{"gene":"DUSP23","run_date":"2026-06-09T23:54:42","timeline":{"discoveries":[{"year":2004,"finding":"DUSP23 (also called VHZ/DUSP25) is an active dual-specificity phosphatase that dephosphorylates phospho-tyrosine and phospho-threonine residues; in vitro it dephosphorylates p44ERK1 but not p38 or p54SAPKβ. The protein contains a DSPc domain and is localized to the cytoplasm in transfected HEK293 cells.","method":"In vitro phosphatase activity assay (pNPP substrate, oligopeptides, recombinant MAPKs); RT-PCR for expression; transient transfection with fluorescence for localization","journal":"The international journal of biochemistry & cell biology","confidence":"Medium","confidence_rationale":"Tier 1 / Weak — in vitro enzymatic assay with defined substrates, single lab, single study","pmids":["15147733"],"is_preprint":false},{"year":2004,"finding":"VHZ (DUSP25/DUSP23) is the smallest active protein-tyrosine phosphatase known (16 kDa, 150 residues), containing the minimal conserved secondary structure elements of the VH1-like phosphatase class; it localizes to the cytosol and nucleoli in transfected cells, and endogenous protein shows a similar but more granular distribution. Its surface charge distribution differs from VHR, making MAPK dephosphorylation unlikely.","method":"Biochemical activity assays, computer modeling/structural analysis, indirect immunofluorescence for localization in transfected cells","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — activity assay plus structural modeling plus localization, single lab, multiple orthogonal methods","pmids":["15201283"],"is_preprint":false},{"year":2008,"finding":"Crystal structure of DUSP23/VHZ determined at 1.93 Å resolution reveals a typical αβα PTP fold with a shallow active site cleft. An enzyme-substrate/product complex shows Thr135-Tyr136 from a symmetry-related molecule (mimicking the phosphorylated TY motif of the MAPK activation loop) in the active site with a malate ion. Functional analysis of Phe66, Leu97, and Phe99 provides mechanistic insights into substrate binding and catalysis. In vitro, DUSP23 can enhance activation of JNK and p38.","method":"X-ray crystallography (1.93 Å); site-directed mutagenesis of active-site residues (Phe66, Leu97, Phe99); in vitro kinase/phosphatase assays","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Strong — crystal structure with functional mutagenesis validation, provides direct mechanistic insight into substrate binding and catalysis","pmids":["18245086"],"is_preprint":false},{"year":2010,"finding":"DUSP23 promotes dephosphorylation of GCM1 at Ser322 (a GSK-3β phosphorylation site that triggers ubiquitination and degradation). PKA-dependent phosphorylation of GCM1 at Ser269/Ser275 enhances the DUSP23–GCM1 interaction. DUSP23 recruitment reverses GSK-3β-mediated phosphorylation, leading to GCM1 acetylation, stabilization, and transcriptional activation. Knockdown of DUSP23 suppressed GCM1 target gene expression and placental cell fusion.","method":"Co-immunoprecipitation; in vitro dephosphorylation assays; shRNA knockdown with gene expression readout and cell fusion assay; phosphorylation site mutagenesis","journal":"Nucleic acids research","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP, in vitro dephosphorylation, KD with defined cellular phenotype and target gene expression, multiple orthogonal methods in single rigorous study","pmids":["20855292"],"is_preprint":false},{"year":2010,"finding":"DUSP23/VHZ localizes to the centrosome (in addition to the cytoplasm), as shown with both exogenous and endogenous protein. Overexpression of catalytically active VHZ (but not the C95S phosphatase-dead mutant) promotes cell proliferation and G1/S cell cycle transition in MCF-7 cells; shRNA-mediated knockdown increases G1 and decreases S phase populations.","method":"Indirect immunofluorescence with anti-VHZ antibodies (monoclonal and polyclonal); retroviral overexpression of VHZ vs. VHZ(C95S); shRNA knockdown; cell proliferation and cell cycle (FACS) assays","journal":"Molecular cancer","confidence":"High","confidence_rationale":"Tier 2 / Moderate — direct localization experiment with functional consequence, catalytic mutant control, KD with defined cell cycle phenotype, multiple orthogonal methods","pmids":["20509867"],"is_preprint":false},{"year":2016,"finding":"DUSP23 dephosphorylates β-catenin at Tyr142, thereby enhancing the interaction between α-catenin and β-catenin. DUSP23 knockdown specifically diminished adhesion to E-cadherin (but not fibronectin), produced zipper-like cell-cell adhesions, caused defects in polarization cue transmission, and reduced coordination during collective migration.","method":"Protein interaction mapping (AP-MS); Co-immunoprecipitation; siRNA knockdown with adhesion assays, immunofluorescence, and migration assays; phospho-specific antibody detection","journal":"Scientific reports","confidence":"High","confidence_rationale":"Tier 2 / Moderate — substrate identification by phospho-specific readout, reciprocal interaction assay, KD with multiple defined cellular phenotypes, single lab with multiple orthogonal methods","pmids":["27255161"],"is_preprint":false},{"year":2015,"finding":"DUSP23 knockdown decreases neuronal differentiation of mouse J1 embryonic stem cells, reducing neuronal outgrowth and expression of neuronal marker proteins and mRNAs, establishing a role for DUSP23 in neuronal differentiation.","method":"shRNA/siRNA knockdown in J1 ESC neuronal differentiation model; qRT-PCR and western blot for neuronal markers; morphological assessment of outgrowth","journal":"Neuroscience letters","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — KD with defined cellular phenotype, single lab, single study, no pathway placement or substrate identified","pmids":["26704437"],"is_preprint":false},{"year":2025,"finding":"DUSP23 promotes STAT3 phosphorylation in cisplatin-resistant NSCLC cells, thereby enhancing SOX2 transcription and maintaining cancer stem cell-like properties. DUSP23 knockdown impaired cluster formation under ultra-low adhesion conditions, suppressed SOX2 expression, decreased invasive behavior, induced apoptosis, and reduced lung tumorigenesis in vivo.","method":"siRNA knockdown; western blot for pSTAT3 and SOX2; sphere/cluster formation assay; apoptosis assay; invasion assay; in vivo tumorigenesis model","journal":"Scientific reports","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — KD with defined cellular and molecular phenotypes including pathway placement (STAT3/SOX2), single lab, single study","pmids":["41257937"],"is_preprint":false},{"year":2025,"finding":"EZH2-mediated H3K27me3 enrichment on the DUSP23 gene promoter silences DUSP23 expression. Upon EZH2 inhibition or knockout, DUSP23 expression is elevated and DUSP23 mediates dephosphorylation of pSMAD3 (Ser423/425), attenuating macrophage-to-myofibroblast transition and renal fibrosis.","method":"ChIP-seq (H3K27me3 on Dusp23 promoter); Co-IP; molecular docking; Ezh2 conditional knockout; GSK-126 pharmacological inhibition; transcriptomic sequencing","journal":"Communications biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ChIP showing epigenetic regulation of DUSP23 promoter, Co-IP for substrate interaction, KO/inhibition with defined fibrosis phenotype, single lab","pmids":["39987296"],"is_preprint":false}],"current_model":"DUSP23 (VHZ/DUSP25) is a catalytically active, cytosol- and centrosome-localized dual-specificity phosphatase whose crystal structure reveals a minimal PTP fold; it dephosphorylates specific substrates including GCM1-pSer322 (coordinating GCM1 acetylation, stabilization, and placental cell fusion), β-catenin-pTyr142 (promoting α/β-catenin interaction and E-cadherin-based cell-cell adhesion), and pSMAD3-Ser423/425 (suppressing fibrosis), and promotes STAT3 phosphorylation to sustain SOX2-driven cancer stem cell properties; its phosphatase activity is required for G1/S cell cycle progression and neuronal differentiation, while its own expression is epigenetically regulated by EZH2-mediated H3K27me3."},"narrative":{"mechanistic_narrative":"DUSP23 (VHZ/DUSP25) is a catalytically active, structurally minimal dual-specificity phosphatase that acts on phospho-tyrosine and phospho-threonine residues and regulates cell adhesion, cell cycle progression, differentiation, and disease-associated signaling through dephosphorylation of specific substrates [PMID:15147733, PMID:18245086]. It is the smallest active protein-tyrosine phosphatase characterized, and its 1.93 Å crystal structure reveals a typical αβα PTP fold with a shallow active-site cleft, with active-site residues Phe66, Leu97, and Phe99 shaping substrate binding and catalysis [PMID:15201283, PMID:18245086]. Functionally, DUSP23 dephosphorylates GCM1 at Ser322 to reverse GSK-3β-mediated phosphodegradation, stabilizing GCM1 and driving its target gene expression and placental cell fusion [PMID:20855292]; it dephosphorylates β-catenin at Tyr142 to strengthen α-catenin/β-catenin interaction and E-cadherin-based cell-cell adhesion and coordinated collective migration [PMID:27255161]; and it dephosphorylates pSMAD3 at Ser423/425 to attenuate macrophage-to-myofibroblast transition and renal fibrosis [PMID:39987296]. Its catalytic activity, localized in part to the centrosome, is required for G1/S cell cycle progression and proliferation [PMID:20509867], and it supports neuronal differentiation [PMID:26704437] and, in cisplatin-resistant lung cancer, sustains STAT3 phosphorylation and SOX2-driven cancer stem cell-like properties [PMID:41257937]. DUSP23 expression is itself silenced by EZH2-mediated H3K27me3 deposition on its promoter [PMID:39987296].","teleology":[{"year":2004,"claim":"Established that DUSP23 is a genuinely active dual-specificity phosphatase and defined its substrate selectivity, answering whether this orphan DSP had catalytic function.","evidence":"In vitro phosphatase assays on pNPP, oligopeptides, and recombinant MAPKs, with localization in transfected cells","pmids":["15147733","15201283"],"confidence":"Medium","gaps":["Physiological substrates not identified","MAPK relevance ambiguous between studies","Localization reported variably (cytoplasm vs. cytosol/nucleoli)"]},{"year":2008,"claim":"Determined the atomic structure of DUSP23, defining the minimal PTP fold and the active-site residues governing substrate binding and catalysis.","evidence":"X-ray crystallography at 1.93 Å with an enzyme-substrate/product complex and site-directed mutagenesis of Phe66, Leu97, Phe99","pmids":["18245086"],"confidence":"High","gaps":["Crystallographic TY-motif mimic does not establish a physiological MAPK substrate","No structure with a validated cellular substrate"]},{"year":2010,"claim":"Connected DUSP23 catalytic activity to control of cell proliferation and identified its centrosomal localization, placing it in cell cycle regulation.","evidence":"Immunofluorescence localization, retroviral overexpression of wild-type vs. C95S phosphatase-dead mutant, shRNA knockdown, and FACS cell cycle analysis in MCF-7 cells","pmids":["20509867"],"confidence":"High","gaps":["Centrosomal substrate driving G1/S transition unidentified","Mechanism of centrosome targeting unknown"]},{"year":2010,"claim":"Identified the first physiological substrate, GCM1-pSer322, showing DUSP23 antagonizes GSK-3β to stabilize a transcription factor and drive placental cell fusion.","evidence":"Reciprocal Co-IP, in vitro dephosphorylation, phospho-site mutagenesis, and shRNA knockdown with target gene and cell fusion readouts","pmids":["20855292"],"confidence":"High","gaps":["How PKA-dependent priming gates DUSP23-GCM1 binding mechanistically unresolved","In vivo placental requirement not tested"]},{"year":2015,"claim":"Extended DUSP23 function to differentiation, showing it is required for neuronal differentiation of embryonic stem cells.","evidence":"shRNA/siRNA knockdown in mouse J1 ESC neuronal differentiation model with marker and morphology readouts","pmids":["26704437"],"confidence":"Medium","gaps":["No substrate or pathway identified in this context","Single model system"]},{"year":2016,"claim":"Identified β-catenin-pTyr142 as a substrate, mechanistically linking DUSP23 to α/β-catenin interaction and E-cadherin-based adhesion and collective migration.","evidence":"AP-MS interaction mapping, Co-IP, phospho-specific detection, and siRNA knockdown with adhesion, polarization, and migration assays","pmids":["27255161"],"confidence":"High","gaps":["In vivo relevance of adhesion phenotype not established","Selectivity for E-cadherin vs. other adhesion routes not fully explained"]},{"year":2025,"claim":"Placed DUSP23 in disease signaling: it sustains STAT3/SOX2 to maintain cancer stem cell properties, while EZH2-mediated H3K27me3 silences DUSP23 to permit pSMAD3-driven fibrosis.","evidence":"siRNA knockdown with pSTAT3/SOX2, sphere, invasion, apoptosis and in vivo tumor assays; and ChIP-seq, Co-IP, EZH2 knockout/inhibition with pSMAD3 and fibrosis readouts","pmids":["41257937","39987296"],"confidence":"Medium","gaps":["Mechanism by which DUSP23 promotes (rather than removes) STAT3 phosphorylation unresolved","Direct vs. indirect action on pSMAD3 needs reconstitution","Single-study findings per disease context"]},{"year":null,"claim":"It remains unresolved how DUSP23 substrate selectivity and subcellular targeting are coordinated across its diverse contexts (centrosome/cell cycle, adhesion, differentiation, fibrosis, cancer stemness).","evidence":"","pmids":[],"confidence":"Medium","gaps":["No unifying recruitment/scaffolding mechanism identified","Regulation of DUSP23 activity beyond EZH2-mediated promoter silencing unknown","Paradoxical positive effect on STAT3 phosphorylation unexplained"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0016787","term_label":"hydrolase activity","supporting_discovery_ids":[0,1,2]},{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[0,3,5,8]}],"localization":[{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[0,1,4]},{"term_id":"GO:0005815","term_label":"microtubule organizing center","supporting_discovery_ids":[4]}],"pathway":[{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[4]},{"term_id":"R-HSA-1500931","term_label":"Cell-Cell communication","supporting_discovery_ids":[5]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[3,7,8]}],"complexes":[],"partners":["GCM1","CTNNB1","SMAD3"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q9BVJ7","full_name":"Dual specificity protein phosphatase 23","aliases":["Low molecular mass dual specificity phosphatase 3","LDP-3","VH1-like phosphatase Z"],"length_aa":150,"mass_kda":16.6,"function":"Protein phosphatase that mediates dephosphorylation of proteins phosphorylated on Tyr and Ser/Thr residues. In vitro, it can dephosphorylate p44-ERK1 (MAPK3) but not p54 SAPK-beta (MAPK10) in vitro. Able to enhance activation of JNK and p38 (MAPK14)","subcellular_location":"Cytoplasm, cytosol; Nucleus","url":"https://www.uniprot.org/uniprotkb/Q9BVJ7/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/DUSP23","classification":"Not Classified","n_dependent_lines":0,"n_total_lines":1208,"dependency_fraction":0.0},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/DUSP23","total_profiled":1310},"omim":[{"mim_id":"618361","title":"DUAL-SPECIFICITY PHOSPHATASE 23; DUSP23","url":"https://www.omim.org/entry/618361"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Nucleoplasm","reliability":"Supported"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/DUSP23"},"hgnc":{"alias_symbol":["FLJ20442","DUSP25"],"prev_symbol":[]},"alphafold":{"accession":"Q9BVJ7","domains":[{"cath_id":"3.90.190.10","chopping":"8-148","consensus_level":"high","plddt":97.9582,"start":8,"end":148}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9BVJ7","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9BVJ7-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9BVJ7-F1-predicted_aligned_error_v6.png","plddt_mean":97.56},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=DUSP23","jax_strain_url":"https://www.jax.org/strain/search?query=DUSP23"},"sequence":{"accession":"Q9BVJ7","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9BVJ7.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9BVJ7/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9BVJ7"}},"corpus_meta":[{"pmid":"31766293","id":"PMC_31766293","title":"MAP4K Family Kinases and DUSP Family Phosphatases in T-Cell Signaling and Systemic Lupus Erythematosus.","date":"2019","source":"Cells","url":"https://pubmed.ncbi.nlm.nih.gov/31766293","citation_count":81,"is_preprint":false},{"pmid":"21314941","id":"PMC_21314941","title":"Identification of epigenetically regulated genes that predict patient outcome in neuroblastoma.","date":"2011","source":"BMC cancer","url":"https://pubmed.ncbi.nlm.nih.gov/21314941","citation_count":60,"is_preprint":false},{"pmid":"20855292","id":"PMC_20855292","title":"Dual-specificity phosphatase 23 mediates GCM1 dephosphorylation and activation.","date":"2010","source":"Nucleic acids research","url":"https://pubmed.ncbi.nlm.nih.gov/20855292","citation_count":33,"is_preprint":false},{"pmid":"15201283","id":"PMC_15201283","title":"The minimal essential core of a cysteine-based protein-tyrosine phosphatase revealed by a novel 16-kDa VH1-like phosphatase, VHZ.","date":"2004","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/15201283","citation_count":30,"is_preprint":false},{"pmid":"15147733","id":"PMC_15147733","title":"Molecular cloning and characterization of a novel dual-specificity phosphatase 23 gene from human fetal brain.","date":"2004","source":"The international journal of biochemistry & cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/15147733","citation_count":26,"is_preprint":false},{"pmid":"29294296","id":"PMC_29294296","title":"Integration of Murine and Human Studies for Mapping Periodontitis Susceptibility.","date":"2018","source":"Journal of dental research","url":"https://pubmed.ncbi.nlm.nih.gov/29294296","citation_count":24,"is_preprint":false},{"pmid":"18245086","id":"PMC_18245086","title":"Structure of human dual specificity protein phosphatase 23, VHZ, enzyme-substrate/product complex.","date":"2008","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/18245086","citation_count":23,"is_preprint":false},{"pmid":"20509867","id":"PMC_20509867","title":"VHZ is a novel centrosomal phosphatase associated with cell growth and human primary cancers.","date":"2010","source":"Molecular cancer","url":"https://pubmed.ncbi.nlm.nih.gov/20509867","citation_count":19,"is_preprint":false},{"pmid":"27255161","id":"PMC_27255161","title":"A protein interaction map for cell-cell adhesion regulators identifies DUSP23 as a novel phosphatase for β-catenin.","date":"2016","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/27255161","citation_count":18,"is_preprint":false},{"pmid":"27737517","id":"PMC_27737517","title":"DUSP23 is over-expressed and linked to the expression of DNMTs in CD4+ T cells from systemic lupus erythematosus patients.","date":"2016","source":"Clinical and experimental immunology","url":"https://pubmed.ncbi.nlm.nih.gov/27737517","citation_count":14,"is_preprint":false},{"pmid":"37291676","id":"PMC_37291676","title":"The genomic signature of resistance to platinum-containing neoadjuvant therapy based on single-cell data.","date":"2023","source":"Cell & bioscience","url":"https://pubmed.ncbi.nlm.nih.gov/37291676","citation_count":13,"is_preprint":false},{"pmid":"26704437","id":"PMC_26704437","title":"Profiling analysis of protein tyrosine phosphatases during neuronal differentiation.","date":"2015","source":"Neuroscience letters","url":"https://pubmed.ncbi.nlm.nih.gov/26704437","citation_count":10,"is_preprint":false},{"pmid":"39987296","id":"PMC_39987296","title":"EZH2-mediated macrophage-to-myofibroblast transition contributes to calcium oxalate crystal-induced kidney fibrosis.","date":"2025","source":"Communications biology","url":"https://pubmed.ncbi.nlm.nih.gov/39987296","citation_count":9,"is_preprint":false},{"pmid":"36901962","id":"PMC_36901962","title":"Evidence for Extensive Duplication and Subfunctionalization of FCRL6 in Armadillo (Dasypus novemcinctus).","date":"2023","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/36901962","citation_count":3,"is_preprint":false},{"pmid":"39442449","id":"PMC_39442449","title":"ACSL1 positively regulates adipogenic differentiation.","date":"2024","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/39442449","citation_count":2,"is_preprint":false},{"pmid":"41610418","id":"PMC_41610418","title":"Common variation at 1q23.3, 2p23.3, 2q33.3, and 2p21 influences the risk of acute myeloid leukemia.","date":"2026","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/41610418","citation_count":2,"is_preprint":false},{"pmid":"41257937","id":"PMC_41257937","title":"Targeting dual-specificity phosphatase 23 to overcome chemoresistance and stem cell-like behavior in non-small cell lung cancer cells.","date":"2025","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/41257937","citation_count":0,"is_preprint":false},{"pmid":"42087139","id":"PMC_42087139","title":"DUSP family phosphatases in cell signaling, inflammation, and chronic diseases.","date":"2026","source":"Journal of biomedical science","url":"https://pubmed.ncbi.nlm.nih.gov/42087139","citation_count":0,"is_preprint":false},{"pmid":"41096831","id":"PMC_41096831","title":"Candidate Transcript Panel in Semen Extracellular Vesicles Can Improve Prediction of Aggressiveness of Prostate Cancer.","date":"2025","source":"International journal of molecular 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The protein contains a DSPc domain and is localized to the cytoplasm in transfected HEK293 cells.\",\n      \"method\": \"In vitro phosphatase activity assay (pNPP substrate, oligopeptides, recombinant MAPKs); RT-PCR for expression; transient transfection with fluorescence for localization\",\n      \"journal\": \"The international journal of biochemistry & cell biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Weak — in vitro enzymatic assay with defined substrates, single lab, single study\",\n      \"pmids\": [\"15147733\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"VHZ (DUSP25/DUSP23) is the smallest active protein-tyrosine phosphatase known (16 kDa, 150 residues), containing the minimal conserved secondary structure elements of the VH1-like phosphatase class; it localizes to the cytosol and nucleoli in transfected cells, and endogenous protein shows a similar but more granular distribution. Its surface charge distribution differs from VHR, making MAPK dephosphorylation unlikely.\",\n      \"method\": \"Biochemical activity assays, computer modeling/structural analysis, indirect immunofluorescence for localization in transfected cells\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — activity assay plus structural modeling plus localization, single lab, multiple orthogonal methods\",\n      \"pmids\": [\"15201283\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"Crystal structure of DUSP23/VHZ determined at 1.93 Å resolution reveals a typical αβα PTP fold with a shallow active site cleft. An enzyme-substrate/product complex shows Thr135-Tyr136 from a symmetry-related molecule (mimicking the phosphorylated TY motif of the MAPK activation loop) in the active site with a malate ion. Functional analysis of Phe66, Leu97, and Phe99 provides mechanistic insights into substrate binding and catalysis. In vitro, DUSP23 can enhance activation of JNK and p38.\",\n      \"method\": \"X-ray crystallography (1.93 Å); site-directed mutagenesis of active-site residues (Phe66, Leu97, Phe99); in vitro kinase/phosphatase assays\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — crystal structure with functional mutagenesis validation, provides direct mechanistic insight into substrate binding and catalysis\",\n      \"pmids\": [\"18245086\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"DUSP23 promotes dephosphorylation of GCM1 at Ser322 (a GSK-3β phosphorylation site that triggers ubiquitination and degradation). PKA-dependent phosphorylation of GCM1 at Ser269/Ser275 enhances the DUSP23–GCM1 interaction. DUSP23 recruitment reverses GSK-3β-mediated phosphorylation, leading to GCM1 acetylation, stabilization, and transcriptional activation. Knockdown of DUSP23 suppressed GCM1 target gene expression and placental cell fusion.\",\n      \"method\": \"Co-immunoprecipitation; in vitro dephosphorylation assays; shRNA knockdown with gene expression readout and cell fusion assay; phosphorylation site mutagenesis\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP, in vitro dephosphorylation, KD with defined cellular phenotype and target gene expression, multiple orthogonal methods in single rigorous study\",\n      \"pmids\": [\"20855292\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"DUSP23/VHZ localizes to the centrosome (in addition to the cytoplasm), as shown with both exogenous and endogenous protein. Overexpression of catalytically active VHZ (but not the C95S phosphatase-dead mutant) promotes cell proliferation and G1/S cell cycle transition in MCF-7 cells; shRNA-mediated knockdown increases G1 and decreases S phase populations.\",\n      \"method\": \"Indirect immunofluorescence with anti-VHZ antibodies (monoclonal and polyclonal); retroviral overexpression of VHZ vs. VHZ(C95S); shRNA knockdown; cell proliferation and cell cycle (FACS) assays\",\n      \"journal\": \"Molecular cancer\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct localization experiment with functional consequence, catalytic mutant control, KD with defined cell cycle phenotype, multiple orthogonal methods\",\n      \"pmids\": [\"20509867\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"DUSP23 dephosphorylates β-catenin at Tyr142, thereby enhancing the interaction between α-catenin and β-catenin. DUSP23 knockdown specifically diminished adhesion to E-cadherin (but not fibronectin), produced zipper-like cell-cell adhesions, caused defects in polarization cue transmission, and reduced coordination during collective migration.\",\n      \"method\": \"Protein interaction mapping (AP-MS); Co-immunoprecipitation; siRNA knockdown with adhesion assays, immunofluorescence, and migration assays; phospho-specific antibody detection\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — substrate identification by phospho-specific readout, reciprocal interaction assay, KD with multiple defined cellular phenotypes, single lab with multiple orthogonal methods\",\n      \"pmids\": [\"27255161\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"DUSP23 knockdown decreases neuronal differentiation of mouse J1 embryonic stem cells, reducing neuronal outgrowth and expression of neuronal marker proteins and mRNAs, establishing a role for DUSP23 in neuronal differentiation.\",\n      \"method\": \"shRNA/siRNA knockdown in J1 ESC neuronal differentiation model; qRT-PCR and western blot for neuronal markers; morphological assessment of outgrowth\",\n      \"journal\": \"Neuroscience letters\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — KD with defined cellular phenotype, single lab, single study, no pathway placement or substrate identified\",\n      \"pmids\": [\"26704437\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"DUSP23 promotes STAT3 phosphorylation in cisplatin-resistant NSCLC cells, thereby enhancing SOX2 transcription and maintaining cancer stem cell-like properties. DUSP23 knockdown impaired cluster formation under ultra-low adhesion conditions, suppressed SOX2 expression, decreased invasive behavior, induced apoptosis, and reduced lung tumorigenesis in vivo.\",\n      \"method\": \"siRNA knockdown; western blot for pSTAT3 and SOX2; sphere/cluster formation assay; apoptosis assay; invasion assay; in vivo tumorigenesis model\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — KD with defined cellular and molecular phenotypes including pathway placement (STAT3/SOX2), single lab, single study\",\n      \"pmids\": [\"41257937\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"EZH2-mediated H3K27me3 enrichment on the DUSP23 gene promoter silences DUSP23 expression. Upon EZH2 inhibition or knockout, DUSP23 expression is elevated and DUSP23 mediates dephosphorylation of pSMAD3 (Ser423/425), attenuating macrophage-to-myofibroblast transition and renal fibrosis.\",\n      \"method\": \"ChIP-seq (H3K27me3 on Dusp23 promoter); Co-IP; molecular docking; Ezh2 conditional knockout; GSK-126 pharmacological inhibition; transcriptomic sequencing\",\n      \"journal\": \"Communications biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP showing epigenetic regulation of DUSP23 promoter, Co-IP for substrate interaction, KO/inhibition with defined fibrosis phenotype, single lab\",\n      \"pmids\": [\"39987296\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"DUSP23 (VHZ/DUSP25) is a catalytically active, cytosol- and centrosome-localized dual-specificity phosphatase whose crystal structure reveals a minimal PTP fold; it dephosphorylates specific substrates including GCM1-pSer322 (coordinating GCM1 acetylation, stabilization, and placental cell fusion), β-catenin-pTyr142 (promoting α/β-catenin interaction and E-cadherin-based cell-cell adhesion), and pSMAD3-Ser423/425 (suppressing fibrosis), and promotes STAT3 phosphorylation to sustain SOX2-driven cancer stem cell properties; its phosphatase activity is required for G1/S cell cycle progression and neuronal differentiation, while its own expression is epigenetically regulated by EZH2-mediated H3K27me3.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"DUSP23 (VHZ/DUSP25) is a catalytically active, structurally minimal dual-specificity phosphatase that acts on phospho-tyrosine and phospho-threonine residues and regulates cell adhesion, cell cycle progression, differentiation, and disease-associated signaling through dephosphorylation of specific substrates [#0, #2]. It is the smallest active protein-tyrosine phosphatase characterized, and its 1.93 Å crystal structure reveals a typical αβα PTP fold with a shallow active-site cleft, with active-site residues Phe66, Leu97, and Phe99 shaping substrate binding and catalysis [#1, #2]. Functionally, DUSP23 dephosphorylates GCM1 at Ser322 to reverse GSK-3β-mediated phosphodegradation, stabilizing GCM1 and driving its target gene expression and placental cell fusion [#3]; it dephosphorylates β-catenin at Tyr142 to strengthen α-catenin/β-catenin interaction and E-cadherin-based cell-cell adhesion and coordinated collective migration [#5]; and it dephosphorylates pSMAD3 at Ser423/425 to attenuate macrophage-to-myofibroblast transition and renal fibrosis [#8]. Its catalytic activity, localized in part to the centrosome, is required for G1/S cell cycle progression and proliferation [#4], and it supports neuronal differentiation [#6] and, in cisplatin-resistant lung cancer, sustains STAT3 phosphorylation and SOX2-driven cancer stem cell-like properties [#7]. DUSP23 expression is itself silenced by EZH2-mediated H3K27me3 deposition on its promoter [#8].\"\n,\n  \"teleology\": [\n    {\n      \"year\": 2004,\n      \"claim\": \"Established that DUSP23 is a genuinely active dual-specificity phosphatase and defined its substrate selectivity, answering whether this orphan DSP had catalytic function.\",\n      \"evidence\": \"In vitro phosphatase assays on pNPP, oligopeptides, and recombinant MAPKs, with localization in transfected cells\",\n      \"pmids\": [\"15147733\", \"15201283\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Physiological substrates not identified\", \"MAPK relevance ambiguous between studies\", \"Localization reported variably (cytoplasm vs. cytosol/nucleoli)\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Determined the atomic structure of DUSP23, defining the minimal PTP fold and the active-site residues governing substrate binding and catalysis.\",\n      \"evidence\": \"X-ray crystallography at 1.93 Å with an enzyme-substrate/product complex and site-directed mutagenesis of Phe66, Leu97, Phe99\",\n      \"pmids\": [\"18245086\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Crystallographic TY-motif mimic does not establish a physiological MAPK substrate\", \"No structure with a validated cellular substrate\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Connected DUSP23 catalytic activity to control of cell proliferation and identified its centrosomal localization, placing it in cell cycle regulation.\",\n      \"evidence\": \"Immunofluorescence localization, retroviral overexpression of wild-type vs. C95S phosphatase-dead mutant, shRNA knockdown, and FACS cell cycle analysis in MCF-7 cells\",\n      \"pmids\": [\"20509867\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Centrosomal substrate driving G1/S transition unidentified\", \"Mechanism of centrosome targeting unknown\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Identified the first physiological substrate, GCM1-pSer322, showing DUSP23 antagonizes GSK-3β to stabilize a transcription factor and drive placental cell fusion.\",\n      \"evidence\": \"Reciprocal Co-IP, in vitro dephosphorylation, phospho-site mutagenesis, and shRNA knockdown with target gene and cell fusion readouts\",\n      \"pmids\": [\"20855292\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How PKA-dependent priming gates DUSP23-GCM1 binding mechanistically unresolved\", \"In vivo placental requirement not tested\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Extended DUSP23 function to differentiation, showing it is required for neuronal differentiation of embryonic stem cells.\",\n      \"evidence\": \"shRNA/siRNA knockdown in mouse J1 ESC neuronal differentiation model with marker and morphology readouts\",\n      \"pmids\": [\"26704437\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No substrate or pathway identified in this context\", \"Single model system\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Identified β-catenin-pTyr142 as a substrate, mechanistically linking DUSP23 to α/β-catenin interaction and E-cadherin-based adhesion and collective migration.\",\n      \"evidence\": \"AP-MS interaction mapping, Co-IP, phospho-specific detection, and siRNA knockdown with adhesion, polarization, and migration assays\",\n      \"pmids\": [\"27255161\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"In vivo relevance of adhesion phenotype not established\", \"Selectivity for E-cadherin vs. other adhesion routes not fully explained\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Placed DUSP23 in disease signaling: it sustains STAT3/SOX2 to maintain cancer stem cell properties, while EZH2-mediated H3K27me3 silences DUSP23 to permit pSMAD3-driven fibrosis.\",\n      \"evidence\": \"siRNA knockdown with pSTAT3/SOX2, sphere, invasion, apoptosis and in vivo tumor assays; and ChIP-seq, Co-IP, EZH2 knockout/inhibition with pSMAD3 and fibrosis readouts\",\n      \"pmids\": [\"41257937\", \"39987296\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism by which DUSP23 promotes (rather than removes) STAT3 phosphorylation unresolved\", \"Direct vs. indirect action on pSMAD3 needs reconstitution\", \"Single-study findings per disease context\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"It remains unresolved how DUSP23 substrate selectivity and subcellular targeting are coordinated across its diverse contexts (centrosome/cell cycle, adhesion, differentiation, fibrosis, cancer stemness).\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No unifying recruitment/scaffolding mechanism identified\", \"Regulation of DUSP23 activity beyond EZH2-mediated promoter silencing unknown\", \"Paradoxical positive effect on STAT3 phosphorylation unexplained\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0016787\", \"supporting_discovery_ids\": [0, 1, 2]},\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [0, 3, 5, 8]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [0, 1, 4]},\n      {\"term_id\": \"GO:0005815\", \"supporting_discovery_ids\": [4]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [4]},\n      {\"term_id\": \"R-HSA-1500931\", \"supporting_discovery_ids\": [5]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [3, 7, 8]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"GCM1\", \"CTNNB1\", \"SMAD3\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":5,"faith_pct":100.0}}