{"gene":"ZC3H3","run_date":"2026-06-11T09:02:06","timeline":{"discoveries":[{"year":2009,"finding":"Drosophila dZC3H3 (ortholog of human ZC3H3) couples mRNA polyadenylation and nuclear export: depletion of dZC3H3 causes transcript hyperadenylation; targeted co-immunoprecipitation/LC-MS/MS identified physical interactions with components of both the mRNA nuclear export and polyadenylation machineries. Depletion of human ZC3H3 by siRNA caused an mRNA export defect, with nuclear poly(A) RNA sequestered in foci outside SC35-containing speckles, indicating a shift from normal subnuclear distribution of poly(A) RNA.","method":"siRNA knockdown, co-immunoprecipitation, LC-MS/MS, immunofluorescence/poly(A) RNA localization","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP with MS, knockdown with defined cellular phenotype (hyperadenylation, export defect), functional conservation shown in both Drosophila and human cells","pmids":["19364924"],"is_preprint":false},{"year":2020,"finding":"Human ZC3H3 is a component of the PAXT (Poly(A) Tail eXosome Targeting) connection required for nuclear polyadenylated RNA decay. ZC3H3 interacts directly with the core PAXT dimer (MTR4–ZFC3H1). Loss of ZC3H3 results in accumulation of PAXT RNA substrates, establishing it as a limiting factor for PAXT activity.","method":"Co-immunoprecipitation of MTR4-ZFC3H1 complexes, nuclear pA+-RNA bound proteome characterization, siRNA/shRNA knockdown with RNA substrate accumulation readout","journal":"Nucleic acids research","confidence":"High","confidence_rationale":"Tier 2 / Strong — direct interaction established by Co-IP, loss-of-function (KD) shows defined substrate accumulation phenotype, multiple orthogonal methods in single study","pmids":["31950173"],"is_preprint":false},{"year":2024,"finding":"ZC3H3 functions as a transient/peripheral PAXT component recruited to the 3' end of short RNAs with fewer exons, triggering a conformational switch ('opening') in ZFC3H1 that enables exosome recruitment and degradation. Longer RNAs with more exons are preferentially exported rather than degraded, revealing that ZC3H3 (together with RBM26/27) reshapes RNA fate by activating ZFC3H1 in a transcript-feature-dependent manner.","method":"Biochemical fractionation, Co-IP, ZFC3H1 conformation assays, RNA-seq, functional knockdown, epistasis analysis","journal":"Molecular cell","confidence":"High","confidence_rationale":"Tier 2 / Strong — mechanistic pathway placement via epistasis and Co-IP, with defined molecular conformational switch and RNA-feature-dependent sorting readout","pmids":["39461342"],"is_preprint":false},{"year":2025,"finding":"In fission yeast Schizosaccharomyces japonicus, the ZC3H3 ortholog Red5 interacts with the nuclear poly(A)-binding protein Pab2/PABPN1 (interaction dependent on Pab2 N-terminal region) and with the RBM26/27 ortholog Rmn1; this complex is essential for constitutive heterochromatin formation at centromeres, linking ZC3H3-family proteins to heterochromatin assembly via nuclear condensate formation.","method":"Co-immunoprecipitation, deletion mutant analysis, histone H3K9 methylation assay, localization imaging","journal":"PLoS genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal Co-IP and genetic deletion with defined heterochromatin phenotype, but in a distantly related fission yeast ortholog (Red5), single lab","pmids":["40163528"],"is_preprint":false}],"current_model":"ZC3H3 is a CCCH-type zinc finger protein that physically couples nuclear polyadenylation with mRNA export (preventing hyperadenylation and retaining poly(A) RNA in correct subnuclear compartments), and also functions as a transient, transcript-feature-sensitive component of the PAXT complex, where it directly binds the MTR4–ZFC3H1 core and, together with RBM26/27, triggers ZFC3H1 conformational activation to recruit the nuclear RNA exosome for degradation of short, poorly-spliced nuclear RNAs."},"narrative":{"mechanistic_narrative":"ZC3H3 is a CCCH-type zinc finger protein that governs the fate of nuclear polyadenylated RNA, coupling 3'-end processing with the choice between nuclear export and exosome-mediated decay [PMID:19364924, PMID:39461342]. It physically bridges the mRNA polyadenylation and nuclear export machineries: its depletion causes transcript hyperadenylation and mislocalization of poly(A) RNA into foci outside SC35 speckles, producing an mRNA export defect [PMID:19364924]. ZC3H3 also serves as a limiting factor for the PAXT (Poly(A) Tail eXosome Targeting) connection, binding directly to the core MTR4–ZFC3H1 dimer, such that its loss leads to accumulation of PAXT substrate RNAs [PMID:31950173]. Mechanistically it acts as a transient, peripheral PAXT component that, together with RBM26/27, is recruited to the 3' ends of short RNAs with few exons and triggers a conformational opening of ZFC3H1 that licenses exosome recruitment and degradation, while longer multi-exon transcripts are preferentially exported — thereby reshaping RNA fate in a transcript-feature-dependent manner [PMID:39461342]. Conservation of this module extends to fission yeast, where the ZC3H3 ortholog Red5 partners with the nuclear poly(A)-binding protein Pab2/PABPN1 and the RBM26/27 ortholog Rmn1 to drive constitutive centromeric heterochromatin formation [PMID:40163528].","teleology":[{"year":2009,"claim":"Established the founding role of ZC3H3 as a physical coupler of mRNA polyadenylation and nuclear export, answering whether a single factor links 3'-end maturation to RNA fate in the nucleus.","evidence":"siRNA knockdown with poly(A) RNA localization, reciprocal Co-IP and LC-MS/MS in Drosophila and human cells","pmids":["19364924"],"confidence":"High","gaps":["Did not define which interaction surface mediates polyadenylation versus export coupling","Did not resolve whether the export defect is a direct or downstream consequence of hyperadenylation"]},{"year":2020,"claim":"Placed ZC3H3 within the PAXT decay pathway by showing direct binding to the MTR4–ZFC3H1 core, reframing it from an export factor to a limiting activator of nuclear RNA degradation.","evidence":"Co-IP of MTR4–ZFC3H1 complexes, nuclear pA+-RNA bound proteome characterization, siRNA/shRNA knockdown with substrate accumulation readout","pmids":["31950173"],"confidence":"High","gaps":["Did not define the molecular mechanism by which ZC3H3 activates PAXT","Did not reconcile decay role with the earlier export-coupling function"]},{"year":2024,"claim":"Defined the mechanism of ZC3H3 action — a transcript-feature-dependent conformational switch in ZFC3H1 — explaining how it sorts short, poorly-spliced RNAs to degradation versus exporting longer transcripts.","evidence":"Biochemical fractionation, Co-IP, ZFC3H1 conformation assays, RNA-seq, knockdown and epistasis analysis","pmids":["39461342"],"confidence":"High","gaps":["Structural basis of the ZFC3H1 conformational opening not resolved","How ZC3H3/RBM26/27 sense exon number and transcript length is undefined"]},{"year":2025,"claim":"Extended the ZC3H3 functional module to heterochromatin biology, showing the conserved ortholog couples poly(A)-binding and RBM26/27-family proteins to centromeric heterochromatin assembly.","evidence":"Co-IP, deletion mutant analysis, H3K9 methylation assay and localization imaging in S. japonicus (Red5 ortholog)","pmids":["40163528"],"confidence":"Medium","gaps":["Demonstrated in a distantly related fission yeast ortholog, single lab","Whether human ZC3H3 contributes to heterochromatin formation is not established","Role of condensate formation in this process not mechanistically dissected"]},{"year":null,"claim":"How ZC3H3's two roles — export coupling and PAXT-dependent decay — are coordinated on the same transcript pool, and the structural basis of its recognition of RNA features, remain open.","evidence":"","pmids":[],"confidence":"High","gaps":["No structure of ZC3H3 bound to PAXT or RNA","Determinants of transcript-feature sensing not defined","Direct RNA-binding specificity of ZC3H3 itself not characterized"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0003723","term_label":"RNA binding","supporting_discovery_ids":[2]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[1,2]}],"localization":[{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[0]},{"term_id":"GO:0005654","term_label":"nucleoplasm","supporting_discovery_ids":[0]}],"pathway":[{"term_id":"R-HSA-8953854","term_label":"Metabolism of RNA","supporting_discovery_ids":[0,1,2]}],"complexes":["PAXT"],"partners":["MTR4","ZFC3H1","RBM26","RBM27","PABPN1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q8IXZ2","full_name":"Zinc finger CCCH domain-containing protein 3","aliases":["Smad-interacting CPSF-like factor"],"length_aa":948,"mass_kda":101.9,"function":"Required for the export of polyadenylated mRNAs from the nucleus (PubMed:19364924). Enhances ACVR1B-induced SMAD-dependent transcription. Binds to single-stranded DNA but not to double-stranded DNA in vitro. Involved in RNA cleavage (By similarity)","subcellular_location":"Nucleus","url":"https://www.uniprot.org/uniprotkb/Q8IXZ2/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/ZC3H3","classification":"Not Classified","n_dependent_lines":278,"n_total_lines":1208,"dependency_fraction":0.23013245033112584},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/ZC3H3","total_profiled":1310},"omim":[{"mim_id":"620082","title":"RNA-BINDING MOTIF PROTEIN 27; RBM27","url":"https://www.omim.org/entry/620082"},{"mim_id":"620081","title":"RNA-BINDING MOTIF PROTEIN 26; RBM26","url":"https://www.omim.org/entry/620081"},{"mim_id":"618640","title":"ZINC FINGER CCCH DOMAIN-CONTAINING PROTEIN 3; ZC3H3","url":"https://www.omim.org/entry/618640"},{"mim_id":"118960","title":"CLATHRIN, LIGHT POLYPEPTIDE A; CLTA","url":"https://www.omim.org/entry/118960"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Nucleoplasm","reliability":"Approved"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/ZC3H3"},"hgnc":{"alias_symbol":["KIAA0150"],"prev_symbol":["ZC3HDC3"]},"alphafold":{"accession":"Q8IXZ2","domains":[{"cath_id":"-","chopping":"672-722","consensus_level":"medium","plddt":89.5671,"start":672,"end":722},{"cath_id":"-","chopping":"724-799","consensus_level":"medium","plddt":87.9549,"start":724,"end":799}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8IXZ2","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q8IXZ2-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q8IXZ2-F1-predicted_aligned_error_v6.png","plddt_mean":51.69},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=ZC3H3","jax_strain_url":"https://www.jax.org/strain/search?query=ZC3H3"},"sequence":{"accession":"Q8IXZ2","fasta_url":"https://rest.uniprot.org/uniprotkb/Q8IXZ2.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q8IXZ2/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8IXZ2"}},"corpus_meta":[{"pmid":"33611339","id":"PMC_33611339","title":"The role of m6A modification in the biological functions and diseases.","date":"2021","source":"Signal transduction and targeted therapy","url":"https://pubmed.ncbi.nlm.nih.gov/33611339","citation_count":1823,"is_preprint":false},{"pmid":"8590280","id":"PMC_8590280","title":"Prediction of the coding sequences of unidentified human genes. IV. The coding sequences of 40 new genes (KIAA0121-KIAA0160) deduced by analysis of cDNA clones from human cell line KG-1.","date":"1995","source":"DNA research : an international journal for rapid publication of reports on genes and genomes","url":"https://pubmed.ncbi.nlm.nih.gov/8590280","citation_count":124,"is_preprint":false},{"pmid":"31950173","id":"PMC_31950173","title":"The human ZC3H3 and RBM26/27 proteins are critical for PAXT-mediated nuclear RNA decay.","date":"2020","source":"Nucleic acids research","url":"https://pubmed.ncbi.nlm.nih.gov/31950173","citation_count":62,"is_preprint":false},{"pmid":"15289881","id":"PMC_15289881","title":"Identification and characterization of human DFNA5L, mouse Dfna5l, and rat Dfna5l genes in silico.","date":"2004","source":"International journal of oncology","url":"https://pubmed.ncbi.nlm.nih.gov/15289881","citation_count":47,"is_preprint":false},{"pmid":"19364924","id":"PMC_19364924","title":"A conserved CCCH-type zinc finger protein regulates mRNA nuclear adenylation and export.","date":"2009","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/19364924","citation_count":41,"is_preprint":false},{"pmid":"30925123","id":"PMC_30925123","title":"Genome-wide association study identifies the PLAG1-OXR1 region on BTA14 for carcass meat yield in cattle.","date":"2019","source":"Physiological genomics","url":"https://pubmed.ncbi.nlm.nih.gov/30925123","citation_count":21,"is_preprint":false},{"pmid":"33059309","id":"PMC_33059309","title":"Epigenome-wide DNA methylation profiling of portal vein tumor thrombosis (PVTT) tissues in hepatocellular carcinoma patients.","date":"2020","source":"Neoplasia (New York, N.Y.)","url":"https://pubmed.ncbi.nlm.nih.gov/33059309","citation_count":18,"is_preprint":false},{"pmid":"36471401","id":"PMC_36471401","title":"Quantification of DNA methylation for carcinogenic risk estimation in patients with non-alcoholic steatohepatitis.","date":"2022","source":"Clinical epigenetics","url":"https://pubmed.ncbi.nlm.nih.gov/36471401","citation_count":10,"is_preprint":false},{"pmid":"35872280","id":"PMC_35872280","title":"Proteomic analysis reveals zinc-finger CCHC-type containing protein 3 as a factor inhibiting virus infection by promoting innate signaling.","date":"2022","source":"Virus research","url":"https://pubmed.ncbi.nlm.nih.gov/35872280","citation_count":9,"is_preprint":false},{"pmid":"39461342","id":"PMC_39461342","title":"Dual modes of ZFC3H1 confer selectivity in nuclear RNA sorting.","date":"2024","source":"Molecular cell","url":"https://pubmed.ncbi.nlm.nih.gov/39461342","citation_count":6,"is_preprint":false},{"pmid":"38302914","id":"PMC_38302914","title":"Identification of differentially methylated regions associated with both liver fibrosis and hepatocellular carcinoma.","date":"2024","source":"BMC gastroenterology","url":"https://pubmed.ncbi.nlm.nih.gov/38302914","citation_count":6,"is_preprint":false},{"pmid":"40163528","id":"PMC_40163528","title":"The nuclear poly(A)-binding protein Pab2/PABPN1 promotes heterochromatin assembly through the formation of Pab2 nuclear condensates.","date":"2025","source":"PLoS genetics","url":"https://pubmed.ncbi.nlm.nih.gov/40163528","citation_count":0,"is_preprint":false},{"pmid":"41815123","id":"PMC_41815123","title":"Identification of immune-related targets of N6-methyladenosine regulators in hepatocellular carcinoma via RNA-seq analysis.","date":"2026","source":"Translational cancer research","url":"https://pubmed.ncbi.nlm.nih.gov/41815123","citation_count":0,"is_preprint":false},{"pmid":"41898833","id":"PMC_41898833","title":"Characterization of a Familial Goldenhar Syndrome Case Using Whole-Exome Sequencing.","date":"2026","source":"Genes","url":"https://pubmed.ncbi.nlm.nih.gov/41898833","citation_count":0,"is_preprint":false},{"pmid":"41952686","id":"PMC_41952686","title":"Novel transcriptomic alterations in poorly differentiated endometrial carcinomas: evidence from South African women.","date":"2026","source":"Frontiers in oncology","url":"https://pubmed.ncbi.nlm.nih.gov/41952686","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":10716,"output_tokens":1274,"usd":0.025629,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":7920,"output_tokens":2070,"usd":0.045675,"stage2_stop_reason":"end_turn"},"total_usd":0.071304,"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\": 2009,\n      \"finding\": \"Drosophila dZC3H3 (ortholog of human ZC3H3) couples mRNA polyadenylation and nuclear export: depletion of dZC3H3 causes transcript hyperadenylation; targeted co-immunoprecipitation/LC-MS/MS identified physical interactions with components of both the mRNA nuclear export and polyadenylation machineries. Depletion of human ZC3H3 by siRNA caused an mRNA export defect, with nuclear poly(A) RNA sequestered in foci outside SC35-containing speckles, indicating a shift from normal subnuclear distribution of poly(A) RNA.\",\n      \"method\": \"siRNA knockdown, co-immunoprecipitation, LC-MS/MS, immunofluorescence/poly(A) RNA localization\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP with MS, knockdown with defined cellular phenotype (hyperadenylation, export defect), functional conservation shown in both Drosophila and human cells\",\n      \"pmids\": [\"19364924\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Human ZC3H3 is a component of the PAXT (Poly(A) Tail eXosome Targeting) connection required for nuclear polyadenylated RNA decay. ZC3H3 interacts directly with the core PAXT dimer (MTR4–ZFC3H1). Loss of ZC3H3 results in accumulation of PAXT RNA substrates, establishing it as a limiting factor for PAXT activity.\",\n      \"method\": \"Co-immunoprecipitation of MTR4-ZFC3H1 complexes, nuclear pA+-RNA bound proteome characterization, siRNA/shRNA knockdown with RNA substrate accumulation readout\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — direct interaction established by Co-IP, loss-of-function (KD) shows defined substrate accumulation phenotype, multiple orthogonal methods in single study\",\n      \"pmids\": [\"31950173\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"ZC3H3 functions as a transient/peripheral PAXT component recruited to the 3' end of short RNAs with fewer exons, triggering a conformational switch ('opening') in ZFC3H1 that enables exosome recruitment and degradation. Longer RNAs with more exons are preferentially exported rather than degraded, revealing that ZC3H3 (together with RBM26/27) reshapes RNA fate by activating ZFC3H1 in a transcript-feature-dependent manner.\",\n      \"method\": \"Biochemical fractionation, Co-IP, ZFC3H1 conformation assays, RNA-seq, functional knockdown, epistasis analysis\",\n      \"journal\": \"Molecular cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — mechanistic pathway placement via epistasis and Co-IP, with defined molecular conformational switch and RNA-feature-dependent sorting readout\",\n      \"pmids\": [\"39461342\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"In fission yeast Schizosaccharomyces japonicus, the ZC3H3 ortholog Red5 interacts with the nuclear poly(A)-binding protein Pab2/PABPN1 (interaction dependent on Pab2 N-terminal region) and with the RBM26/27 ortholog Rmn1; this complex is essential for constitutive heterochromatin formation at centromeres, linking ZC3H3-family proteins to heterochromatin assembly via nuclear condensate formation.\",\n      \"method\": \"Co-immunoprecipitation, deletion mutant analysis, histone H3K9 methylation assay, localization imaging\",\n      \"journal\": \"PLoS genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal Co-IP and genetic deletion with defined heterochromatin phenotype, but in a distantly related fission yeast ortholog (Red5), single lab\",\n      \"pmids\": [\"40163528\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"ZC3H3 is a CCCH-type zinc finger protein that physically couples nuclear polyadenylation with mRNA export (preventing hyperadenylation and retaining poly(A) RNA in correct subnuclear compartments), and also functions as a transient, transcript-feature-sensitive component of the PAXT complex, where it directly binds the MTR4–ZFC3H1 core and, together with RBM26/27, triggers ZFC3H1 conformational activation to recruit the nuclear RNA exosome for degradation of short, poorly-spliced nuclear RNAs.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"ZC3H3 is a CCCH-type zinc finger protein that governs the fate of nuclear polyadenylated RNA, coupling 3'-end processing with the choice between nuclear export and exosome-mediated decay [#0, #2]. It physically bridges the mRNA polyadenylation and nuclear export machineries: its depletion causes transcript hyperadenylation and mislocalization of poly(A) RNA into foci outside SC35 speckles, producing an mRNA export defect [#0]. ZC3H3 also serves as a limiting factor for the PAXT (Poly(A) Tail eXosome Targeting) connection, binding directly to the core MTR4\\u2013ZFC3H1 dimer, such that its loss leads to accumulation of PAXT substrate RNAs [#1]. Mechanistically it acts as a transient, peripheral PAXT component that, together with RBM26/27, is recruited to the 3' ends of short RNAs with few exons and triggers a conformational opening of ZFC3H1 that licenses exosome recruitment and degradation, while longer multi-exon transcripts are preferentially exported \\u2014 thereby reshaping RNA fate in a transcript-feature-dependent manner [#2]. Conservation of this module extends to fission yeast, where the ZC3H3 ortholog Red5 partners with the nuclear poly(A)-binding protein Pab2/PABPN1 and the RBM26/27 ortholog Rmn1 to drive constitutive centromeric heterochromatin formation [#3].\",\n  \"teleology\": [\n    {\n      \"year\": 2009,\n      \"claim\": \"Established the founding role of ZC3H3 as a physical coupler of mRNA polyadenylation and nuclear export, answering whether a single factor links 3'-end maturation to RNA fate in the nucleus.\",\n      \"evidence\": \"siRNA knockdown with poly(A) RNA localization, reciprocal Co-IP and LC-MS/MS in Drosophila and human cells\",\n      \"pmids\": [\"19364924\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not define which interaction surface mediates polyadenylation versus export coupling\", \"Did not resolve whether the export defect is a direct or downstream consequence of hyperadenylation\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Placed ZC3H3 within the PAXT decay pathway by showing direct binding to the MTR4\\u2013ZFC3H1 core, reframing it from an export factor to a limiting activator of nuclear RNA degradation.\",\n      \"evidence\": \"Co-IP of MTR4\\u2013ZFC3H1 complexes, nuclear pA+-RNA bound proteome characterization, siRNA/shRNA knockdown with substrate accumulation readout\",\n      \"pmids\": [\"31950173\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not define the molecular mechanism by which ZC3H3 activates PAXT\", \"Did not reconcile decay role with the earlier export-coupling function\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Defined the mechanism of ZC3H3 action \\u2014 a transcript-feature-dependent conformational switch in ZFC3H1 \\u2014 explaining how it sorts short, poorly-spliced RNAs to degradation versus exporting longer transcripts.\",\n      \"evidence\": \"Biochemical fractionation, Co-IP, ZFC3H1 conformation assays, RNA-seq, knockdown and epistasis analysis\",\n      \"pmids\": [\"39461342\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of the ZFC3H1 conformational opening not resolved\", \"How ZC3H3/RBM26/27 sense exon number and transcript length is undefined\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Extended the ZC3H3 functional module to heterochromatin biology, showing the conserved ortholog couples poly(A)-binding and RBM26/27-family proteins to centromeric heterochromatin assembly.\",\n      \"evidence\": \"Co-IP, deletion mutant analysis, H3K9 methylation assay and localization imaging in S. japonicus (Red5 ortholog)\",\n      \"pmids\": [\"40163528\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Demonstrated in a distantly related fission yeast ortholog, single lab\", \"Whether human ZC3H3 contributes to heterochromatin formation is not established\", \"Role of condensate formation in this process not mechanistically dissected\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How ZC3H3's two roles \\u2014 export coupling and PAXT-dependent decay \\u2014 are coordinated on the same transcript pool, and the structural basis of its recognition of RNA features, remain open.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"High\",\n      \"gaps\": [\"No structure of ZC3H3 bound to PAXT or RNA\", \"Determinants of transcript-feature sensing not defined\", \"Direct RNA-binding specificity of ZC3H3 itself not characterized\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0003723\", \"supporting_discovery_ids\": [2]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [1, 2]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"GO:0005654\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-8953854\", \"supporting_discovery_ids\": [0, 1, 2]}\n    ],\n    \"complexes\": [\"PAXT\"],\n    \"partners\": [\"MTR4\", \"ZFC3H1\", \"RBM26\", \"RBM27\", \"PABPN1\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":5,"faith_pct":100.0}}