosomal membrane and prevents its autophagic degradation; beyond autophagy, TBC1D25 directly binds TAK1 to suppress TAK1-JNK/p38 signaling and pathological cardiac remodeling, and it localizes to the osteoclast sealing zone where it is required for bone resorption and multinucleation.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"TBC1D25 (OATL1) is an autophagosome-resident TBC-domain RabGAP that couples autophagosomal membrane maturation to Rab GTPase regulation [#0]. It is recruited to isolation membranes and autophagosomes through a direct interaction with Atg8/LC3 family proteins, and its GAP activity targets Rab33B; both the Atg8-binding and GAP activities are required for it to promote autophagosome\\u2013lysosome fusion [#0]. Unlike degraded LC3-binding adaptors, TBC1D25 lacks oligomerization capacity, which restricts it to the outer autophagosomal membrane and exempts it from autophagic turnover; forced oligomerization redistributes it to inner and outer membranes and converts it into an autophagic substrate, establishing oligomerization state as the determinant of whether an LC3-binder is degraded [#1]. Beyond autophagy, TBC1D25 directly binds TAK1 (MAP3K7) through its C-terminal region and suppresses TAK1 auto-phosphorylation and downstream JNK/p38 activation, restraining pathological cardiac hypertrophy and fibrosis [#2]. It also localizes to the osteoclast sealing zone and ruffled membrane where it is required for bone resorption and multinucleation [#4]. A TBC1D25 missense variant predicted to disrupt Atg8 binding segregates with X-linked oligozoospermia, linking its autophagy-related function to spermatogenesis [#5].\",\n  \"teleology\": [\n    {\n      \"year\": 2011,\n      \"claim\": \"Established TBC1D25/OATL1 as the molecular link between the LC3 conjugation system and Rab-regulated autophagosome maturation, defining how a RabGAP is positioned on autophagic membranes to drive fusion.\",\n      \"evidence\": \"Co-IP, direct binding and in vitro GAP assays, siRNA loss-of-function with autophagosome\\u2013lysosome fusion readout, fluorescence localization\",\n      \"pmids\": [\"21383079\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Whether Rab33B is the sole physiological substrate during fusion is not resolved\",\n        \"Spatial coordination with Atg16L1 and the fusion machinery not mapped\",\n        \"Structural basis of LC3 binding not determined\"\n      ]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Answered why an LC3-binding protein avoids being engulfed and degraded, showing that oligomerization state, not LC3-binding per se, dictates membrane-side localization and autophagic fate.\",\n      \"evidence\": \"TBC1D25/p62 chimeras, forced-oligomerization constructs, EM ultrastructural localization, autophagic degradation assays\",\n      \"pmids\": [\"26902585\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Endogenous regulators that might modulate TBC1D25 oligomerization unknown\",\n        \"Generality of the oligomerization rule to other LC3 adaptors not tested broadly\"\n      ]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Placed TBC1D25 within an endocytic/intracellular trafficking pathway alongside Rab33b and Myosin VI, hinting at a role beyond classical autophagosome maturation.\",\n      \"evidence\": \"RNAi high-content screen of 408 genes with fluorescent nanoparticle trafficking quantification in HeLa cells\",\n      \"pmids\": [\"27374232\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"Single siRNA hit in a large screen with no TBC1D25-specific mechanistic follow-up\",\n        \"Direct involvement versus indirect effect on trafficking unresolved\"\n      ]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Extended TBC1D25 function beyond autophagy by defining it as a direct negative regulator of TAK1-JNK/p38 signaling that protects against pathological cardiac remodeling.\",\n      \"evidence\": \"Reciprocal Co-IP and GST pull-down domain mapping, TBC1D25-KO mouse with TAC, overexpression in H9C2/NRCMs with Angiotensin II, phospho-TAK1/JNK/p38 western blot\",\n      \"pmids\": [\"32210723\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Whether GAP activity contributes to TAK1 regulation or this is a scaffold-only function unknown\",\n        \"Single-lab data without independent replication\",\n        \"Relationship between the autophagic and cardiac signaling roles not integrated\"\n      ]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Implicated TBC1D25 in osteoclast biology by localizing it to the actin-rich sealing zone and showing it is required for resorption and multinucleation.\",\n      \"evidence\": \"Immunofluorescence colocalization with F-actin in human osteoclasts, siRNA knockdown with bone resorption pit and multinucleation assays\",\n      \"pmids\": [\"33353759\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Molecular mechanism connecting RabGAP/Atg8 activity to sealing-zone function not defined\",\n        \"Single-lab data; no genetic in vivo bone phenotype\"\n      ]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Linked TBC1D25's Atg8-binding function to human disease by identifying a missense variant segregating with X-linked oligozoospermia.\",\n      \"evidence\": \"Exome sequencing and family segregation analysis; functional consequence inferred from the predicted Atg8-binding site\",\n      \"pmids\": [\"33460826\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"The specific variant was not functionally validated in cell or animal models\",\n        \"Causality versus association not established\",\n        \"Mechanistic role of TBC1D25 in spermatogenesis untested\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How TBC1D25's autophagic RabGAP role, its TAK1-suppressing scaffold role, and its osteoclast sealing-zone function are mechanistically unified within one protein remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"No structural model integrating LC3-binding, GAP, and TAK1-binding regions\",\n        \"Whether GAP activity is required for non-autophagic functions unknown\",\n        \"In vivo physiological substrate spectrum of the GAP domain undefined\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [0, 2]},\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0031410\", \"supporting_discovery_ids\": [0, 1]},\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [4]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-9612973\", \"supporting_discovery_ids\": [0, 1]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [2]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"MAP3K7\", \"RAB33B\", \"MAP1LC3B\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":6,"faith_pct":100.0}}