{"gene":"NGDN","run_date":"2026-04-29T11:37:56","timeline":{"discoveries":[{"year":1998,"finding":"The yeast ortholog of NGDN, Lcp5p (LCP5), localizes predominantly to the nucleolus and is required for early pre-rRNA cleavage steps (A0–A2) that produce mature 18S rRNA. Depletion of Lcp5p impairs pre-rRNA processing, reduces polysome levels, and antibodies against Lcp5p immunoprecipitate the U3 snoRNA (snR17), indicating direct involvement in the small subunit processome.","method":"Genetic depletion, in vivo pre-rRNA processing assays, polysome analysis, indirect immunofluorescence, co-immunoprecipitation of snoRNA","journal":"RNA (New York, N.Y.)","confidence":"High","confidence_rationale":"Tier 2 — multiple orthogonal methods (depletion phenotype, processing assay, immunofluorescence, snoRNA co-IP) in a single rigorous study of the yeast ortholog","pmids":["9814757"],"is_preprint":false},{"year":2008,"finding":"Human NGDN (CANu1) localizes to nucleoli via its C-terminal domain, is required for maintenance of ribosomal structure, and its siRNA-mediated silencing causes ribosomal stress leading to G1 cell-cycle arrest, induction of p53, and translocation of B23 (nucleophosmin) from nucleolus to nucleoplasm. Upon UV damage, CANu1 translocates from nucleolus to nuclear foci with increased mobility.","method":"GFP-fusion localization, siRNA knockdown, cell-cycle analysis (flow cytometry), immunoblotting for p53 and B23, FRAP after UV damage","journal":"Genes to cells : devoted to molecular & cellular mechanisms","confidence":"Medium","confidence_rationale":"Tier 2 — multiple functional readouts (localization, KD phenotype, p53/B23 translocation) but single lab study","pmids":["18547334"],"is_preprint":false},{"year":2011,"finding":"shRNA-mediated depletion of Neuroguidin/CANu1 (NGDN) in human osteosarcoma U2OS cells sensitizes them to doxorubicin, increasing apoptosis ~3-fold. Mechanistically, NGDN depletion induces p21 expression and PARP cleavage and elevates caspase-3/7 activity. In the presence of doxorubicin, NGDN translocates from nucleolus to nuclear foci.","method":"shRNA knockdown, cell viability assay, apoptosis assay, immunoblotting (p21, cleaved PARP), caspase-3/7 activity assay, fluorescence microscopy","journal":"BMB reports","confidence":"Medium","confidence_rationale":"Tier 2/3 — multiple mechanistic readouts (p21, PARP, caspase) with functional KD phenotype, single lab","pmids":["21266106"],"is_preprint":false},{"year":2012,"finding":"Neuroguidin (Ngd/NGDN) functions as a translation inhibitory factor within a dendritic CPEB-associated polyadenylation complex together with poly(A) polymerase Gld2 and deadenylase PARN. Ngd opposes Gld2 in controlling dendritic mRNA polyadenylation: shRNA depletion of Ngd enhances NR2A (NMDA receptor subunit) expression in dendrites and potentiates protein synthesis-dependent long-term potentiation (LTP) at hippocampal dentate gyrus synapses.","method":"Co-immunoprecipitation, shRNA knockdown in neurons, dendritic polyadenylation assays, immunofluorescence, in vivo LTP electrophysiology","journal":"Molecular cell","confidence":"High","confidence_rationale":"Tier 1–2 — biochemical complex identification by Co-IP combined with functional KD in neurons with defined electrophysiological readout (LTP) and mRNA target identification","pmids":["22727665"],"is_preprint":false},{"year":2016,"finding":"Human NGDN (neuroguidin) forms a salt-stable trimeric complex with AATF/Che-1 and NOL10, termed the ANN complex, all localized to nucleoli. The UTP3/SAS10 domain of NGDN and the WD40 repeats of NOL10 are required for complex formation, as shown by domain-mapping experiments. All three members are mutually dependent for protein stability. The ANN complex is required for nucleolar processing of pre-rRNA at the 5'ETS and ITS1 cleavage sites, supporting 40S ribosomal subunit maturation and 18S rRNA production.","method":"Co-immunoprecipitation/immunoprecipitation (salt-stable complex), domain-mapping pulldowns, siRNA depletion of each member, pre-rRNA processing assays (Northern blot/pulse-chase), nucleolar localization by immunofluorescence","journal":"Nucleic acids research","confidence":"High","confidence_rationale":"Tier 1–2 — salt-stable complex biochemistry, domain mapping, individual KD with identical rRNA processing phenotypes, multiple orthogonal methods in one study","pmids":["27599843"],"is_preprint":false},{"year":2022,"finding":"The cryo-EM structure of the yeast Bfr2-Lcp5 complex (ortholog of the NGDN-containing module) was determined at 3.99–7.24 Å resolution within the 90S small subunit processome. The Bfr2-Lcp5 interaction interface was structurally characterized using AlphaFold-assisted modeling, validated by circular dichroism of recombinant proteins and protein-protein interaction assays. The complex interaction architecture resembles that of the exosome factors Rrp6-Rrp47, and the module regulates transitions of the 90S processome.","method":"CryoEM structure determination (3.99–7.24 Å), AlphaFold-assisted modeling, circular dichroism of recombinant proteins, protein-protein interaction validation","journal":"Communications biology","confidence":"High","confidence_rationale":"Tier 1 — cryo-EM structure with AlphaFold validation and biochemical confirmation of interactions for the yeast ortholog complex","pmids":["35650250"],"is_preprint":false},{"year":2012,"finding":"NGDN was identified as a component of the mRNA-bound proteome (mRNA interactome) of human HeLa cells by UV crosslinking and oligo(dT) purification coupled with quantitative proteomics, indicating it physically associates with mRNA in vivo.","method":"UV crosslinking, oligo(dT) purification, quantitative mass spectrometry (interactome capture)","journal":"Cell","confidence":"Medium","confidence_rationale":"Tier 2 — rigorous biochemical method (UV crosslinking + MS) identifying NGDN as an RNA-binding protein, but no functional follow-up for NGDN specifically","pmids":["22658674"],"is_preprint":false},{"year":2006,"finding":"NGDN was identified among proteins phosphorylated in vivo on the human mitotic spindle, as detected by mass spectrometry-based phosphoproteomics of purified mitotic spindles.","method":"Mass spectrometry-based phosphoproteomics from purified human mitotic spindles","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"Low","confidence_rationale":"Tier 3 — phosphorylation site identified by MS in a large-scale screen with no functional follow-up for NGDN","pmids":["16565220"],"is_preprint":false}],"current_model":"NGDN (neuroguidin/CANu1) is a nucleolar protein that functions in two established contexts: (1) as a core component of the trimeric ANN complex (with AATF and NOL10), where its UTP3/SAS10 domain mediates complex assembly and all three members cooperate to drive 5'ETS and ITS1 cleavage steps in pre-rRNA processing for 40S ribosomal subunit maturation; and (2) in dendrites, as a translation inhibitory factor within the CPEB polyadenylation complex that opposes poly(A) polymerase Gld2, thereby suppressing local mRNA polyadenylation and restraining synaptic plasticity (LTP) at hippocampal synapses."},"narrative":{"teleology":[{"year":1998,"claim":"Establishing that the NGDN ortholog Lcp5p is a nucleolar factor required for the earliest pre-rRNA cleavage events (A0–A2) answered whether this protein family participates in small ribosomal subunit biogenesis.","evidence":"Genetic depletion, pre-rRNA processing assays, polysome analysis, snoRNA co-IP, and immunofluorescence in S. cerevisiae","pmids":["9814757"],"confidence":"High","gaps":["Mammalian ortholog function not yet tested","Direct RNA-binding sites on pre-rRNA unknown","Mechanism by which Lcp5p promotes cleavage undefined"]},{"year":2008,"claim":"Demonstrating that human NGDN (CANu1) localizes to nucleoli and that its depletion causes ribosomal stress, p53 activation, and G1 arrest extended the yeast findings to a conserved mammalian ribosome biogenesis function and linked it to cell-cycle control.","evidence":"GFP-fusion imaging, siRNA knockdown, flow cytometry, immunoblotting for p53 and B23 in human cells","pmids":["18547334"],"confidence":"Medium","gaps":["Specific rRNA processing step affected in human cells not mapped","Whether p53 induction is direct or secondary to ribosomal stress not distinguished","UV-induced translocation mechanism unclear"]},{"year":2011,"claim":"Showing that NGDN depletion sensitizes cells to doxorubicin-induced apoptosis with p21 induction and caspase activation revealed that ribosomal stress from NGDN loss cooperates with DNA damage signaling.","evidence":"shRNA knockdown, viability/apoptosis assays, immunoblotting for p21 and cleaved PARP, caspase-3/7 activity in U2OS cells","pmids":["21266106"],"confidence":"Medium","gaps":["Causal relationship between rRNA processing defect and drug sensitivity not formally tested","Whether NGDN has a direct role in DNA damage response versus indirect ribosomal stress remains unresolved"]},{"year":2012,"claim":"Identifying NGDN as a translation-inhibitory factor within the dendritic CPEB–Gld2–PARN complex that controls NR2A mRNA polyadenylation and LTP established a second, cytoplasmic role for NGDN distinct from ribosome biogenesis.","evidence":"Co-immunoprecipitation, shRNA knockdown in hippocampal neurons, dendritic polyadenylation assays, in vivo LTP electrophysiology","pmids":["22727665"],"confidence":"High","gaps":["Full repertoire of CPEB-target mRNAs regulated by NGDN unknown","Structural basis of NGDN–CPEB interaction unresolved","How NGDN partitions between nucleolar and dendritic pools unclear"]},{"year":2012,"claim":"UV-crosslinking interactome capture confirmed NGDN as an in vivo mRNA-binding protein in human cells, consistent with its dual roles in rRNA and mRNA metabolism.","evidence":"UV crosslinking, oligo(dT) purification, quantitative mass spectrometry in HeLa cells","pmids":["22658674"],"confidence":"Medium","gaps":["Specific mRNA targets bound by NGDN not identified","Whether mRNA binding reflects cytoplasmic CPEB function, nucleolar function, or both is unknown"]},{"year":2016,"claim":"Biochemical characterization of the salt-stable ANN complex (AATF–NGDN–NOL10), with domain-mapping showing the UTP3/SAS10 domain of NGDN is essential for assembly, and demonstration that all three subunits are required for 5'ETS and ITS1 cleavage, defined the molecular unit through which NGDN acts in 40S maturation.","evidence":"Co-IP/domain-mapping pulldowns, siRNA depletion of each member, Northern blot and pulse-chase pre-rRNA processing in human cells","pmids":["27599843"],"confidence":"High","gaps":["How the ANN complex is recruited to the pre-ribosomal particle in human cells unknown","Whether additional factors bridge ANN to the U3 snoRNP not determined"]},{"year":2022,"claim":"Cryo-EM structure of the yeast Bfr2–Lcp5 module within the 90S processome provided the first atomic-level view of how the NGDN ortholog integrates into the ribosome assembly machinery and revealed an interaction architecture resembling the exosome cofactor Rrp6–Rrp47 pair.","evidence":"Cryo-EM (3.99–7.24 Å), AlphaFold-assisted modeling, circular dichroism, protein–protein interaction assays in yeast","pmids":["35650250"],"confidence":"High","gaps":["Human ANN complex structure not yet determined","Functional significance of the Rrp6–Rrp47-like architecture for processome transitions not tested in vivo","How post-translational modifications regulate the Bfr2–Lcp5 module unknown"]},{"year":null,"claim":"How NGDN partitions between its nucleolar ribosome biogenesis role and its cytoplasmic CPEB-dependent translational control role, whether cell-type-specific mechanisms govern this partitioning, and whether a high-resolution structure of the human ANN complex can be obtained remain major open questions.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structural data for the human ANN complex","Regulatory signals controlling NGDN nucleolar vs. dendritic localization unknown","Physiological consequences of NGDN loss in vivo (knockout animal) not reported"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0003723","term_label":"RNA binding","supporting_discovery_ids":[0,3,6]},{"term_id":"GO:0045182","term_label":"translation regulator activity","supporting_discovery_ids":[3]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[3]}],"localization":[{"term_id":"GO:0005730","term_label":"nucleolus","supporting_discovery_ids":[0,1,4]},{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[1,2]}],"pathway":[{"term_id":"R-HSA-8953854","term_label":"Metabolism of RNA","supporting_discovery_ids":[0,4,5]},{"term_id":"R-HSA-392499","term_label":"Metabolism of proteins","supporting_discovery_ids":[0,4,5]},{"term_id":"R-HSA-112316","term_label":"Neuronal System","supporting_discovery_ids":[3]}],"complexes":["ANN complex (AATF–NGDN–NOL10)","CPEB polyadenylation complex","90S small subunit processome (yeast ortholog)"],"partners":["AATF","NOL10","CPEB1","PAPD4","PARN"],"other_free_text":[]},"mechanistic_narrative":"NGDN (neuroguidin/CANu1) is a nucleolar RNA-binding protein that functions in ribosome biogenesis and translational control. Within the nucleolus, NGDN assembles with AATF and NOL10 into the salt-stable trimeric ANN complex via its UTP3/SAS10 domain; all three subunits are mutually required for stability and for pre-rRNA cleavage at the 5'ETS and ITS1 sites that generate mature 18S rRNA for 40S subunit biogenesis [PMID:27599843, PMID:9814757]. Loss of NGDN triggers ribosomal stress, p53 induction, G1 arrest, and sensitization to DNA-damaging agents [PMID:18547334, PMID:21266106]. In hippocampal dendrites, NGDN acts as a translation-inhibitory factor within the CPEB polyadenylation complex, opposing poly(A) polymerase Gld2 to suppress local mRNA polyadenylation and restrain protein synthesis-dependent long-term potentiation [PMID:22727665]."},"prefetch_data":{"uniprot":{"accession":"Q8NEJ9","full_name":"Neuroguidin","aliases":["Centromere accumulated nuclear protein 1","CANu1","EIF4E-binding protein"],"length_aa":315,"mass_kda":35.9,"function":"Part of the small subunit (SSU) processome, first precursor of the small eukaryotic ribosomal subunit. During the assembly of the SSU processome in the nucleolus, many ribosome biogenesis factors, an RNA chaperone and ribosomal proteins associate with the nascent pre-rRNA and work in concert to generate RNA folding, modifications, rearrangements and cleavage as well as targeted degradation of pre-ribosomal RNA by the RNA exosome. Its dissociation from the complex determines the transition from state pre-A1 to state pre-A1* (PubMed:34516797). Inhibits mRNA translation in a cytoplasmic polyadenylation element (CPE)-dependent manner (By similarity)","subcellular_location":"Nucleus; Nucleus, nucleolus; Chromosome, centromere; Cytoplasm; Cell projection, axon; Cell projection, dendrite; Cell projection, filopodium","url":"https://www.uniprot.org/uniprotkb/Q8NEJ9/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":true,"resolved_as":"","url":"https://depmap.org/portal/gene/NGDN","classification":"Common Essential","n_dependent_lines":613,"n_total_lines":1208,"dependency_fraction":0.5074503311258278},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"AATF","stoichiometry":4.0}],"url":"https://opencell.sf.czbiohub.org/search/NGDN","total_profiled":1310},"omim":[{"mim_id":"610777","title":"NEUROGUIDIN; NGDN","url":"https://www.omim.org/entry/610777"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Nucleoli","reliability":"Approved"},{"location":"Mitochondria","reliability":"Approved"},{"location":"Nucleoplasm","reliability":"Additional"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/NGDN"},"hgnc":{"alias_symbol":["DKFZP564O092","LCP5","lpd-2","NGD","CANu1"],"prev_symbol":["C14orf120"]},"alphafold":{"accession":"Q8NEJ9","domains":[{"cath_id":"-","chopping":"226-264","consensus_level":"medium","plddt":84.0551,"start":226,"end":264},{"cath_id":"1.20.58","chopping":"16-120","consensus_level":"medium","plddt":90.6828,"start":16,"end":120},{"cath_id":"1.20.5","chopping":"186-218","consensus_level":"medium","plddt":85.3676,"start":186,"end":218}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8NEJ9","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q8NEJ9-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q8NEJ9-F1-predicted_aligned_error_v6.png","plddt_mean":75.75},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=NGDN","jax_strain_url":"https://www.jax.org/strain/search?query=NGDN"},"sequence":{"accession":"Q8NEJ9","fasta_url":"https://rest.uniprot.org/uniprotkb/Q8NEJ9.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q8NEJ9/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8NEJ9"}},"corpus_meta":[{"pmid":"9262371","id":"PMC_9262371","title":"II. 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cellular proteomics : MCP","url":"https://pubmed.ncbi.nlm.nih.gov/30021884","citation_count":101,"is_preprint":false,"source_track":"gene2pubmed"}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":9107,"output_tokens":1414,"usd":0.024265},"stage2":{"model":"claude-opus-4-6","input_tokens":4639,"output_tokens":1785,"usd":0.10173},"total_usd":0.314293,"stage1_batch_id":"msgbatch_012ZiiCUBfB62NCTQd4Bk1Jo","stage2_batch_id":"msgbatch_01Xuqq9aUHoQouS7UVGZNStZ","note":"batch pricing = 50% of standard","round2_stage1":{"model":"claude-sonnet-4-6","input_tokens":20927,"output_tokens":3791,"usd":0.059823},"round2_rules_fired":"R3","round2_stage2":{"model":"claude-opus-4-6","input_tokens":5860,"output_tokens":2254,"usd":0.128475}},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2016,\n      \"finding\": \"Human NGDN (neuroguidin) forms a salt-stable trimeric protein complex with AATF/Che-1 and NOL10, designated the ANN complex, which localizes to nucleoli and functions in 40S ribosomal subunit biogenesis. The UTP3/SAS10 domain of NGDN is required for complex formation. All three ANN complex members are required for 18S rRNA maturation, specifically affecting nucleolar cleavage steps in the 5'ETS and ITS1 regions of the ribosomal RNA precursor.\",\n      \"method\": \"Immunoprecipitation, domain mapping, siRNA depletion, Northern blotting for pre-rRNA processing intermediates\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal Co-IP, domain mapping, multiple orthogonal functional assays (depletion + pre-rRNA processing analysis), moderate evidence from single lab\",\n      \"pmids\": [\"27599843\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"NGDN (CANu1) localizes to nucleoli via its C-terminus, and siRNA-mediated silencing causes ribosomal stress, G1 cell cycle arrest, induction of p53, and translocation of B23 from the nucleolus. Upon UV damage, NGDN translocates from nucleolus to nuclear foci and shows increased mobility (FRAP).\",\n      \"method\": \"GFP fusion localization, siRNA knockdown, FRAP, immunofluorescence\",\n      \"journal\": \"Genes to cells : devoted to molecular & cellular mechanisms\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2/3 — direct localization experiment with functional consequence (KD + defined phenotype), single lab with multiple readouts\",\n      \"pmids\": [\"18547334\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"Depletion of NGDN (Neuroguidin/CANu1) in human U2OS osteosarcoma cells sensitizes them to doxorubicin-induced apoptosis, induces p21 expression, PARP cleavage, and increased caspase-3/7 activity; NGDN translocates from nucleoli to nuclear foci in response to doxorubicin.\",\n      \"method\": \"shRNA knockdown, flow cytometry (apoptosis), caspase activity assay, immunofluorescence\",\n      \"journal\": \"BMB reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 — single lab, single knockdown approach with multiple phenotypic readouts but limited mechanistic depth\",\n      \"pmids\": [\"21266106\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1998,\n      \"finding\": \"Yeast Lcp5p (ortholog of NGDN) is an essential nucleolar protein required for early pre-rRNA cleavage steps A0–A2 leading to mature 18S rRNA, and antibodies against Lcp5p co-immunoprecipitate the U3 snoRNA (snR17), indicating direct involvement in pre-rRNA processing.\",\n      \"method\": \"Conditional mutant analysis, in vivo depletion, polysome profiling, indirect immunofluorescence, RNA co-immunoprecipitation\",\n      \"journal\": \"RNA (New York, N.Y.)\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — ortholog in S. cerevisiae, multiple orthogonal methods (genetic, biochemical, localization), foundational paper with 44 citations\",\n      \"pmids\": [\"9814757\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"The yeast Bfr2-Lcp5 complex (Bfr2 is ortholog of NGDN's partner; Lcp5 is ortholog of NGDN) was resolved by AlphaFold-assisted cryo-EM within the 90S small subunit processome at 3.99–7.24 Å resolution. The complex facilitates incorporation of the 5' domain of 18S rRNA into the 90S processome prior to A1 cleavage, and its interaction mode mimics the exosome Rrp6-Rrp47 complex.\",\n      \"method\": \"CryoEM structure determination (AlphaFold-assisted), circular dichroism, protein-protein interaction assays\",\n      \"journal\": \"Communications biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 — cryo-EM structure with functional context in yeast ortholog, single study\",\n      \"pmids\": [\"35650250\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"NGDN (neuroguidin/CANu1) is an essential nucleolar protein that forms a stable trimeric complex (ANN complex) with AATF and NOL10 via its UTP3/SAS10 domain, localizes to the nucleolus through its C-terminus, and is required for early pre-rRNA cleavage steps (5'ETS and ITS1) that produce the 18S rRNA of the 40S ribosomal subunit; its yeast ortholog Lcp5p associates with the U3 snoRNA and the 90S processome, and its depletion causes ribosomal stress, p53 induction, and G1 arrest.\"\n}\n```\n\n--- ROUND 2 (R2/R3, augmented corpus) ---\n\nI'll classify each paper first, then extract discoveries only from KEEP papers.\n\n**Classification:**\n\n- [1] (PMID:9262371) — NGD 94-1 is a dopamine D4 receptor ligand. EXCLUDE (alias collision — \"NGD\" here is a drug compound name, not the gene NGDN).\n- [2] (PMID:9814757) — LCP5 in yeast, involved in 18S rRNA maturation. This is the yeast ortholog of NGDN (Lcp5p/Bfr2 is the yeast ortholog). KEEP.\n- [3] (PMID:9262370) — NGD 94-1 dopamine D4 antagonist. EXCLUDE (alias collision).\n- [4] (PMID:29901258) — NGD = nicotinamide guanine dinucleotide. EXCLUDE (alias collision).\n- [5] (PMID:31511627) — NGD = nicotinamide guanine dinucleotide. EXCLUDE.\n- [6] (PMID:24040053) — NGD 98-2 and NGD 9002 are CRF1 receptor antagonists. EXCLUDE.\n- [7] (PMID:27599843) — AATF/Che-1 forms complex with NGDN and NOL10. KEEP.\n- [8] (PMID:30112426) — NGD = nicotinamide guanine dinucleotide. EXCLUDE.\n- [9] (PMID:10395031) — NGD 94-1 dopamine D4. EXCLUDE.\n- [10] (PMID:21618986) — NGD 98-2 CRF-1 antagonist. EXCLUDE.\n- [11] (PMID:18547334) — CANu1 (alternate name for NGDN/neuroguidin). KEEP.\n- [12] (PMID:15693171) — Aspergillus niger NGd-280 (fungal strain). EXCLUDE (symbol collision, unrelated organism context).\n- [13] (PMID:35142296) — NGD = nodular gill disease. EXCLUDE.\n- [14] (PMID:35650250) — Bfr2-Lcp5 complex in yeast (ortholog of NGDN). KEEP.\n- [15] (PMID:21266106) — Neuroguidin/CANu1 depletion in osteosarcoma cells. KEEP.\n- [16] (PMID:40207436) — NGD = nodular gill disease. EXCLUDE.\n\n**Gene2pubmed additional papers:**\n- PMID:32353859 — SARS-CoV-2 interactome; NGDN may appear as a hit but this is a large screen, not a mechanistic study of NGDN specifically. However, if NGDN is identified as a physical interactor, it could be noted. The abstract mentions 332 interactions but doesn't specifically describe NGDN mechanism. EXCLUDE (no specific NGDN mechanistic finding described).\n- PMID:22658674 — mRNA interactome; NGDN may be identified as RBP. This is relevant if NGDN is identified as RNA-binding. KEEP (NGDN identified as mRNA-binding protein).\n- PMID:12477932 — MGC cDNA sequencing. EXCLUDE (no mechanistic finding).\n- PMID:26186194 — BioPlex interactome. EXCLUDE (large screen, no specific NGDN mechanism described in abstract).\n- PMID:28514442 — BioPlex 2.0. EXCLUDE (same).\n- PMID:26496610 — Human interactome. EXCLUDE.\n- PMID:25416956 — Human interactome. EXCLUDE.\n- PMID:22681889 — mRNA-bound proteome. KEEP (identifies NGDN as RNA-binding).\n- PMID:32296183 — HuRI. EXCLUDE.\n- PMID:14702039 — FLJ cDNA. EXCLUDE.\n- PMID:33961781 — BioPlex 3.0. EXCLUDE.\n- PMID:21873635 — GO phylogenetic. EXCLUDE.\n- PMID:33060197 — Comparative coronavirus. EXCLUDE.\n- PMID:15489334 — MGC. EXCLUDE.\n- PMID:35271311 — OpenCell. KEEP (localization data for NGDN).\n- PMID:26344197 — Metazoan complexes. EXCLUDE (abstract doesn't specifically describe NGDN).\n- PMID:34079125 — BioID proximity map. EXCLUDE (abstract level).\n- PMID:16565220 — Phosphoproteome of mitotic spindle. KEEP (NGDN phosphorylation identified).\n- PMID:17207965 — hORFeome. EXCLUDE.\n- PMID:29568061 — MAC-tag. EXCLUDE.\n- PMID:25468996 — E-cadherin interactome. EXCLUDE.\n- PMID:30804502 — BRCA1-BARD1. EXCLUDE.\n- PMID:30177828 — Zika virus. EXCLUDE.\n- PMID:27926873 — FOXA1/MLL3. EXCLUDE.\n- PMID:21081503 — PRMT5/RioK1. EXCLUDE.\n- PMID:24457600 — EED/PRC. EXCLUDE.\n- PMID:22727665 — CPEB polyadenylation, neuroguidin (Ngd). KEEP.\n- PMID:33545068 — Autophagy receptor cargo. EXCLUDE.\n- PMID:29478914 — DCPS/AML. EXCLUDE.\n- PMID:30021884 — Histone crosslinking MS. EXCLUDE.\n\n```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1998,\n      \"finding\": \"The yeast ortholog of NGDN, Lcp5p (LCP5), localizes predominantly to the nucleolus and is required for early pre-rRNA cleavage steps (A0–A2) that produce mature 18S rRNA. Depletion of Lcp5p impairs pre-rRNA processing, reduces polysome levels, and antibodies against Lcp5p immunoprecipitate the U3 snoRNA (snR17), indicating direct involvement in the small subunit processome.\",\n      \"method\": \"Genetic depletion, in vivo pre-rRNA processing assays, polysome analysis, indirect immunofluorescence, co-immunoprecipitation of snoRNA\",\n      \"journal\": \"RNA (New York, N.Y.)\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal methods (depletion phenotype, processing assay, immunofluorescence, snoRNA co-IP) in a single rigorous study of the yeast ortholog\",\n      \"pmids\": [\"9814757\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"Human NGDN (CANu1) localizes to nucleoli via its C-terminal domain, is required for maintenance of ribosomal structure, and its siRNA-mediated silencing causes ribosomal stress leading to G1 cell-cycle arrest, induction of p53, and translocation of B23 (nucleophosmin) from nucleolus to nucleoplasm. Upon UV damage, CANu1 translocates from nucleolus to nuclear foci with increased mobility.\",\n      \"method\": \"GFP-fusion localization, siRNA knockdown, cell-cycle analysis (flow cytometry), immunoblotting for p53 and B23, FRAP after UV damage\",\n      \"journal\": \"Genes to cells : devoted to molecular & cellular mechanisms\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — multiple functional readouts (localization, KD phenotype, p53/B23 translocation) but single lab study\",\n      \"pmids\": [\"18547334\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"shRNA-mediated depletion of Neuroguidin/CANu1 (NGDN) in human osteosarcoma U2OS cells sensitizes them to doxorubicin, increasing apoptosis ~3-fold. Mechanistically, NGDN depletion induces p21 expression and PARP cleavage and elevates caspase-3/7 activity. In the presence of doxorubicin, NGDN translocates from nucleolus to nuclear foci.\",\n      \"method\": \"shRNA knockdown, cell viability assay, apoptosis assay, immunoblotting (p21, cleaved PARP), caspase-3/7 activity assay, fluorescence microscopy\",\n      \"journal\": \"BMB reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2/3 — multiple mechanistic readouts (p21, PARP, caspase) with functional KD phenotype, single lab\",\n      \"pmids\": [\"21266106\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Neuroguidin (Ngd/NGDN) functions as a translation inhibitory factor within a dendritic CPEB-associated polyadenylation complex together with poly(A) polymerase Gld2 and deadenylase PARN. Ngd opposes Gld2 in controlling dendritic mRNA polyadenylation: shRNA depletion of Ngd enhances NR2A (NMDA receptor subunit) expression in dendrites and potentiates protein synthesis-dependent long-term potentiation (LTP) at hippocampal dentate gyrus synapses.\",\n      \"method\": \"Co-immunoprecipitation, shRNA knockdown in neurons, dendritic polyadenylation assays, immunofluorescence, in vivo LTP electrophysiology\",\n      \"journal\": \"Molecular cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 — biochemical complex identification by Co-IP combined with functional KD in neurons with defined electrophysiological readout (LTP) and mRNA target identification\",\n      \"pmids\": [\"22727665\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Human NGDN (neuroguidin) forms a salt-stable trimeric complex with AATF/Che-1 and NOL10, termed the ANN complex, all localized to nucleoli. The UTP3/SAS10 domain of NGDN and the WD40 repeats of NOL10 are required for complex formation, as shown by domain-mapping experiments. All three members are mutually dependent for protein stability. The ANN complex is required for nucleolar processing of pre-rRNA at the 5'ETS and ITS1 cleavage sites, supporting 40S ribosomal subunit maturation and 18S rRNA production.\",\n      \"method\": \"Co-immunoprecipitation/immunoprecipitation (salt-stable complex), domain-mapping pulldowns, siRNA depletion of each member, pre-rRNA processing assays (Northern blot/pulse-chase), nucleolar localization by immunofluorescence\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 — salt-stable complex biochemistry, domain mapping, individual KD with identical rRNA processing phenotypes, multiple orthogonal methods in one study\",\n      \"pmids\": [\"27599843\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"The cryo-EM structure of the yeast Bfr2-Lcp5 complex (ortholog of the NGDN-containing module) was determined at 3.99–7.24 Å resolution within the 90S small subunit processome. The Bfr2-Lcp5 interaction interface was structurally characterized using AlphaFold-assisted modeling, validated by circular dichroism of recombinant proteins and protein-protein interaction assays. The complex interaction architecture resembles that of the exosome factors Rrp6-Rrp47, and the module regulates transitions of the 90S processome.\",\n      \"method\": \"CryoEM structure determination (3.99–7.24 Å), AlphaFold-assisted modeling, circular dichroism of recombinant proteins, protein-protein interaction validation\",\n      \"journal\": \"Communications biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — cryo-EM structure with AlphaFold validation and biochemical confirmation of interactions for the yeast ortholog complex\",\n      \"pmids\": [\"35650250\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"NGDN was identified as a component of the mRNA-bound proteome (mRNA interactome) of human HeLa cells by UV crosslinking and oligo(dT) purification coupled with quantitative proteomics, indicating it physically associates with mRNA in vivo.\",\n      \"method\": \"UV crosslinking, oligo(dT) purification, quantitative mass spectrometry (interactome capture)\",\n      \"journal\": \"Cell\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — rigorous biochemical method (UV crosslinking + MS) identifying NGDN as an RNA-binding protein, but no functional follow-up for NGDN specifically\",\n      \"pmids\": [\"22658674\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"NGDN was identified among proteins phosphorylated in vivo on the human mitotic spindle, as detected by mass spectrometry-based phosphoproteomics of purified mitotic spindles.\",\n      \"method\": \"Mass spectrometry-based phosphoproteomics from purified human mitotic spindles\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 — phosphorylation site identified by MS in a large-scale screen with no functional follow-up for NGDN\",\n      \"pmids\": [\"16565220\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"NGDN (neuroguidin/CANu1) is a nucleolar protein that functions in two established contexts: (1) as a core component of the trimeric ANN complex (with AATF and NOL10), where its UTP3/SAS10 domain mediates complex assembly and all three members cooperate to drive 5'ETS and ITS1 cleavage steps in pre-rRNA processing for 40S ribosomal subunit maturation; and (2) in dendrites, as a translation inhibitory factor within the CPEB polyadenylation complex that opposes poly(A) polymerase Gld2, thereby suppressing local mRNA polyadenylation and restraining synaptic plasticity (LTP) at hippocampal synapses.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"NGDN (neuroguidin/CANu1) is a nucleolar protein essential for 40S ribosomal subunit biogenesis, functioning in early pre-rRNA cleavage steps that generate mature 18S rRNA. It forms a salt-stable trimeric complex (ANN) with AATF and NOL10 via its UTP3/SAS10 domain, and this complex is required for cleavage in the 5'ETS and ITS1 regions of the pre-rRNA precursor [PMID:27599843]. The yeast ortholog Lcp5p associates with U3 snoRNA and the 90S processome, where cryo-EM reveals that the Bfr2–Lcp5 complex facilitates incorporation of the 18S rRNA 5' domain prior to A1 cleavage [PMID:9814757, PMID:35650250]. Depletion of NGDN causes ribosomal stress, p53 induction, G1 arrest, and sensitization to genotoxic agents [PMID:18547334, PMID:21266106].\",\n  \"teleology\": [\n    {\n      \"year\": 1998,\n      \"claim\": \"Identification of Lcp5p as an essential nucleolar factor for 18S rRNA maturation established that the NGDN gene family is directly required for early pre-rRNA cleavage and linked it to the U3 snoRNA machinery.\",\n      \"evidence\": \"Conditional depletion of Lcp5p in S. cerevisiae with polysome profiling, RNA co-IP of U3 snoRNA, and indirect immunofluorescence\",\n      \"pmids\": [\"9814757\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"No direct binding partners of Lcp5p beyond U3 snoRNA were identified\",\n        \"Structural basis for Lcp5p function within the processome was unknown\",\n        \"Whether the human ortholog shared identical cleavage requirements was untested\"\n      ]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Demonstrating that human NGDN localizes to nucleoli via its C-terminus and that its depletion triggers ribosomal stress, p53 activation, and G1 arrest established the cellular consequences of NGDN loss in mammalian cells.\",\n      \"evidence\": \"GFP fusion localization, siRNA knockdown, FRAP, and immunofluorescence in human cells\",\n      \"pmids\": [\"18547334\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"The direct molecular target or rRNA processing step affected by NGDN depletion in human cells was not determined\",\n        \"The mechanism linking NGDN loss to p53 induction (nucleolar stress vs. DNA damage) was not dissected\",\n        \"Protein complex partners of human NGDN were not identified\"\n      ]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Showing that NGDN depletion sensitizes cancer cells to doxorubicin-induced apoptosis revealed a functional connection between NGDN's nucleolar role and genotoxic stress responses.\",\n      \"evidence\": \"shRNA knockdown in U2OS cells with apoptosis assays, caspase activity, and immunofluorescence\",\n      \"pmids\": [\"21266106\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Whether sensitization is a direct effect of impaired ribosome biogenesis or a separate DNA-damage function was not resolved\",\n        \"No rescue experiments were performed to confirm specificity\"\n      ]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Discovery of the ANN complex (AATF–NGDN–NOL10) and the requirement of NGDN's UTP3/SAS10 domain for complex formation defined the molecular framework through which NGDN promotes 5'ETS and ITS1 cleavage in human pre-rRNA processing.\",\n      \"evidence\": \"Reciprocal immunoprecipitation, domain truncation mapping, siRNA depletion with Northern blot analysis of pre-rRNA intermediates\",\n      \"pmids\": [\"27599843\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Whether the ANN complex contacts rRNA or snoRNAs directly was not determined\",\n        \"No structural information for the human ANN complex was obtained\",\n        \"How the ANN complex integrates into the human SSU processome was not resolved\"\n      ]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Cryo-EM resolution of the yeast Bfr2–Lcp5 complex within the 90S processome revealed how the NGDN ortholog facilitates 18S rRNA 5' domain incorporation and provided the first structural framework for its mechanism.\",\n      \"evidence\": \"AlphaFold-assisted cryo-EM at 3.99–7.24 Å resolution of the yeast 90S processome with protein interaction assays\",\n      \"pmids\": [\"35650250\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Structure is of the yeast orthologs; whether the human ANN complex occupies an equivalent position is unknown\",\n        \"Functional validation of the structural contacts (e.g., site-directed mutagenesis) was not performed\",\n        \"The exosome Rrp6–Rrp47 mimicry was noted but its functional significance was not tested\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"A high-resolution structure of the human ANN complex and its position within the human SSU processome, as well as the direct RNA contacts made by NGDN, remain uncharacterized.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"No structure of the human ANN complex exists\",\n        \"Whether NGDN directly binds pre-rRNA or snoRNAs in human cells has not been tested by CLIP or crosslinking\",\n        \"The mechanistic basis of NGDN's nucleolar-to-nuclear translocation upon DNA damage is undefined\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0003723\", \"supporting_discovery_ids\": [3, 4]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005730\", \"supporting_discovery_ids\": [0, 1, 3]},\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [1, 2]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-8953854\", \"supporting_discovery_ids\": [0, 3, 4]},\n      {\"term_id\": \"R-HSA-392499\", \"supporting_discovery_ids\": [0, 3]}\n    ],\n    \"complexes\": [\n      \"ANN complex (AATF-NGDN-NOL10)\",\n      \"90S processome (SSU processome, via yeast ortholog)\"\n    ],\n    \"partners\": [\n      \"AATF\",\n      \"NOL10\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```\n\n--- ROUND 2 (R2/R3, augmented corpus) ---\n\n```json\n{\n  \"mechanistic_narrative\": \"NGDN (neuroguidin/CANu1) is a nucleolar RNA-binding protein that functions in ribosome biogenesis and translational control. Within the nucleolus, NGDN assembles with AATF and NOL10 into the salt-stable trimeric ANN complex via its UTP3/SAS10 domain; all three subunits are mutually required for stability and for pre-rRNA cleavage at the 5'ETS and ITS1 sites that generate mature 18S rRNA for 40S subunit biogenesis [PMID:27599843, PMID:9814757]. Loss of NGDN triggers ribosomal stress, p53 induction, G1 arrest, and sensitization to DNA-damaging agents [PMID:18547334, PMID:21266106]. In hippocampal dendrites, NGDN acts as a translation-inhibitory factor within the CPEB polyadenylation complex, opposing poly(A) polymerase Gld2 to suppress local mRNA polyadenylation and restrain protein synthesis-dependent long-term potentiation [PMID:22727665].\",\n  \"teleology\": [\n    {\n      \"year\": 1998,\n      \"claim\": \"Establishing that the NGDN ortholog Lcp5p is a nucleolar factor required for the earliest pre-rRNA cleavage events (A0–A2) answered whether this protein family participates in small ribosomal subunit biogenesis.\",\n      \"evidence\": \"Genetic depletion, pre-rRNA processing assays, polysome analysis, snoRNA co-IP, and immunofluorescence in S. cerevisiae\",\n      \"pmids\": [\"9814757\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mammalian ortholog function not yet tested\", \"Direct RNA-binding sites on pre-rRNA unknown\", \"Mechanism by which Lcp5p promotes cleavage undefined\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Demonstrating that human NGDN (CANu1) localizes to nucleoli and that its depletion causes ribosomal stress, p53 activation, and G1 arrest extended the yeast findings to a conserved mammalian ribosome biogenesis function and linked it to cell-cycle control.\",\n      \"evidence\": \"GFP-fusion imaging, siRNA knockdown, flow cytometry, immunoblotting for p53 and B23 in human cells\",\n      \"pmids\": [\"18547334\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Specific rRNA processing step affected in human cells not mapped\", \"Whether p53 induction is direct or secondary to ribosomal stress not distinguished\", \"UV-induced translocation mechanism unclear\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Showing that NGDN depletion sensitizes cells to doxorubicin-induced apoptosis with p21 induction and caspase activation revealed that ribosomal stress from NGDN loss cooperates with DNA damage signaling.\",\n      \"evidence\": \"shRNA knockdown, viability/apoptosis assays, immunoblotting for p21 and cleaved PARP, caspase-3/7 activity in U2OS cells\",\n      \"pmids\": [\"21266106\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Causal relationship between rRNA processing defect and drug sensitivity not formally tested\", \"Whether NGDN has a direct role in DNA damage response versus indirect ribosomal stress remains unresolved\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Identifying NGDN as a translation-inhibitory factor within the dendritic CPEB–Gld2–PARN complex that controls NR2A mRNA polyadenylation and LTP established a second, cytoplasmic role for NGDN distinct from ribosome biogenesis.\",\n      \"evidence\": \"Co-immunoprecipitation, shRNA knockdown in hippocampal neurons, dendritic polyadenylation assays, in vivo LTP electrophysiology\",\n      \"pmids\": [\"22727665\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Full repertoire of CPEB-target mRNAs regulated by NGDN unknown\", \"Structural basis of NGDN–CPEB interaction unresolved\", \"How NGDN partitions between nucleolar and dendritic pools unclear\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"UV-crosslinking interactome capture confirmed NGDN as an in vivo mRNA-binding protein in human cells, consistent with its dual roles in rRNA and mRNA metabolism.\",\n      \"evidence\": \"UV crosslinking, oligo(dT) purification, quantitative mass spectrometry in HeLa cells\",\n      \"pmids\": [\"22658674\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Specific mRNA targets bound by NGDN not identified\", \"Whether mRNA binding reflects cytoplasmic CPEB function, nucleolar function, or both is unknown\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Biochemical characterization of the salt-stable ANN complex (AATF–NGDN–NOL10), with domain-mapping showing the UTP3/SAS10 domain of NGDN is essential for assembly, and demonstration that all three subunits are required for 5'ETS and ITS1 cleavage, defined the molecular unit through which NGDN acts in 40S maturation.\",\n      \"evidence\": \"Co-IP/domain-mapping pulldowns, siRNA depletion of each member, Northern blot and pulse-chase pre-rRNA processing in human cells\",\n      \"pmids\": [\"27599843\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How the ANN complex is recruited to the pre-ribosomal particle in human cells unknown\", \"Whether additional factors bridge ANN to the U3 snoRNP not determined\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Cryo-EM structure of the yeast Bfr2–Lcp5 module within the 90S processome provided the first atomic-level view of how the NGDN ortholog integrates into the ribosome assembly machinery and revealed an interaction architecture resembling the exosome cofactor Rrp6–Rrp47 pair.\",\n      \"evidence\": \"Cryo-EM (3.99–7.24 Å), AlphaFold-assisted modeling, circular dichroism, protein–protein interaction assays in yeast\",\n      \"pmids\": [\"35650250\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Human ANN complex structure not yet determined\", \"Functional significance of the Rrp6–Rrp47-like architecture for processome transitions not tested in vivo\", \"How post-translational modifications regulate the Bfr2–Lcp5 module unknown\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How NGDN partitions between its nucleolar ribosome biogenesis role and its cytoplasmic CPEB-dependent translational control role, whether cell-type-specific mechanisms govern this partitioning, and whether a high-resolution structure of the human ANN complex can be obtained remain major open questions.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No structural data for the human ANN complex\", \"Regulatory signals controlling NGDN nucleolar vs. dendritic localization unknown\", \"Physiological consequences of NGDN loss in vivo (knockout animal) not reported\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0003723\", \"supporting_discovery_ids\": [0, 3, 6]},\n      {\"term_id\": \"GO:0045182\", \"supporting_discovery_ids\": [3]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [3]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005730\", \"supporting_discovery_ids\": [0, 1, 4]},\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [1, 2]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-8953854\", \"supporting_discovery_ids\": [0, 4, 5]},\n      {\"term_id\": \"R-HSA-392499\", \"supporting_discovery_ids\": [0, 4, 5]},\n      {\"term_id\": \"R-HSA-112316\", \"supporting_discovery_ids\": [3]}\n    ],\n    \"complexes\": [\n      \"ANN complex (AATF–NGDN–NOL10)\",\n      \"CPEB polyadenylation complex\",\n      \"90S small subunit processome (yeast ortholog)\"\n    ],\n    \"partners\": [\n      \"AATF\",\n      \"NOL10\",\n      \"CPEB1\",\n      \"PAPD4\",\n      \"PARN\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```"}