{"gene":"ZBTB1","run_date":"2026-06-11T09:02:06","timeline":{"discoveries":[{"year":2014,"finding":"ZBTB1 acts as a critical upstream regulator of translesion DNA synthesis (TLS) by promoting PCNA monoubiquitination and TLS polymerase recruitment. Its UBZ4 domain is required for these activities. ZBTB1 associates with the transcriptional repressor KAP-1, and ZBTB1 depletion impairs formation of phospho-KAP-1 at UV damage sites and reduces RAD18 recruitment; phosphorylation of KAP-1 is necessary for efficient PCNA modification. ZBTB1 is proposed to localize phospho-KAP-1 to chromatin to enhance RAD18 accessibility.","method":"Co-immunoprecipitation (ZBTB1–KAP-1 association), domain mutagenesis (UBZ4 motif), siRNA depletion with UV survival assay, immunofluorescence of phospho-KAP-1 foci, PCNA monoubiquitination assay, RAD18 recruitment analysis","journal":"Molecular cell","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP, domain mutagenesis, multiple orthogonal functional assays (UV survival, PCNA ubiquitination, foci formation) in a single focused study","pmids":["24657165"],"is_preprint":false},{"year":2020,"finding":"ZBTB1 binds to the ASNS (asparagine synthetase) promoter and promotes ASNS transcription, enabling asparagine biosynthesis under nutrient stress. Loss of ZBTB1 reduces ASNS expression and sensitizes T cell leukemia cells to L-asparaginase.","method":"Functional genomics screens under distinct amino acid deprivation conditions, ZBTB1 knockout, chromatin immunoprecipitation (ChIP) demonstrating ZBTB1 binding to the ASNS promoter, ASNS expression analysis, L-asparaginase sensitivity assay","journal":"Cell metabolism","confidence":"High","confidence_rationale":"Tier 2 / Moderate — CRISPR KO combined with ChIP and functional metabolic readout in a single focused study with multiple orthogonal methods","pmids":["32268116"],"is_preprint":false},{"year":2011,"finding":"ZBTB1 is required cell-intrinsically for T cell development and lymphopoiesis; a point mutation within Zbtb1 identified by positional cloning abolishes T cell generation, establishing ZBTB1 as a transcriptional regulator essential for lymphoid lineage specification.","method":"ENU mutagenesis screen, positional cloning, retroviral transduction rescue, analysis of somatic reversion event, competitive bone marrow reconstitution","journal":"The Journal of experimental medicine","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic rescue by retroviral transduction and somatic reversion confirm causality; multiple orthogonal approaches in one study","pmids":["22201126"],"is_preprint":false},{"year":2011,"finding":"ZBTB1 localizes to the nucleus forming dot-like structures and functions as a transcriptional repressor that suppresses cAMP response element (CRE)-driven transcription; both the BTB/POZ domain and zinc finger motifs contribute to this repression.","method":"Subcellular localization analysis (fluorescence microscopy), transcriptional activity reporter assay in COS7 cells, domain deletion analysis","journal":"Molecular and cellular biochemistry","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — reporter assay and localization in a single lab; domain mapping provides additional mechanistic support but no endogenous target validation","pmids":["21706167"],"is_preprint":false},{"year":2016,"finding":"ZBTB1 maintains genome integrity in lymphoid progenitors by enabling efficient S-phase checkpoint activation; Zbtb1-mutant (ScanT) progenitors exhibit increased replication stress, elevated DNA damage, and p53-mediated apoptosis. Prevention of apoptosis via Bcl2 overexpression or p53 deficiency rescues early lymphoid and myeloid development but not the later DN3 T cell stage, indicating a checkpoint-independent requirement for Zbtb1.","method":"Bone marrow chimera competition assay, transgenic Bcl2 expression, p53 knockout epistasis, DNA damage marker analysis (γH2AX), S-phase checkpoint assay, flow cytometry of developmental stages","journal":"Journal of immunology","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic epistasis with multiple rescue alleles (Bcl2 tg, p53 KO) combined with mechanistic DNA damage readouts; replicated across multiple progenitor stages","pmids":["27402700"],"is_preprint":false},{"year":2016,"finding":"ZBTB1 prevents activation of a default myeloid differentiation program in lymphoid-primed multipotent progenitors (LMPPs); Zbtb1 expression is maintained during lymphoid but downregulated during myeloid development, and its deficiency directs LMPPs toward myeloid fate even under lymphoid-inducing conditions and without myeloid cytokines. This myeloid bias is independent of p53-mediated apoptosis.","method":"In vitro differentiation of Zbtb1-deficient LMPPs under lymphoid conditions, myeloid gene signature analysis, Bcl2/p53 epistasis to exclude apoptotic mechanism","journal":"Oncotarget","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vitro lineage fate assay combined with epistasis, single lab","pmids":["27542215"],"is_preprint":false},{"year":2017,"finding":"Zbtb1 is required cell-intrinsically for the development of NKp46+ RORγt+ ILC3 cells in the intestinal lamina propria; Zbtb1-deficient ILC3 precursors fail to upregulate T-bet and acquire IFN-γ production characteristic of NKp46+ ILC3s.","method":"Bone marrow chimera assay (cell-intrinsic test), co-culture with OP9-DL1 stroma, flow cytometry for T-bet and IFN-γ expression, C. rodentium infection challenge","journal":"Oncotarget","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — cell-intrinsic demonstration via chimeras and in vitro co-culture, single lab","pmids":["28915559"],"is_preprint":false},{"year":2022,"finding":"Zbtb1 interacts with the bridging factor Lmo2 in lymphoid progenitors and, together with Cbfa2t3, forms a complex that co-binds the Tcf7 upstream enhancer region. This complex maintains responsiveness to Notch-mediated inductive signaling for T-lineage differentiation; CRISPR-mediated disruption of Zbtb1 impairs T-cell development initiation, and transduction with Tcf7 rescues the T-lineage potential of Zbtb1-deficient progenitors.","method":"Two-step affinity purification + LC-MS/MS (Lmo2 interactome), CRISPR/Cas9 acute disruption, RNA-seq transcriptome analysis, ChIP-seq (Lmo2, Zbtb1, Cbfa2t3 co-binding at Tcf7 locus), Tcf7 retroviral rescue","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — proteomics-identified interaction confirmed by ChIP-seq co-binding, genetic rescue with Tcf7, and CRISPR disruption in primary progenitors; multiple orthogonal methods","pmids":["36126774"],"is_preprint":false},{"year":2020,"finding":"ZBTB1 acts as a transcriptional repressor of HER2 by occupying the ERα-binding site within the HER2 intron in tamoxifen-resistant breast cancer cells, suppressing tamoxifen-induced HER2 transcription. miR-23b-3p directly targets the ZBTB1 3′UTR, reducing ZBTB1 levels and thereby elevating HER2 expression and aerobic glycolysis.","method":"ChIP demonstrating ZBTB1 occupancy at the HER2 intron ERα-binding site, miRNA target validation (luciferase or direct binding assay implied), HER2 expression analysis upon ZBTB1 overexpression/knockdown, tamoxifen resistance assays in vitro and in vivo","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ChIP for direct ZBTB1 binding plus functional tamoxifen resistance readout, single lab","pmids":["32690611"],"is_preprint":false},{"year":2023,"finding":"ZBTB1 physically interacts with EYA3 isoforms (identified by mass spectrometry) and acts as a major transcription factor partner controlling gene expression during myogenesis; EYA3 isoforms differentially regulate transcription in complex with ZBTB1 or SIX4, indicating isoform-specific transcriptional control during muscle cell differentiation.","method":"Mass spectrometry-based proteomics (EYA3 interactome), genome-wide transcriptomic analysis, myoblast differentiation assays","journal":"iScience","confidence":"Low","confidence_rationale":"Tier 3 / Weak — MS interaction identified in a single study focused on EYA3 splicing; ZBTB1-specific functional validation not described in abstract","pmids":["38026174"],"is_preprint":false}],"current_model":"ZBTB1 is a nuclear BTB/POZ zinc-finger transcriptional repressor that has context-dependent activating roles: it promotes ASNS transcription to support asparagine synthesis under nutrient stress; represses HER2 transcription via direct promoter occupancy; maintains genome integrity in replicating immune progenitors by facilitating KAP-1 phosphorylation and RAD18-dependent PCNA monoubiquitination upstream of translesion synthesis; and, in lymphoid progenitors, forms a complex with Lmo2 and Cbfa2t3 that binds the Tcf7 enhancer to sustain Notch-responsive T-lineage differentiation."},"narrative":{"mechanistic_narrative":"ZBTB1 is a nuclear BTB/POZ zinc-finger transcription factor that functions both as a sequence-specific transcriptional repressor and as a determinant of genome integrity and lineage choice in replicating progenitors [PMID:21706167, PMID:22201126]. As a DNA-binding regulator it occupies defined promoter/enhancer elements with context-dependent outputs: it activates ASNS transcription to sustain asparagine biosynthesis under amino-acid stress, and its loss sensitizes T-cell leukemia cells to L-asparaginase [PMID:32268116], while it represses transcription from CRE-containing reporters and directly occupies the ERα-binding site within the HER2 intron to suppress HER2 induction [PMID:21706167, PMID:32690611]. Independently of its transcriptional outputs, ZBTB1 promotes translesion DNA synthesis: through its UBZ4 domain and association with KAP-1 it facilitates phospho-KAP-1 chromatin localization, RAD18 recruitment, and PCNA monoubiquitination at sites of UV damage [PMID:24657165], and in lymphoid progenitors it limits replication stress and enables efficient S-phase checkpoint activation, preventing p53-dependent apoptosis [PMID:27402700]. These activities underpin a cell-intrinsic requirement for ZBTB1 in lymphoid lineage specification: it forms a complex with Lmo2 and Cbfa2t3 that co-binds the Tcf7 enhancer to maintain Notch-responsive T-lineage differentiation, with Tcf7 re-expression rescuing ZBTB1-deficient progenitors [PMID:36126774, PMID:22201126]. ZBTB1 also restrains a default myeloid program in multipotent progenitors and is required for intestinal ILC3 development [PMID:27542215, PMID:28915559].","teleology":[{"year":2011,"claim":"Established ZBTB1 as a cell-intrinsic genetic requirement for T-cell development, defining it as an essential transcriptional regulator of lymphoid lineage specification rather than a dispensable factor.","evidence":"ENU mutagenesis with positional cloning, retroviral rescue, somatic reversion, and competitive bone marrow reconstitution in mice","pmids":["22201126"],"confidence":"High","gaps":["Did not identify the direct transcriptional targets driving lineage specification","Molecular mechanism (DNA binding vs. genome maintenance) left unresolved"]},{"year":2011,"claim":"Defined ZBTB1's molecular activity as a nuclear transcriptional repressor and mapped the contributing domains, providing the first biochemical framework for its function.","evidence":"Fluorescence localization, CRE-driven reporter assays in COS7 cells, and domain deletion analysis","pmids":["21706167"],"confidence":"Medium","gaps":["No endogenous target genes validated","Reporter-based repression not linked to a physiological context"]},{"year":2014,"claim":"Revealed an unexpected non-transcriptional role: ZBTB1 promotes translesion synthesis upstream of PCNA monoubiquitination, linking it to DNA damage tolerance.","evidence":"Reciprocal Co-IP with KAP-1, UBZ4 domain mutagenesis, UV survival assays, PCNA monoubiquitination and RAD18 recruitment assays, phospho-KAP-1 foci imaging","pmids":["24657165"],"confidence":"High","gaps":["How ZBTB1 reconciles transcriptional and TLS functions is unclear","Structural basis of UBZ4-dependent action not resolved"]},{"year":2016,"claim":"Connected the genome-maintenance function to lymphoid biology by showing ZBTB1 limits replication stress and enables S-phase checkpoint activation, while distinguishing checkpoint-dependent from checkpoint-independent developmental requirements.","evidence":"Bone marrow chimera competition, Bcl2 transgene and p53-knockout epistasis, γH2AX/DNA damage and S-phase checkpoint assays","pmids":["27402700"],"confidence":"High","gaps":["Identity of the checkpoint-independent function at the DN3 stage not defined","Direct molecular targets in progenitors not mapped"]},{"year":2016,"claim":"Showed ZBTB1 actively suppresses a default myeloid fate in multipotent progenitors, demonstrating a transcriptional lineage-gatekeeper role separate from its apoptosis-related functions.","evidence":"In vitro differentiation of Zbtb1-deficient LMPPs under lymphoid conditions with myeloid signature analysis and Bcl2/p53 epistasis","pmids":["27542215"],"confidence":"Medium","gaps":["Direct repressed myeloid genes not identified","Single-lab in vitro system"]},{"year":2017,"claim":"Extended the lineage requirement beyond conventional T cells to innate lymphoid cells, showing ZBTB1 is needed cell-intrinsically for NKp46+ RORγt+ ILC3 development.","evidence":"Bone marrow chimeras, OP9-DL1 co-culture, flow cytometry for T-bet/IFN-γ, and C. rodentium challenge","pmids":["28915559"],"confidence":"Medium","gaps":["Transcriptional targets controlling ILC3 fate not defined","Mechanistic overlap with T-lineage program unknown"]},{"year":2020,"claim":"Identified a metabolic gene-regulatory function: ZBTB1 directly binds the ASNS promoter to drive asparagine synthesis, defining a druggable vulnerability in T-cell leukemia.","evidence":"Amino-acid deprivation functional genomics screens, ZBTB1 knockout, ChIP at the ASNS promoter, and L-asparaginase sensitivity assays","pmids":["32268116"],"confidence":"High","gaps":["Cofactors mediating activation vs. repression not determined","Whether ASNS regulation operates in non-leukemic contexts unclear"]},{"year":2020,"claim":"Demonstrated direct promoter occupancy underlying repression of HER2 and placed ZBTB1 in a miR-23b-3p regulatory axis governing tamoxifen resistance in breast cancer.","evidence":"ChIP at the HER2 intronic ERα site, miRNA 3'UTR target validation, ZBTB1 gain/loss-of-function with HER2 readouts, and tamoxifen resistance assays in vitro and in vivo","pmids":["32690611"],"confidence":"Medium","gaps":["Corepressor machinery at the HER2 locus not identified","Single-lab functional validation"]},{"year":2022,"claim":"Resolved a mechanistic basis for T-lineage control by showing ZBTB1 forms a Lmo2–Cbfa2t3 complex at the Tcf7 enhancer that sustains Notch-responsive differentiation, with Tcf7 epistatically downstream.","evidence":"Two-step affinity purification with LC-MS/MS (Lmo2 interactome), CRISPR disruption, RNA-seq, ChIP-seq co-binding at Tcf7, and Tcf7 retroviral rescue in progenitors","pmids":["36126774"],"confidence":"High","gaps":["Whether this complex governs the non-T lineage functions is untested","Mechanism by which the complex confers Notch responsiveness not detailed"]},{"year":2023,"claim":"Suggested a broader transcription-factor partnership repertoire by placing ZBTB1 in an EYA3 isoform interactome during myogenesis.","evidence":"Mass spectrometry of the EYA3 interactome with genome-wide transcriptomics and myoblast differentiation assays","pmids":["38026174"],"confidence":"Low","gaps":["ZBTB1-specific functional validation not described","Direct DNA targets and isoform specificity of ZBTB1 in muscle unresolved"]},{"year":null,"claim":"How ZBTB1 switches between transcriptional repression, transcriptional activation, and direct DNA-damage-tolerance functions—and what cofactors dictate each mode—remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structural model integrating the BTB/POZ, zinc-finger, and UBZ4 domains","Genome-wide direct target catalog across cell types incomplete","Determinants of activator-vs-repressor behavior unknown"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140110","term_label":"transcription regulator activity","supporting_discovery_ids":[1,3,7,8]},{"term_id":"GO:0003677","term_label":"DNA binding","supporting_discovery_ids":[1,3,8]},{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[0]}],"localization":[{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[3]},{"term_id":"GO:0005694","term_label":"chromosome","supporting_discovery_ids":[0]}],"pathway":[{"term_id":"R-HSA-74160","term_label":"Gene expression (Transcription)","supporting_discovery_ids":[1,3,7,8]},{"term_id":"R-HSA-73894","term_label":"DNA Repair","supporting_discovery_ids":[0,4]},{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[2,5,6,7]},{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[2,6,7]}],"complexes":["ZBTB1-Lmo2-Cbfa2t3 complex"],"partners":["KAP-1","RAD18","LMO2","CBFA2T3","EYA3"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q9Y2K1","full_name":"Zinc finger and BTB domain-containing protein 1","aliases":[],"length_aa":713,"mass_kda":82.0,"function":"Acts as a transcriptional repressor (PubMed:20797634). Represses cAMP-responsive element (CRE)-mediated transcriptional activation (PubMed:21706167). In addition, has a role in translesion DNA synthesis. Requires for UV-inducible RAD18 loading, PCNA monoubiquitination, POLH recruitment to replication factories and efficient translesion DNA synthesis (PubMed:24657165). Plays a key role in the transcriptional regulation of T lymphocyte development (By similarity)","subcellular_location":"Nucleus; Nucleus, nucleoplasm","url":"https://www.uniprot.org/uniprotkb/Q9Y2K1/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/ZBTB1","classification":"Not Classified","n_dependent_lines":15,"n_total_lines":1208,"dependency_fraction":0.012417218543046357},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/ZBTB1","total_profiled":1310},"omim":[{"mim_id":"616578","title":"ZINC FINGER- AND BTB DOMAIN-CONTAINING PROTEIN 1; ZBTB1","url":"https://www.omim.org/entry/616578"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Nucleoplasm","reliability":"Supported"},{"location":"Nuclear membrane","reliability":"Additional"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/ZBTB1"},"hgnc":{"alias_symbol":["KIAA0997","ZNF909"],"prev_symbol":[]},"alphafold":{"accession":"Q9Y2K1","domains":[{"cath_id":"3.30.160","chopping":"673-713","consensus_level":"medium","plddt":80.668,"start":673,"end":713}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9Y2K1","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9Y2K1-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9Y2K1-F1-predicted_aligned_error_v6.png","plddt_mean":54.16},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=ZBTB1","jax_strain_url":"https://www.jax.org/strain/search?query=ZBTB1"},"sequence":{"accession":"Q9Y2K1","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9Y2K1.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9Y2K1/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9Y2K1"}},"corpus_meta":[{"pmid":"32268116","id":"PMC_32268116","title":"ZBTB1 Regulates Asparagine Synthesis and Leukemia Cell Response to L-Asparaginase.","date":"2020","source":"Cell metabolism","url":"https://pubmed.ncbi.nlm.nih.gov/32268116","citation_count":66,"is_preprint":false},{"pmid":"24657165","id":"PMC_24657165","title":"Transcriptional repressor ZBTB1 promotes chromatin remodeling and translesion DNA synthesis.","date":"2014","source":"Molecular cell","url":"https://pubmed.ncbi.nlm.nih.gov/24657165","citation_count":53,"is_preprint":false},{"pmid":"22201126","id":"PMC_22201126","title":"ZBTB1 is a determinant of lymphoid development.","date":"2011","source":"The Journal of experimental medicine","url":"https://pubmed.ncbi.nlm.nih.gov/22201126","citation_count":39,"is_preprint":false},{"pmid":"32690611","id":"PMC_32690611","title":"A novel tumor suppressor ZBTB1 regulates tamoxifen resistance and aerobic glycolysis through suppressing HER2 expression in breast cancer.","date":"2020","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/32690611","citation_count":22,"is_preprint":false},{"pmid":"27402700","id":"PMC_27402700","title":"Zbtb1 Safeguards Genome Integrity and Prevents p53-Mediated Apoptosis in Proliferating Lymphoid Progenitors.","date":"2016","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/27402700","citation_count":16,"is_preprint":false},{"pmid":"21706167","id":"PMC_21706167","title":"Novel human BTB/POZ domain-containing zinc finger protein ZBTB1 inhibits transcriptional activities of CRE.","date":"2011","source":"Molecular and cellular biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/21706167","citation_count":15,"is_preprint":false},{"pmid":"28915559","id":"PMC_28915559","title":"Zbtb1 controls NKp46+ ROR-gamma-T+ innate lymphoid cell (ILC3) development.","date":"2017","source":"Oncotarget","url":"https://pubmed.ncbi.nlm.nih.gov/28915559","citation_count":8,"is_preprint":false},{"pmid":"27542215","id":"PMC_27542215","title":"Zbtb1 prevents default myeloid differentiation of lymphoid-primed multipotent progenitors.","date":"2016","source":"Oncotarget","url":"https://pubmed.ncbi.nlm.nih.gov/27542215","citation_count":8,"is_preprint":false},{"pmid":"38026174","id":"PMC_38026174","title":"RBFOX2 regulated EYA3 isoforms partner with SIX4 or ZBTB1 to control transcription during myogenesis.","date":"2023","source":"iScience","url":"https://pubmed.ncbi.nlm.nih.gov/38026174","citation_count":7,"is_preprint":false},{"pmid":"35394175","id":"PMC_35394175","title":"Circ_0000442 functions as a tumor repressor in breast cancer by impacting miR-1229-3p and upregulating ZBTB1.","date":"2022","source":"Mammalian genome : official journal of the International Mammalian Genome Society","url":"https://pubmed.ncbi.nlm.nih.gov/35394175","citation_count":5,"is_preprint":false},{"pmid":"36126774","id":"PMC_36126774","title":"Transcription factor Zbtb1 interacts with bridging factor Lmo2 and maintains the T-lineage differentiation capacity of lymphoid progenitor cells.","date":"2022","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/36126774","citation_count":4,"is_preprint":false},{"pmid":"34290994","id":"PMC_34290994","title":"MicroRNA and circRNA Expression Analysis in a Zbtb1 Gene Knockout Monoclonal EL4 Cell Line.","date":"2021","source":"Frontiers in cellular and infection microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/34290994","citation_count":3,"is_preprint":false},{"pmid":"35547816","id":"PMC_35547816","title":"Effects of the Zbtb1 Gene on Chromatin Spatial Structure and Lymphatic Development: Combined Analysis of Hi-C, ATAC-Seq and RNA-Seq.","date":"2022","source":"Frontiers in cell and developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/35547816","citation_count":1,"is_preprint":false},{"pmid":"34956935","id":"PMC_34956935","title":"Analysis of lncRNAs and mRNA Expression in the ZBTB1 Knockout Monoclonal EL4 Cell Line and Combined Analysis With miRNAs and circRNAs.","date":"2021","source":"Frontiers in cellular and infection microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/34956935","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":8382,"output_tokens":2896,"usd":0.034293,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":10262,"output_tokens":3675,"usd":0.071593,"stage2_stop_reason":"end_turn"},"total_usd":0.105886,"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\": 2014,\n      \"finding\": \"ZBTB1 acts as a critical upstream regulator of translesion DNA synthesis (TLS) by promoting PCNA monoubiquitination and TLS polymerase recruitment. Its UBZ4 domain is required for these activities. ZBTB1 associates with the transcriptional repressor KAP-1, and ZBTB1 depletion impairs formation of phospho-KAP-1 at UV damage sites and reduces RAD18 recruitment; phosphorylation of KAP-1 is necessary for efficient PCNA modification. ZBTB1 is proposed to localize phospho-KAP-1 to chromatin to enhance RAD18 accessibility.\",\n      \"method\": \"Co-immunoprecipitation (ZBTB1–KAP-1 association), domain mutagenesis (UBZ4 motif), siRNA depletion with UV survival assay, immunofluorescence of phospho-KAP-1 foci, PCNA monoubiquitination assay, RAD18 recruitment analysis\",\n      \"journal\": \"Molecular cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP, domain mutagenesis, multiple orthogonal functional assays (UV survival, PCNA ubiquitination, foci formation) in a single focused study\",\n      \"pmids\": [\"24657165\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"ZBTB1 binds to the ASNS (asparagine synthetase) promoter and promotes ASNS transcription, enabling asparagine biosynthesis under nutrient stress. Loss of ZBTB1 reduces ASNS expression and sensitizes T cell leukemia cells to L-asparaginase.\",\n      \"method\": \"Functional genomics screens under distinct amino acid deprivation conditions, ZBTB1 knockout, chromatin immunoprecipitation (ChIP) demonstrating ZBTB1 binding to the ASNS promoter, ASNS expression analysis, L-asparaginase sensitivity assay\",\n      \"journal\": \"Cell metabolism\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — CRISPR KO combined with ChIP and functional metabolic readout in a single focused study with multiple orthogonal methods\",\n      \"pmids\": [\"32268116\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"ZBTB1 is required cell-intrinsically for T cell development and lymphopoiesis; a point mutation within Zbtb1 identified by positional cloning abolishes T cell generation, establishing ZBTB1 as a transcriptional regulator essential for lymphoid lineage specification.\",\n      \"method\": \"ENU mutagenesis screen, positional cloning, retroviral transduction rescue, analysis of somatic reversion event, competitive bone marrow reconstitution\",\n      \"journal\": \"The Journal of experimental medicine\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic rescue by retroviral transduction and somatic reversion confirm causality; multiple orthogonal approaches in one study\",\n      \"pmids\": [\"22201126\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"ZBTB1 localizes to the nucleus forming dot-like structures and functions as a transcriptional repressor that suppresses cAMP response element (CRE)-driven transcription; both the BTB/POZ domain and zinc finger motifs contribute to this repression.\",\n      \"method\": \"Subcellular localization analysis (fluorescence microscopy), transcriptional activity reporter assay in COS7 cells, domain deletion analysis\",\n      \"journal\": \"Molecular and cellular biochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — reporter assay and localization in a single lab; domain mapping provides additional mechanistic support but no endogenous target validation\",\n      \"pmids\": [\"21706167\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"ZBTB1 maintains genome integrity in lymphoid progenitors by enabling efficient S-phase checkpoint activation; Zbtb1-mutant (ScanT) progenitors exhibit increased replication stress, elevated DNA damage, and p53-mediated apoptosis. Prevention of apoptosis via Bcl2 overexpression or p53 deficiency rescues early lymphoid and myeloid development but not the later DN3 T cell stage, indicating a checkpoint-independent requirement for Zbtb1.\",\n      \"method\": \"Bone marrow chimera competition assay, transgenic Bcl2 expression, p53 knockout epistasis, DNA damage marker analysis (γH2AX), S-phase checkpoint assay, flow cytometry of developmental stages\",\n      \"journal\": \"Journal of immunology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic epistasis with multiple rescue alleles (Bcl2 tg, p53 KO) combined with mechanistic DNA damage readouts; replicated across multiple progenitor stages\",\n      \"pmids\": [\"27402700\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"ZBTB1 prevents activation of a default myeloid differentiation program in lymphoid-primed multipotent progenitors (LMPPs); Zbtb1 expression is maintained during lymphoid but downregulated during myeloid development, and its deficiency directs LMPPs toward myeloid fate even under lymphoid-inducing conditions and without myeloid cytokines. This myeloid bias is independent of p53-mediated apoptosis.\",\n      \"method\": \"In vitro differentiation of Zbtb1-deficient LMPPs under lymphoid conditions, myeloid gene signature analysis, Bcl2/p53 epistasis to exclude apoptotic mechanism\",\n      \"journal\": \"Oncotarget\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vitro lineage fate assay combined with epistasis, single lab\",\n      \"pmids\": [\"27542215\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Zbtb1 is required cell-intrinsically for the development of NKp46+ RORγt+ ILC3 cells in the intestinal lamina propria; Zbtb1-deficient ILC3 precursors fail to upregulate T-bet and acquire IFN-γ production characteristic of NKp46+ ILC3s.\",\n      \"method\": \"Bone marrow chimera assay (cell-intrinsic test), co-culture with OP9-DL1 stroma, flow cytometry for T-bet and IFN-γ expression, C. rodentium infection challenge\",\n      \"journal\": \"Oncotarget\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — cell-intrinsic demonstration via chimeras and in vitro co-culture, single lab\",\n      \"pmids\": [\"28915559\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Zbtb1 interacts with the bridging factor Lmo2 in lymphoid progenitors and, together with Cbfa2t3, forms a complex that co-binds the Tcf7 upstream enhancer region. This complex maintains responsiveness to Notch-mediated inductive signaling for T-lineage differentiation; CRISPR-mediated disruption of Zbtb1 impairs T-cell development initiation, and transduction with Tcf7 rescues the T-lineage potential of Zbtb1-deficient progenitors.\",\n      \"method\": \"Two-step affinity purification + LC-MS/MS (Lmo2 interactome), CRISPR/Cas9 acute disruption, RNA-seq transcriptome analysis, ChIP-seq (Lmo2, Zbtb1, Cbfa2t3 co-binding at Tcf7 locus), Tcf7 retroviral rescue\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — proteomics-identified interaction confirmed by ChIP-seq co-binding, genetic rescue with Tcf7, and CRISPR disruption in primary progenitors; multiple orthogonal methods\",\n      \"pmids\": [\"36126774\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"ZBTB1 acts as a transcriptional repressor of HER2 by occupying the ERα-binding site within the HER2 intron in tamoxifen-resistant breast cancer cells, suppressing tamoxifen-induced HER2 transcription. miR-23b-3p directly targets the ZBTB1 3′UTR, reducing ZBTB1 levels and thereby elevating HER2 expression and aerobic glycolysis.\",\n      \"method\": \"ChIP demonstrating ZBTB1 occupancy at the HER2 intron ERα-binding site, miRNA target validation (luciferase or direct binding assay implied), HER2 expression analysis upon ZBTB1 overexpression/knockdown, tamoxifen resistance assays in vitro and in vivo\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP for direct ZBTB1 binding plus functional tamoxifen resistance readout, single lab\",\n      \"pmids\": [\"32690611\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"ZBTB1 physically interacts with EYA3 isoforms (identified by mass spectrometry) and acts as a major transcription factor partner controlling gene expression during myogenesis; EYA3 isoforms differentially regulate transcription in complex with ZBTB1 or SIX4, indicating isoform-specific transcriptional control during muscle cell differentiation.\",\n      \"method\": \"Mass spectrometry-based proteomics (EYA3 interactome), genome-wide transcriptomic analysis, myoblast differentiation assays\",\n      \"journal\": \"iScience\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — MS interaction identified in a single study focused on EYA3 splicing; ZBTB1-specific functional validation not described in abstract\",\n      \"pmids\": [\"38026174\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"ZBTB1 is a nuclear BTB/POZ zinc-finger transcriptional repressor that has context-dependent activating roles: it promotes ASNS transcription to support asparagine synthesis under nutrient stress; represses HER2 transcription via direct promoter occupancy; maintains genome integrity in replicating immune progenitors by facilitating KAP-1 phosphorylation and RAD18-dependent PCNA monoubiquitination upstream of translesion synthesis; and, in lymphoid progenitors, forms a complex with Lmo2 and Cbfa2t3 that binds the Tcf7 enhancer to sustain Notch-responsive T-lineage differentiation.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"ZBTB1 is a nuclear BTB/POZ zinc-finger transcription factor that functions both as a sequence-specific transcriptional repressor and as a determinant of genome integrity and lineage choice in replicating progenitors [#3, #2]. As a DNA-binding regulator it occupies defined promoter/enhancer elements with context-dependent outputs: it activates ASNS transcription to sustain asparagine biosynthesis under amino-acid stress, and its loss sensitizes T-cell leukemia cells to L-asparaginase [#1], while it represses transcription from CRE-containing reporters and directly occupies the ERα-binding site within the HER2 intron to suppress HER2 induction [#3, #8]. Independently of its transcriptional outputs, ZBTB1 promotes translesion DNA synthesis: through its UBZ4 domain and association with KAP-1 it facilitates phospho-KAP-1 chromatin localization, RAD18 recruitment, and PCNA monoubiquitination at sites of UV damage [#0], and in lymphoid progenitors it limits replication stress and enables efficient S-phase checkpoint activation, preventing p53-dependent apoptosis [#4]. These activities underpin a cell-intrinsic requirement for ZBTB1 in lymphoid lineage specification: it forms a complex with Lmo2 and Cbfa2t3 that co-binds the Tcf7 enhancer to maintain Notch-responsive T-lineage differentiation, with Tcf7 re-expression rescuing ZBTB1-deficient progenitors [#7, #2]. ZBTB1 also restrains a default myeloid program in multipotent progenitors and is required for intestinal ILC3 development [#5, #6].\",\n  \"teleology\": [\n    {\n      \"year\": 2011,\n      \"claim\": \"Established ZBTB1 as a cell-intrinsic genetic requirement for T-cell development, defining it as an essential transcriptional regulator of lymphoid lineage specification rather than a dispensable factor.\",\n      \"evidence\": \"ENU mutagenesis with positional cloning, retroviral rescue, somatic reversion, and competitive bone marrow reconstitution in mice\",\n      \"pmids\": [\"22201126\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not identify the direct transcriptional targets driving lineage specification\", \"Molecular mechanism (DNA binding vs. genome maintenance) left unresolved\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Defined ZBTB1's molecular activity as a nuclear transcriptional repressor and mapped the contributing domains, providing the first biochemical framework for its function.\",\n      \"evidence\": \"Fluorescence localization, CRE-driven reporter assays in COS7 cells, and domain deletion analysis\",\n      \"pmids\": [\"21706167\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No endogenous target genes validated\", \"Reporter-based repression not linked to a physiological context\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Revealed an unexpected non-transcriptional role: ZBTB1 promotes translesion synthesis upstream of PCNA monoubiquitination, linking it to DNA damage tolerance.\",\n      \"evidence\": \"Reciprocal Co-IP with KAP-1, UBZ4 domain mutagenesis, UV survival assays, PCNA monoubiquitination and RAD18 recruitment assays, phospho-KAP-1 foci imaging\",\n      \"pmids\": [\"24657165\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How ZBTB1 reconciles transcriptional and TLS functions is unclear\", \"Structural basis of UBZ4-dependent action not resolved\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Connected the genome-maintenance function to lymphoid biology by showing ZBTB1 limits replication stress and enables S-phase checkpoint activation, while distinguishing checkpoint-dependent from checkpoint-independent developmental requirements.\",\n      \"evidence\": \"Bone marrow chimera competition, Bcl2 transgene and p53-knockout epistasis, γH2AX/DNA damage and S-phase checkpoint assays\",\n      \"pmids\": [\"27402700\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Identity of the checkpoint-independent function at the DN3 stage not defined\", \"Direct molecular targets in progenitors not mapped\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Showed ZBTB1 actively suppresses a default myeloid fate in multipotent progenitors, demonstrating a transcriptional lineage-gatekeeper role separate from its apoptosis-related functions.\",\n      \"evidence\": \"In vitro differentiation of Zbtb1-deficient LMPPs under lymphoid conditions with myeloid signature analysis and Bcl2/p53 epistasis\",\n      \"pmids\": [\"27542215\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct repressed myeloid genes not identified\", \"Single-lab in vitro system\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Extended the lineage requirement beyond conventional T cells to innate lymphoid cells, showing ZBTB1 is needed cell-intrinsically for NKp46+ RORγt+ ILC3 development.\",\n      \"evidence\": \"Bone marrow chimeras, OP9-DL1 co-culture, flow cytometry for T-bet/IFN-γ, and C. rodentium challenge\",\n      \"pmids\": [\"28915559\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Transcriptional targets controlling ILC3 fate not defined\", \"Mechanistic overlap with T-lineage program unknown\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Identified a metabolic gene-regulatory function: ZBTB1 directly binds the ASNS promoter to drive asparagine synthesis, defining a druggable vulnerability in T-cell leukemia.\",\n      \"evidence\": \"Amino-acid deprivation functional genomics screens, ZBTB1 knockout, ChIP at the ASNS promoter, and L-asparaginase sensitivity assays\",\n      \"pmids\": [\"32268116\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Cofactors mediating activation vs. repression not determined\", \"Whether ASNS regulation operates in non-leukemic contexts unclear\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Demonstrated direct promoter occupancy underlying repression of HER2 and placed ZBTB1 in a miR-23b-3p regulatory axis governing tamoxifen resistance in breast cancer.\",\n      \"evidence\": \"ChIP at the HER2 intronic ERα site, miRNA 3'UTR target validation, ZBTB1 gain/loss-of-function with HER2 readouts, and tamoxifen resistance assays in vitro and in vivo\",\n      \"pmids\": [\"32690611\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Corepressor machinery at the HER2 locus not identified\", \"Single-lab functional validation\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Resolved a mechanistic basis for T-lineage control by showing ZBTB1 forms a Lmo2–Cbfa2t3 complex at the Tcf7 enhancer that sustains Notch-responsive differentiation, with Tcf7 epistatically downstream.\",\n      \"evidence\": \"Two-step affinity purification with LC-MS/MS (Lmo2 interactome), CRISPR disruption, RNA-seq, ChIP-seq co-binding at Tcf7, and Tcf7 retroviral rescue in progenitors\",\n      \"pmids\": [\"36126774\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether this complex governs the non-T lineage functions is untested\", \"Mechanism by which the complex confers Notch responsiveness not detailed\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Suggested a broader transcription-factor partnership repertoire by placing ZBTB1 in an EYA3 isoform interactome during myogenesis.\",\n      \"evidence\": \"Mass spectrometry of the EYA3 interactome with genome-wide transcriptomics and myoblast differentiation assays\",\n      \"pmids\": [\"38026174\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"ZBTB1-specific functional validation not described\", \"Direct DNA targets and isoform specificity of ZBTB1 in muscle unresolved\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How ZBTB1 switches between transcriptional repression, transcriptional activation, and direct DNA-damage-tolerance functions—and what cofactors dictate each mode—remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No structural model integrating the BTB/POZ, zinc-finger, and UBZ4 domains\", \"Genome-wide direct target catalog across cell types incomplete\", \"Determinants of activator-vs-repressor behavior unknown\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140110\", \"supporting_discovery_ids\": [1, 3, 7, 8]},\n      {\"term_id\": \"GO:0003677\", \"supporting_discovery_ids\": [1, 3, 8]},\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [3]},\n      {\"term_id\": \"GO:0005694\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-74160\", \"supporting_discovery_ids\": [1, 3, 7, 8]},\n      {\"term_id\": \"R-HSA-73894\", \"supporting_discovery_ids\": [0, 4]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [2, 5, 6, 7]},\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [2, 6, 7]}\n    ],\n    \"complexes\": [\"ZBTB1-Lmo2-Cbfa2t3 complex\"],\n    \"partners\": [\"KAP-1\", \"RAD18\", \"LMO2\", \"CBFA2T3\", \"EYA3\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":5,"faith_pct":100.0}}