{"gene":"ZRANB2","run_date":"2026-06-11T09:02:07","timeline":{"discoveries":[{"year":2009,"finding":"The two RanBP2-type zinc finger (ZnF) domains of ZRANB2 are single-stranded RNA-binding domains that each recognize an AGGUAA motif with high affinity and specificity; the two domains combine to recognize AGGUAA(Nx)AGGUAA double sites. X-ray crystallography revealed that recognition is dominated by side-chain hydrogen bonds to the bases and formation of a guanine-tryptophan-guanine 'ladder.'","method":"X-ray crystallography, RNA-binding assays, mutagenesis","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 1 / Strong — crystal structure combined with binding assays and sequence-specificity mapping in a single rigorous study","pmids":["19304800"],"is_preprint":false},{"year":2001,"finding":"ZRANB2 (ZNF265) interacts with the essential splicing factors U1-70K and U2AF35, co-immunoprecipitates with mRNA from splicing extracts, alters splicing patterns of Tra2-beta1 transcripts in a dose-dependent manner, and colocalizes with SMN, U1-70K, SC35, p300 and YY1 in the nucleus. Nuclear localization requires the RS domain.","method":"Co-immunoprecipitation, yeast two-hybrid, confocal microscopy, transfection of EGFP fusions, minigene splicing assay","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP, yeast two-hybrid, and functional splicing assay in same study; independently referenced by multiple subsequent papers","pmids":["11448987"],"is_preprint":false},{"year":2003,"finding":"A single RanBP2-type zinc finger domain from ZNF265 forms a stable, monomeric structure with zinc, adopting a novel zinc-ribbon-like fold of two stacked beta-hairpins oriented ~80° to each other sandwiching the zinc ion, and is capable of binding RNA as demonstrated by gel-shift assay.","method":"NMR solution structure determination, zinc-binding characterization (UV spectroscopy), RNA gel-shift assay","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Moderate — NMR structure plus functional RNA-binding assay in one study","pmids":["12657633"],"is_preprint":false},{"year":2006,"finding":"ZRANB2 (ZNF265) interacts with the novel spliceosomal protein XE7 (SFRS17A); this interaction was identified by yeast two-hybrid with ZNF265 as bait and confirmed by co-immunoprecipitation. ZRANB2 and XE7 colocalize in nuclear speckles.","method":"Yeast two-hybrid screen, co-immunoprecipitation, confocal microscopy","journal":"Nucleic acids research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — yeast two-hybrid confirmed by Co-IP and colocalization, single lab","pmids":["16982639"],"is_preprint":false},{"year":2013,"finding":"ZRANB2 is a component of the supraspliceosome, as shown by glycerol-gradient fractionation of nuclear supernatants. Tyrosine kinase-induced phosphorylation affects ZRANB2's subcellular location within the supraspliceosome. Overexpression of ZRANB2 in HeLa cells altered the alternative splicing of at least 12 primary transcripts including CENTB1, WDR78, CAPN10, SALL1, and others.","method":"Glycerol gradient fractionation, Western blotting, Affymetrix exon array transcriptome profiling","journal":"Molecular biology reports","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct fractionation experiment plus transcriptome-level splicing analysis, single lab","pmids":["23666063"],"is_preprint":false},{"year":2012,"finding":"ZRANB2 (Zranb2) interacts with Smad1, Smad5, and Smad8 (strongly) and Smad4 (weakly) in the nucleus. The glutamine-rich domain mediates interaction with Smad1, and the SR domain is required for BMP inhibitory activity and nuclear localization. Overexpression inhibits BMP signaling in C2C12 cells; knockdown enhances BMP activity. Zranb2 suppresses Smad transcriptional activity without affecting Smad phosphorylation, nuclear localization, or DNA binding.","method":"Proteomics pulldown (Smad1-binding protein screen), co-immunoprecipitation, deletion analysis, C2C12 overexpression/knockdown BMP reporter assay, zebrafish mRNA injection","journal":"Journal of cellular biochemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal methods (pulldown, Co-IP, deletion mutants, functional assay), single lab","pmids":["22021003"],"is_preprint":false},{"year":2015,"finding":"ZRANB2 binds the DRD2 pre-mRNA at a site containing the rs1076560 SNP; the rs1076560(T) variant disrupts the ZRANB2 binding site, diminishes binding affinity between DRD2 pre-mRNA and ZRANB2, and abolishes ZRANB2-mediated modulation of short:long DRD2 isoform-expression ratios in cell culture minigene assays.","method":"RNA-protein binding assay, DRD2 minigene splicing assay in cell culture, genetic association study (mechanistic component)","journal":"Molecular psychiatry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct binding and functional minigene assay with allele-specific comparison, single lab","pmids":["26347318"],"is_preprint":false},{"year":2016,"finding":"Zebrafish ZRANB2 is a maternal LPS-binding protein; recombinant ZRANB2 acts as a pattern recognition receptor binding LPS and Gram-negative bacteria and directly kills bacteria. The first ZnF_RBZ domain (residues 11–37) is indispensable for antimicrobial activity. Microinjection of recombinant ZRANB2 into zebrafish embryos enhanced resistance to bacterial challenge.","method":"Recombinant protein binding assays, bacterial killing assays, domain deletion analysis, microinjection into zebrafish embryos, antibody neutralization","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal in vitro and in vivo functional assays, single lab; zebrafish ortholog context","pmids":["26740623"],"is_preprint":false},{"year":2020,"finding":"Arsenite (As3+) binds to and displaces Zn2+ from both C4 zinc finger motifs of ZRANB2, altering ZRANB2 structure and impairing its splicing function on TRA2B mRNA. As3+ exposure also induces ZRANB2 protein (but not mRNA) expression as a homeostatic response. Zinc can displace As3+ from As3+-bound ZRANB2 zinc finger peptides in a cell-free system.","method":"Synthetic peptide binding assays (intrinsic fluorescence, UV spectrophotometry, colorimetric zinc assay, LC-MS/MS), RT-qPCR, immunoblotting, RT-PCR splicing assay in HaCaT cells","journal":"Chemical research in toxicology","confidence":"Medium","confidence_rationale":"Tier 1–2 / Moderate — in vitro biochemical reconstitution with multiple methods plus cellular functional readout, single lab","pmids":["32274925"],"is_preprint":false},{"year":2020,"finding":"ZRANB2 and SYF2 control overlapping alternative splicing programs in doxorubicin-resistant breast cancer cells that converge on inclusion of ECT2 exon 5 (ECT2-Ex5+). Both ZRANB2 and SYF2 associate with ECT2 pre-mRNA, and depletion of either partially reverses doxorubicin resistance and affects S-phase accumulation.","method":"RNAi screen on splicing factors, RNA-seq, RNA immunoprecipitation (RIP), antisense oligonucleotide functional rescue, xenograft tumor model","journal":"Nucleic acids research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — RIP demonstrating direct pre-mRNA association, RNA-seq splicing programs, in vivo xenograft validation, single lab","pmids":["31943118"],"is_preprint":false},{"year":2022,"finding":"Zinc supplementation prevents arsenite-induced dysregulation of ZRANB2 splicing function on TRA2B and blocks the induction of ZRANB2 protein expression in human keratinocytes (HaCaT cells), consistent with the model that iAs disrupts zinc coordination in ZRANB2 zinc fingers.","method":"Zinc supplementation experiments in HaCaT cells, RT-PCR splicing assay, immunoblotting","journal":"Environmental toxicology and pharmacology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — cellular functional rescue experiment confirming prior mechanistic model, single lab","pmids":["35764259"],"is_preprint":false},{"year":2024,"finding":"Both ZF domains of ZRANB2 require Zn(II) coordination for proper folding and RNA binding; HDX-MS revealed that Zn binding induces a more rigid structure in each domain (greater effect in ZF1), while RNA binding produces greater protection in ZF2. High-affinity RNA binding to TRA2B pre-mRNA requires Zn coordination by both domains.","method":"Competitive Co(II)/Zn(II) UV-vis titrations, circular dichroism, hydrogen-deuterium exchange mass spectrometry (HDX-MS), fluorescence anisotropy RNA binding assay","journal":"Biochemistry","confidence":"High","confidence_rationale":"Tier 1 / Moderate — multiple orthogonal biophysical methods (HDX-MS, CD, FA) on recombinant domains in a single rigorous study","pmids":["39681856"],"is_preprint":false},{"year":2026,"finding":"Persulfidation of ZRANB2 cysteine residues by H2S (with superoxide as an intermediate) causes loss of Zn(II)-dependent structure and abrogates RNA binding to TRA2B pre-mRNA and optimized RNA oligonucleotides. This modification is reversible by reductant in vitro. Cellular treatment with H2S decreases formation of a TRA2B splice product, linking persulfidation to impaired ZRANB2 splicing function in cells.","method":"In vitro persulfidation assay with recombinant ZRANB2-2D, fluorescence anisotropy RNA binding, circular dichroism, cellular H2S treatment with RT-PCR splicing readout, reductant rescue","journal":"Journal of inorganic biochemistry","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro biochemical reconstitution with multiple orthogonal methods plus cellular functional validation and reductant rescue, single lab","pmids":["41558086"],"is_preprint":false},{"year":2007,"finding":"Mouse ZNF265-1 (ZRANB2 ortholog) inhibits exon inclusion in GluR-B (Flop exon) and SMN2 (exon 7) minigene splicing assays, demonstrating its role as a splicing repressor for these pre-mRNA targets. Both isoforms localize to the nucleus.","method":"Minigene splicing assay in cell culture, subcellular localization by imaging","journal":"Neurochemical research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct minigene functional assay with two distinct targets, mouse ortholog, single lab","pmids":["17805964"],"is_preprint":false}],"current_model":"ZRANB2 is an SR-domain splicing factor whose two RanBP2-type C4 zinc finger domains each bind AGGUAA single-stranded RNA motifs (structurally defined by X-ray crystallography) to regulate alternative splice-site selection; Zn(II) coordination is required for domain folding and high-affinity RNA binding, and this activity is reversibly disrupted by arsenite-mediated zinc displacement or persulfidation of the zinc-coordinating cysteines by H2S. In the nucleus, ZRANB2 is a component of the supraspliceosome, interacts directly with the spliceosomal proteins U1-70K, U2AF35, and XE7/SFRS17A, modulates splicing of numerous transcripts including Tra2-beta1, DRD2, ECT2, TRA2B, GluR-B, and SMN2, and also suppresses BMP signaling by forming a nuclear complex with Smad1/5/8 via its glutamine-rich domain."},"narrative":{"mechanistic_narrative":"ZRANB2 is a nuclear SR-domain splicing regulator that controls alternative splice-site selection through two RanBP2-type C4 zinc finger domains, each of which folds around a coordinated Zn(II) ion and recognizes single-stranded AGGUAA RNA motifs with high specificity, with the tandem domains engaging AGGUAA(Nx)AGGUAA double sites via base-specific hydrogen bonds and a guanine-tryptophan-guanine 'ladder' [PMID:19304800, PMID:12657633, PMID:39681856]. As a component of the supraspliceosome that interacts with the essential splicing factors U1-70K and U2AF35 and the spliceosomal protein XE7/SFRS17A, ZRANB2 modulates the splicing of numerous transcripts and acts as a splicing repressor in minigene assays for targets including Tra2-beta1, GluR-B, and SMN2 [PMID:11448987, PMID:16982639, PMID:23666063, PMID:17805964]. It binds DRD2 pre-mRNA at a site disrupted by the rs1076560 SNP to alter isoform ratios, and cooperates with SYF2 on ECT2 exon 5 inclusion to drive doxorubicin resistance in breast cancer cells [PMID:26347318, PMID:31943118]. The integrity of this RNA-binding activity is governed by zinc coordination: arsenite displaces Zn(II) from both zinc fingers and impairs splicing of TRA2B, an effect blocked by zinc supplementation, and H2S-mediated persulfidation of the zinc-coordinating cysteines likewise abolishes RNA binding in a reductant-reversible manner [PMID:32274925, PMID:35764259, PMID:39681856, PMID:41558086]. Beyond splicing, ZRANB2 suppresses BMP signaling by forming a nuclear complex with Smad1/5/8 through its glutamine-rich domain, inhibiting Smad transcriptional activity without affecting Smad phosphorylation, nuclear localization, or DNA binding [PMID:22021003].","teleology":[{"year":2001,"claim":"Established ZRANB2 as a bona fide splicing factor by linking it physically to the core splicing machinery and demonstrating functional control over splice-site choice.","evidence":"Reciprocal Co-IP, yeast two-hybrid, confocal colocalization, and Tra2-beta1 minigene splicing assay","pmids":["11448987"],"confidence":"High","gaps":["Did not define the RNA sequence recognized","Mechanism of splice-site selection not resolved"]},{"year":2003,"claim":"Resolved the fold of a single RanBP2-type zinc finger, showing it is a zinc-stabilized RNA-binding module rather than a protein-interaction motif.","evidence":"NMR solution structure, zinc-binding UV spectroscopy, RNA gel-shift on recombinant domain","pmids":["12657633"],"confidence":"High","gaps":["RNA sequence specificity unknown","Role of the second tandem domain not addressed"]},{"year":2006,"claim":"Expanded the ZRANB2 interactome within nuclear speckles by identifying the spliceosomal protein XE7/SFRS17A as a partner.","evidence":"Yeast two-hybrid screen with Co-IP and confocal colocalization","pmids":["16982639"],"confidence":"Medium","gaps":["Functional consequence of the XE7 interaction for splicing unresolved","Single-lab interaction"]},{"year":2007,"claim":"Demonstrated that ZRANB2 acts as a splicing repressor on defined disease-relevant targets, broadening its regulatory repertoire.","evidence":"GluR-B and SMN2 minigene splicing assays with mouse ortholog plus localization imaging","pmids":["17805964"],"confidence":"Medium","gaps":["Direct binding to these pre-mRNAs not shown","Ortholog context"]},{"year":2009,"claim":"Defined the molecular code of ZRANB2 RNA recognition, showing each zinc finger reads an AGGUAA motif with the tandem pair binding double sites.","evidence":"X-ray crystallography, RNA-binding assays, mutagenesis","pmids":["19304800"],"confidence":"High","gaps":["Which endogenous transcripts contain functional AGGUAA sites not mapped","Link to spliceosome assembly not structural"]},{"year":2012,"claim":"Revealed a splicing-independent role for ZRANB2 as a nuclear repressor of BMP/Smad transcriptional output.","evidence":"Smad1 pulldown, Co-IP, deletion mapping, C2C12 BMP reporter assays, zebrafish mRNA injection","pmids":["22021003"],"confidence":"Medium","gaps":["Mechanism of Smad transcriptional suppression not defined","Whether this competes with splicing function unknown"]},{"year":2013,"claim":"Placed ZRANB2 in the supraspliceosome and showed its position is phosphorylation-regulated, with transcriptome-wide splicing effects.","evidence":"Glycerol gradient fractionation, Western blot, Affymetrix exon array profiling","pmids":["23666063"],"confidence":"Medium","gaps":["Direct binding to the altered transcripts not demonstrated","Kinase responsible not identified"]},{"year":2015,"claim":"Connected ZRANB2 RNA binding to a human genetic variant by showing the DRD2 rs1076560 SNP disrupts its binding site and isoform regulation.","evidence":"RNA-protein binding assay and allele-specific DRD2 minigene splicing assay","pmids":["26347318"],"confidence":"Medium","gaps":["In vivo relevance of altered DRD2 isoforms not established","Single-lab functional assay"]},{"year":2020,"claim":"Identified ZRANB2 as a zinc-displacement target of arsenite, linking environmental toxicant exposure to impaired splicing function.","evidence":"Synthetic peptide binding assays, LC-MS/MS, RT-qPCR, immunoblotting, TRA2B splicing assay in HaCaT cells","pmids":["32274925"],"confidence":"Medium","gaps":["Full-length protein behavior versus peptides not tested","Downstream physiological consequences unresolved"]},{"year":2020,"claim":"Showed ZRANB2 drives a chemoresistance splicing program with SYF2 by converging on ECT2 exon 5 inclusion.","evidence":"RNAi screen, RNA-seq, RIP, antisense oligonucleotide rescue, xenograft model","pmids":["31943118"],"confidence":"Medium","gaps":["Direct versus indirect role in ECT2 splicing not fully separated from SYF2","Mechanism of cooperation with SYF2 unknown"]},{"year":2022,"claim":"Confirmed the zinc-coordination model in cells by showing zinc supplementation rescues arsenite-induced ZRANB2 splicing dysfunction.","evidence":"Zinc supplementation, RT-PCR splicing assay, immunoblotting in HaCaT cells","pmids":["35764259"],"confidence":"Medium","gaps":["Direct measurement of intracellular zinc occupancy not performed","Single cell type"]},{"year":2024,"claim":"Quantified how zinc and RNA reshape each zinc finger, establishing that both domains require Zn(II) for folding and high-affinity TRA2B binding.","evidence":"Co(II)/Zn(II) UV-vis titrations, circular dichroism, HDX-MS, fluorescence anisotropy","pmids":["39681856"],"confidence":"High","gaps":["Behavior in the context of the full supraspliceosome not addressed","Cellular zinc regulation of these dynamics not measured"]},{"year":2026,"claim":"Identified persulfidation of zinc-coordinating cysteines as a reversible redox switch that inactivates ZRANB2 RNA binding.","evidence":"In vitro persulfidation, fluorescence anisotropy, CD, cellular H2S treatment with RT-PCR splicing readout, reductant rescue","pmids":["41558086"],"confidence":"High","gaps":["Physiological signaling context of H2S regulation unclear","In vivo persulfidation occupancy not quantified"]},{"year":null,"claim":"How ZRANB2's two distinct activities — AGGUAA-directed alternative splicing and Smad-mediated BMP repression — are coordinated, and how metal/redox sensing tunes them under physiological conditions, remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No integrated model linking splicing and BMP roles","Genome-wide endogenous binding map lacking","Physiological signals controlling zinc/persulfidation states unknown"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0003723","term_label":"RNA binding","supporting_discovery_ids":[0,2,6,9,11,12]},{"term_id":"GO:0140110","term_label":"transcription regulator activity","supporting_discovery_ids":[5]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[1,4,13]}],"localization":[{"term_id":"GO:0005654","term_label":"nucleoplasm","supporting_discovery_ids":[1,3,5]},{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[1,5,13]}],"pathway":[{"term_id":"R-HSA-8953854","term_label":"Metabolism of RNA","supporting_discovery_ids":[0,1,4,13]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[5]}],"complexes":["supraspliceosome"],"partners":["U1-70K","U2AF35","SFRS17A","SMAD1","SMAD5","SYF2"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"O95218","full_name":"Zinc finger Ran-binding domain-containing protein 2","aliases":["Zinc finger protein 265","Zinc finger, splicing"],"length_aa":330,"mass_kda":37.4,"function":"Splice factor required for alternative splicing of TRA2B/SFRS10 transcripts. Binds to ssRNA containing the consensus sequence 5'-AGGUAA-3' (PubMed:21256132). May interfere with constitutive 5'-splice site selection","subcellular_location":"Nucleus","url":"https://www.uniprot.org/uniprotkb/O95218/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/ZRANB2","classification":"Not Classified","n_dependent_lines":473,"n_total_lines":1208,"dependency_fraction":0.39155629139072845},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/ZRANB2","total_profiled":1310},"omim":[{"mim_id":"604347","title":"ZINC FINGER RANBP2-TYPE DOMAIN-CONTAINING PROTEIN 2; ZRANB2","url":"https://www.omim.org/entry/604347"},{"mim_id":"312095","title":"A-KINASE ANCHOR PROTEIN 17A; AKAP17A","url":"https://www.omim.org/entry/312095"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Enhanced","locations":[{"location":"Nucleoplasm","reliability":"Enhanced"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/ZRANB2"},"hgnc":{"alias_symbol":["ZIS","ZIS1","ZIS2"],"prev_symbol":["ZNF265"]},"alphafold":{"accession":"O95218","domains":[{"cath_id":"4.10.1060.10","chopping":"1-44","consensus_level":"medium","plddt":74.4384,"start":1,"end":44},{"cath_id":"-","chopping":"46-95","consensus_level":"medium","plddt":72.131,"start":46,"end":95}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/O95218","model_url":"https://alphafold.ebi.ac.uk/files/AF-O95218-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-O95218-F1-predicted_aligned_error_v6.png","plddt_mean":56.59},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=ZRANB2","jax_strain_url":"https://www.jax.org/strain/search?query=ZRANB2"},"sequence":{"accession":"O95218","fasta_url":"https://rest.uniprot.org/uniprotkb/O95218.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/O95218/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/O95218"}},"corpus_meta":[{"pmid":"19304800","id":"PMC_19304800","title":"The zinc fingers of the SR-like protein ZRANB2 are single-stranded RNA-binding domains that recognize 5' splice site-like sequences.","date":"2009","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/19304800","citation_count":75,"is_preprint":false},{"pmid":"11448987","id":"PMC_11448987","title":"ZNF265--a novel spliceosomal protein able to induce alternative splicing.","date":"2001","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/11448987","citation_count":63,"is_preprint":false},{"pmid":"30744670","id":"PMC_30744670","title":"ZRANB2/SNHG20/FOXK1 Axis regulates Vasculogenic mimicry formation in glioma.","date":"2019","source":"Journal of experimental & clinical cancer research : CR","url":"https://pubmed.ncbi.nlm.nih.gov/30744670","citation_count":52,"is_preprint":false},{"pmid":"31943118","id":"PMC_31943118","title":"ZRANB2 and SYF2-mediated splicing programs converging on ECT2 are involved in breast cancer cell resistance to doxorubicin.","date":"2020","source":"Nucleic acids research","url":"https://pubmed.ncbi.nlm.nih.gov/31943118","citation_count":36,"is_preprint":false},{"pmid":"9374836","id":"PMC_9374836","title":"Zis: a developmentally regulated gene expressed in juxtaglomerular cells.","date":"1997","source":"The American journal of physiology","url":"https://pubmed.ncbi.nlm.nih.gov/9374836","citation_count":34,"is_preprint":false},{"pmid":"12657633","id":"PMC_12657633","title":"The structure of the zinc finger domain from human splicing factor ZNF265 fold.","date":"2003","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/12657633","citation_count":32,"is_preprint":false},{"pmid":"23666063","id":"PMC_23666063","title":"ZRANB2 localizes to supraspliceosomes and influences the alternative splicing of multiple genes in the transcriptome.","date":"2013","source":"Molecular biology 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function of mouse ZNF265.","date":"2007","source":"Neurochemical research","url":"https://pubmed.ncbi.nlm.nih.gov/17805964","citation_count":10,"is_preprint":false},{"pmid":"19567205","id":"PMC_19567205","title":"Expression of IL-1alpha, IL-6, TGF-beta, FasL and ZNF265 during sertoli cell infection by ureaplasma urealyticum.","date":"2009","source":"Cellular & molecular immunology","url":"https://pubmed.ncbi.nlm.nih.gov/19567205","citation_count":9,"is_preprint":false},{"pmid":"35764259","id":"PMC_35764259","title":"Zinc supplementation prevents arsenic-induced dysregulation of ZRANB2 splice function.","date":"2022","source":"Environmental toxicology and pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/35764259","citation_count":8,"is_preprint":false},{"pmid":"35602293","id":"PMC_35602293","title":"HLA-DQB1-AS1 Promotes Cell Proliferation, Inhibits Apoptosis, and Binds with ZRANB2 Protein in Hepatocellular Carcinoma.","date":"2022","source":"Journal of oncology","url":"https://pubmed.ncbi.nlm.nih.gov/35602293","citation_count":7,"is_preprint":false},{"pmid":"22778693","id":"PMC_22778693","title":"Intron Retention and TE Exonization Events in ZRANB2.","date":"2012","source":"Comparative and functional genomics","url":"https://pubmed.ncbi.nlm.nih.gov/22778693","citation_count":6,"is_preprint":false},{"pmid":"39681856","id":"PMC_39681856","title":"Zinc and RNA Binding Is Linked to the Conformational Flexibility of ZRANB2: A CCCC-Type Zinc Finger Protein.","date":"2024","source":"Biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/39681856","citation_count":3,"is_preprint":false},{"pmid":"19052380","id":"PMC_19052380","title":"Crystallization of a ZRANB2-RNA complex.","date":"2008","source":"Acta crystallographica. Section F, Structural biology and crystallization communications","url":"https://pubmed.ncbi.nlm.nih.gov/19052380","citation_count":3,"is_preprint":false},{"pmid":"40273967","id":"PMC_40273967","title":"Long noncoding RNA ZRANB2-AS2 promotes endothelial cell dysfunction by inhibiting phosphorylation of acetyl-CoA carboxylase 1 in diabetes.","date":"2025","source":"Experimental cell research","url":"https://pubmed.ncbi.nlm.nih.gov/40273967","citation_count":1,"is_preprint":false},{"pmid":"41558086","id":"PMC_41558086","title":"Persulfidation of the zinc finger protein ZRANB2 modulates its RNA binding and alternative splicing function.","date":"2026","source":"Journal of inorganic biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/41558086","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":13888,"output_tokens":3725,"usd":0.04877,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":11404,"output_tokens":3787,"usd":0.075847,"stage2_stop_reason":"end_turn"},"total_usd":0.124617,"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\": \"The two RanBP2-type zinc finger (ZnF) domains of ZRANB2 are single-stranded RNA-binding domains that each recognize an AGGUAA motif with high affinity and specificity; the two domains combine to recognize AGGUAA(Nx)AGGUAA double sites. X-ray crystallography revealed that recognition is dominated by side-chain hydrogen bonds to the bases and formation of a guanine-tryptophan-guanine 'ladder.'\",\n      \"method\": \"X-ray crystallography, RNA-binding assays, mutagenesis\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — crystal structure combined with binding assays and sequence-specificity mapping in a single rigorous study\",\n      \"pmids\": [\"19304800\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"ZRANB2 (ZNF265) interacts with the essential splicing factors U1-70K and U2AF35, co-immunoprecipitates with mRNA from splicing extracts, alters splicing patterns of Tra2-beta1 transcripts in a dose-dependent manner, and colocalizes with SMN, U1-70K, SC35, p300 and YY1 in the nucleus. Nuclear localization requires the RS domain.\",\n      \"method\": \"Co-immunoprecipitation, yeast two-hybrid, confocal microscopy, transfection of EGFP fusions, minigene splicing assay\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP, yeast two-hybrid, and functional splicing assay in same study; independently referenced by multiple subsequent papers\",\n      \"pmids\": [\"11448987\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"A single RanBP2-type zinc finger domain from ZNF265 forms a stable, monomeric structure with zinc, adopting a novel zinc-ribbon-like fold of two stacked beta-hairpins oriented ~80° to each other sandwiching the zinc ion, and is capable of binding RNA as demonstrated by gel-shift assay.\",\n      \"method\": \"NMR solution structure determination, zinc-binding characterization (UV spectroscopy), RNA gel-shift assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — NMR structure plus functional RNA-binding assay in one study\",\n      \"pmids\": [\"12657633\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"ZRANB2 (ZNF265) interacts with the novel spliceosomal protein XE7 (SFRS17A); this interaction was identified by yeast two-hybrid with ZNF265 as bait and confirmed by co-immunoprecipitation. ZRANB2 and XE7 colocalize in nuclear speckles.\",\n      \"method\": \"Yeast two-hybrid screen, co-immunoprecipitation, confocal microscopy\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — yeast two-hybrid confirmed by Co-IP and colocalization, single lab\",\n      \"pmids\": [\"16982639\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"ZRANB2 is a component of the supraspliceosome, as shown by glycerol-gradient fractionation of nuclear supernatants. Tyrosine kinase-induced phosphorylation affects ZRANB2's subcellular location within the supraspliceosome. Overexpression of ZRANB2 in HeLa cells altered the alternative splicing of at least 12 primary transcripts including CENTB1, WDR78, CAPN10, SALL1, and others.\",\n      \"method\": \"Glycerol gradient fractionation, Western blotting, Affymetrix exon array transcriptome profiling\",\n      \"journal\": \"Molecular biology reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct fractionation experiment plus transcriptome-level splicing analysis, single lab\",\n      \"pmids\": [\"23666063\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"ZRANB2 (Zranb2) interacts with Smad1, Smad5, and Smad8 (strongly) and Smad4 (weakly) in the nucleus. The glutamine-rich domain mediates interaction with Smad1, and the SR domain is required for BMP inhibitory activity and nuclear localization. Overexpression inhibits BMP signaling in C2C12 cells; knockdown enhances BMP activity. Zranb2 suppresses Smad transcriptional activity without affecting Smad phosphorylation, nuclear localization, or DNA binding.\",\n      \"method\": \"Proteomics pulldown (Smad1-binding protein screen), co-immunoprecipitation, deletion analysis, C2C12 overexpression/knockdown BMP reporter assay, zebrafish mRNA injection\",\n      \"journal\": \"Journal of cellular biochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal methods (pulldown, Co-IP, deletion mutants, functional assay), single lab\",\n      \"pmids\": [\"22021003\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"ZRANB2 binds the DRD2 pre-mRNA at a site containing the rs1076560 SNP; the rs1076560(T) variant disrupts the ZRANB2 binding site, diminishes binding affinity between DRD2 pre-mRNA and ZRANB2, and abolishes ZRANB2-mediated modulation of short:long DRD2 isoform-expression ratios in cell culture minigene assays.\",\n      \"method\": \"RNA-protein binding assay, DRD2 minigene splicing assay in cell culture, genetic association study (mechanistic component)\",\n      \"journal\": \"Molecular psychiatry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct binding and functional minigene assay with allele-specific comparison, single lab\",\n      \"pmids\": [\"26347318\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Zebrafish ZRANB2 is a maternal LPS-binding protein; recombinant ZRANB2 acts as a pattern recognition receptor binding LPS and Gram-negative bacteria and directly kills bacteria. The first ZnF_RBZ domain (residues 11–37) is indispensable for antimicrobial activity. Microinjection of recombinant ZRANB2 into zebrafish embryos enhanced resistance to bacterial challenge.\",\n      \"method\": \"Recombinant protein binding assays, bacterial killing assays, domain deletion analysis, microinjection into zebrafish embryos, antibody neutralization\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal in vitro and in vivo functional assays, single lab; zebrafish ortholog context\",\n      \"pmids\": [\"26740623\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Arsenite (As3+) binds to and displaces Zn2+ from both C4 zinc finger motifs of ZRANB2, altering ZRANB2 structure and impairing its splicing function on TRA2B mRNA. As3+ exposure also induces ZRANB2 protein (but not mRNA) expression as a homeostatic response. Zinc can displace As3+ from As3+-bound ZRANB2 zinc finger peptides in a cell-free system.\",\n      \"method\": \"Synthetic peptide binding assays (intrinsic fluorescence, UV spectrophotometry, colorimetric zinc assay, LC-MS/MS), RT-qPCR, immunoblotting, RT-PCR splicing assay in HaCaT cells\",\n      \"journal\": \"Chemical research in toxicology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1–2 / Moderate — in vitro biochemical reconstitution with multiple methods plus cellular functional readout, single lab\",\n      \"pmids\": [\"32274925\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"ZRANB2 and SYF2 control overlapping alternative splicing programs in doxorubicin-resistant breast cancer cells that converge on inclusion of ECT2 exon 5 (ECT2-Ex5+). Both ZRANB2 and SYF2 associate with ECT2 pre-mRNA, and depletion of either partially reverses doxorubicin resistance and affects S-phase accumulation.\",\n      \"method\": \"RNAi screen on splicing factors, RNA-seq, RNA immunoprecipitation (RIP), antisense oligonucleotide functional rescue, xenograft tumor model\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — RIP demonstrating direct pre-mRNA association, RNA-seq splicing programs, in vivo xenograft validation, single lab\",\n      \"pmids\": [\"31943118\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Zinc supplementation prevents arsenite-induced dysregulation of ZRANB2 splicing function on TRA2B and blocks the induction of ZRANB2 protein expression in human keratinocytes (HaCaT cells), consistent with the model that iAs disrupts zinc coordination in ZRANB2 zinc fingers.\",\n      \"method\": \"Zinc supplementation experiments in HaCaT cells, RT-PCR splicing assay, immunoblotting\",\n      \"journal\": \"Environmental toxicology and pharmacology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — cellular functional rescue experiment confirming prior mechanistic model, single lab\",\n      \"pmids\": [\"35764259\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"Both ZF domains of ZRANB2 require Zn(II) coordination for proper folding and RNA binding; HDX-MS revealed that Zn binding induces a more rigid structure in each domain (greater effect in ZF1), while RNA binding produces greater protection in ZF2. High-affinity RNA binding to TRA2B pre-mRNA requires Zn coordination by both domains.\",\n      \"method\": \"Competitive Co(II)/Zn(II) UV-vis titrations, circular dichroism, hydrogen-deuterium exchange mass spectrometry (HDX-MS), fluorescence anisotropy RNA binding assay\",\n      \"journal\": \"Biochemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — multiple orthogonal biophysical methods (HDX-MS, CD, FA) on recombinant domains in a single rigorous study\",\n      \"pmids\": [\"39681856\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"Persulfidation of ZRANB2 cysteine residues by H2S (with superoxide as an intermediate) causes loss of Zn(II)-dependent structure and abrogates RNA binding to TRA2B pre-mRNA and optimized RNA oligonucleotides. This modification is reversible by reductant in vitro. Cellular treatment with H2S decreases formation of a TRA2B splice product, linking persulfidation to impaired ZRANB2 splicing function in cells.\",\n      \"method\": \"In vitro persulfidation assay with recombinant ZRANB2-2D, fluorescence anisotropy RNA binding, circular dichroism, cellular H2S treatment with RT-PCR splicing readout, reductant rescue\",\n      \"journal\": \"Journal of inorganic biochemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro biochemical reconstitution with multiple orthogonal methods plus cellular functional validation and reductant rescue, single lab\",\n      \"pmids\": [\"41558086\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"Mouse ZNF265-1 (ZRANB2 ortholog) inhibits exon inclusion in GluR-B (Flop exon) and SMN2 (exon 7) minigene splicing assays, demonstrating its role as a splicing repressor for these pre-mRNA targets. Both isoforms localize to the nucleus.\",\n      \"method\": \"Minigene splicing assay in cell culture, subcellular localization by imaging\",\n      \"journal\": \"Neurochemical research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct minigene functional assay with two distinct targets, mouse ortholog, single lab\",\n      \"pmids\": [\"17805964\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"ZRANB2 is an SR-domain splicing factor whose two RanBP2-type C4 zinc finger domains each bind AGGUAA single-stranded RNA motifs (structurally defined by X-ray crystallography) to regulate alternative splice-site selection; Zn(II) coordination is required for domain folding and high-affinity RNA binding, and this activity is reversibly disrupted by arsenite-mediated zinc displacement or persulfidation of the zinc-coordinating cysteines by H2S. In the nucleus, ZRANB2 is a component of the supraspliceosome, interacts directly with the spliceosomal proteins U1-70K, U2AF35, and XE7/SFRS17A, modulates splicing of numerous transcripts including Tra2-beta1, DRD2, ECT2, TRA2B, GluR-B, and SMN2, and also suppresses BMP signaling by forming a nuclear complex with Smad1/5/8 via its glutamine-rich domain.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"ZRANB2 is a nuclear SR-domain splicing regulator that controls alternative splice-site selection through two RanBP2-type C4 zinc finger domains, each of which folds around a coordinated Zn(II) ion and recognizes single-stranded AGGUAA RNA motifs with high specificity, with the tandem domains engaging AGGUAA(Nx)AGGUAA double sites via base-specific hydrogen bonds and a guanine-tryptophan-guanine 'ladder' [#0, #2, #11]. As a component of the supraspliceosome that interacts with the essential splicing factors U1-70K and U2AF35 and the spliceosomal protein XE7/SFRS17A, ZRANB2 modulates the splicing of numerous transcripts and acts as a splicing repressor in minigene assays for targets including Tra2-beta1, GluR-B, and SMN2 [#1, #3, #4, #13]. It binds DRD2 pre-mRNA at a site disrupted by the rs1076560 SNP to alter isoform ratios, and cooperates with SYF2 on ECT2 exon 5 inclusion to drive doxorubicin resistance in breast cancer cells [#6, #9]. The integrity of this RNA-binding activity is governed by zinc coordination: arsenite displaces Zn(II) from both zinc fingers and impairs splicing of TRA2B, an effect blocked by zinc supplementation, and H2S-mediated persulfidation of the zinc-coordinating cysteines likewise abolishes RNA binding in a reductant-reversible manner [#8, #10, #11, #12]. Beyond splicing, ZRANB2 suppresses BMP signaling by forming a nuclear complex with Smad1/5/8 through its glutamine-rich domain, inhibiting Smad transcriptional activity without affecting Smad phosphorylation, nuclear localization, or DNA binding [#5].\",\n  \"teleology\": [\n    {\n      \"year\": 2001,\n      \"claim\": \"Established ZRANB2 as a bona fide splicing factor by linking it physically to the core splicing machinery and demonstrating functional control over splice-site choice.\",\n      \"evidence\": \"Reciprocal Co-IP, yeast two-hybrid, confocal colocalization, and Tra2-beta1 minigene splicing assay\",\n      \"pmids\": [\"11448987\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not define the RNA sequence recognized\", \"Mechanism of splice-site selection not resolved\"]\n    },\n    {\n      \"year\": 2003,\n      \"claim\": \"Resolved the fold of a single RanBP2-type zinc finger, showing it is a zinc-stabilized RNA-binding module rather than a protein-interaction motif.\",\n      \"evidence\": \"NMR solution structure, zinc-binding UV spectroscopy, RNA gel-shift on recombinant domain\",\n      \"pmids\": [\"12657633\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"RNA sequence specificity unknown\", \"Role of the second tandem domain not addressed\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"Expanded the ZRANB2 interactome within nuclear speckles by identifying the spliceosomal protein XE7/SFRS17A as a partner.\",\n      \"evidence\": \"Yeast two-hybrid screen with Co-IP and confocal colocalization\",\n      \"pmids\": [\"16982639\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Functional consequence of the XE7 interaction for splicing unresolved\", \"Single-lab interaction\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Demonstrated that ZRANB2 acts as a splicing repressor on defined disease-relevant targets, broadening its regulatory repertoire.\",\n      \"evidence\": \"GluR-B and SMN2 minigene splicing assays with mouse ortholog plus localization imaging\",\n      \"pmids\": [\"17805964\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct binding to these pre-mRNAs not shown\", \"Ortholog context\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Defined the molecular code of ZRANB2 RNA recognition, showing each zinc finger reads an AGGUAA motif with the tandem pair binding double sites.\",\n      \"evidence\": \"X-ray crystallography, RNA-binding assays, mutagenesis\",\n      \"pmids\": [\"19304800\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Which endogenous transcripts contain functional AGGUAA sites not mapped\", \"Link to spliceosome assembly not structural\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Revealed a splicing-independent role for ZRANB2 as a nuclear repressor of BMP/Smad transcriptional output.\",\n      \"evidence\": \"Smad1 pulldown, Co-IP, deletion mapping, C2C12 BMP reporter assays, zebrafish mRNA injection\",\n      \"pmids\": [\"22021003\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism of Smad transcriptional suppression not defined\", \"Whether this competes with splicing function unknown\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Placed ZRANB2 in the supraspliceosome and showed its position is phosphorylation-regulated, with transcriptome-wide splicing effects.\",\n      \"evidence\": \"Glycerol gradient fractionation, Western blot, Affymetrix exon array profiling\",\n      \"pmids\": [\"23666063\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct binding to the altered transcripts not demonstrated\", \"Kinase responsible not identified\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Connected ZRANB2 RNA binding to a human genetic variant by showing the DRD2 rs1076560 SNP disrupts its binding site and isoform regulation.\",\n      \"evidence\": \"RNA-protein binding assay and allele-specific DRD2 minigene splicing assay\",\n      \"pmids\": [\"26347318\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"In vivo relevance of altered DRD2 isoforms not established\", \"Single-lab functional assay\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Identified ZRANB2 as a zinc-displacement target of arsenite, linking environmental toxicant exposure to impaired splicing function.\",\n      \"evidence\": \"Synthetic peptide binding assays, LC-MS/MS, RT-qPCR, immunoblotting, TRA2B splicing assay in HaCaT cells\",\n      \"pmids\": [\"32274925\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Full-length protein behavior versus peptides not tested\", \"Downstream physiological consequences unresolved\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Showed ZRANB2 drives a chemoresistance splicing program with SYF2 by converging on ECT2 exon 5 inclusion.\",\n      \"evidence\": \"RNAi screen, RNA-seq, RIP, antisense oligonucleotide rescue, xenograft model\",\n      \"pmids\": [\"31943118\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct versus indirect role in ECT2 splicing not fully separated from SYF2\", \"Mechanism of cooperation with SYF2 unknown\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Confirmed the zinc-coordination model in cells by showing zinc supplementation rescues arsenite-induced ZRANB2 splicing dysfunction.\",\n      \"evidence\": \"Zinc supplementation, RT-PCR splicing assay, immunoblotting in HaCaT cells\",\n      \"pmids\": [\"35764259\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct measurement of intracellular zinc occupancy not performed\", \"Single cell type\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Quantified how zinc and RNA reshape each zinc finger, establishing that both domains require Zn(II) for folding and high-affinity TRA2B binding.\",\n      \"evidence\": \"Co(II)/Zn(II) UV-vis titrations, circular dichroism, HDX-MS, fluorescence anisotropy\",\n      \"pmids\": [\"39681856\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Behavior in the context of the full supraspliceosome not addressed\", \"Cellular zinc regulation of these dynamics not measured\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Identified persulfidation of zinc-coordinating cysteines as a reversible redox switch that inactivates ZRANB2 RNA binding.\",\n      \"evidence\": \"In vitro persulfidation, fluorescence anisotropy, CD, cellular H2S treatment with RT-PCR splicing readout, reductant rescue\",\n      \"pmids\": [\"41558086\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Physiological signaling context of H2S regulation unclear\", \"In vivo persulfidation occupancy not quantified\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How ZRANB2's two distinct activities — AGGUAA-directed alternative splicing and Smad-mediated BMP repression — are coordinated, and how metal/redox sensing tunes them under physiological conditions, remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No integrated model linking splicing and BMP roles\", \"Genome-wide endogenous binding map lacking\", \"Physiological signals controlling zinc/persulfidation states unknown\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0003723\", \"supporting_discovery_ids\": [0, 2, 6, 9, 11, 12]},\n      {\"term_id\": \"GO:0140110\", \"supporting_discovery_ids\": [5]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [1, 4, 13]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005654\", \"supporting_discovery_ids\": [1, 3, 5]},\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [1, 5, 13]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-8953854\", \"supporting_discovery_ids\": [0, 1, 4, 13]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [5]}\n    ],\n    \"complexes\": [\"supraspliceosome\"],\n    \"partners\": [\"U1-70K\", \"U2AF35\", \"SFRS17A\", \"SMAD1\", \"SMAD5\", \"SYF2\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":5,"faith_pct":100.0}}