{"gene":"NUP50","run_date":"2026-06-10T05:19:52","timeline":{"discoveries":[{"year":2005,"finding":"Crystal structure of the importin-α:Nup50 complex reveals that the Nup50 N-terminal domain binds at two sites on importin-α (one overlapping the secondary NLS-binding site, one extending along the importin-α C-terminus), and mutagenesis shows both sites are required for Nup50 to actively displace NLS cargo from importin-α, establishing Nup50's role in import complex disassembly and importin recycling rather than merely accompanying the import complex.","method":"Crystal structure determination, site-directed mutagenesis, in vitro NLS displacement assays","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 1 / Strong — crystal structure plus mutagenesis plus functional displacement assay in a single rigorous study","pmids":["16222336"],"is_preprint":false},{"year":2000,"finding":"Nup50 is specifically localized to the nucleoplasmic fibrils of the nuclear pore complex; microinjection of anti-Nup50 antibodies into nuclei strongly inhibits export of leucine-rich NES-containing proteins but not classical NLS-mediated import; CRM1 directly binds a fragment of Nup50 in vitro, while several other import/export receptors do not, establishing Nup50 as a direct binding site for CRM1-dependent export complexes on the nuclear face of the NPC.","method":"Immunogold electron microscopy, nuclear microinjection of antibodies, in vitro binding assay","journal":"Molecular and cellular biology","confidence":"High","confidence_rationale":"Tier 2 / Moderate — reciprocal functional inhibition by antibody microinjection plus direct in vitro CRM1 binding, two orthogonal methods in one study","pmids":["10891499"],"is_preprint":false},{"year":2002,"finding":"Npap60/Nup50 is a Ran-binding protein that functions as a cofactor for importin-α:β-mediated nuclear import; it acts as a tri-stable switch: its C-terminus binds importin-β through RanGTP, its N-terminus binds the C-terminus of importin-α, and a central domain binds importin-β; endogenous Npap60 can shuttle and is accessible from the cytoplasmic side of the nuclear envelope.","method":"Biochemical binding assays, nuclear import reconstitution, domain mapping, immunolocalization","journal":"Cell","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple domain-mapping binding assays plus functional import reconstitution, replicated across multiple approaches in one rigorous study","pmids":["12176322"],"is_preprint":false},{"year":2000,"finding":"Nup50 interacts with p27(Kip1) by two-hybrid and co-immunoprecipitates with Nup153 from mammalian cells; targeted Nup50 deletion in mice causes late embryonic lethality, neural tube defects, and intrauterine growth retardation, with abnormalities in p27(Kip1) expression and cell proliferation in the neuroepithelium, but no cell-cycle or p27 defects in Nup50-null MEFs.","method":"Yeast two-hybrid, co-immunoprecipitation, gene targeting/knockout in mice, phenotypic analysis","journal":"Molecular and cellular biology","confidence":"High","confidence_rationale":"Tier 2 / Moderate — reciprocal interaction data plus in vivo knockout with defined developmental phenotype, two orthogonal approaches","pmids":["10891500"],"is_preprint":false},{"year":2009,"finding":"The two human Npap60 isoforms (Npap60L/NUP50 and Npap60S) have opposing functions: Npap60S stabilizes importin-α binding to NLS-cargo whereas Npap60L promotes release of NLS-cargo from importin-α; in vivo, Npap60S suppresses and Npap60L accelerates nuclear import of classical NLS-cargo.","method":"In vitro binding assays, in vivo time-lapse nuclear import assays","journal":"Molecular biology of the cell","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vitro and in vivo functional assays in one study, single lab","pmids":["20016008"],"is_preprint":false},{"year":2012,"finding":"Nup153 provides the scaffold for Nup50 at the nuclear pore via a dual interface: an interaction between Nup50's N-terminal domain and the unique N-terminal region of Nup153 is required for NPC localization of Nup50, while a second importin-α-dependent interaction at the distal tail of Nup153 also involves Nup50's N-terminal domain; disruption of this interface decreases nuclear import efficiency.","method":"Domain mapping, binding assays, import efficiency assays","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — domain-deletion mapping of dual interface plus functional import assay, single lab","pmids":["23007389"],"is_preprint":false},{"year":2014,"finding":"Nup50 is a mobile nucleoporin present both at the NPC and in the nucleoplasm; its dynamic shuttling between these locations depends on active RNA Pol II transcription and requires the N-terminal half (importin-α- and Nup153-binding domains), but is independent of importin-α, Nup153, and Nup98; depletion of Nup50 does not affect proliferation but inhibits differentiation of C2C12 myoblasts into myotubes, indicating a transport-independent role in chromatin biology.","method":"FRAP/live-cell imaging, RNAi depletion, transcription inhibition, myoblast differentiation assay","journal":"Molecular biology of the cell","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — live-cell localization with functional consequence (differentiation defect), multiple conditions tested, single lab","pmids":["24943837"],"is_preprint":false},{"year":2010,"finding":"In C. elegans, loss of nucleoporin NPP-16/NUP50 suppresses anoxia-induced prophase arrest; CDK-1 remains in its inactive form in wild-type arrested prophase blastomeres under anoxia, but this inactive state is not detected in npp-16 mutant embryos, placing NPP-16/NUP50 upstream of CDK-1 inactivation in the prophase checkpoint response to oxygen deprivation.","method":"Genetic loss-of-function (C. elegans mutants), immunofluorescence for CDK-1 phosphorylation state, epistasis analysis","journal":"Molecular biology of the cell","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic epistasis in C. elegans ortholog with phosphorylation readout, single lab","pmids":["20053678"],"is_preprint":false},{"year":2017,"finding":"Nup50 promotes recruitment of 53BP1 to DNA double-strand break repair foci; this requirement is abrogated in BRCA1- or BARD1-deficient cells (but not BRCA2-deficient cells), placing Nup50 in a pathway that counteracts BRCA1-mediated events to favor 53BP1-dependent NHEJ over homologous recombination.","method":"RNAi depletion, immunofluorescence of 53BP1 foci, genetic epistasis with BRCA1/BARD1/BRCA2 knockouts","journal":"Journal of cell science","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — epistasis analysis across multiple genetic backgrounds with defined foci readout, single lab","pmids":["28751496"],"is_preprint":false},{"year":2021,"finding":"Nup50 plays a role in NPC assembly at mitotic exit independent of its nuclear transport function; an N-terminal fragment of Nup50 stimulates the RanGEF RCC1, and Nup50 mutants defective in RCC1 binding/stimulation cannot support NPC assembly in vitro, while excess RCC1 compensates for Nup50 loss; a conserved central 46-residue region is required for Nup153 and MEL28/ELYS binding and NPC interaction.","method":"RNAi knockdown, immunodepletion in Xenopus egg extracts, in vitro NPC assembly assay, domain mapping, mutagenesis, RCC1 stimulation assay","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro reconstitution with mutagenesis, Xenopus immunodepletion, RCC1 rescue experiment; multiple orthogonal approaches","pmids":["34725842"],"is_preprint":false},{"year":2026,"finding":"GALNT7 O-glycosylates NUP50 at the nuclear envelope, stabilizing the NUP50 protein; this modification activates fatty acid β-oxidation pathways and promotes lung adenocarcinoma cell metastasis; NUP50 O-glycosylation mutant (NUP50-MUT) blocks the tumor-promoting effects of GALNT7 overexpression in vivo.","method":"Co-localization, glycosylation assays, knockdown/overexpression, Western blot, xenograft and lung metastasis mouse models, NUP50-MUT rescue","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — mutagenesis of glycosylation site plus in vivo rescue experiment, single lab, 2026 publication","pmids":["42173248"],"is_preprint":false},{"year":2025,"finding":"AMPK post-translationally regulates the abundance of NPP-16/NUP50 in response to nutrient availability and energetic stress in C. elegans; the intrinsically disordered region (IDR) of NPP-16/NUP50 directly interacts with the transcriptional machinery to transactivate promoters of lipid catabolic genes, extending lifespan independently of its nuclear transport function; this AMPK-NUP50 axis is reported to be conserved in humans.","method":"Genetic epistasis (C. elegans), in vitro interaction of IDR with transcriptional machinery, lifespan assays, transcriptomic analysis","journal":"bioRxiv","confidence":"Low","confidence_rationale":"Tier 3 / Weak — preprint, single lab, IDR-transcription machinery interaction details sparse in abstract","pmids":["bio_10.1101_2025.02.17.638704"],"is_preprint":true},{"year":2021,"finding":"Knockdown of NUP50 significantly inhibits HIV-1 replication in cell models, and hsa-miR-191-5p represses NUP50 expression to exert its antiviral effect.","method":"siRNA knockdown, viral replication assay, miRNA target validation","journal":"Archives of virology","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, single method (knockdown + replication assay), mechanism of NUP50's role in HIV replication not defined","pmids":["33420627"],"is_preprint":false}],"current_model":"NUP50 is a nucleoplasmically oriented nuclear pore complex component that uses its N-terminal domain to bind two sites on importin-α and actively displace NLS cargo, coordinating import complex disassembly and importin recycling; it is a Ran-binding protein and tri-stable switch that also interacts with importin-β (via RanGTP through its C-terminus) to stimulate classical NLS-mediated import; it is scaffolded at the NPC via a dual interface with Nup153; it directly binds CRM1 to support leucine-rich NES-dependent protein export; it stimulates the RanGEF RCC1 via its N-terminal domain to drive NPC reassembly at mitotic exit; it is mobile between NPC and nucleoplasm in a transcription-dependent, transport-independent manner, and is required for myoblast differentiation and 53BP1 recruitment to DNA damage foci (antagonizing BRCA1); it is O-glycosylated by GALNT7 to stabilize the protein and activate fatty acid β-oxidation; and in C. elegans its abundance is regulated by AMPK, with its IDR directly engaging transcriptional machinery to promote lipid catabolism and longevity."},"narrative":{"mechanistic_narrative":"NUP50 is a nucleoplasmically oriented component of the nuclear pore complex that operates at the heart of the importin-α/β transport cycle and, separately, in chromatin-linked processes [PMID:10891499, PMID:12176322]. Its N-terminal domain engages importin-α at two sites—one overlapping the secondary NLS-binding site and one extending along the importin-α C-terminus—and both are required to actively displace NLS cargo, defining NUP50 as a catalyst of import-complex disassembly and importin recycling rather than a passive accompanying factor [PMID:16222336]. NUP50 is itself a Ran-binding protein that acts as a tri-stable switch: its C-terminus binds importin-β through RanGTP, its N-terminus binds importin-α, and a central domain binds importin-β, allowing it to function as a cofactor that stimulates classical NLS import [PMID:12176322], while alternative isoforms tune this activity in opposing directions toward cargo stabilization versus release [PMID:20016008]. NUP50 directly binds CRM1 on the nuclear face of the NPC and is required for leucine-rich NES-dependent protein export [PMID:10891499]. It is scaffolded at the pore by a dual interface with Nup153, disruption of which lowers import efficiency [PMID:23007389]. Beyond transport, NUP50 has a transport-independent role in NPC reassembly at mitotic exit: its N-terminal fragment stimulates the RanGEF RCC1, and a conserved central region mediates Nup153 and MEL28/ELYS binding required for assembly [PMID:34725842]. NUP50 also shuttles between the NPC and nucleoplasm in a transcription-dependent manner and contributes to chromatin biology, being required for myoblast differentiation [PMID:24943837] and for recruitment of 53BP1 to DNA double-strand break foci in a pathway that counteracts BRCA1/BARD1 to favor NHEJ [PMID:28751496]. Targeted deletion in mice causes late embryonic lethality with neural tube defects, accompanied by altered p27(Kip1) expression in the neuroepithelium [PMID:10891500].","teleology":[{"year":2000,"claim":"Established NUP50's spatial position and a directional transport role by showing it sits on nucleoplasmic NPC fibrils and is a direct docking site for CRM1-dependent export, answering whether it serves import or export functions.","evidence":"Immunogold EM, intranuclear antibody microinjection, and in vitro CRM1 binding in mammalian cells","pmids":["10891499"],"confidence":"High","gaps":["Did not resolve how CRM1 binding is coordinated with cargo release","Structural basis of the CRM1 interaction not defined"]},{"year":2000,"claim":"Connected NUP50 to cell-cycle regulators and development by identifying p27(Kip1) and Nup153 as partners and revealing an essential in vivo role, framing NUP50 as more than a transport factor.","evidence":"Yeast two-hybrid, co-immunoprecipitation, and gene-targeted knockout mice with phenotyping","pmids":["10891500"],"confidence":"High","gaps":["p27 and proliferation defects absent in null MEFs, leaving the mechanism tissue-context dependent and undefined","Molecular basis linking NUP50 loss to neural tube defects unknown"]},{"year":2002,"claim":"Defined NUP50 as a Ran-binding tri-stable switch and import cofactor, explaining mechanistically how it engages both importin-α and importin-β to drive the transport cycle.","evidence":"Domain-mapping binding assays, import reconstitution, and immunolocalization","pmids":["12176322"],"confidence":"High","gaps":["How the three binding states interconvert kinetically in vivo not resolved","Stoichiometry within assembled import complexes undefined"]},{"year":2005,"claim":"Resolved the structural and functional logic of NUP50's importin-α engagement, showing two binding sites are jointly required to actively displace NLS cargo and establishing its disassembly/recycling role.","evidence":"Crystal structure of the importin-α:Nup50 complex, site-directed mutagenesis, in vitro NLS displacement assays","pmids":["16222336"],"confidence":"High","gaps":["Did not address CRM1 or importin-β interaction geometry","In vivo contribution of displacement vs recycling not quantified"]},{"year":2009,"claim":"Showed isoform identity dictates the direction of NUP50 activity, with Npap60S stabilizing and Npap60L promoting release of importin-α:NLS-cargo, adding a layer of regulatory tuning to import.","evidence":"In vitro binding assays and in vivo time-lapse nuclear import assays","pmids":["20016008"],"confidence":"Medium","gaps":["Single lab; isoform ratios and their regulation in tissues unknown","Structural basis for opposing isoform functions not defined"]},{"year":2010,"claim":"Placed the NUP50 ortholog upstream of CDK-1 inactivation in an anoxia-induced prophase checkpoint, linking the nucleoporin to cell-cycle arrest under stress.","evidence":"C. elegans loss-of-function mutants, CDK-1 phospho-state immunofluorescence, epistasis","pmids":["20053678"],"confidence":"Medium","gaps":["Molecular mechanism connecting NPP-16 to CDK-1 inactivation unknown","Mammalian conservation not tested"]},{"year":2012,"claim":"Defined how NUP50 is anchored at the pore, identifying a dual Nup153 interface required for NUP50 localization and import efficiency.","evidence":"Domain mapping, binding assays, import efficiency assays","pmids":["23007389"],"confidence":"Medium","gaps":["Single lab; relative contribution of the two interfaces in vivo unresolved","Whether anchoring regulates the import switch not addressed"]},{"year":2014,"claim":"Revealed NUP50 as a mobile nucleoporin whose NPC-nucleoplasm shuttling depends on active transcription, uncovering a transport-independent role in chromatin biology required for myoblast differentiation.","evidence":"FRAP/live-cell imaging, RNAi, transcription inhibition, C2C12 differentiation assay","pmids":["24943837"],"confidence":"Medium","gaps":["Chromatin targets engaged during differentiation not identified","Mechanistic basis of transcription-dependent mobility undefined"]},{"year":2017,"claim":"Implicated NUP50 in DNA double-strand break repair choice, showing it promotes 53BP1 focus recruitment in a BRCA1/BARD1-dependent manner to favor NHEJ over homologous recombination.","evidence":"RNAi depletion, 53BP1 immunofluorescence, epistasis with BRCA1/BARD1/BRCA2 knockouts","pmids":["28751496"],"confidence":"Medium","gaps":["Direct molecular link between NUP50 and 53BP1 recruitment unknown","Whether this requires NPC localization or the mobile pool not resolved"]},{"year":2021,"claim":"Separated NUP50's assembly function from transport, demonstrating it stimulates RCC1 to drive NPC reassembly at mitotic exit and mapping a conserved central region for Nup153/ELYS binding.","evidence":"Xenopus egg extract immunodepletion, in vitro NPC assembly, mutagenesis, RCC1 stimulation and rescue assays","pmids":["34725842"],"confidence":"High","gaps":["How RCC1 stimulation is spatially restricted during assembly not defined","Relationship between assembly role and transcription-dependent mobility unexplored"]},{"year":2021,"claim":"Linked NUP50 to viral biology and microRNA control, showing its knockdown impairs HIV-1 replication and that miR-191-5p represses it.","evidence":"siRNA knockdown, viral replication assay, miRNA target validation","pmids":["33420627"],"confidence":"Low","gaps":["Mechanism of NUP50's role in HIV-1 replication not defined","Single method without orthogonal validation"]},{"year":2026,"claim":"Connected NUP50 to metabolic and oncogenic signaling, showing GALNT7-mediated O-glycosylation stabilizes NUP50, activates fatty acid β-oxidation, and promotes lung adenocarcinoma metastasis.","evidence":"Glycosylation assays, knockdown/overexpression, NUP50-MUT rescue, xenograft and lung metastasis mouse models","pmids":["42173248"],"confidence":"Medium","gaps":["How NUP50 glycosylation mechanistically activates β-oxidation unknown","Single lab; precise glycosylated residues' structural impact undefined"]},{"year":2025,"claim":"Proposed a transport-independent metabolic-longevity function in which AMPK controls NUP50 abundance and its IDR transactivates lipid catabolic genes.","evidence":"C. elegans genetic epistasis, in vitro IDR-transcriptional machinery interaction, lifespan and transcriptomic analysis (preprint)","pmids":["bio_10.1101_2025.02.17.638704"],"confidence":"Low","gaps":["Preprint; IDR-transcription machinery interaction details sparse","Human conservation asserted but not directly demonstrated"]},{"year":null,"claim":"How NUP50's distinct activities—import-complex disassembly, CRM1-dependent export, RCC1-stimulated NPC assembly, and transcription-coupled chromatin/repair functions—are integrated and regulated within a single protein remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No unified model connecting the transport-dependent and transport-independent roles","Regulatory switching between functions undefined","Direct chromatin/repair binding partners not identified"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[0,2]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[0,2,9]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[0,2,5]}],"localization":[{"term_id":"GO:0005635","term_label":"nuclear envelope","supporting_discovery_ids":[1,10]},{"term_id":"GO:0005654","term_label":"nucleoplasm","supporting_discovery_ids":[6]}],"pathway":[{"term_id":"R-HSA-9609507","term_label":"Protein localization","supporting_discovery_ids":[0,1,2]},{"term_id":"R-HSA-1852241","term_label":"Organelle biogenesis and maintenance","supporting_discovery_ids":[9]},{"term_id":"R-HSA-73894","term_label":"DNA Repair","supporting_discovery_ids":[8]}],"complexes":["nuclear pore complex"],"partners":["KPNA (IMPORTIN-Α)","KPNB1 (IMPORTIN-Β)","NUP153","XPO1/CRM1","RCC1","MEL28/ELYS","CDKN1B/P27KIP1","RAN"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q9UKX7","full_name":"Nuclear pore complex protein Nup50","aliases":["50 kDa nucleoporin","Nuclear pore-associated protein 60 kDa-like","Nucleoporin Nup50"],"length_aa":468,"mass_kda":50.1,"function":"Component of the nuclear pore complex that has a direct role in nuclear protein import (PubMed:20016008). Actively displaces NLSs from importin-alpha, and facilitates disassembly of the importin-alpha:beta-cargo complex and importin recycling (PubMed:20016008). Interacts with regulatory proteins of cell cycle progression including CDKN1B (By similarity). This interaction is required for correct intracellular transport and degradation of CDKN1B (By similarity)","subcellular_location":"Nucleus, nuclear pore complex; Nucleus membrane","url":"https://www.uniprot.org/uniprotkb/Q9UKX7/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":true,"resolved_as":"","url":"https://depmap.org/portal/gene/NUP50","classification":"Common Essential","n_dependent_lines":702,"n_total_lines":1208,"dependency_fraction":0.5811258278145696},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"KPNA1","stoichiometry":10.0},{"gene":"KPNA4","stoichiometry":10.0},{"gene":"KPNA6","stoichiometry":10.0},{"gene":"KPNB1","stoichiometry":10.0},{"gene":"NUP153","stoichiometry":10.0},{"gene":"KPNA2","stoichiometry":4.0},{"gene":"RAN","stoichiometry":4.0},{"gene":"ATG4B","stoichiometry":0.2},{"gene":"CSE1L","stoichiometry":0.2},{"gene":"EMC9","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/NUP50","total_profiled":1310},"omim":[{"mim_id":"604646","title":"NUCLEOPORIN, 50-KD; NUP50","url":"https://www.omim.org/entry/604646"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Enhanced","locations":[{"location":"Nucleoplasm","reliability":"Enhanced"},{"location":"Nuclear membrane","reliability":"Enhanced"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/NUP50"},"hgnc":{"alias_symbol":[],"prev_symbol":["NPAP60L"]},"alphafold":{"accession":"Q9UKX7","domains":[{"cath_id":"2.30.29.30","chopping":"358-465","consensus_level":"medium","plddt":93.0769,"start":358,"end":465}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9UKX7","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9UKX7-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9UKX7-F1-predicted_aligned_error_v6.png","plddt_mean":64.44},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=NUP50","jax_strain_url":"https://www.jax.org/strain/search?query=NUP50"},"sequence":{"accession":"Q9UKX7","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9UKX7.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9UKX7/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9UKX7"}},"corpus_meta":[{"pmid":"16222336","id":"PMC_16222336","title":"Nup50/Npap60 function in nuclear protein import complex disassembly and importin recycling.","date":"2005","source":"The EMBO journal","url":"https://pubmed.ncbi.nlm.nih.gov/16222336","citation_count":131,"is_preprint":false},{"pmid":"10891499","id":"PMC_10891499","title":"Nup50, a nucleoplasmically oriented nucleoporin with a role in nuclear protein export.","date":"2000","source":"Molecular and cellular biology","url":"https://pubmed.ncbi.nlm.nih.gov/10891499","citation_count":113,"is_preprint":false},{"pmid":"12176322","id":"PMC_12176322","title":"Npap60/Nup50 is a tri-stable switch that stimulates importin-alpha:beta-mediated nuclear protein import.","date":"2002","source":"Cell","url":"https://pubmed.ncbi.nlm.nih.gov/12176322","citation_count":102,"is_preprint":false},{"pmid":"10891500","id":"PMC_10891500","title":"Characterization and targeted disruption of murine Nup50, a p27(Kip1)-interacting component of the nuclear pore complex.","date":"2000","source":"Molecular and cellular biology","url":"https://pubmed.ncbi.nlm.nih.gov/10891500","citation_count":94,"is_preprint":false},{"pmid":"24943837","id":"PMC_24943837","title":"Nup50 is required for cell differentiation and exhibits transcription-dependent dynamics.","date":"2014","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/24943837","citation_count":60,"is_preprint":false},{"pmid":"23007389","id":"PMC_23007389","title":"The Nup153-Nup50 protein interface and its role in nuclear import.","date":"2012","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/23007389","citation_count":51,"is_preprint":false},{"pmid":"20016008","id":"PMC_20016008","title":"Two isoforms of Npap60 (Nup50) differentially regulate nuclear protein import.","date":"2009","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/20016008","citation_count":27,"is_preprint":false},{"pmid":"34725842","id":"PMC_34725842","title":"The nucleoporin Nup50 activates the Ran guanine nucleotide exchange factor RCC1 to promote NPC assembly at the end of mitosis.","date":"2021","source":"The EMBO journal","url":"https://pubmed.ncbi.nlm.nih.gov/34725842","citation_count":22,"is_preprint":false},{"pmid":"20053678","id":"PMC_20053678","title":"NPP-16/Nup50 function and CDK-1 inactivation are associated with anoxia-induced prophase arrest in Caenorhabditis elegans.","date":"2010","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/20053678","citation_count":20,"is_preprint":false},{"pmid":"28751496","id":"PMC_28751496","title":"Nup153 and Nup50 promote recruitment of 53BP1 to DNA repair foci by antagonizing BRCA1-dependent events.","date":"2017","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/28751496","citation_count":19,"is_preprint":false},{"pmid":"33420627","id":"PMC_33420627","title":"hsa-miR-191-5p inhibits replication of human immunodeficiency virus type 1 by downregulating the expression of NUP50.","date":"2021","source":"Archives of virology","url":"https://pubmed.ncbi.nlm.nih.gov/33420627","citation_count":14,"is_preprint":false},{"pmid":"10449902","id":"PMC_10449902","title":"Mapping and complex expression pattern of the human NPAP60L nucleoporin gene.","date":"1999","source":"Cytogenetics and cell genetics","url":"https://pubmed.ncbi.nlm.nih.gov/10449902","citation_count":10,"is_preprint":false},{"pmid":"26515778","id":"PMC_26515778","title":"NUP50 is necessary for the survival of primordial germ cells in mouse embryos.","date":"2015","source":"Reproduction (Cambridge, England)","url":"https://pubmed.ncbi.nlm.nih.gov/26515778","citation_count":8,"is_preprint":false},{"pmid":"35549614","id":"PMC_35549614","title":"Nup50 plays more than one instrument.","date":"2022","source":"Cell cycle (Georgetown, Tex.)","url":"https://pubmed.ncbi.nlm.nih.gov/35549614","citation_count":6,"is_preprint":false},{"pmid":"42173248","id":"PMC_42173248","title":"GALNT7-induced O-glycosylation of NUP50 activates fatty acid β-oxidation to promote lung adenocarcinoma metastasis.","date":"2026","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/42173248","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.02.17.638704","title":"The nuclear pore complex connects energy sensing to transcriptional plasticity in longevity","date":"2025-02-17","source":"bioRxiv","url":"https://doi.org/10.1101/2025.02.17.638704","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":8525,"output_tokens":3494,"usd":0.038992,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":11060,"output_tokens":4317,"usd":0.081613,"stage2_stop_reason":"end_turn"},"total_usd":0.120605,"stage1_batch_id":"msgbatch_013a8chtv3AWyTqv4z4sEF4C","stage2_batch_id":"msgbatch_01AHsuW63vinsvuTgzmQ3n62","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2005,\n      \"finding\": \"Crystal structure of the importin-α:Nup50 complex reveals that the Nup50 N-terminal domain binds at two sites on importin-α (one overlapping the secondary NLS-binding site, one extending along the importin-α C-terminus), and mutagenesis shows both sites are required for Nup50 to actively displace NLS cargo from importin-α, establishing Nup50's role in import complex disassembly and importin recycling rather than merely accompanying the import complex.\",\n      \"method\": \"Crystal structure determination, site-directed mutagenesis, in vitro NLS displacement assays\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — crystal structure plus mutagenesis plus functional displacement assay in a single rigorous study\",\n      \"pmids\": [\"16222336\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"Nup50 is specifically localized to the nucleoplasmic fibrils of the nuclear pore complex; microinjection of anti-Nup50 antibodies into nuclei strongly inhibits export of leucine-rich NES-containing proteins but not classical NLS-mediated import; CRM1 directly binds a fragment of Nup50 in vitro, while several other import/export receptors do not, establishing Nup50 as a direct binding site for CRM1-dependent export complexes on the nuclear face of the NPC.\",\n      \"method\": \"Immunogold electron microscopy, nuclear microinjection of antibodies, in vitro binding assay\",\n      \"journal\": \"Molecular and cellular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal functional inhibition by antibody microinjection plus direct in vitro CRM1 binding, two orthogonal methods in one study\",\n      \"pmids\": [\"10891499\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"Npap60/Nup50 is a Ran-binding protein that functions as a cofactor for importin-α:β-mediated nuclear import; it acts as a tri-stable switch: its C-terminus binds importin-β through RanGTP, its N-terminus binds the C-terminus of importin-α, and a central domain binds importin-β; endogenous Npap60 can shuttle and is accessible from the cytoplasmic side of the nuclear envelope.\",\n      \"method\": \"Biochemical binding assays, nuclear import reconstitution, domain mapping, immunolocalization\",\n      \"journal\": \"Cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple domain-mapping binding assays plus functional import reconstitution, replicated across multiple approaches in one rigorous study\",\n      \"pmids\": [\"12176322\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"Nup50 interacts with p27(Kip1) by two-hybrid and co-immunoprecipitates with Nup153 from mammalian cells; targeted Nup50 deletion in mice causes late embryonic lethality, neural tube defects, and intrauterine growth retardation, with abnormalities in p27(Kip1) expression and cell proliferation in the neuroepithelium, but no cell-cycle or p27 defects in Nup50-null MEFs.\",\n      \"method\": \"Yeast two-hybrid, co-immunoprecipitation, gene targeting/knockout in mice, phenotypic analysis\",\n      \"journal\": \"Molecular and cellular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal interaction data plus in vivo knockout with defined developmental phenotype, two orthogonal approaches\",\n      \"pmids\": [\"10891500\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"The two human Npap60 isoforms (Npap60L/NUP50 and Npap60S) have opposing functions: Npap60S stabilizes importin-α binding to NLS-cargo whereas Npap60L promotes release of NLS-cargo from importin-α; in vivo, Npap60S suppresses and Npap60L accelerates nuclear import of classical NLS-cargo.\",\n      \"method\": \"In vitro binding assays, in vivo time-lapse nuclear import assays\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vitro and in vivo functional assays in one study, single lab\",\n      \"pmids\": [\"20016008\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Nup153 provides the scaffold for Nup50 at the nuclear pore via a dual interface: an interaction between Nup50's N-terminal domain and the unique N-terminal region of Nup153 is required for NPC localization of Nup50, while a second importin-α-dependent interaction at the distal tail of Nup153 also involves Nup50's N-terminal domain; disruption of this interface decreases nuclear import efficiency.\",\n      \"method\": \"Domain mapping, binding assays, import efficiency assays\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — domain-deletion mapping of dual interface plus functional import assay, single lab\",\n      \"pmids\": [\"23007389\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Nup50 is a mobile nucleoporin present both at the NPC and in the nucleoplasm; its dynamic shuttling between these locations depends on active RNA Pol II transcription and requires the N-terminal half (importin-α- and Nup153-binding domains), but is independent of importin-α, Nup153, and Nup98; depletion of Nup50 does not affect proliferation but inhibits differentiation of C2C12 myoblasts into myotubes, indicating a transport-independent role in chromatin biology.\",\n      \"method\": \"FRAP/live-cell imaging, RNAi depletion, transcription inhibition, myoblast differentiation assay\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — live-cell localization with functional consequence (differentiation defect), multiple conditions tested, single lab\",\n      \"pmids\": [\"24943837\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"In C. elegans, loss of nucleoporin NPP-16/NUP50 suppresses anoxia-induced prophase arrest; CDK-1 remains in its inactive form in wild-type arrested prophase blastomeres under anoxia, but this inactive state is not detected in npp-16 mutant embryos, placing NPP-16/NUP50 upstream of CDK-1 inactivation in the prophase checkpoint response to oxygen deprivation.\",\n      \"method\": \"Genetic loss-of-function (C. elegans mutants), immunofluorescence for CDK-1 phosphorylation state, epistasis analysis\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic epistasis in C. elegans ortholog with phosphorylation readout, single lab\",\n      \"pmids\": [\"20053678\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Nup50 promotes recruitment of 53BP1 to DNA double-strand break repair foci; this requirement is abrogated in BRCA1- or BARD1-deficient cells (but not BRCA2-deficient cells), placing Nup50 in a pathway that counteracts BRCA1-mediated events to favor 53BP1-dependent NHEJ over homologous recombination.\",\n      \"method\": \"RNAi depletion, immunofluorescence of 53BP1 foci, genetic epistasis with BRCA1/BARD1/BRCA2 knockouts\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — epistasis analysis across multiple genetic backgrounds with defined foci readout, single lab\",\n      \"pmids\": [\"28751496\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"Nup50 plays a role in NPC assembly at mitotic exit independent of its nuclear transport function; an N-terminal fragment of Nup50 stimulates the RanGEF RCC1, and Nup50 mutants defective in RCC1 binding/stimulation cannot support NPC assembly in vitro, while excess RCC1 compensates for Nup50 loss; a conserved central 46-residue region is required for Nup153 and MEL28/ELYS binding and NPC interaction.\",\n      \"method\": \"RNAi knockdown, immunodepletion in Xenopus egg extracts, in vitro NPC assembly assay, domain mapping, mutagenesis, RCC1 stimulation assay\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro reconstitution with mutagenesis, Xenopus immunodepletion, RCC1 rescue experiment; multiple orthogonal approaches\",\n      \"pmids\": [\"34725842\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"GALNT7 O-glycosylates NUP50 at the nuclear envelope, stabilizing the NUP50 protein; this modification activates fatty acid β-oxidation pathways and promotes lung adenocarcinoma cell metastasis; NUP50 O-glycosylation mutant (NUP50-MUT) blocks the tumor-promoting effects of GALNT7 overexpression in vivo.\",\n      \"method\": \"Co-localization, glycosylation assays, knockdown/overexpression, Western blot, xenograft and lung metastasis mouse models, NUP50-MUT rescue\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — mutagenesis of glycosylation site plus in vivo rescue experiment, single lab, 2026 publication\",\n      \"pmids\": [\"42173248\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"AMPK post-translationally regulates the abundance of NPP-16/NUP50 in response to nutrient availability and energetic stress in C. elegans; the intrinsically disordered region (IDR) of NPP-16/NUP50 directly interacts with the transcriptional machinery to transactivate promoters of lipid catabolic genes, extending lifespan independently of its nuclear transport function; this AMPK-NUP50 axis is reported to be conserved in humans.\",\n      \"method\": \"Genetic epistasis (C. elegans), in vitro interaction of IDR with transcriptional machinery, lifespan assays, transcriptomic analysis\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — preprint, single lab, IDR-transcription machinery interaction details sparse in abstract\",\n      \"pmids\": [\"bio_10.1101_2025.02.17.638704\"],\n      \"is_preprint\": true\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"Knockdown of NUP50 significantly inhibits HIV-1 replication in cell models, and hsa-miR-191-5p represses NUP50 expression to exert its antiviral effect.\",\n      \"method\": \"siRNA knockdown, viral replication assay, miRNA target validation\",\n      \"journal\": \"Archives of virology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, single method (knockdown + replication assay), mechanism of NUP50's role in HIV replication not defined\",\n      \"pmids\": [\"33420627\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"NUP50 is a nucleoplasmically oriented nuclear pore complex component that uses its N-terminal domain to bind two sites on importin-α and actively displace NLS cargo, coordinating import complex disassembly and importin recycling; it is a Ran-binding protein and tri-stable switch that also interacts with importin-β (via RanGTP through its C-terminus) to stimulate classical NLS-mediated import; it is scaffolded at the NPC via a dual interface with Nup153; it directly binds CRM1 to support leucine-rich NES-dependent protein export; it stimulates the RanGEF RCC1 via its N-terminal domain to drive NPC reassembly at mitotic exit; it is mobile between NPC and nucleoplasm in a transcription-dependent, transport-independent manner, and is required for myoblast differentiation and 53BP1 recruitment to DNA damage foci (antagonizing BRCA1); it is O-glycosylated by GALNT7 to stabilize the protein and activate fatty acid β-oxidation; and in C. elegans its abundance is regulated by AMPK, with its IDR directly engaging transcriptional machinery to promote lipid catabolism and longevity.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"NUP50 is a nucleoplasmically oriented component of the nuclear pore complex that operates at the heart of the importin-\\u03b1/\\u03b2 transport cycle and, separately, in chromatin-linked processes [#1, #2]. Its N-terminal domain engages importin-\\u03b1 at two sites\\u2014one overlapping the secondary NLS-binding site and one extending along the importin-\\u03b1 C-terminus\\u2014and both are required to actively displace NLS cargo, defining NUP50 as a catalyst of import-complex disassembly and importin recycling rather than a passive accompanying factor [#0]. NUP50 is itself a Ran-binding protein that acts as a tri-stable switch: its C-terminus binds importin-\\u03b2 through RanGTP, its N-terminus binds importin-\\u03b1, and a central domain binds importin-\\u03b2, allowing it to function as a cofactor that stimulates classical NLS import [#2], while alternative isoforms tune this activity in opposing directions toward cargo stabilization versus release [#4]. NUP50 directly binds CRM1 on the nuclear face of the NPC and is required for leucine-rich NES-dependent protein export [#1]. It is scaffolded at the pore by a dual interface with Nup153, disruption of which lowers import efficiency [#5]. Beyond transport, NUP50 has a transport-independent role in NPC reassembly at mitotic exit: its N-terminal fragment stimulates the RanGEF RCC1, and a conserved central region mediates Nup153 and MEL28/ELYS binding required for assembly [#9]. NUP50 also shuttles between the NPC and nucleoplasm in a transcription-dependent manner and contributes to chromatin biology, being required for myoblast differentiation [#6] and for recruitment of 53BP1 to DNA double-strand break foci in a pathway that counteracts BRCA1/BARD1 to favor NHEJ [#8]. Targeted deletion in mice causes late embryonic lethality with neural tube defects, accompanied by altered p27(Kip1) expression in the neuroepithelium [#3].\",\n  \"teleology\": [\n    {\n      \"year\": 2000,\n      \"claim\": \"Established NUP50's spatial position and a directional transport role by showing it sits on nucleoplasmic NPC fibrils and is a direct docking site for CRM1-dependent export, answering whether it serves import or export functions.\",\n      \"evidence\": \"Immunogold EM, intranuclear antibody microinjection, and in vitro CRM1 binding in mammalian cells\",\n      \"pmids\": [\"10891499\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not resolve how CRM1 binding is coordinated with cargo release\", \"Structural basis of the CRM1 interaction not defined\"]\n    },\n    {\n      \"year\": 2000,\n      \"claim\": \"Connected NUP50 to cell-cycle regulators and development by identifying p27(Kip1) and Nup153 as partners and revealing an essential in vivo role, framing NUP50 as more than a transport factor.\",\n      \"evidence\": \"Yeast two-hybrid, co-immunoprecipitation, and gene-targeted knockout mice with phenotyping\",\n      \"pmids\": [\"10891500\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"p27 and proliferation defects absent in null MEFs, leaving the mechanism tissue-context dependent and undefined\", \"Molecular basis linking NUP50 loss to neural tube defects unknown\"]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"Defined NUP50 as a Ran-binding tri-stable switch and import cofactor, explaining mechanistically how it engages both importin-\\u03b1 and importin-\\u03b2 to drive the transport cycle.\",\n      \"evidence\": \"Domain-mapping binding assays, import reconstitution, and immunolocalization\",\n      \"pmids\": [\"12176322\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How the three binding states interconvert kinetically in vivo not resolved\", \"Stoichiometry within assembled import complexes undefined\"]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"Resolved the structural and functional logic of NUP50's importin-\\u03b1 engagement, showing two binding sites are jointly required to actively displace NLS cargo and establishing its disassembly/recycling role.\",\n      \"evidence\": \"Crystal structure of the importin-\\u03b1:Nup50 complex, site-directed mutagenesis, in vitro NLS displacement assays\",\n      \"pmids\": [\"16222336\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not address CRM1 or importin-\\u03b2 interaction geometry\", \"In vivo contribution of displacement vs recycling not quantified\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Showed isoform identity dictates the direction of NUP50 activity, with Npap60S stabilizing and Npap60L promoting release of importin-\\u03b1:NLS-cargo, adding a layer of regulatory tuning to import.\",\n      \"evidence\": \"In vitro binding assays and in vivo time-lapse nuclear import assays\",\n      \"pmids\": [\"20016008\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab; isoform ratios and their regulation in tissues unknown\", \"Structural basis for opposing isoform functions not defined\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Placed the NUP50 ortholog upstream of CDK-1 inactivation in an anoxia-induced prophase checkpoint, linking the nucleoporin to cell-cycle arrest under stress.\",\n      \"evidence\": \"C. elegans loss-of-function mutants, CDK-1 phospho-state immunofluorescence, epistasis\",\n      \"pmids\": [\"20053678\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Molecular mechanism connecting NPP-16 to CDK-1 inactivation unknown\", \"Mammalian conservation not tested\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Defined how NUP50 is anchored at the pore, identifying a dual Nup153 interface required for NUP50 localization and import efficiency.\",\n      \"evidence\": \"Domain mapping, binding assays, import efficiency assays\",\n      \"pmids\": [\"23007389\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab; relative contribution of the two interfaces in vivo unresolved\", \"Whether anchoring regulates the import switch not addressed\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Revealed NUP50 as a mobile nucleoporin whose NPC-nucleoplasm shuttling depends on active transcription, uncovering a transport-independent role in chromatin biology required for myoblast differentiation.\",\n      \"evidence\": \"FRAP/live-cell imaging, RNAi, transcription inhibition, C2C12 differentiation assay\",\n      \"pmids\": [\"24943837\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Chromatin targets engaged during differentiation not identified\", \"Mechanistic basis of transcription-dependent mobility undefined\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Implicated NUP50 in DNA double-strand break repair choice, showing it promotes 53BP1 focus recruitment in a BRCA1/BARD1-dependent manner to favor NHEJ over homologous recombination.\",\n      \"evidence\": \"RNAi depletion, 53BP1 immunofluorescence, epistasis with BRCA1/BARD1/BRCA2 knockouts\",\n      \"pmids\": [\"28751496\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct molecular link between NUP50 and 53BP1 recruitment unknown\", \"Whether this requires NPC localization or the mobile pool not resolved\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Separated NUP50's assembly function from transport, demonstrating it stimulates RCC1 to drive NPC reassembly at mitotic exit and mapping a conserved central region for Nup153/ELYS binding.\",\n      \"evidence\": \"Xenopus egg extract immunodepletion, in vitro NPC assembly, mutagenesis, RCC1 stimulation and rescue assays\",\n      \"pmids\": [\"34725842\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How RCC1 stimulation is spatially restricted during assembly not defined\", \"Relationship between assembly role and transcription-dependent mobility unexplored\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Linked NUP50 to viral biology and microRNA control, showing its knockdown impairs HIV-1 replication and that miR-191-5p represses it.\",\n      \"evidence\": \"siRNA knockdown, viral replication assay, miRNA target validation\",\n      \"pmids\": [\"33420627\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Mechanism of NUP50's role in HIV-1 replication not defined\", \"Single method without orthogonal validation\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Connected NUP50 to metabolic and oncogenic signaling, showing GALNT7-mediated O-glycosylation stabilizes NUP50, activates fatty acid \\u03b2-oxidation, and promotes lung adenocarcinoma metastasis.\",\n      \"evidence\": \"Glycosylation assays, knockdown/overexpression, NUP50-MUT rescue, xenograft and lung metastasis mouse models\",\n      \"pmids\": [\"42173248\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"How NUP50 glycosylation mechanistically activates \\u03b2-oxidation unknown\", \"Single lab; precise glycosylated residues' structural impact undefined\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Proposed a transport-independent metabolic-longevity function in which AMPK controls NUP50 abundance and its IDR transactivates lipid catabolic genes.\",\n      \"evidence\": \"C. elegans genetic epistasis, in vitro IDR-transcriptional machinery interaction, lifespan and transcriptomic analysis (preprint)\",\n      \"pmids\": [\"bio_10.1101_2025.02.17.638704\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Preprint; IDR-transcription machinery interaction details sparse\", \"Human conservation asserted but not directly demonstrated\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How NUP50's distinct activities\\u2014import-complex disassembly, CRM1-dependent export, RCC1-stimulated NPC assembly, and transcription-coupled chromatin/repair functions\\u2014are integrated and regulated within a single protein remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No unified model connecting the transport-dependent and transport-independent roles\", \"Regulatory switching between functions undefined\", \"Direct chromatin/repair binding partners not identified\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [0, 2]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [0, 2, 9]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [0, 2, 5]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005635\", \"supporting_discovery_ids\": [1, 10]},\n      {\"term_id\": \"GO:0005654\", \"supporting_discovery_ids\": [6]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-9609507\", \"supporting_discovery_ids\": [0, 1, 2]},\n      {\"term_id\": \"R-HSA-1852241\", \"supporting_discovery_ids\": [9]},\n      {\"term_id\": \"R-HSA-73894\", \"supporting_discovery_ids\": [8]}\n    ],\n    \"complexes\": [\"nuclear pore complex\"],\n    \"partners\": [\"KPNA (importin-\\u03b1)\", \"KPNB1 (importin-\\u03b2)\", \"NUP153\", \"XPO1/CRM1\", \"RCC1\", \"MEL28/ELYS\", \"CDKN1B/p27Kip1\", \"RAN\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":8,"faith_total":8,"faith_pct":100.0}}