{"gene":"BICD1","run_date":"2026-06-09T22:02:44","timeline":{"discoveries":[{"year":1997,"finding":"BICD1 encodes a coiled-coil protein with amphipathic helices and a leucine zipper motif, structurally homologous to Drosophila Bicaudal-D, and is expressed in brain, heart, and skeletal muscle, suggesting it is a component of a cytoskeleton-based mRNA sorting mechanism.","method":"cDNA cloning, predicted amino acid sequence analysis, Northern blot analysis","journal":"Genomics","confidence":"Low","confidence_rationale":"Tier 3 / Weak — structural inference from sequence analysis and expression data only; no direct functional assay performed","pmids":["9367685"],"is_preprint":false},{"year":2008,"finding":"A regulatory SNP (rs2630578) in intron 1 of BICD1 is associated with reduced BICD1 mRNA levels (44% lower in C allele carriers) and shorter telomere length in leukocytes, implicating BICD1 in telomere length homeostasis.","method":"Genome-wide linkage analysis, fine-mapping, quantitative mRNA expression analysis in leukocytes","journal":"Human molecular genetics","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — linkage and association replicated in extended sample with eQTL evidence, but mechanism is inferential (no direct functional assay on BICD1 protein and telomeres)","pmids":["18487243"],"is_preprint":false},{"year":2011,"finding":"C. elegans bicd-1 (BICD1 ortholog) regulates dendrite branch formation in PVD sensory neurons and operates in a conserved pathway with dynein component dhc-1 and kinesin-1 component unc-116, and interacts genetically with the repulsive guidance receptor unc-5.","method":"RNAi knockdown, genetic epistasis analysis, cell-specific expression studies","journal":"Development (Cambridge, England)","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic epistasis with multiple motor complex components established in a defined cellular context; single lab but multiple genetic interactions tested","pmids":["21205795"],"is_preprint":false},{"year":2014,"finding":"The C-terminal coiled-coil region (CC3) of mouse BICD1 was crystallized and diffraction data collected to 1.50 Å resolution; CC3 links cargo proteins such as Rab6 and RanBP2 to the dynein motor complex, and a complex of CC3 with constitutively active Rab6 was prepared for structural analysis.","method":"X-ray crystallography, complex preparation with constitutively active Rab6 mutant","journal":"Acta crystallographica. Section F, Structural biology communications","confidence":"Medium","confidence_rationale":"Tier 1 / Weak — crystal structure obtained and Rab6 complex prepared, but functional validation of the interaction is not described in this crystallographic report; single study","pmids":["25084392"],"is_preprint":false},{"year":2018,"finding":"BICD1 acts as a dynein motor adaptor that mediates HIF1α nuclear translocation in mesenchymal stem cells under hypoxia; hypoxia stimulates direct binding of HIF1α to BICD1 and to dynein intermediate chain (Dynein IC), and this interaction is abolished by BICD1 silencing. Akt activation and GSK3β silencing enhance HIF1α-BICD1 binding and nuclear translocation. BICD1 silencing abolished hypoxia-induced glycolytic reprogramming and increased mitochondrial ROS and apoptosis.","method":"Co-immunoprecipitation (direct binding), siRNA knockdown, overexpression, Akt inhibition/activation, GSK3β silencing, functional readouts (glycolysis, ROS, apoptosis, in vivo wound healing)","journal":"Cell death and differentiation","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal co-IP showing direct binding, multiple orthogonal methods (knockdown, overexpression, pharmacological modulation), functional consequences confirmed in vitro and in vivo","pmids":["30464225"],"is_preprint":false},{"year":2020,"finding":"PTPN23, a member of the ESCRT machinery, was identified as a BICD1 interactor; molecular mapping showed PTPN23 binds the N-terminus of BICD1 (the same region essential for dynein recruitment), but is not a canonical BICD1 cargo. Loss of PTPN23 phenocopies BICD1 knockdown, causing accumulation of BDNF-activated p75NTR and TrkB in swollen vacuole-like compartments, establishing BICD1 as a key factor for lysosomal degradation of activated neurotrophin receptors.","method":"Proteomics/mass spectrometry (BICD1 interactome), molecular domain mapping, BICD1 and PTPN23 knockdown with endosomal trafficking readouts (fluorescence microscopy of receptor accumulation)","journal":"Journal of cell science","confidence":"High","confidence_rationale":"Tier 2 / Moderate — interactome proteomics plus domain mapping plus loss-of-function phenotype with defined subcellular readout; single lab with multiple orthogonal methods","pmids":["32079660"],"is_preprint":false},{"year":2023,"finding":"Biallelic loss-of-function frameshift variants in BICD1 (c.1683dup) cause complete absence of BICD1 protein (detected by western blot of patient fibroblasts) and are associated with peripheral neuropathy and hearing loss in a human family.","method":"Exome sequencing, segregation analysis, western blotting of patient-derived fibroblasts, RNA analysis","journal":"International journal of molecular sciences","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — protein loss confirmed by western blot in patient cells with genetic segregation, but single family; authors note definitive evidence requires replication","pmids":["37240244"],"is_preprint":false},{"year":2024,"finding":"KDM4E activates BICD1 expression by reducing H3K9me3 deposition at the BICD1 promoter; BICD1 physically interacts with PAR1 and promotes PAR1 endocytosis, blocking PAR1 signaling in triple-negative breast cancer cells.","method":"KDM4E knockdown/overexpression, ChIP (H3K9me3 at BICD1 promoter), Co-immunoprecipitation (BICD1-PAR1 interaction), functional assays (cell viability, migration, apoptosis)","journal":"Molecular carcinogenesis","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — co-IP plus epigenetic mechanism plus functional rescue, single lab with multiple orthogonal methods","pmids":["38607237"],"is_preprint":false},{"year":2026,"finding":"YAP directly binds the BICD1 promoter and enhances its transcriptional activity. BICD1 interacts with HIF-1α via its C-terminal CC3 domain, promoting HIF-1α nuclear translocation and transcriptional activity. AKT activation or GSK3β knockdown enhances the BICD1-HIF-1α interaction.","method":"ChIP (YAP binding to BICD1 promoter), Co-immunoprecipitation (BICD1 CC3 domain with HIF-1α), BICD1 knockdown/overexpression, domain deletion mapping, in vivo xenograft model","journal":"Pathology, research and practice","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ChIP plus domain-mapped co-IP plus in vivo model, single lab, multiple orthogonal methods","pmids":["42156301"],"is_preprint":false}],"current_model":"BICD1 is a dynein motor adaptor with a coiled-coil architecture whose C-terminal CC3 domain links cargo proteins (including Rab6, RanBP2, and HIF-1α) to the dynein complex; it mediates HIF-1α nuclear translocation (facilitated by AKT/GSK3β signaling) in stem cells under hypoxia, directs lysosomal degradation of activated neurotrophin receptors (TrkB, p75NTR) in motor neurons via interaction with the ESCRT component PTPN23 at its N-terminus, promotes PAR1 endocytosis through direct physical interaction with PAR1, and in C. elegans acts in a pathway with dynein and kinesin-1 to regulate dendritic branching; biallelic loss-of-function in humans causes peripheral neuropathy and hearing loss."},"narrative":{"mechanistic_narrative":"BICD1 is a coiled-coil dynein motor adaptor that links specific cargoes to the dynein complex and thereby controls their intracellular trafficking and the downstream signaling and degradative outcomes that depend on it [PMID:25084392, PMID:30464225]. Its C-terminal CC3 region engages cargo proteins including Rab6, RanBP2, and HIF-1α, while its N-terminus mediates dynein recruitment and also binds the ESCRT component PTPN23 [PMID:25084392, PMID:32079660, PMID:42156301]. Through this adaptor activity BICD1 drives lysosomal degradation of BDNF-activated neurotrophin receptors p75NTR and TrkB, with loss of either BICD1 or PTPN23 causing receptor accumulation in swollen vacuole-like compartments [PMID:32079660]. In a distinct trafficking role, BICD1 binds PAR1 and promotes its endocytosis [PMID:38607237]. Under hypoxia, BICD1 binds HIF-1α and dynein intermediate chain to mediate HIF-1α nuclear translocation and hypoxia-induced glycolytic reprogramming, an interaction enhanced by AKT activation and GSK3β loss; BICD1 itself is transcriptionally controlled, being induced by YAP and by KDM4E-mediated reduction of H3K9me3 at its promoter [PMID:30464225, PMID:38607237, PMID:42156301]. Biallelic loss-of-function frameshift variants in BICD1 that abolish the protein cause peripheral neuropathy and hearing loss [PMID:37240244]. A conserved role in motor-dependent neuronal morphogenesis is supported by the C. elegans ortholog, which regulates dendrite branching in a pathway with dynein and kinesin-1 [PMID:21205795].","teleology":[{"year":1997,"claim":"Establishing BICD1's molecular identity, cloning revealed a coiled-coil protein homologous to Drosophila Bicaudal-D, framing the initial hypothesis that it participates in cytoskeleton-based intracellular sorting.","evidence":"cDNA cloning, sequence analysis, and Northern blot in brain, heart, and skeletal muscle","pmids":["9367685"],"confidence":"Low","gaps":["No direct functional assay; sorting role inferred from sequence homology only","No cargo or motor partner identified"]},{"year":2008,"claim":"A regulatory SNP linking reduced BICD1 expression to shorter telomeres implicated BICD1 in telomere length homeostasis, though by association rather than mechanism.","evidence":"Genome-wide linkage, fine-mapping, and leukocyte eQTL analysis","pmids":["18487243"],"confidence":"Medium","gaps":["No direct functional link between BICD1 protein and telomere maintenance demonstrated","Mechanism connecting an adaptor protein to telomere length unexplained"]},{"year":2011,"claim":"Genetic epistasis in C. elegans placed the BICD1 ortholog in a conserved motor pathway, establishing a role in neuronal dendrite morphogenesis alongside dynein and kinesin-1.","evidence":"RNAi, genetic epistasis with dhc-1, unc-116, and unc-5, and cell-specific expression in PVD neurons","pmids":["21205795"],"confidence":"Medium","gaps":["Direct physical interaction with motor components not biochemically shown","Relevance to mammalian BICD1 function inferred from orthology"]},{"year":2014,"claim":"Crystallization of the CC3 domain and preparation of a CC3-active Rab6 complex defined the structural cargo-binding module that links Rab6 and RanBP2 to dynein.","evidence":"X-ray crystallography to 1.50 Å and complex preparation with constitutively active Rab6","pmids":["25084392"],"confidence":"Medium","gaps":["Functional validation of the CC3-Rab6 interaction not described in the report","No full structure of the adaptor-motor-cargo assembly"]},{"year":2018,"claim":"Identifying BICD1 as the adaptor that couples HIF-1α to dynein for nuclear translocation revealed a signaling function beyond canonical cargo transport, controlling hypoxic metabolic reprogramming.","evidence":"Reciprocal co-IP, siRNA, overexpression, AKT/GSK3β modulation, and functional readouts (glycolysis, ROS, apoptosis, in vivo wound healing) in mesenchymal stem cells","pmids":["30464225"],"confidence":"High","gaps":["Structural basis of the HIF-1α-BICD1 interaction not resolved in this study","How AKT/GSK3β signaling biochemically enhances binding unclear"]},{"year":2020,"claim":"Discovery of the BICD1-PTPN23 interaction connected the adaptor to the ESCRT machinery, establishing BICD1 as a determinant of lysosomal degradation of activated neurotrophin receptors.","evidence":"Interactome proteomics, domain mapping, and BICD1/PTPN23 knockdown with receptor-trafficking microscopy (p75NTR, TrkB)","pmids":["32079660"],"confidence":"High","gaps":["PTPN23 binds the N-terminus and is not a canonical cargo; the mechanistic interplay with dynein recruitment at the same region unresolved","Single lab; reciprocal validation of the receptor-degradation pathway limited"]},{"year":2023,"claim":"Biallelic loss-of-function variants abolishing BICD1 protein tied the gene to a human Mendelian phenotype of peripheral neuropathy and hearing loss.","evidence":"Exome sequencing, segregation, and western blot of patient fibroblasts confirming protein absence","pmids":["37240244"],"confidence":"Medium","gaps":["Single family; replication needed for definitive causality","Mechanism linking BICD1 loss to specific neuropathy and auditory phenotypes not established"]},{"year":2024,"claim":"Identification of BICD1 as a PAR1 interactor that drives PAR1 endocytosis, and as a target of KDM4E-mediated H3K9me3 demethylation, extended its adaptor role to receptor signaling control in cancer cells.","evidence":"KDM4E manipulation, ChIP for H3K9me3 at the BICD1 promoter, co-IP of BICD1-PAR1, and functional assays in triple-negative breast cancer cells","pmids":["38607237"],"confidence":"Medium","gaps":["Whether dynein is required for BICD1-mediated PAR1 endocytosis not tested","Single lab; direct vs. indirect nature of BICD1-PAR1 binding not fully delineated"]},{"year":2026,"claim":"Mapping HIF-1α binding to the CC3 domain and identifying YAP as a transcriptional activator of BICD1 integrated the adaptor's signaling role with upstream control of its own expression.","evidence":"ChIP for YAP at the BICD1 promoter, domain-mapped co-IP of CC3 with HIF-1α, knockdown/overexpression, and xenograft model","pmids":["42156301"],"confidence":"Medium","gaps":["Structural detail of the CC3-HIF-1α interface not resolved","Single lab; in vivo relevance beyond the xenograft system unexplored"]},{"year":null,"claim":"How BICD1 selects among its diverse cargoes (Rab6, RanBP2, HIF-1α, PAR1) and coordinates dynein recruitment with ESCRT-dependent degradation versus nuclear delivery remains unresolved.","evidence":"","pmids":[],"confidence":"Low","gaps":["No unified structural model of cargo-specific BICD1-dynein assemblies","Mechanism reconciling N-terminal PTPN23 binding with N-terminal dynein recruitment unknown","Tissue-specific basis of the human neuropathy/hearing-loss phenotype uncharacterized"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[3,4,5]},{"term_id":"GO:0008092","term_label":"cytoskeletal protein binding","supporting_discovery_ids":[3,4]}],"localization":[{"term_id":"GO:0005768","term_label":"endosome","supporting_discovery_ids":[5]},{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[4]}],"pathway":[{"term_id":"R-HSA-5653656","term_label":"Vesicle-mediated transport","supporting_discovery_ids":[5,7]},{"term_id":"R-HSA-9609507","term_label":"Protein localization","supporting_discovery_ids":[4]},{"term_id":"R-HSA-8953897","term_label":"Cellular responses to stimuli","supporting_discovery_ids":[4]}],"complexes":[],"partners":["DYNC1I (DYNEIN INTERMEDIATE CHAIN)","RAB6","RANBP2","HIF1A","PTPN23","PAR1 (F2R)"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q96G01","full_name":"Protein bicaudal D homolog 1","aliases":[],"length_aa":975,"mass_kda":110.8,"function":"Regulates coat complex coatomer protein I (COPI)-independent Golgi-endoplasmic reticulum transport by recruiting the dynein-dynactin motor complex","subcellular_location":"Golgi apparatus","url":"https://www.uniprot.org/uniprotkb/Q96G01/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/BICD1","classification":"Not Classified","n_dependent_lines":12,"n_total_lines":1208,"dependency_fraction":0.009933774834437087},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/BICD1","total_profiled":1310},"omim":[{"mim_id":"617003","title":"BICD FAMILY-LIKE CARGO ADAPTOR 2; BICDL2","url":"https://www.omim.org/entry/617003"},{"mim_id":"615852","title":"RAS-ASSOCIATED PROTEIN RAB6B; RAB6B","url":"https://www.omim.org/entry/615852"},{"mim_id":"609797","title":"BICD CARGO ADAPTOR 2; BICD2","url":"https://www.omim.org/entry/609797"},{"mim_id":"609113","title":"TELOMERE LENGTH, MEAN LEUKOCYTE; LTL","url":"https://www.omim.org/entry/609113"},{"mim_id":"602204","title":"BICD CARGO ADAPTOR 1; BICD1","url":"https://www.omim.org/entry/602204"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Uncertain","locations":[{"location":"Vesicles","reliability":"Uncertain"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/BICD1"},"hgnc":{"alias_symbol":[],"prev_symbol":[]},"alphafold":{"accession":"Q96G01","domains":[],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q96G01","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q96G01-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q96G01-F1-predicted_aligned_error_v6.png","plddt_mean":71.31},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=BICD1","jax_strain_url":"https://www.jax.org/strain/search?query=BICD1"},"sequence":{"accession":"Q96G01","fasta_url":"https://rest.uniprot.org/uniprotkb/Q96G01.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q96G01/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q96G01"}},"corpus_meta":[{"pmid":"20709820","id":"PMC_20709820","title":"Genome-wide association study identifies BICD1 as a susceptibility gene for emphysema.","date":"2010","source":"American journal of respiratory and critical care medicine","url":"https://pubmed.ncbi.nlm.nih.gov/20709820","citation_count":96,"is_preprint":false},{"pmid":"18487243","id":"PMC_18487243","title":"A regulatory SNP of the BICD1 gene contributes to telomere length variation in humans.","date":"2008","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/18487243","citation_count":52,"is_preprint":false},{"pmid":"21205795","id":"PMC_21205795","title":"C. elegans bicd-1, homolog of the Drosophila dynein accessory factor Bicaudal D, regulates the branching of PVD sensory neuron dendrites.","date":"2011","source":"Development (Cambridge, England)","url":"https://pubmed.ncbi.nlm.nih.gov/21205795","citation_count":51,"is_preprint":false},{"pmid":"9367685","id":"PMC_9367685","title":"A human homologue (BICD1) of the Drosophila bicaudal-D gene.","date":"1997","source":"Genomics","url":"https://pubmed.ncbi.nlm.nih.gov/9367685","citation_count":31,"is_preprint":false},{"pmid":"30464225","id":"PMC_30464225","title":"BICD1 mediates HIF1α nuclear translocation in mesenchymal stem cells during hypoxia adaptation.","date":"2018","source":"Cell death and differentiation","url":"https://pubmed.ncbi.nlm.nih.gov/30464225","citation_count":30,"is_preprint":false},{"pmid":"32079660","id":"PMC_32079660","title":"PTPN23 binds the dynein adaptor BICD1 and is required for endocytic sorting of neurotrophin receptors.","date":"2020","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/32079660","citation_count":12,"is_preprint":false},{"pmid":"25792135","id":"PMC_25792135","title":"hTERT, BICD1 and chromosome 18 polymorphisms associated with telomere length affect kidney allograft function after transplantation.","date":"2015","source":"Kidney & blood pressure research","url":"https://pubmed.ncbi.nlm.nih.gov/25792135","citation_count":9,"is_preprint":false},{"pmid":"38607237","id":"PMC_38607237","title":"Baicalein promotes KDM4E to induce BICD1 and inhibit triple-negative breast cancer progression by blocking PAR1 signaling.","date":"2024","source":"Molecular carcinogenesis","url":"https://pubmed.ncbi.nlm.nih.gov/38607237","citation_count":7,"is_preprint":false},{"pmid":"31846791","id":"PMC_31846791","title":"A genome-wide by PM10 interaction study identifies novel loci for lung function near BICD1 and IL1RN-IL1F10 genes in Korean adults.","date":"2019","source":"Chemosphere","url":"https://pubmed.ncbi.nlm.nih.gov/31846791","citation_count":5,"is_preprint":false},{"pmid":"25084392","id":"PMC_25084392","title":"Crystallographic characterization of the C-terminal coiled-coil region of mouse Bicaudal-D1 (BICD1).","date":"2014","source":"Acta crystallographica. Section F, Structural biology communications","url":"https://pubmed.ncbi.nlm.nih.gov/25084392","citation_count":4,"is_preprint":false},{"pmid":"27496426","id":"PMC_27496426","title":"BICD1 and Chromosome 18 Polymorphisms Associated With Recipients' Telomere Length Affect Kidney Allograft Function After Transplantation.","date":"2016","source":"Transplantation proceedings","url":"https://pubmed.ncbi.nlm.nih.gov/27496426","citation_count":3,"is_preprint":false},{"pmid":"37240244","id":"PMC_37240244","title":"Biallelic Loss-of-Function Variants in BICD1 Are Associated with Peripheral Neuropathy and Hearing Loss.","date":"2023","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/37240244","citation_count":0,"is_preprint":false},{"pmid":"42156301","id":"PMC_42156301","title":"YAP-induced BICD1 promotes hepatocellular carcinoma cell proliferation, stemness, and migration by facilitating the nuclear translocation of HIF-1α.","date":"2026","source":"Pathology, research and practice","url":"https://pubmed.ncbi.nlm.nih.gov/42156301","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":9017,"output_tokens":2431,"usd":0.031758,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":9602,"output_tokens":3441,"usd":0.067017,"stage2_stop_reason":"end_turn"},"total_usd":0.098775,"stage1_batch_id":"msgbatch_0179Z2pxRYBsXi2xADneafRw","stage2_batch_id":"msgbatch_01LaY9ZaVdgjWArcZo9eqQE5","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1997,\n      \"finding\": \"BICD1 encodes a coiled-coil protein with amphipathic helices and a leucine zipper motif, structurally homologous to Drosophila Bicaudal-D, and is expressed in brain, heart, and skeletal muscle, suggesting it is a component of a cytoskeleton-based mRNA sorting mechanism.\",\n      \"method\": \"cDNA cloning, predicted amino acid sequence analysis, Northern blot analysis\",\n      \"journal\": \"Genomics\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — structural inference from sequence analysis and expression data only; no direct functional assay performed\",\n      \"pmids\": [\"9367685\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"A regulatory SNP (rs2630578) in intron 1 of BICD1 is associated with reduced BICD1 mRNA levels (44% lower in C allele carriers) and shorter telomere length in leukocytes, implicating BICD1 in telomere length homeostasis.\",\n      \"method\": \"Genome-wide linkage analysis, fine-mapping, quantitative mRNA expression analysis in leukocytes\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — linkage and association replicated in extended sample with eQTL evidence, but mechanism is inferential (no direct functional assay on BICD1 protein and telomeres)\",\n      \"pmids\": [\"18487243\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"C. elegans bicd-1 (BICD1 ortholog) regulates dendrite branch formation in PVD sensory neurons and operates in a conserved pathway with dynein component dhc-1 and kinesin-1 component unc-116, and interacts genetically with the repulsive guidance receptor unc-5.\",\n      \"method\": \"RNAi knockdown, genetic epistasis analysis, cell-specific expression studies\",\n      \"journal\": \"Development (Cambridge, England)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic epistasis with multiple motor complex components established in a defined cellular context; single lab but multiple genetic interactions tested\",\n      \"pmids\": [\"21205795\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"The C-terminal coiled-coil region (CC3) of mouse BICD1 was crystallized and diffraction data collected to 1.50 Å resolution; CC3 links cargo proteins such as Rab6 and RanBP2 to the dynein motor complex, and a complex of CC3 with constitutively active Rab6 was prepared for structural analysis.\",\n      \"method\": \"X-ray crystallography, complex preparation with constitutively active Rab6 mutant\",\n      \"journal\": \"Acta crystallographica. Section F, Structural biology communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Weak — crystal structure obtained and Rab6 complex prepared, but functional validation of the interaction is not described in this crystallographic report; single study\",\n      \"pmids\": [\"25084392\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"BICD1 acts as a dynein motor adaptor that mediates HIF1α nuclear translocation in mesenchymal stem cells under hypoxia; hypoxia stimulates direct binding of HIF1α to BICD1 and to dynein intermediate chain (Dynein IC), and this interaction is abolished by BICD1 silencing. Akt activation and GSK3β silencing enhance HIF1α-BICD1 binding and nuclear translocation. BICD1 silencing abolished hypoxia-induced glycolytic reprogramming and increased mitochondrial ROS and apoptosis.\",\n      \"method\": \"Co-immunoprecipitation (direct binding), siRNA knockdown, overexpression, Akt inhibition/activation, GSK3β silencing, functional readouts (glycolysis, ROS, apoptosis, in vivo wound healing)\",\n      \"journal\": \"Cell death and differentiation\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal co-IP showing direct binding, multiple orthogonal methods (knockdown, overexpression, pharmacological modulation), functional consequences confirmed in vitro and in vivo\",\n      \"pmids\": [\"30464225\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"PTPN23, a member of the ESCRT machinery, was identified as a BICD1 interactor; molecular mapping showed PTPN23 binds the N-terminus of BICD1 (the same region essential for dynein recruitment), but is not a canonical BICD1 cargo. Loss of PTPN23 phenocopies BICD1 knockdown, causing accumulation of BDNF-activated p75NTR and TrkB in swollen vacuole-like compartments, establishing BICD1 as a key factor for lysosomal degradation of activated neurotrophin receptors.\",\n      \"method\": \"Proteomics/mass spectrometry (BICD1 interactome), molecular domain mapping, BICD1 and PTPN23 knockdown with endosomal trafficking readouts (fluorescence microscopy of receptor accumulation)\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — interactome proteomics plus domain mapping plus loss-of-function phenotype with defined subcellular readout; single lab with multiple orthogonal methods\",\n      \"pmids\": [\"32079660\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"Biallelic loss-of-function frameshift variants in BICD1 (c.1683dup) cause complete absence of BICD1 protein (detected by western blot of patient fibroblasts) and are associated with peripheral neuropathy and hearing loss in a human family.\",\n      \"method\": \"Exome sequencing, segregation analysis, western blotting of patient-derived fibroblasts, RNA analysis\",\n      \"journal\": \"International journal of molecular sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — protein loss confirmed by western blot in patient cells with genetic segregation, but single family; authors note definitive evidence requires replication\",\n      \"pmids\": [\"37240244\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"KDM4E activates BICD1 expression by reducing H3K9me3 deposition at the BICD1 promoter; BICD1 physically interacts with PAR1 and promotes PAR1 endocytosis, blocking PAR1 signaling in triple-negative breast cancer cells.\",\n      \"method\": \"KDM4E knockdown/overexpression, ChIP (H3K9me3 at BICD1 promoter), Co-immunoprecipitation (BICD1-PAR1 interaction), functional assays (cell viability, migration, apoptosis)\",\n      \"journal\": \"Molecular carcinogenesis\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — co-IP plus epigenetic mechanism plus functional rescue, single lab with multiple orthogonal methods\",\n      \"pmids\": [\"38607237\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"YAP directly binds the BICD1 promoter and enhances its transcriptional activity. BICD1 interacts with HIF-1α via its C-terminal CC3 domain, promoting HIF-1α nuclear translocation and transcriptional activity. AKT activation or GSK3β knockdown enhances the BICD1-HIF-1α interaction.\",\n      \"method\": \"ChIP (YAP binding to BICD1 promoter), Co-immunoprecipitation (BICD1 CC3 domain with HIF-1α), BICD1 knockdown/overexpression, domain deletion mapping, in vivo xenograft model\",\n      \"journal\": \"Pathology, research and practice\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP plus domain-mapped co-IP plus in vivo model, single lab, multiple orthogonal methods\",\n      \"pmids\": [\"42156301\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"BICD1 is a dynein motor adaptor with a coiled-coil architecture whose C-terminal CC3 domain links cargo proteins (including Rab6, RanBP2, and HIF-1α) to the dynein complex; it mediates HIF-1α nuclear translocation (facilitated by AKT/GSK3β signaling) in stem cells under hypoxia, directs lysosomal degradation of activated neurotrophin receptors (TrkB, p75NTR) in motor neurons via interaction with the ESCRT component PTPN23 at its N-terminus, promotes PAR1 endocytosis through direct physical interaction with PAR1, and in C. elegans acts in a pathway with dynein and kinesin-1 to regulate dendritic branching; biallelic loss-of-function in humans causes peripheral neuropathy and hearing loss.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"BICD1 is a coiled-coil dynein motor adaptor that links specific cargoes to the dynein complex and thereby controls their intracellular trafficking and the downstream signaling and degradative outcomes that depend on it [#3, #4]. Its C-terminal CC3 region engages cargo proteins including Rab6, RanBP2, and HIF-1\\u03b1, while its N-terminus mediates dynein recruitment and also binds the ESCRT component PTPN23 [#3, #5, #8]. Through this adaptor activity BICD1 drives lysosomal degradation of BDNF-activated neurotrophin receptors p75NTR and TrkB, with loss of either BICD1 or PTPN23 causing receptor accumulation in swollen vacuole-like compartments [#5]. In a distinct trafficking role, BICD1 binds PAR1 and promotes its endocytosis [#7]. Under hypoxia, BICD1 binds HIF-1\\u03b1 and dynein intermediate chain to mediate HIF-1\\u03b1 nuclear translocation and hypoxia-induced glycolytic reprogramming, an interaction enhanced by AKT activation and GSK3\\u03b2 loss; BICD1 itself is transcriptionally controlled, being induced by YAP and by KDM4E-mediated reduction of H3K9me3 at its promoter [#4, #7, #8]. Biallelic loss-of-function frameshift variants in BICD1 that abolish the protein cause peripheral neuropathy and hearing loss [#6]. A conserved role in motor-dependent neuronal morphogenesis is supported by the C. elegans ortholog, which regulates dendrite branching in a pathway with dynein and kinesin-1 [#2].\",\n  \"teleology\": [\n    {\n      \"year\": 1997,\n      \"claim\": \"Establishing BICD1's molecular identity, cloning revealed a coiled-coil protein homologous to Drosophila Bicaudal-D, framing the initial hypothesis that it participates in cytoskeleton-based intracellular sorting.\",\n      \"evidence\": \"cDNA cloning, sequence analysis, and Northern blot in brain, heart, and skeletal muscle\",\n      \"pmids\": [\"9367685\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No direct functional assay; sorting role inferred from sequence homology only\", \"No cargo or motor partner identified\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"A regulatory SNP linking reduced BICD1 expression to shorter telomeres implicated BICD1 in telomere length homeostasis, though by association rather than mechanism.\",\n      \"evidence\": \"Genome-wide linkage, fine-mapping, and leukocyte eQTL analysis\",\n      \"pmids\": [\"18487243\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No direct functional link between BICD1 protein and telomere maintenance demonstrated\", \"Mechanism connecting an adaptor protein to telomere length unexplained\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Genetic epistasis in C. elegans placed the BICD1 ortholog in a conserved motor pathway, establishing a role in neuronal dendrite morphogenesis alongside dynein and kinesin-1.\",\n      \"evidence\": \"RNAi, genetic epistasis with dhc-1, unc-116, and unc-5, and cell-specific expression in PVD neurons\",\n      \"pmids\": [\"21205795\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct physical interaction with motor components not biochemically shown\", \"Relevance to mammalian BICD1 function inferred from orthology\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Crystallization of the CC3 domain and preparation of a CC3-active Rab6 complex defined the structural cargo-binding module that links Rab6 and RanBP2 to dynein.\",\n      \"evidence\": \"X-ray crystallography to 1.50 \\u00c5 and complex preparation with constitutively active Rab6\",\n      \"pmids\": [\"25084392\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Functional validation of the CC3-Rab6 interaction not described in the report\", \"No full structure of the adaptor-motor-cargo assembly\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Identifying BICD1 as the adaptor that couples HIF-1\\u03b1 to dynein for nuclear translocation revealed a signaling function beyond canonical cargo transport, controlling hypoxic metabolic reprogramming.\",\n      \"evidence\": \"Reciprocal co-IP, siRNA, overexpression, AKT/GSK3\\u03b2 modulation, and functional readouts (glycolysis, ROS, apoptosis, in vivo wound healing) in mesenchymal stem cells\",\n      \"pmids\": [\"30464225\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of the HIF-1\\u03b1-BICD1 interaction not resolved in this study\", \"How AKT/GSK3\\u03b2 signaling biochemically enhances binding unclear\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Discovery of the BICD1-PTPN23 interaction connected the adaptor to the ESCRT machinery, establishing BICD1 as a determinant of lysosomal degradation of activated neurotrophin receptors.\",\n      \"evidence\": \"Interactome proteomics, domain mapping, and BICD1/PTPN23 knockdown with receptor-trafficking microscopy (p75NTR, TrkB)\",\n      \"pmids\": [\"32079660\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"PTPN23 binds the N-terminus and is not a canonical cargo; the mechanistic interplay with dynein recruitment at the same region unresolved\", \"Single lab; reciprocal validation of the receptor-degradation pathway limited\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Biallelic loss-of-function variants abolishing BICD1 protein tied the gene to a human Mendelian phenotype of peripheral neuropathy and hearing loss.\",\n      \"evidence\": \"Exome sequencing, segregation, and western blot of patient fibroblasts confirming protein absence\",\n      \"pmids\": [\"37240244\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single family; replication needed for definitive causality\", \"Mechanism linking BICD1 loss to specific neuropathy and auditory phenotypes not established\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Identification of BICD1 as a PAR1 interactor that drives PAR1 endocytosis, and as a target of KDM4E-mediated H3K9me3 demethylation, extended its adaptor role to receptor signaling control in cancer cells.\",\n      \"evidence\": \"KDM4E manipulation, ChIP for H3K9me3 at the BICD1 promoter, co-IP of BICD1-PAR1, and functional assays in triple-negative breast cancer cells\",\n      \"pmids\": [\"38607237\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether dynein is required for BICD1-mediated PAR1 endocytosis not tested\", \"Single lab; direct vs. indirect nature of BICD1-PAR1 binding not fully delineated\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Mapping HIF-1\\u03b1 binding to the CC3 domain and identifying YAP as a transcriptional activator of BICD1 integrated the adaptor's signaling role with upstream control of its own expression.\",\n      \"evidence\": \"ChIP for YAP at the BICD1 promoter, domain-mapped co-IP of CC3 with HIF-1\\u03b1, knockdown/overexpression, and xenograft model\",\n      \"pmids\": [\"42156301\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Structural detail of the CC3-HIF-1\\u03b1 interface not resolved\", \"Single lab; in vivo relevance beyond the xenograft system unexplored\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How BICD1 selects among its diverse cargoes (Rab6, RanBP2, HIF-1\\u03b1, PAR1) and coordinates dynein recruitment with ESCRT-dependent degradation versus nuclear delivery remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No unified structural model of cargo-specific BICD1-dynein assemblies\", \"Mechanism reconciling N-terminal PTPN23 binding with N-terminal dynein recruitment unknown\", \"Tissue-specific basis of the human neuropathy/hearing-loss phenotype uncharacterized\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [3, 4, 5]},\n      {\"term_id\": \"GO:0008092\", \"supporting_discovery_ids\": [3, 4]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005768\", \"supporting_discovery_ids\": [5]},\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [4]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-5653656\", \"supporting_discovery_ids\": [5, 7]},\n      {\"term_id\": \"R-HSA-9609507\", \"supporting_discovery_ids\": [4]},\n      {\"term_id\": \"R-HSA-8953897\", \"supporting_discovery_ids\": [4]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"DYNC1I (dynein intermediate chain)\", \"Rab6\", \"RanBP2\", \"HIF1A\", \"PTPN23\", \"PAR1 (F2R)\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":7,"faith_pct":85.71428571428571}}