{"gene":"NOC4L","run_date":"2026-06-10T05:19:52","timeline":{"discoveries":[{"year":2016,"finding":"NOC4L (along with NOP14 and UTP14A) forms a nucleolar subcomplex with the RNA methyltransferase EMG1 and is required for EMG1's recruitment to nucleoli, placing NOC4L as a component of a pre-ribosomal assembly module needed for small ribosomal subunit biogenesis.","method":"Co-immunoprecipitation and nucleolar recruitment assays in human cells","journal":"Human molecular genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal co-IP identifying complex membership, single lab, two orthogonal methods (co-IP + localization assay)","pmids":["27798105"],"is_preprint":false},{"year":2022,"finding":"NOC4L physically interacts with SIRT1 (via NOC4L C-terminus and SIRT1 catalytic domain) and inhibits SIRT1-mediated deacetylation of p53, thereby increasing p53 acetylation and promoting apoptosis in a p53-dependent manner under nucleolar stress.","method":"Co-immunoprecipitation in cells, in vitro direct binding assay, domain-mapping mutagenesis, overexpression/knockdown with apoptosis and acetylation readouts, nude mouse xenograft model","journal":"Oncogene","confidence":"High","confidence_rationale":"Tier 1-2 / Moderate — in vitro direct interaction confirmed, domain mapping by mutagenesis, multiple cellular readouts (acetylation, apoptosis), and in vivo xenograft; single lab but multiple orthogonal methods","pmids":["36030331"],"is_preprint":false},{"year":2021,"finding":"In macrophages, NOC4L interacts with TLR4 to inhibit TLR4 endocytosis and block the downstream TRIF signaling pathway, thereby attenuating low-grade systemic inflammation and insulin resistance; macrophage-specific Noc4l knockout in mice caused insulin resistance and systemic inflammation, while Noc4l overexpression improved glucose metabolism.","method":"Co-immunoprecipitation (NOC4L–TLR4 interaction), macrophage-specific conditional knockout, lentiviral overexpression, transgenic mouse model with metabolic phenotyping","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 2 / Moderate — reciprocal Co-IP for TLR4 interaction, genetic KO and OE in vivo with defined metabolic phenotype, single lab but multiple orthogonal approaches","pmids":["34675215"],"is_preprint":false},{"year":2019,"finding":"Conditional knockout of Noc4l in regulatory T cells (Tregs) causes a lethal autoimmune phenotype resembling Treg-deficient scurfy mice; Noc4l deficiency selectively impairs translation of mRNAs related to Treg activation without globally reducing overall protein synthesis, demonstrating that Noc4l-mediated ribosome biogenesis selectively controls Treg activation.","method":"Conditional knockout mouse model (Treg-specific), polysome/translation profiling, phenotypic characterization (autoimmune disease)","journal":"Cell reports","confidence":"High","confidence_rationale":"Tier 2 / Moderate — conditional KO with defined cellular phenotype plus translational profiling demonstrating selective rather than global translational effect; single lab, multiple orthogonal methods","pmids":["31018134"],"is_preprint":false},{"year":2023,"finding":"During KSHV lytic replication, NOC4L shows enhanced association with small ribosomal subunit precursor complexes, contributing to the composition of specialised ribosomes that preferentially translate viral mRNAs.","method":"Quantitative proteomic analysis of precursor ribosomal complexes; BUD23 depletion and ribosome profiling (NOC4L shown by proteomic association)","journal":"Nature communications","confidence":"Low","confidence_rationale":"Tier 3 / Weak — NOC4L's enhanced association is reported by proteomics but no direct functional experiment on NOC4L itself was performed; mechanistic work focused on BUD23","pmids":["36653366"],"is_preprint":false},{"year":2025,"finding":"Loss of noc4l in zebrafish disrupts 40S/80S ribosomal subunit assembly and reduces polysome levels (demonstrated by sucrose gradient analysis), causing overall translational inhibition, microcephaly, micrognathia, and embryonic lethality; pharmacological PPARγ activation partially rescues craniofacial and neurodevelopmental defects, and p53 pathway inhibition provides partial rescue independently of metabolic pathways.","method":"Zebrafish noc4l knockout, sucrose gradient sedimentation (polysome profiling), pharmacological rescue (rosiglitazone, p53 inhibitor), proliferation/apoptosis assays","journal":"Journal of molecular cell biology","confidence":"High","confidence_rationale":"Tier 2 / Moderate — genetic KO with defined developmental phenotype, direct ribosome assembly assay (sucrose gradient), pharmacological epistasis; single lab but multiple orthogonal methods","pmids":["41358835"],"is_preprint":false},{"year":2024,"finding":"NOC4L expression increases in activated CD4+ T cells and is closely associated with cell proliferation and division; in vitro co-immunoprecipitation identified interactions between NOC4L and proteins involved in ribosome assembly and cell proliferation during Th1 and Th17 activation.","method":"Flow cytometry (expression), in vitro co-immunoprecipitation (interactome during T cell activation), transgenic reporter mice (Noc4lmCherry)","journal":"Sheng wu gong cheng xue bao = Chinese journal of biotechnology","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single Co-IP/pulldown for interactors, no functional validation of individual interactions, single lab","pmids":["39584333"],"is_preprint":false}],"current_model":"NOC4L is a nucleolar ribosome biogenesis factor that forms a subcomplex with NOP14, UTP14A, and EMG1 to promote 40S small ribosomal subunit maturation; beyond this canonical housekeeping role, NOC4L exerts cell-type-specific regulatory functions by (1) binding SIRT1 to inhibit p53 deacetylation and promote apoptosis under nucleolar stress, (2) interacting with TLR4 in macrophages to block endosomal TLR4/TRIF signaling and attenuate insulin resistance, and (3) enabling selective translational programs in regulatory and conventional T cells required for their activation and immune tolerance."},"narrative":{"mechanistic_narrative":"NOC4L is a nucleolar ribosome biogenesis factor that supports maturation of the 40S small ribosomal subunit. It forms a pre-ribosomal assembly module with NOP14 and UTP14A and is required to recruit the RNA methyltransferase EMG1 to nucleoli [PMID:27798105]. Loss of NOC4L disrupts 40S/80S subunit assembly and depletes polysomes, producing global translational inhibition and developmental defects including microcephaly and micrognathia; p53 pathway inhibition partially rescues these phenotypes [PMID:41358835]. Beyond this housekeeping role, NOC4L exerts cell-type-specific regulatory functions. It physically binds SIRT1 through its C-terminus and the SIRT1 catalytic domain to inhibit SIRT1-mediated deacetylation of p53, thereby raising p53 acetylation and promoting p53-dependent apoptosis under nucleolar stress [PMID:36030331]. In macrophages, NOC4L interacts with TLR4 to block TLR4 endocytosis and downstream TRIF signaling, attenuating systemic inflammation and insulin resistance; macrophage-specific knockout causes insulin resistance while overexpression improves glucose metabolism [PMID:34675215]. In regulatory T cells, NOC4L-dependent ribosome biogenesis selectively controls translation of mRNAs required for Treg activation without globally reducing protein synthesis, and its loss produces a lethal autoimmune phenotype [PMID:31018134].","teleology":[{"year":2016,"claim":"Establishing where NOC4L acts molecularly, this work placed it within a defined pre-ribosomal assembly module required to deliver a downstream maturation enzyme to the nucleolus.","evidence":"Co-immunoprecipitation and nucleolar recruitment assays in human cells","pmids":["27798105"],"confidence":"Medium","gaps":["Direct demonstration of which 40S maturation step NOC4L catalyzes or scaffolds was not resolved","Stoichiometry and architecture of the NOC4L-NOP14-UTP14A-EMG1 module not defined","Single lab"]},{"year":2019,"claim":"This addressed whether NOC4L's ribosome role is purely housekeeping by showing it selectively governs the translational program of Treg activation rather than bulk protein synthesis.","evidence":"Treg-specific conditional knockout mouse with polysome/translation profiling and autoimmune phenotyping","pmids":["31018134"],"confidence":"High","gaps":["Mechanism conferring selectivity for activation-related mRNAs unknown","Whether selective translation is intrinsic to NOC4L or to specialized ribosomes not determined"]},{"year":2021,"claim":"This identified an extra-ribosomal signaling role, showing NOC4L restrains innate immune activation and metabolic disease by physically controlling TLR4 trafficking.","evidence":"Co-IP, macrophage-specific conditional knockout, lentiviral overexpression, and transgenic metabolic phenotyping in mice","pmids":["34675215"],"confidence":"High","gaps":["How a nucleolar factor accesses TLR4 at the membrane/endosome is unexplained","Structural basis of the NOC4L-TLR4 interaction not mapped","Relationship between this role and ribosome biogenesis unclear"]},{"year":2022,"claim":"This linked NOC4L to the p53 stress axis, showing it directly inhibits SIRT1 to boost p53 acetylation and apoptosis under nucleolar stress.","evidence":"Cellular and in vitro direct binding assays, domain-mapping mutagenesis, acetylation/apoptosis readouts, and nude mouse xenograft","pmids":["36030331"],"confidence":"High","gaps":["Whether this regulation operates in normal physiology or only stress/tumor contexts is unclear","Connection between SIRT1 binding and the ribosome biogenesis function not established"]},{"year":2023,"claim":"This raised the possibility that NOC4L contributes to specialized ribosomes co-opted during viral infection.","evidence":"Quantitative proteomics of precursor ribosomal complexes during KSHV lytic replication (NOC4L shown by association only)","pmids":["36653366"],"confidence":"Low","gaps":["No direct functional experiment on NOC4L was performed; association is correlative","Mechanistic work centered on BUD23 rather than NOC4L"]},{"year":2025,"claim":"This confirmed at the organismal level that NOC4L is essential for 40S/80S subunit assembly and that its developmental phenotypes are partly p53-driven.","evidence":"Zebrafish knockout with sucrose gradient polysome profiling and pharmacological epistasis (PPARγ activation, p53 inhibition)","pmids":["41358835"],"confidence":"High","gaps":["Molecular step in assembly directly blocked by NOC4L loss not pinpointed","Basis for tissue-selective craniofacial/neurodevelopmental vulnerability unknown"]},{"year":null,"claim":"How NOC4L reconciles its core nucleolar ribosome-assembly function with its distinct extra-ribosomal interactions (SIRT1, TLR4) across cell types remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structural model of NOC4L or its assembly module","Unknown whether moonlighting functions require nucleolar localization","Mechanism of mRNA-selective translation control undefined"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[1,2]},{"term_id":"GO:0005198","term_label":"structural molecule activity","supporting_discovery_ids":[0,5]}],"localization":[{"term_id":"GO:0005730","term_label":"nucleolus","supporting_discovery_ids":[0]}],"pathway":[{"term_id":"R-HSA-1852241","term_label":"Organelle biogenesis and maintenance","supporting_discovery_ids":[0,5]},{"term_id":"R-HSA-8953854","term_label":"Metabolism of RNA","supporting_discovery_ids":[0,3,5]}],"complexes":[],"partners":["NOP14","UTP14A","EMG1","SIRT1","TLR4"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q9BVI4","full_name":"Nucleolar complex protein 4 homolog","aliases":["NOC4-like protein","Nucleolar complex-associated protein 4-like protein"],"length_aa":516,"mass_kda":58.5,"function":"","subcellular_location":"Nucleus membrane; Nucleus, nucleolus","url":"https://www.uniprot.org/uniprotkb/Q9BVI4/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":true,"resolved_as":"","url":"https://depmap.org/portal/gene/NOC4L","classification":"Common Essential","n_dependent_lines":1178,"n_total_lines":1208,"dependency_fraction":0.9751655629139073},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"IPO5","stoichiometry":10.0},{"gene":"EMG1","stoichiometry":4.0},{"gene":"BYSL","stoichiometry":0.2},{"gene":"TSR1","stoichiometry":0.2},{"gene":"FAM207A","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/NOC4L","total_profiled":1310},"omim":[{"mim_id":"612819","title":"NUCLEOLAR COMPLEX-ASSOCIATED PROTEIN 4 HOMOLOG; NOC4L","url":"https://www.omim.org/entry/612819"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Nucleoli","reliability":"Supported"},{"location":"Nucleoplasm","reliability":"Additional"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in many","driving_tissues":[],"url":"https://www.proteinatlas.org/search/NOC4L"},"hgnc":{"alias_symbol":["MGC3162","NET49","UTP19","Noc4"],"prev_symbol":[]},"alphafold":{"accession":"Q9BVI4","domains":[{"cath_id":"-","chopping":"342-350_361-409_417-491","consensus_level":"medium","plddt":92.8144,"start":342,"end":491}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9BVI4","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9BVI4-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9BVI4-F1-predicted_aligned_error_v6.png","plddt_mean":89.44},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=NOC4L","jax_strain_url":"https://www.jax.org/strain/search?query=NOC4L"},"sequence":{"accession":"Q9BVI4","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9BVI4.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9BVI4/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9BVI4"}},"corpus_meta":[{"pmid":"27798105","id":"PMC_27798105","title":"Effects of the Bowen-Conradi syndrome mutation in EMG1 on its nuclear import, stability and nucleolar recruitment.","date":"2016","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/27798105","citation_count":40,"is_preprint":false},{"pmid":"36653366","id":"PMC_36653366","title":"Kaposi's sarcoma-associated herpesvirus induces specialised ribosomes to efficiently translate viral lytic mRNAs.","date":"2023","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/36653366","citation_count":19,"is_preprint":false},{"pmid":"31018134","id":"PMC_31018134","title":"Noc4L-Mediated Ribosome Biogenesis Controls Activation of Regulatory and Conventional T Cells.","date":"2019","source":"Cell reports","url":"https://pubmed.ncbi.nlm.nih.gov/31018134","citation_count":17,"is_preprint":false},{"pmid":"36030331","id":"PMC_36030331","title":"Nucleolar protein NOC4L inhibits tumorigenesis and progression by attenuating SIRT1-mediated p53 deacetylation.","date":"2022","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/36030331","citation_count":16,"is_preprint":false},{"pmid":"34675215","id":"PMC_34675215","title":"Macrophage deletion of Noc4l triggers endosomal TLR4/TRIF signal and leads to insulin resistance.","date":"2021","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/34675215","citation_count":13,"is_preprint":false},{"pmid":"33194643","id":"PMC_33194643","title":"Differentially Methylated Regions in Desmoid-Type Fibromatosis: A Comparison Between CTNNB1 S45F and T41A Tumors.","date":"2020","source":"Frontiers in oncology","url":"https://pubmed.ncbi.nlm.nih.gov/33194643","citation_count":12,"is_preprint":false},{"pmid":"38262548","id":"PMC_38262548","title":"Novel islands of GGC and GCC repeats coincide with human evolution.","date":"2024","source":"Gene","url":"https://pubmed.ncbi.nlm.nih.gov/38262548","citation_count":5,"is_preprint":false},{"pmid":"35702822","id":"PMC_35702822","title":"Oncogenic fusion transcript analysis identified ADAP1-NOC4L, potentially associated with metastatic colorectal cancer.","date":"2022","source":"Cancer medicine","url":"https://pubmed.ncbi.nlm.nih.gov/35702822","citation_count":3,"is_preprint":false},{"pmid":"39928227","id":"PMC_39928227","title":"Identification of critical genes and drug repurposing targets in entorhinal cortex of Alzheimer's disease.","date":"2025","source":"Neurogenetics","url":"https://pubmed.ncbi.nlm.nih.gov/39928227","citation_count":1,"is_preprint":false},{"pmid":"41358835","id":"PMC_41358835","title":"NOC4L coordinates neuronal and pharyngeal arch development by regulating ribosome biogenesis.","date":"2025","source":"Journal of molecular cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/41358835","citation_count":0,"is_preprint":false},{"pmid":"39584333","id":"PMC_39584333","title":"[Functions of nucleolar complex associated 4 homolog in activated T cells].","date":"2024","source":"Sheng wu gong cheng xue bao = Chinese journal of biotechnology","url":"https://pubmed.ncbi.nlm.nih.gov/39584333","citation_count":0,"is_preprint":false},{"pmid":"42135716","id":"PMC_42135716","title":"Multi-omics integration identifies ribosome biogenesis-active macrophage subpopulation and its key gene GNL2 in driving liver hepatocellular carcinoma progression and mechanisms.","date":"2026","source":"Cancer cell international","url":"https://pubmed.ncbi.nlm.nih.gov/42135716","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":8093,"output_tokens":1856,"usd":0.026059,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":8814,"output_tokens":2445,"usd":0.052597,"stage2_stop_reason":"end_turn"},"total_usd":0.078656,"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\": 2016,\n      \"finding\": \"NOC4L (along with NOP14 and UTP14A) forms a nucleolar subcomplex with the RNA methyltransferase EMG1 and is required for EMG1's recruitment to nucleoli, placing NOC4L as a component of a pre-ribosomal assembly module needed for small ribosomal subunit biogenesis.\",\n      \"method\": \"Co-immunoprecipitation and nucleolar recruitment assays in human cells\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal co-IP identifying complex membership, single lab, two orthogonal methods (co-IP + localization assay)\",\n      \"pmids\": [\"27798105\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"NOC4L physically interacts with SIRT1 (via NOC4L C-terminus and SIRT1 catalytic domain) and inhibits SIRT1-mediated deacetylation of p53, thereby increasing p53 acetylation and promoting apoptosis in a p53-dependent manner under nucleolar stress.\",\n      \"method\": \"Co-immunoprecipitation in cells, in vitro direct binding assay, domain-mapping mutagenesis, overexpression/knockdown with apoptosis and acetylation readouts, nude mouse xenograft model\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Moderate — in vitro direct interaction confirmed, domain mapping by mutagenesis, multiple cellular readouts (acetylation, apoptosis), and in vivo xenograft; single lab but multiple orthogonal methods\",\n      \"pmids\": [\"36030331\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"In macrophages, NOC4L interacts with TLR4 to inhibit TLR4 endocytosis and block the downstream TRIF signaling pathway, thereby attenuating low-grade systemic inflammation and insulin resistance; macrophage-specific Noc4l knockout in mice caused insulin resistance and systemic inflammation, while Noc4l overexpression improved glucose metabolism.\",\n      \"method\": \"Co-immunoprecipitation (NOC4L–TLR4 interaction), macrophage-specific conditional knockout, lentiviral overexpression, transgenic mouse model with metabolic phenotyping\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal Co-IP for TLR4 interaction, genetic KO and OE in vivo with defined metabolic phenotype, single lab but multiple orthogonal approaches\",\n      \"pmids\": [\"34675215\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"Conditional knockout of Noc4l in regulatory T cells (Tregs) causes a lethal autoimmune phenotype resembling Treg-deficient scurfy mice; Noc4l deficiency selectively impairs translation of mRNAs related to Treg activation without globally reducing overall protein synthesis, demonstrating that Noc4l-mediated ribosome biogenesis selectively controls Treg activation.\",\n      \"method\": \"Conditional knockout mouse model (Treg-specific), polysome/translation profiling, phenotypic characterization (autoimmune disease)\",\n      \"journal\": \"Cell reports\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — conditional KO with defined cellular phenotype plus translational profiling demonstrating selective rather than global translational effect; single lab, multiple orthogonal methods\",\n      \"pmids\": [\"31018134\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"During KSHV lytic replication, NOC4L shows enhanced association with small ribosomal subunit precursor complexes, contributing to the composition of specialised ribosomes that preferentially translate viral mRNAs.\",\n      \"method\": \"Quantitative proteomic analysis of precursor ribosomal complexes; BUD23 depletion and ribosome profiling (NOC4L shown by proteomic association)\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — NOC4L's enhanced association is reported by proteomics but no direct functional experiment on NOC4L itself was performed; mechanistic work focused on BUD23\",\n      \"pmids\": [\"36653366\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Loss of noc4l in zebrafish disrupts 40S/80S ribosomal subunit assembly and reduces polysome levels (demonstrated by sucrose gradient analysis), causing overall translational inhibition, microcephaly, micrognathia, and embryonic lethality; pharmacological PPARγ activation partially rescues craniofacial and neurodevelopmental defects, and p53 pathway inhibition provides partial rescue independently of metabolic pathways.\",\n      \"method\": \"Zebrafish noc4l knockout, sucrose gradient sedimentation (polysome profiling), pharmacological rescue (rosiglitazone, p53 inhibitor), proliferation/apoptosis assays\",\n      \"journal\": \"Journal of molecular cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic KO with defined developmental phenotype, direct ribosome assembly assay (sucrose gradient), pharmacological epistasis; single lab but multiple orthogonal methods\",\n      \"pmids\": [\"41358835\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"NOC4L expression increases in activated CD4+ T cells and is closely associated with cell proliferation and division; in vitro co-immunoprecipitation identified interactions between NOC4L and proteins involved in ribosome assembly and cell proliferation during Th1 and Th17 activation.\",\n      \"method\": \"Flow cytometry (expression), in vitro co-immunoprecipitation (interactome during T cell activation), transgenic reporter mice (Noc4lmCherry)\",\n      \"journal\": \"Sheng wu gong cheng xue bao = Chinese journal of biotechnology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single Co-IP/pulldown for interactors, no functional validation of individual interactions, single lab\",\n      \"pmids\": [\"39584333\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"NOC4L is a nucleolar ribosome biogenesis factor that forms a subcomplex with NOP14, UTP14A, and EMG1 to promote 40S small ribosomal subunit maturation; beyond this canonical housekeeping role, NOC4L exerts cell-type-specific regulatory functions by (1) binding SIRT1 to inhibit p53 deacetylation and promote apoptosis under nucleolar stress, (2) interacting with TLR4 in macrophages to block endosomal TLR4/TRIF signaling and attenuate insulin resistance, and (3) enabling selective translational programs in regulatory and conventional T cells required for their activation and immune tolerance.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"NOC4L is a nucleolar ribosome biogenesis factor that supports maturation of the 40S small ribosomal subunit. It forms a pre-ribosomal assembly module with NOP14 and UTP14A and is required to recruit the RNA methyltransferase EMG1 to nucleoli [#0]. Loss of NOC4L disrupts 40S/80S subunit assembly and depletes polysomes, producing global translational inhibition and developmental defects including microcephaly and micrognathia; p53 pathway inhibition partially rescues these phenotypes [#5]. Beyond this housekeeping role, NOC4L exerts cell-type-specific regulatory functions. It physically binds SIRT1 through its C-terminus and the SIRT1 catalytic domain to inhibit SIRT1-mediated deacetylation of p53, thereby raising p53 acetylation and promoting p53-dependent apoptosis under nucleolar stress [#1]. In macrophages, NOC4L interacts with TLR4 to block TLR4 endocytosis and downstream TRIF signaling, attenuating systemic inflammation and insulin resistance; macrophage-specific knockout causes insulin resistance while overexpression improves glucose metabolism [#2]. In regulatory T cells, NOC4L-dependent ribosome biogenesis selectively controls translation of mRNAs required for Treg activation without globally reducing protein synthesis, and its loss produces a lethal autoimmune phenotype [#3].\",\n  \"teleology\": [\n    {\n      \"year\": 2016,\n      \"claim\": \"Establishing where NOC4L acts molecularly, this work placed it within a defined pre-ribosomal assembly module required to deliver a downstream maturation enzyme to the nucleolus.\",\n      \"evidence\": \"Co-immunoprecipitation and nucleolar recruitment assays in human cells\",\n      \"pmids\": [\"27798105\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Direct demonstration of which 40S maturation step NOC4L catalyzes or scaffolds was not resolved\",\n        \"Stoichiometry and architecture of the NOC4L-NOP14-UTP14A-EMG1 module not defined\",\n        \"Single lab\"\n      ]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"This addressed whether NOC4L's ribosome role is purely housekeeping by showing it selectively governs the translational program of Treg activation rather than bulk protein synthesis.\",\n      \"evidence\": \"Treg-specific conditional knockout mouse with polysome/translation profiling and autoimmune phenotyping\",\n      \"pmids\": [\"31018134\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Mechanism conferring selectivity for activation-related mRNAs unknown\",\n        \"Whether selective translation is intrinsic to NOC4L or to specialized ribosomes not determined\"\n      ]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"This identified an extra-ribosomal signaling role, showing NOC4L restrains innate immune activation and metabolic disease by physically controlling TLR4 trafficking.\",\n      \"evidence\": \"Co-IP, macrophage-specific conditional knockout, lentiviral overexpression, and transgenic metabolic phenotyping in mice\",\n      \"pmids\": [\"34675215\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"How a nucleolar factor accesses TLR4 at the membrane/endosome is unexplained\",\n        \"Structural basis of the NOC4L-TLR4 interaction not mapped\",\n        \"Relationship between this role and ribosome biogenesis unclear\"\n      ]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"This linked NOC4L to the p53 stress axis, showing it directly inhibits SIRT1 to boost p53 acetylation and apoptosis under nucleolar stress.\",\n      \"evidence\": \"Cellular and in vitro direct binding assays, domain-mapping mutagenesis, acetylation/apoptosis readouts, and nude mouse xenograft\",\n      \"pmids\": [\"36030331\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Whether this regulation operates in normal physiology or only stress/tumor contexts is unclear\",\n        \"Connection between SIRT1 binding and the ribosome biogenesis function not established\"\n      ]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"This raised the possibility that NOC4L contributes to specialized ribosomes co-opted during viral infection.\",\n      \"evidence\": \"Quantitative proteomics of precursor ribosomal complexes during KSHV lytic replication (NOC4L shown by association only)\",\n      \"pmids\": [\"36653366\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"No direct functional experiment on NOC4L was performed; association is correlative\",\n        \"Mechanistic work centered on BUD23 rather than NOC4L\"\n      ]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"This confirmed at the organismal level that NOC4L is essential for 40S/80S subunit assembly and that its developmental phenotypes are partly p53-driven.\",\n      \"evidence\": \"Zebrafish knockout with sucrose gradient polysome profiling and pharmacological epistasis (PPARγ activation, p53 inhibition)\",\n      \"pmids\": [\"41358835\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Molecular step in assembly directly blocked by NOC4L loss not pinpointed\",\n        \"Basis for tissue-selective craniofacial/neurodevelopmental vulnerability unknown\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How NOC4L reconciles its core nucleolar ribosome-assembly function with its distinct extra-ribosomal interactions (SIRT1, TLR4) across cell types remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"No structural model of NOC4L or its assembly module\",\n        \"Unknown whether moonlighting functions require nucleolar localization\",\n        \"Mechanism of mRNA-selective translation control undefined\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [1, 2]},\n      {\"term_id\": \"GO:0005198\", \"supporting_discovery_ids\": [0, 5]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005730\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1852241\", \"supporting_discovery_ids\": [0, 5]},\n      {\"term_id\": \"R-HSA-8953854\", \"supporting_discovery_ids\": [0, 3, 5]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"NOP14\", \"UTP14A\", \"EMG1\", \"SIRT1\", \"TLR4\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"faith_supported":4,"faith_total":5,"faith_pct":80.0}}