{"gene":"ZCCHC3","run_date":"2026-06-11T09:02:06","timeline":{"discoveries":[{"year":2018,"finding":"ZCCHC3 directly binds dsRNA and enhances the binding of RIG-I and MDA5 to dsRNA, functioning as a co-receptor for RLRs. Additionally, ZCCHC3 recruits the E3 ubiquitin ligase TRIM25 to RIG-I and MDA5 complexes to facilitate K63-linked polyubiquitination and activation of these receptors.","method":"Co-immunoprecipitation, RNA binding assays, KO mouse model with viral challenge, downstream gene induction assays","journal":"Immunity","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP, KO mice with viral phenotype, multiple orthogonal methods (RNA binding, ubiquitination assays), replicated context","pmids":["30193849"],"is_preprint":false},{"year":2018,"finding":"ZCCHC3 directly binds dsDNA and enhances the binding of cGAS to dsDNA, functioning as a co-sensor for cGAS-mediated innate immune signaling. ZCCHC3-deficient mice are more susceptible to HSV-1 and vaccinia virus infection.","method":"dsDNA binding assays, Co-immunoprecipitation, KO mouse model with viral challenge, downstream effector gene induction assays","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 2 / Strong — direct DNA binding assay, co-IP, KO mice with in vivo phenotype, multiple orthogonal methods","pmids":["30135424"],"is_preprint":false},{"year":2020,"finding":"ZCCHC3 promotes recruitment of the adaptor TRIF to TLR3 following poly(I:C) stimulation, thereby positively regulating TLR3-mediated (but not TLR4-mediated) type I interferon and proinflammatory cytokine induction. Zcchc3-/- mice were more resistant to poly(I:C)-induced inflammatory death.","method":"Co-immunoprecipitation, KO mouse model, overexpression studies, downstream gene induction assays","journal":"Journal of molecular cell biology","confidence":"High","confidence_rationale":"Tier 2 / Moderate — Co-IP, KO mice with in vivo phenotype, specificity confirmed by TLR4 negative control","pmids":["32133501"],"is_preprint":false},{"year":2025,"finding":"ZCCHC3 harbors multiple nucleic-acid-binding modules and undergoes liquid-phase condensation upon RNA or DNA binding. RNA-induced ZCCHC3 condensates enrich and activate RLRs and facilitate RLR interaction with MAVS, including assembly of active MAVS filaments confirmed by high-resolution structural analysis. ZCCHC3 also promotes condensation and enrichment of DNA, cGAS, ATP, and GTP, enhancing cGAS signaling. ZCCHC3 mutants defective in RNA/DNA-induced condensation lost regulatory efficiency in both pathways.","method":"Liquid phase condensation assays, cryo-EM/high-resolution structural determination of condensates, mutagenesis, Co-IP, in vitro reconstitution in human cell lines","journal":"Molecular cell","confidence":"High","confidence_rationale":"Tier 1 / Strong — structure determination, mutagenesis, reconstitution, multiple orthogonal methods in single rigorous study","pmids":["39983719"],"is_preprint":false},{"year":2023,"finding":"ZCCHC3 is a stress granule protein that severely restricts LINE-1 retrotransposition. It associates with the LINE-1 ORF1p ribonucleoprotein particle, colocalizes with ORF1p in stress granules, and connects with the RNA exosome complex (a multi-subunit ribonuclease). ZCCHC3 also associates with retrotransposon/antiviral restriction factors MOV10 and ZAP.","method":"Retrotransposition reporter assays, co-immunoprecipitation, subcellular localization (immunofluorescence/stress granule markers), velocity gradient centrifugation","journal":"PLoS genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal methods (co-IP, localization, gradient centrifugation, functional reporter), single lab","pmids":["37405998"],"is_preprint":false},{"year":2022,"finding":"ZCCHC3 inhibits LINE-1 retrotransposition in a manner dependent on its zinc-finger domain. It post-transcriptionally reduces LINE-1 RNA levels by interacting with LINE-1 RNA and ORF1 protein, associating with the LINE-1 RNP and causing RNA degradation.","method":"Retrotransposition reporter assays, zinc-finger domain mutagenesis, RNA co-immunoprecipitation, RT-qPCR for LINE-1 RNA levels","journal":"Frontiers in microbiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional reporter assay with mutagenesis and RNA co-IP, single lab, two orthogonal methods","pmids":["36274734"],"is_preprint":false},{"year":2024,"finding":"ZCCHC3 restricts HIV-1 production through a dual mechanism: (1) it binds to HIV-1 Gag nucleocapsid (GagNC) via its zinc-finger motifs, inhibiting viral genome recruitment and resulting in genome-deficient virion production; (2) it binds to the long terminal repeat (LTR) on the viral genome via a middle-folded domain, sequestering the viral genome to P-bodies and decreasing viral replication.","method":"Co-immunoprecipitation (ZCCHC3–GagNC interaction), live-cell imaging/subcellular localization (P-bodies), virion RNA quantification, domain mutagenesis","journal":"iScience","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP, localization imaging, functional viral assay, mutagenesis; single lab, multiple orthogonal methods","pmids":["38384847"],"is_preprint":false},{"year":2024,"finding":"ZCCHC3 and Efp (an E3 ubiquitin ligase) coordinately promote triple-negative breast cancer cell proliferation by regulating NCAPH expression. ZCCHC3 silencing downregulated NCAPH and repressed TNBC cell proliferation in vitro and tumor growth in vivo.","method":"siRNA knockdown, RNA-sequencing, 3D spheroid culture, xenograft mouse model","journal":"Biochemical and biophysical research communications","confidence":"Low","confidence_rationale":"Tier 3 / Weak — KD with phenotype and transcriptomic readout, but no direct biochemical mechanism linking ZCCHC3 to NCAPH regulation; single lab, single approach","pmids":["39276521"],"is_preprint":false},{"year":2025,"finding":"ZCCHC3 interacts with PEDV N (nucleocapsid) proteins and co-localizes with them. ZCCHC3-mediated inhibition of PEDV replication depends on its zinc finger protease activity, and ZCCHC3 promotes degradation of N proteins via the proteasome pathway.","method":"Co-immunoprecipitation, co-localization, overexpression/knockdown with viral titer measurement, proteasome inhibitor assays","journal":"Veterinary microbiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP, co-localization, proteasome pathway functional assay, single lab, multiple orthogonal methods","pmids":["40068467"],"is_preprint":false},{"year":2026,"finding":"Urocanic acid (UCA) directly binds to the ZCCHC3 protein (confirmed by molecular docking and Drug Affinity Responsive Target Stability assay). ZCCHC3 overexpression activates the cGAS/STING pathway and exacerbates cellular senescence; UCA inhibits this pathway by binding to ZCCHC3.","method":"Molecular docking, Drug Affinity Responsive Target Stability (DARTS) assay combined with Western blot, overexpression in cell and mouse models","journal":"Neurochemical research","confidence":"Low","confidence_rationale":"Tier 3 / Weak — DARTS binding assay and overexpression phenotype, single lab, limited mechanistic detail on how UCA-ZCCHC3 binding suppresses cGAS/STING","pmids":["41885959"],"is_preprint":false}],"current_model":"ZCCHC3 is a multi-functional innate immune co-sensor and restriction factor that binds both dsRNA and dsDNA through multiple nucleic-acid-binding modules; upon nucleic acid engagement it undergoes liquid-phase condensation that enriches and activates RIG-I/MDA5 (facilitating their interaction with MAVS and K63-ubiquitination via TRIM25), enhances cGAS binding to dsDNA and cGAMP synthesis, promotes TRIF recruitment to TLR3, restricts LINE-1 retrotransposition by associating with the L1 ORF1p RNP in stress granules and directing RNA degradation via the RNA exosome, and suppresses HIV-1 and other retroviruses through a dual mechanism involving zinc-finger-mediated GagNC binding (blocking genome packaging) and LTR-binding-mediated viral genome sequestration to P-bodies."},"narrative":{"mechanistic_narrative":"ZCCHC3 is a nucleic-acid-binding co-sensor that potentiates multiple arms of innate antiviral immunity by recognizing both viral RNA and DNA [PMID:30193849, PMID:30135424]. In the RNA-sensing pathway it directly binds dsRNA, enhances dsRNA recognition by RIG-I and MDA5, and recruits the E3 ligase TRIM25 to drive K63-linked polyubiquitination and activation of these receptors [PMID:30193849]; in the DNA-sensing pathway it binds dsDNA and enhances cGAS engagement of DNA, with ZCCHC3-deficient mice showing increased susceptibility to HSV-1 and vaccinia virus [PMID:30135424]. It also promotes recruitment of the adaptor TRIF to TLR3 to support TLR3-restricted type I interferon induction [PMID:32133501]. The unifying biophysical mechanism is liquid-phase condensation: upon RNA or DNA binding ZCCHC3 forms condensates that enrich and activate RLRs, facilitate RLR engagement of MAVS and assembly of active MAVS filaments, and concentrate DNA, cGAS, ATP and GTP to enhance cGAS signaling, with condensation-defective mutants losing activity in both pathways [PMID:39983719]. Beyond pathogen sensing, ZCCHC3 acts as a restriction factor: it binds LINE-1 RNA and the ORF1p ribonucleoprotein in stress granules and routes LINE-1 RNA to degradation via the RNA exosome in a zinc-finger-dependent manner [PMID:37405998, PMID:36274734], and it suppresses HIV-1 through zinc-finger-mediated binding of Gag nucleocapsid that blocks genome packaging together with LTR binding that sequesters the viral genome to P-bodies [PMID:38384847].","teleology":[{"year":2018,"claim":"Established ZCCHC3 as an RLR co-receptor, answering how RIG-I/MDA5 dsRNA sensing is enhanced and linked to ubiquitin-dependent activation.","evidence":"Co-IP, RNA binding assays, and KO mouse viral challenge with downstream gene induction readouts","pmids":["30193849"],"confidence":"High","gaps":["Did not resolve the structural basis of dsRNA binding","Stoichiometry of the ZCCHC3–RIG-I/MDA5–TRIM25 assembly not defined"]},{"year":2018,"claim":"Extended ZCCHC3 function to the DNA-sensing axis, showing it is also a cGAS co-sensor required for full antiviral defense against DNA viruses.","evidence":"dsDNA binding assays, Co-IP, and KO mice challenged with HSV-1 and vaccinia virus","pmids":["30135424"],"confidence":"High","gaps":["How one protein discriminates or simultaneously serves DNA and RNA pathways not addressed","Direct effect on cGAMP output not quantified at this stage"]},{"year":2020,"claim":"Showed ZCCHC3 also operates upstream in TLR3 signaling by promoting TRIF adaptor recruitment, broadening its role beyond cytosolic sensors.","evidence":"Co-IP, overexpression, and KO mice with poly(I:C)-induced inflammatory death, with TLR4 as negative control","pmids":["32133501"],"confidence":"High","gaps":["Direct ZCCHC3–TLR3 or ZCCHC3–TRIF binding interface not mapped","Relationship between endosomal TLR3 role and cytosolic RLR role unclear"]},{"year":2022,"claim":"Identified ZCCHC3 as a LINE-1 restriction factor acting post-transcriptionally, defining a non-immune-signaling activity.","evidence":"Retrotransposition reporter assays, zinc-finger mutagenesis, RNA co-IP, and RT-qPCR of LINE-1 RNA","pmids":["36274734"],"confidence":"Medium","gaps":["Single lab","Direct ribonuclease activity vs. recruitment of a nuclease not distinguished"]},{"year":2023,"claim":"Placed LINE-1 restriction in stress granules and connected it to the RNA exosome, providing a degradation route for ORF1p-bound RNA.","evidence":"Retrotransposition reporters, Co-IP, stress-granule immunofluorescence, and velocity gradient centrifugation","pmids":["37405998"],"confidence":"Medium","gaps":["Single lab","Whether ZCCHC3 directly bridges ORF1p RNP to the exosome or acts via MOV10/ZAP unresolved"]},{"year":2024,"claim":"Defined a dual zinc-finger/LTR-binding mechanism by which ZCCHC3 restricts HIV-1, linking nucleic-acid binding to both packaging block and P-body sequestration.","evidence":"Co-IP of ZCCHC3–GagNC, P-body imaging, virion RNA quantification, and domain mutagenesis","pmids":["38384847"],"confidence":"Medium","gaps":["Single lab","Generality across other retroviruses not tested directly"]},{"year":2025,"claim":"Unified the RNA and DNA co-sensing functions under a single biophysical mechanism—nucleic-acid-induced condensation that concentrates and activates sensors and adaptors.","evidence":"Liquid-phase condensation assays, high-resolution structural analysis of MAVS filaments, mutagenesis, and in vitro reconstitution in human cells","pmids":["39983719"],"confidence":"High","gaps":["Whether condensation is also required for the TLR3, LINE-1, and HIV-1 functions not tested","In vivo relevance of condensation thresholds unknown"]},{"year":2025,"claim":"Extended antiviral activity to a coronavirus by showing ZCCHC3 drives proteasomal degradation of PEDV nucleocapsid.","evidence":"Co-IP, co-localization, knockdown/overexpression viral titer assays, and proteasome inhibitor experiments","pmids":["40068467"],"confidence":"Medium","gaps":["Single lab","Whether ZCCHC3 itself has protease/ligase activity or recruits one is not biochemically resolved"]},{"year":null,"claim":"Whether the condensation mechanism, zinc-finger nucleic-acid binding, and protein-degradation activities are mechanistically linked across the antiviral, retrotransposon-restriction, and reported cancer/senescence contexts remains open.","evidence":"","pmids":[],"confidence":"Low","gaps":["No structural model of ZCCHC3 itself","Reported TNBC/NCAPH and senescence roles rest on low-confidence single-lab phenotypes without direct biochemical mechanism"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0003723","term_label":"RNA binding","supporting_discovery_ids":[0,3,5]},{"term_id":"GO:0003677","term_label":"DNA binding","supporting_discovery_ids":[1,3]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[0,1,2,3]},{"term_id":"GO:0060089","term_label":"molecular transducer activity","supporting_discovery_ids":[0,1]}],"localization":[{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[0,1,3]},{"term_id":"GO:0031410","term_label":"cytoplasmic vesicle","supporting_discovery_ids":[4,6]}],"pathway":[{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[0,1,2]},{"term_id":"R-HSA-1643685","term_label":"Disease","supporting_discovery_ids":[4,5,6]},{"term_id":"R-HSA-8953854","term_label":"Metabolism of RNA","supporting_discovery_ids":[4,5]}],"complexes":[],"partners":["RIGI","MDA5","TRIM25","CGAS","TRIF","MOV10","ZAP"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q9NUD5","full_name":"Zinc finger CCHC domain-containing protein 3","aliases":[],"length_aa":403,"mass_kda":43.5,"function":"Nucleic acid-binding protein involved in innate immune response to DNA and RNA viruses (PubMed:30135424, PubMed:30193849). Binds DNA and RNA in the cytoplasm and acts by promoting recognition of viral nucleic acids by virus sensors, such as RIGI, IFIH1/MDA5 and CGAS (PubMed:30135424, PubMed:30193849). Acts as a co-sensor for recognition of double-stranded DNA (dsDNA) by cGAS in the cytoplasm, thereby playing a role in innate immune response to cytosolic dsDNA and DNA virus (PubMed:30135424). Binds dsDNA and probably acts by promoting sensing of dsDNA by CGAS, leading to enhance CGAS oligomerization and activation (PubMed:30135424). Promotes sensing of viral RNA by RIGI-like receptors proteins RIGI and IFIH1/MDA5 via two mechanisms: binds double-stranded RNA (dsRNA), enhancing the binding of RIGI and IFIH1/MDA5 to dsRNA and promotes 'Lys-63'-linked ubiquitination and subsequent activation of RIGI and IFIH1/MDA5 (PubMed:30193849)","subcellular_location":"Cytoplasm","url":"https://www.uniprot.org/uniprotkb/Q9NUD5/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/ZCCHC3","classification":"Not Classified","n_dependent_lines":1,"n_total_lines":1208,"dependency_fraction":0.0008278145695364238},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"ATG4B","stoichiometry":0.2},{"gene":"CALM2","stoichiometry":0.2},{"gene":"CALM3","stoichiometry":0.2},{"gene":"CFAP298","stoichiometry":0.2},{"gene":"SFPQ","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/ZCCHC3","total_profiled":1310},"omim":[{"mim_id":"618326","title":"ZINC FINGER CCHC DOMAIN-CONTAINING PROTEIN 3; ZCCHC3","url":"https://www.omim.org/entry/618326"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Vesicles","reliability":"Approved"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/ZCCHC3"},"hgnc":{"alias_symbol":["dJ1103G7.7"],"prev_symbol":["C20orf99"]},"alphafold":{"accession":"Q9NUD5","domains":[{"cath_id":"3.30.70.260","chopping":"164-249","consensus_level":"medium","plddt":86.9276,"start":164,"end":249}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9NUD5","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9NUD5-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9NUD5-F1-predicted_aligned_error_v6.png","plddt_mean":65.75},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=ZCCHC3","jax_strain_url":"https://www.jax.org/strain/search?query=ZCCHC3"},"sequence":{"accession":"Q9NUD5","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9NUD5.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9NUD5/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9NUD5"}},"corpus_meta":[{"pmid":"30193849","id":"PMC_30193849","title":"The Zinc-Finger Protein ZCCHC3 Binds RNA and Facilitates Viral RNA Sensing and Activation of the RIG-I-like Receptors.","date":"2018","source":"Immunity","url":"https://pubmed.ncbi.nlm.nih.gov/30193849","citation_count":124,"is_preprint":false},{"pmid":"30135424","id":"PMC_30135424","title":"ZCCHC3 is a co-sensor of cGAS for dsDNA recognition in innate immune response.","date":"2018","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/30135424","citation_count":118,"is_preprint":false},{"pmid":"32133501","id":"PMC_32133501","title":"ZCCHC3 modulates TLR3-mediated signaling by promoting recruitment of TRIF to TLR3.","date":"2020","source":"Journal of molecular cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/32133501","citation_count":27,"is_preprint":false},{"pmid":"33204608","id":"PMC_33204608","title":"ELF1-activated FOXD3-AS1 promotes the migration, invasion and EMT of osteosarcoma cells via sponging miR-296-5p to upregulate ZCCHC3.","date":"2020","source":"Journal of bone oncology","url":"https://pubmed.ncbi.nlm.nih.gov/33204608","citation_count":18,"is_preprint":false},{"pmid":"39983719","id":"PMC_39983719","title":"Nucleic-acid-induced ZCCHC3 condensation promotes broad innate immune responses.","date":"2025","source":"Molecular cell","url":"https://pubmed.ncbi.nlm.nih.gov/39983719","citation_count":12,"is_preprint":false},{"pmid":"37405998","id":"PMC_37405998","title":"ZCCHC3 is a stress granule zinc knuckle protein that strongly suppresses LINE-1 retrotransposition.","date":"2023","source":"PLoS genetics","url":"https://pubmed.ncbi.nlm.nih.gov/37405998","citation_count":8,"is_preprint":false},{"pmid":"39276521","id":"PMC_39276521","title":"ZCCHC3 and Efp coordinately contribute to the pathophysiology of triple-negative breast cancer by modulating NCAPH.","date":"2024","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/39276521","citation_count":6,"is_preprint":false},{"pmid":"38384847","id":"PMC_38384847","title":"Host ZCCHC3 blocks HIV-1 infection and production through a dual mechanism.","date":"2024","source":"iScience","url":"https://pubmed.ncbi.nlm.nih.gov/38384847","citation_count":4,"is_preprint":false},{"pmid":"36274734","id":"PMC_36274734","title":"The Zinc-Finger protein ZCCHC3 inhibits LINE-1 retrotransposition.","date":"2022","source":"Frontiers in microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/36274734","citation_count":1,"is_preprint":false},{"pmid":"40068467","id":"PMC_40068467","title":"ZCCHC3 inhibits PEDV proliferation by degrading nuclear coat proteins via the proteasome pathway.","date":"2025","source":"Veterinary microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/40068467","citation_count":0,"is_preprint":false},{"pmid":"41885959","id":"PMC_41885959","title":"Urocanic Acid Alleviates Cognitive Impairment by Targeting ZCCHC3 and Suppressing the cGAS-STING-Mediated Senescence.","date":"2026","source":"Neurochemical research","url":"https://pubmed.ncbi.nlm.nih.gov/41885959","citation_count":0,"is_preprint":false},{"pmid":"40054441","id":"PMC_40054441","title":"Come together, right now! ZCCHC3 orchestrates cytosolic nucleic acid sensing through phase condensation.","date":"2025","source":"Molecular cell","url":"https://pubmed.ncbi.nlm.nih.gov/40054441","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":7315,"output_tokens":2674,"usd":0.031027,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":9923,"output_tokens":3047,"usd":0.062895,"stage2_stop_reason":"end_turn"},"total_usd":0.093922,"stage1_batch_id":"msgbatch_01UT1AahFPCAyn2uVweS7A9z","stage2_batch_id":"msgbatch_01HuKWtKNT4Pqj1bc8eEP5RV","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2018,\n      \"finding\": \"ZCCHC3 directly binds dsRNA and enhances the binding of RIG-I and MDA5 to dsRNA, functioning as a co-receptor for RLRs. Additionally, ZCCHC3 recruits the E3 ubiquitin ligase TRIM25 to RIG-I and MDA5 complexes to facilitate K63-linked polyubiquitination and activation of these receptors.\",\n      \"method\": \"Co-immunoprecipitation, RNA binding assays, KO mouse model with viral challenge, downstream gene induction assays\",\n      \"journal\": \"Immunity\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP, KO mice with viral phenotype, multiple orthogonal methods (RNA binding, ubiquitination assays), replicated context\",\n      \"pmids\": [\"30193849\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"ZCCHC3 directly binds dsDNA and enhances the binding of cGAS to dsDNA, functioning as a co-sensor for cGAS-mediated innate immune signaling. ZCCHC3-deficient mice are more susceptible to HSV-1 and vaccinia virus infection.\",\n      \"method\": \"dsDNA binding assays, Co-immunoprecipitation, KO mouse model with viral challenge, downstream effector gene induction assays\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — direct DNA binding assay, co-IP, KO mice with in vivo phenotype, multiple orthogonal methods\",\n      \"pmids\": [\"30135424\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"ZCCHC3 promotes recruitment of the adaptor TRIF to TLR3 following poly(I:C) stimulation, thereby positively regulating TLR3-mediated (but not TLR4-mediated) type I interferon and proinflammatory cytokine induction. Zcchc3-/- mice were more resistant to poly(I:C)-induced inflammatory death.\",\n      \"method\": \"Co-immunoprecipitation, KO mouse model, overexpression studies, downstream gene induction assays\",\n      \"journal\": \"Journal of molecular cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP, KO mice with in vivo phenotype, specificity confirmed by TLR4 negative control\",\n      \"pmids\": [\"32133501\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"ZCCHC3 harbors multiple nucleic-acid-binding modules and undergoes liquid-phase condensation upon RNA or DNA binding. RNA-induced ZCCHC3 condensates enrich and activate RLRs and facilitate RLR interaction with MAVS, including assembly of active MAVS filaments confirmed by high-resolution structural analysis. ZCCHC3 also promotes condensation and enrichment of DNA, cGAS, ATP, and GTP, enhancing cGAS signaling. ZCCHC3 mutants defective in RNA/DNA-induced condensation lost regulatory efficiency in both pathways.\",\n      \"method\": \"Liquid phase condensation assays, cryo-EM/high-resolution structural determination of condensates, mutagenesis, Co-IP, in vitro reconstitution in human cell lines\",\n      \"journal\": \"Molecular cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — structure determination, mutagenesis, reconstitution, multiple orthogonal methods in single rigorous study\",\n      \"pmids\": [\"39983719\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"ZCCHC3 is a stress granule protein that severely restricts LINE-1 retrotransposition. It associates with the LINE-1 ORF1p ribonucleoprotein particle, colocalizes with ORF1p in stress granules, and connects with the RNA exosome complex (a multi-subunit ribonuclease). ZCCHC3 also associates with retrotransposon/antiviral restriction factors MOV10 and ZAP.\",\n      \"method\": \"Retrotransposition reporter assays, co-immunoprecipitation, subcellular localization (immunofluorescence/stress granule markers), velocity gradient centrifugation\",\n      \"journal\": \"PLoS genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal methods (co-IP, localization, gradient centrifugation, functional reporter), single lab\",\n      \"pmids\": [\"37405998\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"ZCCHC3 inhibits LINE-1 retrotransposition in a manner dependent on its zinc-finger domain. It post-transcriptionally reduces LINE-1 RNA levels by interacting with LINE-1 RNA and ORF1 protein, associating with the LINE-1 RNP and causing RNA degradation.\",\n      \"method\": \"Retrotransposition reporter assays, zinc-finger domain mutagenesis, RNA co-immunoprecipitation, RT-qPCR for LINE-1 RNA levels\",\n      \"journal\": \"Frontiers in microbiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional reporter assay with mutagenesis and RNA co-IP, single lab, two orthogonal methods\",\n      \"pmids\": [\"36274734\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"ZCCHC3 restricts HIV-1 production through a dual mechanism: (1) it binds to HIV-1 Gag nucleocapsid (GagNC) via its zinc-finger motifs, inhibiting viral genome recruitment and resulting in genome-deficient virion production; (2) it binds to the long terminal repeat (LTR) on the viral genome via a middle-folded domain, sequestering the viral genome to P-bodies and decreasing viral replication.\",\n      \"method\": \"Co-immunoprecipitation (ZCCHC3–GagNC interaction), live-cell imaging/subcellular localization (P-bodies), virion RNA quantification, domain mutagenesis\",\n      \"journal\": \"iScience\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP, localization imaging, functional viral assay, mutagenesis; single lab, multiple orthogonal methods\",\n      \"pmids\": [\"38384847\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"ZCCHC3 and Efp (an E3 ubiquitin ligase) coordinately promote triple-negative breast cancer cell proliferation by regulating NCAPH expression. ZCCHC3 silencing downregulated NCAPH and repressed TNBC cell proliferation in vitro and tumor growth in vivo.\",\n      \"method\": \"siRNA knockdown, RNA-sequencing, 3D spheroid culture, xenograft mouse model\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — KD with phenotype and transcriptomic readout, but no direct biochemical mechanism linking ZCCHC3 to NCAPH regulation; single lab, single approach\",\n      \"pmids\": [\"39276521\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"ZCCHC3 interacts with PEDV N (nucleocapsid) proteins and co-localizes with them. ZCCHC3-mediated inhibition of PEDV replication depends on its zinc finger protease activity, and ZCCHC3 promotes degradation of N proteins via the proteasome pathway.\",\n      \"method\": \"Co-immunoprecipitation, co-localization, overexpression/knockdown with viral titer measurement, proteasome inhibitor assays\",\n      \"journal\": \"Veterinary microbiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP, co-localization, proteasome pathway functional assay, single lab, multiple orthogonal methods\",\n      \"pmids\": [\"40068467\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"Urocanic acid (UCA) directly binds to the ZCCHC3 protein (confirmed by molecular docking and Drug Affinity Responsive Target Stability assay). ZCCHC3 overexpression activates the cGAS/STING pathway and exacerbates cellular senescence; UCA inhibits this pathway by binding to ZCCHC3.\",\n      \"method\": \"Molecular docking, Drug Affinity Responsive Target Stability (DARTS) assay combined with Western blot, overexpression in cell and mouse models\",\n      \"journal\": \"Neurochemical research\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — DARTS binding assay and overexpression phenotype, single lab, limited mechanistic detail on how UCA-ZCCHC3 binding suppresses cGAS/STING\",\n      \"pmids\": [\"41885959\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"ZCCHC3 is a multi-functional innate immune co-sensor and restriction factor that binds both dsRNA and dsDNA through multiple nucleic-acid-binding modules; upon nucleic acid engagement it undergoes liquid-phase condensation that enriches and activates RIG-I/MDA5 (facilitating their interaction with MAVS and K63-ubiquitination via TRIM25), enhances cGAS binding to dsDNA and cGAMP synthesis, promotes TRIF recruitment to TLR3, restricts LINE-1 retrotransposition by associating with the L1 ORF1p RNP in stress granules and directing RNA degradation via the RNA exosome, and suppresses HIV-1 and other retroviruses through a dual mechanism involving zinc-finger-mediated GagNC binding (blocking genome packaging) and LTR-binding-mediated viral genome sequestration to P-bodies.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"ZCCHC3 is a nucleic-acid-binding co-sensor that potentiates multiple arms of innate antiviral immunity by recognizing both viral RNA and DNA [#0, #1]. In the RNA-sensing pathway it directly binds dsRNA, enhances dsRNA recognition by RIG-I and MDA5, and recruits the E3 ligase TRIM25 to drive K63-linked polyubiquitination and activation of these receptors [#0]; in the DNA-sensing pathway it binds dsDNA and enhances cGAS engagement of DNA, with ZCCHC3-deficient mice showing increased susceptibility to HSV-1 and vaccinia virus [#1]. It also promotes recruitment of the adaptor TRIF to TLR3 to support TLR3-restricted type I interferon induction [#2]. The unifying biophysical mechanism is liquid-phase condensation: upon RNA or DNA binding ZCCHC3 forms condensates that enrich and activate RLRs, facilitate RLR engagement of MAVS and assembly of active MAVS filaments, and concentrate DNA, cGAS, ATP and GTP to enhance cGAS signaling, with condensation-defective mutants losing activity in both pathways [#3]. Beyond pathogen sensing, ZCCHC3 acts as a restriction factor: it binds LINE-1 RNA and the ORF1p ribonucleoprotein in stress granules and routes LINE-1 RNA to degradation via the RNA exosome in a zinc-finger-dependent manner [#4, #5], and it suppresses HIV-1 through zinc-finger-mediated binding of Gag nucleocapsid that blocks genome packaging together with LTR binding that sequesters the viral genome to P-bodies [#6].\",\n  \"teleology\": [\n    {\n      \"year\": 2018,\n      \"claim\": \"Established ZCCHC3 as an RLR co-receptor, answering how RIG-I/MDA5 dsRNA sensing is enhanced and linked to ubiquitin-dependent activation.\",\n      \"evidence\": \"Co-IP, RNA binding assays, and KO mouse viral challenge with downstream gene induction readouts\",\n      \"pmids\": [\"30193849\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not resolve the structural basis of dsRNA binding\", \"Stoichiometry of the ZCCHC3–RIG-I/MDA5–TRIM25 assembly not defined\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Extended ZCCHC3 function to the DNA-sensing axis, showing it is also a cGAS co-sensor required for full antiviral defense against DNA viruses.\",\n      \"evidence\": \"dsDNA binding assays, Co-IP, and KO mice challenged with HSV-1 and vaccinia virus\",\n      \"pmids\": [\"30135424\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How one protein discriminates or simultaneously serves DNA and RNA pathways not addressed\", \"Direct effect on cGAMP output not quantified at this stage\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Showed ZCCHC3 also operates upstream in TLR3 signaling by promoting TRIF adaptor recruitment, broadening its role beyond cytosolic sensors.\",\n      \"evidence\": \"Co-IP, overexpression, and KO mice with poly(I:C)-induced inflammatory death, with TLR4 as negative control\",\n      \"pmids\": [\"32133501\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct ZCCHC3–TLR3 or ZCCHC3–TRIF binding interface not mapped\", \"Relationship between endosomal TLR3 role and cytosolic RLR role unclear\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Identified ZCCHC3 as a LINE-1 restriction factor acting post-transcriptionally, defining a non-immune-signaling activity.\",\n      \"evidence\": \"Retrotransposition reporter assays, zinc-finger mutagenesis, RNA co-IP, and RT-qPCR of LINE-1 RNA\",\n      \"pmids\": [\"36274734\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab\", \"Direct ribonuclease activity vs. recruitment of a nuclease not distinguished\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Placed LINE-1 restriction in stress granules and connected it to the RNA exosome, providing a degradation route for ORF1p-bound RNA.\",\n      \"evidence\": \"Retrotransposition reporters, Co-IP, stress-granule immunofluorescence, and velocity gradient centrifugation\",\n      \"pmids\": [\"37405998\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab\", \"Whether ZCCHC3 directly bridges ORF1p RNP to the exosome or acts via MOV10/ZAP unresolved\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Defined a dual zinc-finger/LTR-binding mechanism by which ZCCHC3 restricts HIV-1, linking nucleic-acid binding to both packaging block and P-body sequestration.\",\n      \"evidence\": \"Co-IP of ZCCHC3–GagNC, P-body imaging, virion RNA quantification, and domain mutagenesis\",\n      \"pmids\": [\"38384847\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab\", \"Generality across other retroviruses not tested directly\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Unified the RNA and DNA co-sensing functions under a single biophysical mechanism—nucleic-acid-induced condensation that concentrates and activates sensors and adaptors.\",\n      \"evidence\": \"Liquid-phase condensation assays, high-resolution structural analysis of MAVS filaments, mutagenesis, and in vitro reconstitution in human cells\",\n      \"pmids\": [\"39983719\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether condensation is also required for the TLR3, LINE-1, and HIV-1 functions not tested\", \"In vivo relevance of condensation thresholds unknown\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Extended antiviral activity to a coronavirus by showing ZCCHC3 drives proteasomal degradation of PEDV nucleocapsid.\",\n      \"evidence\": \"Co-IP, co-localization, knockdown/overexpression viral titer assays, and proteasome inhibitor experiments\",\n      \"pmids\": [\"40068467\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab\", \"Whether ZCCHC3 itself has protease/ligase activity or recruits one is not biochemically resolved\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"Whether the condensation mechanism, zinc-finger nucleic-acid binding, and protein-degradation activities are mechanistically linked across the antiviral, retrotransposon-restriction, and reported cancer/senescence contexts remains open.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No structural model of ZCCHC3 itself\", \"Reported TNBC/NCAPH and senescence roles rest on low-confidence single-lab phenotypes without direct biochemical mechanism\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0003723\", \"supporting_discovery_ids\": [0, 3, 5]},\n      {\"term_id\": \"GO:0003677\", \"supporting_discovery_ids\": [1, 3]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [0, 1, 2, 3]},\n      {\"term_id\": \"GO:0060089\", \"supporting_discovery_ids\": [0, 1]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [0, 1, 3]},\n      {\"term_id\": \"GO:0031410\", \"supporting_discovery_ids\": [4, 6]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [0, 1, 2]},\n      {\"term_id\": \"R-HSA-1643685\", \"supporting_discovery_ids\": [4, 5, 6]},\n      {\"term_id\": \"R-HSA-8953854\", \"supporting_discovery_ids\": [4, 5]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"RIGI\", \"MDA5\", \"TRIM25\", \"CGAS\", \"TRIF\", \"MOV10\", \"ZAP\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":5,"faith_pct":100.0}}