{"gene":"DUOXA2","run_date":"2026-04-28T17:46:03","timeline":{"discoveries":[{"year":2007,"finding":"DUOXA2 is required to reconstitute DUOX2 enzymatic (H2O2-generating) activity; a truncated DUOXA2 protein (p.Y246X) lacking transmembrane helix 5 and the C-terminal cytoplasmic domain is inactive in reconstituting DUOX2 in vitro, establishing DUOXA2 as an essential maturation factor for DUOX2 function in thyroid hormone synthesis.","method":"In vitro reconstitution assay; loss-of-function mutant analysis in cell expression system; pedigree/genetic analysis","journal":"The Journal of clinical endocrinology and metabolism","confidence":"High","confidence_rationale":"Tier 1/2 — in vitro reconstitution assay with mutant, replicated across multiple subsequent studies","pmids":["18042646"],"is_preprint":false},{"year":2011,"finding":"DUOXA2 mutation C189R causes complete loss-of-function in reconstituting DUOX2 in vitro, and heterodimerization with specific maturation factors (DUOXA1 and DUOXA2) is essential for the maturation and function of the respective DUOX enzyme complexes; DUOXA1 can partially compensate for DUOXA2 deficiency.","method":"In vitro reconstitution assay; deletion mapping; genetic epistasis analysis","journal":"The Journal of clinical endocrinology and metabolism","confidence":"High","confidence_rationale":"Tier 1/2 — in vitro reconstitution with loss-of-function mutant and genetic rescue experiment","pmids":["21367925"],"is_preprint":false},{"year":2015,"finding":"An intramolecular disulfide bond between Cys-124 in the N-terminal ectodomain and Cys-1162 in an extracellular loop of DUOX2 supports structural formation of interdisulfide bridges between the N-terminal domain of DUOX2 and the two extracellular loops of DUOXA2; oxidative folding of DUOX2 in the ER acts as a chaperone-like event required for stable interaction with DUOXA2 and trafficking of the DUOX2/DUOXA2 complex to the cell surface.","method":"Cysteine mutagenesis; co-immunoprecipitation; cell surface expression assays; redox biochemistry","journal":"Antioxidants & redox signaling","confidence":"High","confidence_rationale":"Tier 1 — active-site/domain mutagenesis with mechanistic follow-up on complex formation and trafficking","pmids":["25761904"],"is_preprint":false},{"year":2011,"finding":"IFN-γ induces DUOXA2 (and DUOX2) expression in human pancreatic cancer cells via the JAK-STAT1 pathway, with Stat1 binding directly to elements of the DUOX2 promoter; p38-MAPK also contributes to this induction, resulting in increased H2O2 production.","method":"Quantitative PCR; STAT1 chromatin immunoprecipitation (ChIP); pharmacological pathway inhibition; ROS assays","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 — ChIP and pharmacological inhibition in cell line, single lab","pmids":["21321110"],"is_preprint":false},{"year":2012,"finding":"Th2 cytokines IL-4 and IL-13 upregulate DUOX2 and DUOXA2 (but not DUOX1/DUOXA1) in human thyrocytes through the JAK1-STAT6 signaling cascade activated by the IL-4 type 2 receptor, leading to increased calcium-stimulated extracellular H2O2 generation.","method":"RT-PCR; pharmacological inhibition of JAK1-STAT6; H2O2 production assays in primary thyrocytes and Caco-2 cells","journal":"Free radical biology & medicine","confidence":"Medium","confidence_rationale":"Tier 2 — pathway inhibition with functional H2O2 output, single lab","pmids":["23010498"],"is_preprint":false},{"year":2019,"finding":"DUOX2 and DUOXA2 form the most active H2O2-generating enzymatic complex at the cell surface compared to DUOX1/DUOXA1; DUOX2/DUOXA2 membrane complexes are more stable than unpaired or cross-paired complexes; glycosylation of DUOXA2 is required for DUOX2 maturation and activity (glycosylation-defective DUOXA2 drastically impairs DUOX2 activity); cell-surface H2O2 produced by the Duox2/DuoxA2 complex causes DNA damage in nuclei.","method":"Inducible HEK293 cell expression system; proximity ligation assay (Duolink); H2O2 production assays normalized to membrane expression; glycosylation-defective mutants; DNA damage readout (γH2AX, comet assay)","journal":"Experimental cell research","confidence":"High","confidence_rationale":"Tier 1/2 — multiple orthogonal methods including proximity ligation, functional assay, and loss-of-glycosylation mutants in the same study","pmids":["31513783"],"is_preprint":false},{"year":2024,"finding":"DUOXA2 is required for apical sorting of DUOX2 to the apical plasma membrane in MDCK epithelial cells; N-glycosylation of DUOXA2 is dispensable for apical recruitment of DUOX2 (unlike DUOXA1 where N-glycosylation is required), and the C-terminal region of DUOXA2 appears to be involved in apical targeting of DUOX2.","method":"MDCK epithelial cell co-expression; immunofluorescence/confocal microscopy; glycosylation-defective DUOXA2 mutants; domain swap/chimera experiments","journal":"Genes to cells : devoted to molecular & cellular mechanisms","confidence":"High","confidence_rationale":"Tier 1/2 — direct localization experiment with functional consequence, mutagenesis, and mechanistic domain mapping","pmids":["39126279"],"is_preprint":false},{"year":2025,"finding":"Ten DUOXA2 variants identified in Chinese CH patients disrupt DUOX2 enzyme activity in vitro, resulting in impaired H2O2 production, confirming the essential role of DUOXA2 in enabling DUOX2 H2O2 generation.","method":"In vitro functional assay (H2O2 production); targeted next-generation sequencing; pedigree analysis","journal":"European journal of endocrinology","confidence":"Medium","confidence_rationale":"Tier 2 — in vitro functional assay with multiple variants, single lab","pmids":["40510014"],"is_preprint":false},{"year":2017,"finding":"DUOXA2 p.Tyr138* is a loss-of-function mutation, confirmed by expression experiments in HEK293 cells, establishing that this truncation abolishes DUOXA2's ability to support DUOX2 activity.","method":"HEK293 cell expression assay; loss-of-function validation","journal":"Endocrine journal","confidence":"Medium","confidence_rationale":"Tier 2 — cell-based reconstitution assay, single lab, single mutation","pmids":["28626131"],"is_preprint":false}],"current_model":"DUOXA2 is a transmembrane maturation factor that heterodimerizes with DUOX2 in the endoplasmic reticulum, where oxidative folding of DUOX2 drives disulfide-bonded complex formation with the extracellular loops of DUOXA2; this complex is then trafficked to the apical plasma membrane (via DUOXA2's C-terminal region, in a glycosylation-independent manner) where it constitutes the primary H2O2-generating enzyme system essential for thyroid hormone biosynthesis and innate mucosal defense, with DUOXA2 expression being transcriptionally regulated by cytokines (IFN-γ via JAK-STAT1; IL-4/IL-13 via JAK1-STAT6) and loss-of-function DUOXA2 mutations causing congenital hypothyroidism through failure to reconstitute DUOX2 enzymatic activity."},"narrative":{"teleology":[{"year":2007,"claim":"It was unknown whether DUOXA2 was merely co-expressed with DUOX2 or functionally required for its activity; in vitro reconstitution showed that DUOXA2 is an essential maturation factor for DUOX2 H2O2 generation and that a patient-derived truncation (p.Y246X) abolishes this function, establishing the first causal link between DUOXA2 loss-of-function and congenital hypothyroidism.","evidence":"In vitro reconstitution assay with loss-of-function mutant in heterologous expression system; pedigree analysis","pmids":["18042646"],"confidence":"High","gaps":["Mechanism by which DUOXA2 enables DUOX2 activity not resolved","Whether DUOXA1 compensates in vivo unknown","Structural basis of heterodimerization undefined"]},{"year":2011,"claim":"The specificity and compensatory capacity of DUOX maturation factors was unclear; functional assays demonstrated that DUOXA2 C189R is a complete loss-of-function mutation and that DUOXA1 can partially substitute for DUOXA2, establishing maturation factor selectivity as a regulatory layer.","evidence":"In vitro reconstitution with C189R mutant; deletion mapping and genetic rescue in cell expression system","pmids":["21367925"],"confidence":"High","gaps":["Molecular interface mediating DUOX2–DUOXA2 specificity unresolved","In vivo contribution of DUOXA1 compensation not tested"]},{"year":2011,"claim":"The transcriptional regulation of DUOXA2 was unknown; IFN-γ was shown to induce DUOXA2 and DUOX2 expression through JAK-STAT1, with STAT1 binding directly to the DUOX2 promoter region, linking innate immune signaling to the DUOX2/DUOXA2 H2O2-generating system.","evidence":"STAT1 ChIP; pharmacological pathway inhibition; qPCR and ROS assays in pancreatic cancer cells","pmids":["21321110"],"confidence":"Medium","gaps":["STAT1 binding to the DUOXA2 promoter specifically was not demonstrated","Relevance to thyroid physiology not established","Findings from a single lab in cancer cell line"]},{"year":2012,"claim":"Whether Th2 cytokines regulate DUOXA2 was unexplored; IL-4 and IL-13 were shown to upregulate DUOX2 and DUOXA2 selectively (not DUOX1/DUOXA1) via JAK1-STAT6 in thyrocytes, demonstrating that distinct cytokine pathways converge on DUOXA2 transcription to modulate H2O2 output.","evidence":"RT-PCR; JAK1-STAT6 pharmacological inhibition; H2O2 production assays in primary thyrocytes and Caco-2 cells","pmids":["23010498"],"confidence":"Medium","gaps":["Direct STAT6 binding to DUOXA2 regulatory regions not shown","Single-lab finding"]},{"year":2015,"claim":"The molecular basis of DUOX2–DUOXA2 complex assembly was undefined; cysteine mutagenesis revealed that oxidative folding of DUOX2 in the ER generates an intramolecular disulfide bond (Cys-124/Cys-1162) that enables interdisulfide bridges with the extracellular loops of DUOXA2, establishing a redox-dependent chaperone-like mechanism for complex stabilization and ER-to-surface trafficking.","evidence":"Cysteine mutagenesis; co-immunoprecipitation; cell surface expression assays; redox biochemistry","pmids":["25761904"],"confidence":"High","gaps":["High-resolution structure of the DUOX2–DUOXA2 complex unavailable","Whether ER oxidoreductases specifically catalyze these bonds unknown"]},{"year":2019,"claim":"The relative activity and stability of different DUOX/DUOXA pairings and the role of DUOXA2 glycosylation were unresolved; DUOX2/DUOXA2 was shown to be the most active and stable H2O2-generating complex, and glycosylation of DUOXA2 was found to be required for DUOX2 maturation and enzymatic activity.","evidence":"Inducible HEK293 system; proximity ligation assay; glycosylation-defective DUOXA2 mutants; H2O2 and DNA damage assays","pmids":["31513783"],"confidence":"High","gaps":["Specific glycosylation sites on DUOXA2 critical for function not mapped","In vivo confirmation of glycosylation requirement lacking"]},{"year":2024,"claim":"How DUOXA2 directs polarized trafficking of DUOX2 to the apical membrane was unknown; domain-swap and glycosylation-mutant experiments showed that the C-terminal region of DUOXA2 mediates apical sorting, and unlike DUOXA1, DUOXA2-driven apical targeting is glycosylation-independent.","evidence":"MDCK co-expression; confocal microscopy; glycosylation-defective mutants; domain chimeras","pmids":["39126279"],"confidence":"High","gaps":["Specific apical sorting motif within the C-terminus not identified","Adaptor proteins mediating apical trafficking unknown"]},{"year":2025,"claim":"The spectrum of pathogenic DUOXA2 variants and their functional consequences was incomplete; ten new DUOXA2 variants from congenital hypothyroidism patients were shown to impair DUOX2 H2O2 production, broadly confirming DUOXA2 as a monogenic cause of CH.","evidence":"In vitro H2O2 production assay; targeted next-generation sequencing; pedigree analysis in Chinese cohort","pmids":["40510014"],"confidence":"Medium","gaps":["Genotype–phenotype correlation across variants not fully resolved","Single-lab study"]},{"year":null,"claim":"A high-resolution structure of the DUOX2–DUOXA2 complex has not been reported, and the precise apical sorting motif within the DUOXA2 C-terminus, the identity of adaptor proteins mediating trafficking, and the specific glycosylation sites critical for DUOX2 maturation remain uncharacterized.","evidence":"","pmids":[],"confidence":"High","gaps":["No cryo-EM or crystal structure of the full heterodimeric complex","Apical sorting signal within DUOXA2 C-terminus unmapped","ER oxidoreductases involved in DUOX2–DUOXA2 disulfide bridge formation unknown"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[0,1,2,6]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[2,5,6]},{"term_id":"GO:0005783","term_label":"endoplasmic reticulum","supporting_discovery_ids":[2]}],"pathway":[{"term_id":"R-HSA-1430728","term_label":"Metabolism","supporting_discovery_ids":[0,5]},{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[3,4]},{"term_id":"R-HSA-9609507","term_label":"Protein localization","supporting_discovery_ids":[2,6]}],"complexes":["DUOX2–DUOXA2"],"partners":["DUOX2","DUOXA1"],"other_free_text":[]},"mechanistic_narrative":"DUOXA2 is an essential transmembrane maturation factor for the NADPH oxidase DUOX2, required for its enzymatic activation, stable complex formation, and apical plasma membrane targeting in thyroid and mucosal epithelia. In the endoplasmic reticulum, oxidative folding of DUOX2 drives formation of interdisulfide bridges between the DUOX2 N-terminal domain and the two extracellular loops of DUOXA2, generating a stable heterodimeric complex that constitutes the primary H2O2-generating system at the cell surface [PMID:25761904, PMID:31513783]. The C-terminal region of DUOXA2 mediates apical sorting of the DUOX2–DUOXA2 complex in a glycosylation-independent manner, whereas glycosylation of DUOXA2 is required for DUOX2 maturation and catalytic activity [PMID:39126279, PMID:31513783]. Loss-of-function mutations in DUOXA2 cause congenital hypothyroidism by abolishing DUOX2-dependent H2O2 production needed for thyroid hormone biosynthesis [PMID:18042646, PMID:40510014]."},"prefetch_data":{"uniprot":{"accession":"Q1HG44","full_name":"Dual oxidase maturation factor 2","aliases":["Dual oxidase activator 2"],"length_aa":320,"mass_kda":34.8,"function":"Required for the maturation and transport of functional DUOX2 from the endoplasmic reticulum to the plasma membrane (PubMed:16651268). Recruits DUOX2 to the apical cell membrane (PubMed:39126279)","subcellular_location":"Endoplasmic reticulum membrane; Apical cell membrane","url":"https://www.uniprot.org/uniprotkb/Q1HG44/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/DUOXA2","classification":"Not Classified","n_dependent_lines":13,"n_total_lines":1208,"dependency_fraction":0.01076158940397351},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/DUOXA2","total_profiled":1310},"omim":[{"mim_id":"612772","title":"DUAL OXIDASE MATURATION FACTOR 2; DUOXA2","url":"https://www.omim.org/entry/612772"},{"mim_id":"612771","title":"DUAL OXIDASE MATURATION FACTOR 1; DUOXA1","url":"https://www.omim.org/entry/612771"},{"mim_id":"606759","title":"DUAL OXIDASE 2; DUOX2","url":"https://www.omim.org/entry/606759"},{"mim_id":"606758","title":"DUAL OXIDASE 1; DUOX1","url":"https://www.omim.org/entry/606758"},{"mim_id":"274900","title":"THYROID DYSHORMONOGENESIS 5; TDH5","url":"https://www.omim.org/entry/274900"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in some","driving_tissues":[{"tissue":"gallbladder","ntpm":60.1},{"tissue":"urinary bladder","ntpm":39.0}],"url":"https://www.proteinatlas.org/search/DUOXA2"},"hgnc":{"alias_symbol":[],"prev_symbol":[]},"alphafold":{"accession":"Q1HG44","domains":[{"cath_id":"-","chopping":"78-169","consensus_level":"medium","plddt":92.6225,"start":78,"end":169}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q1HG44","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q1HG44-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q1HG44-F1-predicted_aligned_error_v6.png","plddt_mean":83.06},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=DUOXA2","jax_strain_url":"https://www.jax.org/strain/search?query=DUOXA2"},"sequence":{"accession":"Q1HG44","fasta_url":"https://rest.uniprot.org/uniprotkb/Q1HG44.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q1HG44/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q1HG44"}},"corpus_meta":[{"pmid":"18042646","id":"PMC_18042646","title":"Biallelic inactivation of the dual oxidase maturation factor 2 (DUOXA2) gene as a novel cause of congenital hypothyroidism.","date":"2007","source":"The Journal of clinical endocrinology and metabolism","url":"https://pubmed.ncbi.nlm.nih.gov/18042646","citation_count":129,"is_preprint":false},{"pmid":"24492313","id":"PMC_24492313","title":"DUOX2 and DUOXA2 form the predominant enzyme system capable of producing the reactive oxygen species H2O2 in active ulcerative colitis and are modulated by 5-aminosalicylic acid.","date":"2014","source":"Inflammatory bowel diseases","url":"https://pubmed.ncbi.nlm.nih.gov/24492313","citation_count":83,"is_preprint":false},{"pmid":"21321110","id":"PMC_21321110","title":"Up-regulation and sustained activation of Stat1 are essential for interferon-gamma (IFN-gamma)-induced dual oxidase 2 (Duox2) and dual oxidase A2 (DuoxA2) expression in human pancreatic cancer cell lines.","date":"2011","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/21321110","citation_count":61,"is_preprint":false},{"pmid":"21367925","id":"PMC_21367925","title":"A single copy of the recently identified dual oxidase maturation factor (DUOXA) 1 gene produces only mild transient hypothyroidism in a patient with a novel biallelic DUOXA2 mutation and monoallelic DUOXA1 deletion.","date":"2011","source":"The Journal of clinical endocrinology and metabolism","url":"https://pubmed.ncbi.nlm.nih.gov/21367925","citation_count":50,"is_preprint":false},{"pmid":"31044655","id":"PMC_31044655","title":"DUOX2/DUOXA2 Mutations Frequently Cause Congenital Hypothyroidism that Evades Detection on Newborn Screening in the United Kingdom.","date":"2019","source":"Thyroid : official journal of the American Thyroid Association","url":"https://pubmed.ncbi.nlm.nih.gov/31044655","citation_count":42,"is_preprint":false},{"pmid":"25761904","id":"PMC_25761904","title":"When an Intramolecular Disulfide Bridge Governs the Interaction of DUOX2 with Its Partner DUOXA2.","date":"2015","source":"Antioxidants & redox signaling","url":"https://pubmed.ncbi.nlm.nih.gov/25761904","citation_count":31,"is_preprint":false},{"pmid":"32425884","id":"PMC_32425884","title":"DUOX2 and DUOXA2 Variants Confer Susceptibility to Thyroid Dysgenesis and Gland-in-situ With Congenital Hypothyroidism.","date":"2020","source":"Frontiers in endocrinology","url":"https://pubmed.ncbi.nlm.nih.gov/32425884","citation_count":28,"is_preprint":false},{"pmid":"23010498","id":"PMC_23010498","title":"Thyroid hydrogen peroxide production is enhanced by the Th2 cytokines, IL-4 and IL-13, through increased expression of the dual oxidase 2 and its maturation factor DUOXA2.","date":"2012","source":"Free radical biology & medicine","url":"https://pubmed.ncbi.nlm.nih.gov/23010498","citation_count":27,"is_preprint":false},{"pmid":"26758695","id":"PMC_26758695","title":"A Novel c.554+5C>T Mutation in the DUOXA2 Gene Combined with p.R885Q Mutation in the DUOX2 Gene Causing Congenital Hypothyroidism.","date":"2015","source":"Journal of clinical research in pediatric endocrinology","url":"https://pubmed.ncbi.nlm.nih.gov/26758695","citation_count":17,"is_preprint":false},{"pmid":"31513783","id":"PMC_31513783","title":"The Dual Oxidase Duox2 stabilized with DuoxA2 in an enzymatic complex at the surface of the cell produces extracellular H2O2 able to induce DNA damage in an inducible cellular model.","date":"2019","source":"Experimental cell research","url":"https://pubmed.ncbi.nlm.nih.gov/31513783","citation_count":15,"is_preprint":false},{"pmid":"28626131","id":"PMC_28626131","title":"Homozygous DUOXA2 mutation (p.Tyr138*) in a girl with congenital hypothyroidism and her apparently unaffected brother: Case report and review of the literature.","date":"2017","source":"Endocrine journal","url":"https://pubmed.ncbi.nlm.nih.gov/28626131","citation_count":10,"is_preprint":false},{"pmid":"28541007","id":"PMC_28541007","title":"Compound Heterozygous Mutations in the DUOX2/DUOXA2 Genes Cause Congenital Hypothyroidism.","date":"2017","source":"Yonsei medical journal","url":"https://pubmed.ncbi.nlm.nih.gov/28541007","citation_count":7,"is_preprint":false},{"pmid":"30110704","id":"PMC_30110704","title":"Fetal Goitrous Hypothyroidism and Polyhydramnios in a Patient with Compound Heterozygous DUOXA2 Mutations.","date":"2018","source":"Hormone research in paediatrics","url":"https://pubmed.ncbi.nlm.nih.gov/30110704","citation_count":7,"is_preprint":false},{"pmid":"39126279","id":"PMC_39126279","title":"The NADPH oxidases DUOX1 and DUOX2 are sorted to the apical plasma membrane in epithelial cells via their respective maturation factors DUOXA1 and DUOXA2.","date":"2024","source":"Genes to cells : devoted to molecular & cellular mechanisms","url":"https://pubmed.ncbi.nlm.nih.gov/39126279","citation_count":6,"is_preprint":false},{"pmid":"32252219","id":"PMC_32252219","title":"Persistent goiter with congenital hypothyroidism due to mutation in DUOXA2 gene.","date":"2020","source":"Annals of pediatric endocrinology & metabolism","url":"https://pubmed.ncbi.nlm.nih.gov/32252219","citation_count":4,"is_preprint":false},{"pmid":"39673194","id":"PMC_39673194","title":"The role of DUOXA2 in the clinical diagnosis of paediatric congenital hypothyroidism.","date":"2024","source":"Annals of medicine","url":"https://pubmed.ncbi.nlm.nih.gov/39673194","citation_count":3,"is_preprint":false},{"pmid":"28100324","id":"PMC_28100324","title":"[Characteristics of DUOXA2 gene mutation in children with congenital hypothyroidism].","date":"2017","source":"Zhongguo dang dai er ke za zhi = Chinese journal of contemporary pediatrics","url":"https://pubmed.ncbi.nlm.nih.gov/28100324","citation_count":3,"is_preprint":false},{"pmid":"27349010","id":"PMC_27349010","title":"Heterozygous Mutations of the DUOXA2 and DUOX2 Genes in Dizygotic Twins with Congenital Hypothyroidism.","date":"2016","source":"Clinical laboratory","url":"https://pubmed.ncbi.nlm.nih.gov/27349010","citation_count":3,"is_preprint":false},{"pmid":"28273705","id":"PMC_28273705","title":"[Genetic analysis of TPO, DUOX2 and DUOXA2 genes in children with permanent congenital hypothyroidism suspected dyshormonogenesis].","date":"2017","source":"Zhonghua er ke za zhi = Chinese journal of pediatrics","url":"https://pubmed.ncbi.nlm.nih.gov/28273705","citation_count":2,"is_preprint":false},{"pmid":"40510014","id":"PMC_40510014","title":"Large-scale screening and functional study of DUOXA2 variant in 599 Chinese patients with congenital hypothyroidism.","date":"2025","source":"European journal of endocrinology","url":"https://pubmed.ncbi.nlm.nih.gov/40510014","citation_count":1,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.07.15.664961","title":"Social stress worsens colitis through β-adrenergic–driven oxidative stress in intestinal mucosal compartments","date":"2025-07-18","source":"bioRxiv","url":"https://doi.org/10.1101/2025.07.15.664961","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2024.08.16.608271","title":"An IL-17-DUOX2 axis controls gastrointestinal colonization by<i>Candida albicans</i>","date":"2024-08-19","source":"bioRxiv","url":"https://doi.org/10.1101/2024.08.16.608271","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":14132,"output_tokens":2364,"usd":0.038928},"stage2":{"model":"claude-opus-4-6","input_tokens":5666,"output_tokens":2448,"usd":0.134295},"total_usd":0.173223,"stage1_batch_id":"msgbatch_0118RScg3WGaGkaZRtWZbtce","stage2_batch_id":"msgbatch_01Cpfzvtbj42aqp5oYZ5Te2s","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2007,\n      \"finding\": \"DUOXA2 is required to reconstitute DUOX2 enzymatic (H2O2-generating) activity; a truncated DUOXA2 protein (p.Y246X) lacking transmembrane helix 5 and the C-terminal cytoplasmic domain is inactive in reconstituting DUOX2 in vitro, establishing DUOXA2 as an essential maturation factor for DUOX2 function in thyroid hormone synthesis.\",\n      \"method\": \"In vitro reconstitution assay; loss-of-function mutant analysis in cell expression system; pedigree/genetic analysis\",\n      \"journal\": \"The Journal of clinical endocrinology and metabolism\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1/2 — in vitro reconstitution assay with mutant, replicated across multiple subsequent studies\",\n      \"pmids\": [\"18042646\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"DUOXA2 mutation C189R causes complete loss-of-function in reconstituting DUOX2 in vitro, and heterodimerization with specific maturation factors (DUOXA1 and DUOXA2) is essential for the maturation and function of the respective DUOX enzyme complexes; DUOXA1 can partially compensate for DUOXA2 deficiency.\",\n      \"method\": \"In vitro reconstitution assay; deletion mapping; genetic epistasis analysis\",\n      \"journal\": \"The Journal of clinical endocrinology and metabolism\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1/2 — in vitro reconstitution with loss-of-function mutant and genetic rescue experiment\",\n      \"pmids\": [\"21367925\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"An intramolecular disulfide bond between Cys-124 in the N-terminal ectodomain and Cys-1162 in an extracellular loop of DUOX2 supports structural formation of interdisulfide bridges between the N-terminal domain of DUOX2 and the two extracellular loops of DUOXA2; oxidative folding of DUOX2 in the ER acts as a chaperone-like event required for stable interaction with DUOXA2 and trafficking of the DUOX2/DUOXA2 complex to the cell surface.\",\n      \"method\": \"Cysteine mutagenesis; co-immunoprecipitation; cell surface expression assays; redox biochemistry\",\n      \"journal\": \"Antioxidants & redox signaling\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — active-site/domain mutagenesis with mechanistic follow-up on complex formation and trafficking\",\n      \"pmids\": [\"25761904\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"IFN-γ induces DUOXA2 (and DUOX2) expression in human pancreatic cancer cells via the JAK-STAT1 pathway, with Stat1 binding directly to elements of the DUOX2 promoter; p38-MAPK also contributes to this induction, resulting in increased H2O2 production.\",\n      \"method\": \"Quantitative PCR; STAT1 chromatin immunoprecipitation (ChIP); pharmacological pathway inhibition; ROS assays\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — ChIP and pharmacological inhibition in cell line, single lab\",\n      \"pmids\": [\"21321110\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Th2 cytokines IL-4 and IL-13 upregulate DUOX2 and DUOXA2 (but not DUOX1/DUOXA1) in human thyrocytes through the JAK1-STAT6 signaling cascade activated by the IL-4 type 2 receptor, leading to increased calcium-stimulated extracellular H2O2 generation.\",\n      \"method\": \"RT-PCR; pharmacological inhibition of JAK1-STAT6; H2O2 production assays in primary thyrocytes and Caco-2 cells\",\n      \"journal\": \"Free radical biology & medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — pathway inhibition with functional H2O2 output, single lab\",\n      \"pmids\": [\"23010498\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"DUOX2 and DUOXA2 form the most active H2O2-generating enzymatic complex at the cell surface compared to DUOX1/DUOXA1; DUOX2/DUOXA2 membrane complexes are more stable than unpaired or cross-paired complexes; glycosylation of DUOXA2 is required for DUOX2 maturation and activity (glycosylation-defective DUOXA2 drastically impairs DUOX2 activity); cell-surface H2O2 produced by the Duox2/DuoxA2 complex causes DNA damage in nuclei.\",\n      \"method\": \"Inducible HEK293 cell expression system; proximity ligation assay (Duolink); H2O2 production assays normalized to membrane expression; glycosylation-defective mutants; DNA damage readout (γH2AX, comet assay)\",\n      \"journal\": \"Experimental cell research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1/2 — multiple orthogonal methods including proximity ligation, functional assay, and loss-of-glycosylation mutants in the same study\",\n      \"pmids\": [\"31513783\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"DUOXA2 is required for apical sorting of DUOX2 to the apical plasma membrane in MDCK epithelial cells; N-glycosylation of DUOXA2 is dispensable for apical recruitment of DUOX2 (unlike DUOXA1 where N-glycosylation is required), and the C-terminal region of DUOXA2 appears to be involved in apical targeting of DUOX2.\",\n      \"method\": \"MDCK epithelial cell co-expression; immunofluorescence/confocal microscopy; glycosylation-defective DUOXA2 mutants; domain swap/chimera experiments\",\n      \"journal\": \"Genes to cells : devoted to molecular & cellular mechanisms\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1/2 — direct localization experiment with functional consequence, mutagenesis, and mechanistic domain mapping\",\n      \"pmids\": [\"39126279\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Ten DUOXA2 variants identified in Chinese CH patients disrupt DUOX2 enzyme activity in vitro, resulting in impaired H2O2 production, confirming the essential role of DUOXA2 in enabling DUOX2 H2O2 generation.\",\n      \"method\": \"In vitro functional assay (H2O2 production); targeted next-generation sequencing; pedigree analysis\",\n      \"journal\": \"European journal of endocrinology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — in vitro functional assay with multiple variants, single lab\",\n      \"pmids\": [\"40510014\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"DUOXA2 p.Tyr138* is a loss-of-function mutation, confirmed by expression experiments in HEK293 cells, establishing that this truncation abolishes DUOXA2's ability to support DUOX2 activity.\",\n      \"method\": \"HEK293 cell expression assay; loss-of-function validation\",\n      \"journal\": \"Endocrine journal\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — cell-based reconstitution assay, single lab, single mutation\",\n      \"pmids\": [\"28626131\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"DUOXA2 is a transmembrane maturation factor that heterodimerizes with DUOX2 in the endoplasmic reticulum, where oxidative folding of DUOX2 drives disulfide-bonded complex formation with the extracellular loops of DUOXA2; this complex is then trafficked to the apical plasma membrane (via DUOXA2's C-terminal region, in a glycosylation-independent manner) where it constitutes the primary H2O2-generating enzyme system essential for thyroid hormone biosynthesis and innate mucosal defense, with DUOXA2 expression being transcriptionally regulated by cytokines (IFN-γ via JAK-STAT1; IL-4/IL-13 via JAK1-STAT6) and loss-of-function DUOXA2 mutations causing congenital hypothyroidism through failure to reconstitute DUOX2 enzymatic activity.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"DUOXA2 is an essential transmembrane maturation factor for the NADPH oxidase DUOX2, required for its enzymatic activation, stable complex formation, and apical plasma membrane targeting in thyroid and mucosal epithelia. In the endoplasmic reticulum, oxidative folding of DUOX2 drives formation of interdisulfide bridges between the DUOX2 N-terminal domain and the two extracellular loops of DUOXA2, generating a stable heterodimeric complex that constitutes the primary H2O2-generating system at the cell surface [PMID:25761904, PMID:31513783]. The C-terminal region of DUOXA2 mediates apical sorting of the DUOX2–DUOXA2 complex in a glycosylation-independent manner, whereas glycosylation of DUOXA2 is required for DUOX2 maturation and catalytic activity [PMID:39126279, PMID:31513783]. Loss-of-function mutations in DUOXA2 cause congenital hypothyroidism by abolishing DUOX2-dependent H2O2 production needed for thyroid hormone biosynthesis [PMID:18042646, PMID:40510014].\",\n  \"teleology\": [\n    {\n      \"year\": 2007,\n      \"claim\": \"It was unknown whether DUOXA2 was merely co-expressed with DUOX2 or functionally required for its activity; in vitro reconstitution showed that DUOXA2 is an essential maturation factor for DUOX2 H2O2 generation and that a patient-derived truncation (p.Y246X) abolishes this function, establishing the first causal link between DUOXA2 loss-of-function and congenital hypothyroidism.\",\n      \"evidence\": \"In vitro reconstitution assay with loss-of-function mutant in heterologous expression system; pedigree analysis\",\n      \"pmids\": [\"18042646\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism by which DUOXA2 enables DUOX2 activity not resolved\", \"Whether DUOXA1 compensates in vivo unknown\", \"Structural basis of heterodimerization undefined\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"The specificity and compensatory capacity of DUOX maturation factors was unclear; functional assays demonstrated that DUOXA2 C189R is a complete loss-of-function mutation and that DUOXA1 can partially substitute for DUOXA2, establishing maturation factor selectivity as a regulatory layer.\",\n      \"evidence\": \"In vitro reconstitution with C189R mutant; deletion mapping and genetic rescue in cell expression system\",\n      \"pmids\": [\"21367925\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular interface mediating DUOX2–DUOXA2 specificity unresolved\", \"In vivo contribution of DUOXA1 compensation not tested\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"The transcriptional regulation of DUOXA2 was unknown; IFN-γ was shown to induce DUOXA2 and DUOX2 expression through JAK-STAT1, with STAT1 binding directly to the DUOX2 promoter region, linking innate immune signaling to the DUOX2/DUOXA2 H2O2-generating system.\",\n      \"evidence\": \"STAT1 ChIP; pharmacological pathway inhibition; qPCR and ROS assays in pancreatic cancer cells\",\n      \"pmids\": [\"21321110\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"STAT1 binding to the DUOXA2 promoter specifically was not demonstrated\", \"Relevance to thyroid physiology not established\", \"Findings from a single lab in cancer cell line\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Whether Th2 cytokines regulate DUOXA2 was unexplored; IL-4 and IL-13 were shown to upregulate DUOX2 and DUOXA2 selectively (not DUOX1/DUOXA1) via JAK1-STAT6 in thyrocytes, demonstrating that distinct cytokine pathways converge on DUOXA2 transcription to modulate H2O2 output.\",\n      \"evidence\": \"RT-PCR; JAK1-STAT6 pharmacological inhibition; H2O2 production assays in primary thyrocytes and Caco-2 cells\",\n      \"pmids\": [\"23010498\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct STAT6 binding to DUOXA2 regulatory regions not shown\", \"Single-lab finding\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"The molecular basis of DUOX2–DUOXA2 complex assembly was undefined; cysteine mutagenesis revealed that oxidative folding of DUOX2 in the ER generates an intramolecular disulfide bond (Cys-124/Cys-1162) that enables interdisulfide bridges with the extracellular loops of DUOXA2, establishing a redox-dependent chaperone-like mechanism for complex stabilization and ER-to-surface trafficking.\",\n      \"evidence\": \"Cysteine mutagenesis; co-immunoprecipitation; cell surface expression assays; redox biochemistry\",\n      \"pmids\": [\"25761904\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"High-resolution structure of the DUOX2–DUOXA2 complex unavailable\", \"Whether ER oxidoreductases specifically catalyze these bonds unknown\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"The relative activity and stability of different DUOX/DUOXA pairings and the role of DUOXA2 glycosylation were unresolved; DUOX2/DUOXA2 was shown to be the most active and stable H2O2-generating complex, and glycosylation of DUOXA2 was found to be required for DUOX2 maturation and enzymatic activity.\",\n      \"evidence\": \"Inducible HEK293 system; proximity ligation assay; glycosylation-defective DUOXA2 mutants; H2O2 and DNA damage assays\",\n      \"pmids\": [\"31513783\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Specific glycosylation sites on DUOXA2 critical for function not mapped\", \"In vivo confirmation of glycosylation requirement lacking\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"How DUOXA2 directs polarized trafficking of DUOX2 to the apical membrane was unknown; domain-swap and glycosylation-mutant experiments showed that the C-terminal region of DUOXA2 mediates apical sorting, and unlike DUOXA1, DUOXA2-driven apical targeting is glycosylation-independent.\",\n      \"evidence\": \"MDCK co-expression; confocal microscopy; glycosylation-defective mutants; domain chimeras\",\n      \"pmids\": [\"39126279\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Specific apical sorting motif within the C-terminus not identified\", \"Adaptor proteins mediating apical trafficking unknown\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"The spectrum of pathogenic DUOXA2 variants and their functional consequences was incomplete; ten new DUOXA2 variants from congenital hypothyroidism patients were shown to impair DUOX2 H2O2 production, broadly confirming DUOXA2 as a monogenic cause of CH.\",\n      \"evidence\": \"In vitro H2O2 production assay; targeted next-generation sequencing; pedigree analysis in Chinese cohort\",\n      \"pmids\": [\"40510014\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Genotype–phenotype correlation across variants not fully resolved\", \"Single-lab study\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"A high-resolution structure of the DUOX2–DUOXA2 complex has not been reported, and the precise apical sorting motif within the DUOXA2 C-terminus, the identity of adaptor proteins mediating trafficking, and the specific glycosylation sites critical for DUOX2 maturation remain uncharacterized.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"High\",\n      \"gaps\": [\"No cryo-EM or crystal structure of the full heterodimeric complex\", \"Apical sorting signal within DUOXA2 C-terminus unmapped\", \"ER oxidoreductases involved in DUOX2–DUOXA2 disulfide bridge formation unknown\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [0, 1, 2, 6]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [2, 5, 6]},\n      {\"term_id\": \"GO:0005783\", \"supporting_discovery_ids\": [2]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1430728\", \"supporting_discovery_ids\": [0, 5]},\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [3, 4]},\n      {\"term_id\": \"R-HSA-9609507\", \"supporting_discovery_ids\": [2, 6]}\n    ],\n    \"complexes\": [\"DUOX2–DUOXA2\"],\n    \"partners\": [\"DUOX2\", \"DUOXA1\"],\n    \"other_free_text\": []\n  }\n}\n```"}