{"gene":"NOXA1","run_date":"2026-06-10T05:19:52","timeline":{"discoveries":[{"year":2007,"finding":"PKA phosphorylates NoxA1 at Ser172 and Ser461, which enhances NoxA1 binding to 14-3-3 proteins (specifically 14-3-3ζ) and induces dissociation of NoxA1 from the Nox1 complex at the plasma membrane, thereby inhibiting Nox1-dependent ROS production. Elevation of cAMP inhibits, and PKA inhibition enhances, Nox1-dependent ROS production through effects on NoxA1.","method":"Site-directed mutagenesis, transfected HEK293 cell model, endogenous Nox1 in colon cell lines, co-immunoprecipitation, cAMP manipulation","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP, site-directed mutagenesis at defined phosphorylation sites, validated in both transfected and endogenous cell systems, two orthogonal functional readouts","pmids":["17913709"],"is_preprint":false},{"year":2010,"finding":"MAP kinases phosphorylate NoxA1 at Ser282, and PKC and PKA phosphorylate NoxA1 at Ser172. These phosphorylations occur basally and down-regulate constitutive NOX1 activity. Single mutants S172A and S282A up-regulate NOX1-derived ROS, and double mutant S172A/S282A further increases ROS. Phosphorylation at these sites decreases NoxA1 binding to both NOX1 and Rac1.","method":"In vitro kinase assays, site-directed mutagenesis, phosphopeptide mapping, transfected HEK293 cell model, ROS measurement","journal":"FASEB journal","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro kinase assay with mutagenesis, phosphopeptide mapping, functional ROS readout, and binding assays; multiple orthogonal methods in one study","pmids":["20110267"],"is_preprint":false},{"year":2010,"finding":"c-Src phosphorylates NoxA1 at Tyr110 and Tks4 at Tyr508; abolishing these phosphorylations blocks the NoxA1–Tks4 interaction and decreases Nox1-dependent ROS generation. Phosphomimetic mutants of both NoxA1 and Tks4 rescue SrcYF-induced invadopodia formation and ECM degradation, while unphosphorylatable mutants block it. NoxA1 interaction with Tks4 and Tks5 scaffold proteins is Src-activity dependent.","method":"Site-directed mutagenesis (phosphomimetic and unphosphorylatable mutants), co-immunoprecipitation, ROS measurement, invadopodia/ECM degradation assays in human colon cancer cells","journal":"Molecular biology of the cell","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP, phosphomimetic/unphosphorylatable rescue experiments, functional invadopodia assay; multiple orthogonal methods","pmids":["20943948"],"is_preprint":false},{"year":2006,"finding":"Noxa1 (the p67phox homologue) is expressed in the cytosolic fraction of mouse vascular smooth muscle cells (VSMC) and co-localizes to the membrane when co-expressed with Noxo1. Antisense knockdown of Noxa1 attenuates basal and agonist (bFGF, EGF)-induced ROS production in mouse VSMC, establishing Noxa1 as the central activator subunit of the smooth muscle NADPH oxidase.","method":"Western blot, immunohistochemistry, fluorescent fusion protein localization, antisense knockdown, L012 chemiluminescence ROS assay","journal":"Free radical biology & medicine","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct localization with functional consequence (antisense KD + ROS readout), single lab, two orthogonal methods","pmids":["16814099"],"is_preprint":false},{"year":2013,"finding":"A peptide mimicking the putative activation domain of NOXA1 (NoxA1ds) potently and selectively inhibits Nox1-derived superoxide production in a reconstituted cell-free system and in whole cells, with no effect on Nox2, Nox4, Nox5, or xanthine oxidase. FRET experiments show NoxA1ds disrupts the direct binding interaction between Nox1 and NOXA1, identifying the NOXA1 activation domain as the critical interface for NOX1 complex assembly.","method":"Cell-free reconstituted Nox1 system, cytochrome c reduction, Amplex Red fluorescence, EPR, FRET (Nox1-YFP/NOXA1-CFP), ELISA, FRAP, confocal microscopy with FITC-labeled peptide","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Strong — reconstituted cell-free system, direct FRET binding disruption assay, multiple orthogonal ROS measurement methods, validated in intact cells","pmids":["24187133"],"is_preprint":false},{"year":2010,"finding":"The isolated tandem SH3 domains of NOXO1 bind p22phox with high affinity, likely in a superSH3 conformation, and the C-terminal tail of NOXO1 competes for p22phox binding, thereby contributing to NOX1 regulation. The NOXO1–NOXA1 interaction differs molecularly from the p47phox–p67phox interaction of the phagocytic oxidase, suggesting functional differences between the two systems.","method":"Isothermal titration calorimetry (ITC), quantitative characterization of protein-protein interactions in vitro","journal":"PloS one","confidence":"Medium","confidence_rationale":"Tier 1 / Moderate — quantitative ITC binding assay with isolated domains, single lab, rigorous in vitro method but no mutagenesis/functional validation","pmids":["20454568"],"is_preprint":false},{"year":2007,"finding":"The NOXA1 SH3 domain is not required for NOX1 activation but modulates the kinetics of active complex formation: truncated NOXA1 lacking SH3 activates NOX1 at an accelerated rate compared to wild-type. A heptapeptide insertion into the SH3 domain (from the NOXA1(inhib) splice variant) inhibits NOXA1 activity by ~90%, acts as a transdominant inhibitor, and abrogates SH3 domain binding to NOXO1 and p47phox.","method":"Transfection into K562 cells stably expressing NOX1/NOXO1, kinetic superoxide generation assays, deletion and insertion mutagenesis, pulldown binding assays","journal":"Free radical biology & medicine","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — mutagenesis with functional reconstitution in cell model, pulldown binding assay, single lab with multiple constructs","pmids":["17602954"],"is_preprint":false},{"year":2008,"finding":"In airway epithelial cells, Noxa1 associates with plasma membrane-bound Duox (Duox1) and acts as an inhibitory regulator of Duox activity. Calcium flux promotes Duox activation by causing dissociation of Noxa1 from Duox. Knockdown of Noxa1 increases basal H2O2 generation. Mutation of a proline-rich domain in the Duox C-terminus (a potential Noxa1-SH3 interaction motif) up-regulates H2O2 production, and the Noxa1 activation domain is not required for Duox regulation.","method":"siRNA knockdown, Duox1 reconstitution in model cell lines, mutagenesis of Noxa1 and Duox1, H2O2 measurement, mucociliary airway epithelium model","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — loss-of-function knockdown with defined phenotype, mutagenesis of interaction domain, reconstitution system; single lab","pmids":["18606821"],"is_preprint":false},{"year":2013,"finding":"PKC-mediated phosphorylation of Noxo1 at Thr341 (directly phosphorylated by PKC in vitro) facilitates Noxo1 interaction with Noxa1, and this interaction is required for PMA-dependent enhancement of Nox1 superoxide production. Alanine substitution at Thr341 reduces both Noxo1 phosphorylation and Nox1-catalyzed superoxide production.","method":"In vitro PKC kinase assay, site-directed mutagenesis (T341A), pulldown binding assay between Noxo1 and Noxa1, superoxide production assay","journal":"The FEBS journal","confidence":"Medium","confidence_rationale":"Tier 1-2 / Moderate — in vitro kinase assay plus mutagenesis plus pulldown plus functional assay; single lab","pmids":["23957209"],"is_preprint":false},{"year":2014,"finding":"PKCβ1 phosphorylates Nox1 at Thr429 in response to TNFα, and this phosphorylation facilitates association of Nox1 with the NoxA1 activation domain. This Nox1-NoxA1 interaction is necessary for NADPH oxidase complex assembly, ROS production, and vascular smooth muscle cell migration.","method":"Mass spectrometry (phosphosite identification), pharmacological PKC inhibition, siRNA silencing of PKCβ1, site-directed mutagenesis (T429), isothermal titration calorimetry (NoxA1ds binding), VSMC migration assay, ROS measurement","journal":"Circulation research","confidence":"High","confidence_rationale":"Tier 1 / Strong — mass spectrometry phosphosite identification, mutagenesis, ITC binding measurement, siRNA knockdown with defined cellular phenotype; multiple orthogonal methods in one study","pmids":["25228390"],"is_preprint":false},{"year":2008,"finding":"siRNA-mediated knockdown of NOXA1 in human vascular endothelial cells potently decreases ROS generation induced by oxidized LDL and angiotensin II, establishing NOXA1 as essential for NAD(P)H oxidase-dependent ROS production in endothelial cells downstream of LOX-1 signaling.","method":"siRNA knockdown, dihydroethidium ROS assay, RT-PCR","journal":"Endothelium","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct loss-of-function with defined ROS phenotype, validated for two stimuli (ox-LDL and Ang II); single lab","pmids":["18568954"],"is_preprint":false},{"year":2012,"finding":"In a pure reconstituted cell-free system using purified cytochrome b558 (Nox2+p22phox), Rac(Q61L), and Noxo1, Noxa1 activates Nox2 with lower efficiency than p67phox: higher EC50, one-third Vmax, lower FAD affinity, and reduced stability of the active complex. These kinetic differences distinguish Noxa1 from the canonical Nox2 activator p67phox.","method":"In vitro reconstituted cell-free NADPH oxidase system with purified proteins, kinetic analysis, FAD affinity measurement","journal":"Archives of biochemistry and biophysics","confidence":"High","confidence_rationale":"Tier 1 / Moderate — purified protein reconstitution with quantitative kinetics, FAD affinity and complex stability measurements; single lab but rigorous in vitro approach","pmids":["22244833"],"is_preprint":false},{"year":2018,"finding":"SMC-specific genetic deletion of Noxa1 in Apoe-/- mice reduces vascular ROS, attenuates TNFα-induced VSMC proliferation and migration, and decreases expression of KLF4 transcription factor and its downstream targets VCAM1, CCL2, and MMP2 in atherosclerotic lesions, placing NOXA1-dependent NOX1 activity upstream of KLF4-mediated VSMC phenotypic switching to macrophage-like cells.","method":"Conditional SMC-specific Noxa1 knockout mouse, endovascular injury model, Western diet atherosclerosis model, immunofluorescence, ROS measurement, VSMC proliferation/migration assays","journal":"Redox biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — conditional KO with cell-type specific deletion, multiple disease models, defined molecular pathway (NOXA1→NOX1→ROS→KLF4→downstream targets), replicated across multiple readouts","pmids":["30576919"],"is_preprint":false},{"year":2022,"finding":"Principal cell-specific Noxa1 knockout mice fail to increase ENaC activity in response to angiotensin II, and pharmacological NOX1 inhibition (ML171) abolishes ANG II-dependent ENaC stimulation, establishing that NOXA1/NOX1 signaling mediates ANG II-dependent activation of the epithelial sodium channel in renal principal cells of the distal nephron.","method":"Principal cell-specific Noxa1 conditional knockout mice, patch-clamp electrophysiology on freshly isolated split-open tubules, ML171 pharmacological inhibition, losartan AT1R blockade","journal":"American journal of physiology. Renal physiology","confidence":"High","confidence_rationale":"Tier 2 / Strong — cell-type specific conditional KO with electrophysiological functional readout, pharmacological validation with selective NOX1 inhibitor and AT1R blocker; multiple orthogonal approaches","pmids":["36201326"],"is_preprint":false},{"year":2022,"finding":"NOXA1 is present in Henle's thick ascending limb and distal nephron epithelial cells. Systemic Noxa1 deletion reduces basal systolic blood pressure and attenuates ANG II-induced increases in renal ENaC levels, ENaC activation in collecting duct principal cells, and sodium retention, with sex-specific differences (males more affected than females).","method":"Noxa1 global knockout mice, telemetry blood pressure measurement, ANG II infusion, immunofluorescence, siRNA knockdown of Noxa1 in renal epithelial cell line, ENaC activity assay","journal":"Antioxidants & redox signaling","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — global KO with telemetry and functional ENaC assay, siRNA validation in cell line; single lab","pmids":["34714114"],"is_preprint":false},{"year":2025,"finding":"Knockdown of Noxa1 in radiotherapy-resistant colorectal cancer cells decreases expression of SLC7A11 and GPX4, increases cellular ROS levels, induces ferroptosis, and sensitizes cells to radiotherapy, placing NOXA1 upstream of the glutathione metabolic pathway (SLC7A11/GPX4 axis) as a suppressor of ferroptosis.","method":"siRNA knockdown of Noxa1 in CRC cell lines, Western blot for SLC7A11 and GPX4, ROS measurement, ferroptosis assay, radiotherapy sensitivity assay, GSVA pathway analysis","journal":"International journal of medical sciences","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, single knockdown approach, no mechanistic dissection of how NOXA1 regulates SLC7A11/GPX4","pmids":["40084254"],"is_preprint":false},{"year":2025,"finding":"ERVWE1 (human endogenous retrovirus W envelope protein) upregulates USF2 transcription factor, which enhances NOXA1 transcription. NOXA1 in turn promotes macroautophagy (increased LC3B II/I ratio, enhanced autophagosome formation, reduced SQSTM1) and inhibits micromitophagy by suppressing PINK1, Parkin, and PDHA1 expression in the context of schizophrenia-related pathology.","method":"Cellular and molecular experiments in neuronal context, LC3B assay, autophagosome formation assay, SQSTM1/PINK1/Parkin/PDHA1 expression, bioinformatics (GSE53987), clinical serum measurements","journal":"Virologica Sinica","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, mixed bioinformatics and cellular methods, limited mechanistic dissection of NOXA1's direct role in autophagy versus upstream regulatory context","pmids":["40419114"],"is_preprint":false}],"current_model":"NOXA1 is the activator subunit (p67phox homologue) of the NOX1 NADPH oxidase complex that directly binds NOX1 through its activation domain to drive superoxide production; its activity is regulated by multi-site phosphorylation (PKA at Ser172/Ser461, PKC/MAPK at Ser172/Ser282, c-Src at Tyr110) that controls its interactions with 14-3-3 proteins, Rac1, NOX1, and scaffold proteins (Tks4/Tks5), thereby governing ROS-dependent processes including VSMC migration/phenotypic switching, invadopodia formation in colon cancer, and renal ENaC-mediated sodium homeostasis; NOXA1 also acts as an inhibitory regulator of Duox in airway cells, where calcium-induced conformational change of Duox relieves Noxa1-mediated constraint."},"narrative":{"mechanistic_narrative":"NOXA1 is the cytosolic activator subunit (p67phox homologue) of the NOX1 NADPH oxidase complex, where it serves as the central driver of regulated superoxide production across vascular, renal, and epithelial tissues [PMID:16814099]. NOXA1 directly engages NOX1 through its activation domain, and a peptide mimicking this domain (NoxA1ds) selectively disrupts the NOX1–NOXA1 interface and blocks NOX1-derived superoxide without affecting NOX2, NOX4, NOX5, or xanthine oxidase [PMID:24187133]. Complex assembly is gated by phosphorylation of the catalytic subunit itself: PKCβ1 phosphorylates NOX1 at Thr429 to promote its association with the NOXA1 activation domain, an interaction required for oxidase assembly and ROS-dependent vascular smooth muscle cell migration [PMID:25228390]. Conversely, multi-site phosphorylation of NOXA1 restrains activity—PKA phosphorylates Ser172/Ser461 to drive 14-3-3ζ binding and dissociation of NOXA1 from the NOX1 complex, while MAPK (Ser282) and PKC/PKA (Ser172) phosphorylation reduce NOXA1 binding to both NOX1 and Rac1, basally suppressing constitutive activity [PMID:17913709, PMID:20110267]. The NOXO1–NOXA1 module is recruited by PKC phosphorylation of NOXO1 at Thr341, and NOXA1's SH3 domain modulates the kinetics of active complex formation [PMID:23957209, PMID:17602954]. c-Src phosphorylation of NOXA1 at Tyr110 (and of Tks4 at Tyr508) couples the oxidase to the Tks4/Tks5 invadopodial scaffolds, driving ROS-dependent invadopodia formation and ECM degradation in colon cancer [PMID:20943948]. Physiologically, NOXA1-dependent NOX1 activity drives KLF4-mediated VSMC phenotypic switching during atherosclerosis [PMID:30576919] and mediates angiotensin II–dependent activation of the renal epithelial sodium channel (ENaC), contributing to sodium handling and blood pressure control [PMID:36201326, PMID:34714114]. In airway epithelium NOXA1 instead acts as an inhibitory regulator of DUOX1, with calcium-induced conformational change relieving this constraint [PMID:18606821].","teleology":[{"year":2006,"claim":"Established NOXA1 as the functional activator subunit of the smooth muscle NADPH oxidase, answering whether the p67phox homologue drives ROS in non-phagocytic cells.","evidence":"Antisense knockdown and fluorescent fusion localization with ROS chemiluminescence in mouse VSMC","pmids":["16814099"],"confidence":"Medium","gaps":["Did not define the molecular interface with NOX1","Single lab, antisense rather than genetic deletion"]},{"year":2007,"claim":"Defined a negative-regulatory mechanism whereby PKA phosphorylation of NOXA1 recruits 14-3-3 and dissociates it from NOX1, linking cAMP signaling to oxidase shutdown.","evidence":"Site-directed mutagenesis of Ser172/Ser461, co-IP, and cAMP manipulation in HEK293 and colon cell lines","pmids":["17913709"],"confidence":"High","gaps":["Did not map which interface region 14-3-3 occludes","Physiological cAMP-elevating stimulus not identified"]},{"year":2007,"claim":"Resolved the role of the NOXA1 SH3 domain, showing it is dispensable for activation but tunes assembly kinetics and is the target of a transdominant inhibitory splice variant.","evidence":"Deletion/insertion mutagenesis and kinetic superoxide assays in K562 cells expressing NOX1/NOXO1, with pulldowns","pmids":["17602954"],"confidence":"Medium","gaps":["In vivo relevance of the NOXA1(inhib) splice variant unknown","Single cell model"]},{"year":2008,"claim":"Revealed a context-specific inhibitory role: NOXA1 constrains DUOX1 in airway epithelium, with calcium relieving the constraint, distinguishing it from its NOX1-activating function.","evidence":"siRNA knockdown, DUOX1 reconstitution, and domain mutagenesis with H2O2 measurement in airway epithelial models","pmids":["18606821"],"confidence":"Medium","gaps":["Structural basis of NOXA1–DUOX1 constraint not defined","How calcium triggers dissociation mechanistically unresolved"]},{"year":2008,"claim":"Extended NOXA1's requirement for stimulus-induced ROS to endothelial cells downstream of LOX-1 signaling.","evidence":"siRNA knockdown with DHE ROS assay in human vascular endothelial cells under ox-LDL and angiotensin II","pmids":["18568954"],"confidence":"Medium","gaps":["Did not establish the NOX isoform partner in endothelium","No reciprocal validation of pathway"]},{"year":2010,"claim":"Mapped basal inhibitory phosphorylation of NOXA1 by MAPK and PKC/PKA and tied it to reduced NOX1 and Rac1 binding, defining how constitutive oxidase output is held in check.","evidence":"In vitro kinase assays, phosphopeptide mapping, mutagenesis (S172A/S282A), and binding/ROS assays in HEK293","pmids":["20110267"],"confidence":"High","gaps":["Did not resolve whether these sites act sequentially or independently in vivo"]},{"year":2010,"claim":"Connected NOXA1 to invadopodia by showing c-Src phosphorylation at Tyr110 couples it to Tks4/Tks5 scaffolds to drive localized ROS and ECM degradation in colon cancer.","evidence":"Phosphomimetic/unphosphorylatable mutant rescue, co-IP, and invadopodia/ECM degradation assays in colon cancer cells","pmids":["20943948"],"confidence":"High","gaps":["In vivo tumor relevance not tested","Spatial coupling of ROS to ECM proteases not mechanistically resolved"]},{"year":2010,"claim":"Quantified the NOXO1–p22phox interaction biophysically and showed the NOXO1–NOXA1 module differs molecularly from the phagocytic p47phox–p67phox pair.","evidence":"Isothermal titration calorimetry with isolated SH3 domains and C-terminal tail","pmids":["20454568"],"confidence":"Medium","gaps":["No functional or mutational validation in cells","Full-length complex architecture not determined"]},{"year":2012,"claim":"Distinguished NOXA1 from p67phox kinetically, showing it activates NOX2 less efficiently in a purified system.","evidence":"Reconstituted cell-free system with purified cytochrome b558, Rac(Q61L), NOXO1, and kinetic/FAD-affinity analysis","pmids":["22244833"],"confidence":"High","gaps":["Physiological significance of NOXA1–NOX2 cross-activation unclear"]},{"year":2013,"claim":"Showed PKC phosphorylation of the NOXO1 partner at Thr341 promotes NOXO1–NOXA1 assembly required for PMA-stimulated NOX1 superoxide.","evidence":"In vitro PKC kinase assay, T341A mutagenesis, pulldown, and superoxide assay","pmids":["23957209"],"confidence":"Medium","gaps":["Cell-type and stimulus generality not established"]},{"year":2013,"claim":"Identified the NOXA1 activation domain as the critical, NOX1-selective assembly interface using a disrupting peptide.","evidence":"Cell-free reconstitution, FRET binding disruption, and multiple ROS readouts with the NoxA1ds peptide","pmids":["24187133"],"confidence":"High","gaps":["Atomic-resolution structure of the interface not solved","Therapeutic delivery of NoxA1ds not addressed"]},{"year":2014,"claim":"Demonstrated that PKCβ1 phosphorylation of NOX1 at Thr429 promotes NOX1–NOXA1 association required for assembly and VSMC migration, providing a TNFα-responsive activation switch on the catalytic subunit.","evidence":"Mass spectrometry phosphosite mapping, T429 mutagenesis, ITC, PKCβ1 siRNA, and VSMC migration/ROS assays","pmids":["25228390"],"confidence":"High","gaps":["Interplay between NOX1 Thr429 phosphorylation and inhibitory NOXA1 phosphorylation not integrated"]},{"year":2018,"claim":"Placed NOXA1-dependent NOX1 activity upstream of KLF4-driven VSMC phenotypic switching in atherosclerosis using cell-type-specific genetics.","evidence":"SMC-specific Noxa1 knockout in Apoe-/- mice, injury and Western-diet models, ROS, and KLF4/VCAM1/CCL2/MMP2 readouts","pmids":["30576919"],"confidence":"High","gaps":["Mechanism linking ROS to KLF4 induction not dissected"]},{"year":2022,"claim":"Established NOXA1/NOX1 as the mediator of angiotensin II–dependent ENaC activation in renal principal cells, defining a physiological sodium-handling role.","evidence":"Principal-cell-specific Noxa1 conditional KO, patch-clamp on split-open tubules, and ML171/losartan pharmacology","pmids":["36201326"],"confidence":"High","gaps":["Molecular link between ROS and ENaC gating not resolved"]},{"year":2022,"claim":"Connected NOXA1 to systemic blood pressure and sex-specific sodium retention through effects on renal ENaC.","evidence":"Global Noxa1 knockout with telemetry, ANG II infusion, immunofluorescence, and renal-cell siRNA ENaC assays","pmids":["34714114"],"confidence":"Medium","gaps":["Basis of sex-specific difference unexplained","Global KO confounds tissue-specific contributions"]},{"year":2025,"claim":"Proposed NOXA1 as a ferroptosis suppressor in radiotherapy-resistant colorectal cancer via the SLC7A11/GPX4 axis.","evidence":"siRNA knockdown in CRC lines with ROS, ferroptosis, and radiosensitivity assays plus GSVA","pmids":["40084254"],"confidence":"Low","gaps":["No mechanistic link between NOXA1 and SLC7A11/GPX4 regulation","Single lab, single knockdown approach"]},{"year":2025,"claim":"Proposed a transcriptional and autophagy-regulatory role for NOXA1 downstream of ERVWE1/USF2 in schizophrenia-related neuronal pathology.","evidence":"Neuronal cellular assays for LC3B/SQSTM1/PINK1/Parkin/PDHA1 with bioinformatics and clinical serum measures","pmids":["40419114"],"confidence":"Low","gaps":["Direct role of NOXA1 in autophagy versus upstream regulatory context not dissected","Mixed bioinformatic/cellular evidence, single lab"]},{"year":null,"claim":"How the multiple phosphorylation switches on NOXA1, NOX1, and NOXO1 are integrated in space and time to set oxidase output in a given tissue remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No atomic structure of the assembled NOX1–NOXO1–NOXA1–Rac complex","Crosstalk between activating (NOX1 Thr429) and inhibitory (NOXA1 Ser172/282/461) phosphorylation not integrated","Mechanism linking localized ROS to downstream effectors (KLF4, ENaC, SLC7A11) undefined"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[0,1,3,4,7]},{"term_id":"GO:0060089","term_label":"molecular transducer activity","supporting_discovery_ids":[3,4,9]}],"localization":[{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[3]},{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[0,3,7]}],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[9,12,13]},{"term_id":"R-HSA-8953897","term_label":"Cellular responses to stimuli","supporting_discovery_ids":[0,1]}],"complexes":["NOX1 NADPH oxidase complex"],"partners":["NOX1","NOXO1","RAC1","YWHAZ","TKS4","TKS5","DUOX1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q86UR1","full_name":"NADPH oxidase activator 1","aliases":["Antigen NY-CO-31","NCF2-like protein","P67phox-like factor","p51-nox"],"length_aa":476,"mass_kda":50.9,"function":"Functions as an activator of NOX1, a superoxide-producing NADPH oxidase. Functions in the production of reactive oxygen species (ROS) which participate in a variety of biological processes including host defense, hormone biosynthesis, oxygen sensing and signal transduction. May also activate CYBB/gp91phox and NOX3","subcellular_location":"Cytoplasm; Cell membrane","url":"https://www.uniprot.org/uniprotkb/Q86UR1/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/NOXA1","classification":"Not Classified","n_dependent_lines":1,"n_total_lines":1208,"dependency_fraction":0.0008278145695364238},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/NOXA1","total_profiled":1310},"omim":[{"mim_id":"611256","title":"NADPH OXIDASE ORGANIZER 1; NOXO1","url":"https://www.omim.org/entry/611256"},{"mim_id":"611255","title":"NADPH OXIDASE ACTIVATOR 1; NOXA1","url":"https://www.omim.org/entry/611255"},{"mim_id":"300951","title":"RING FINGER PROTEIN 113A; RNF113A","url":"https://www.omim.org/entry/300951"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Vesicles","reliability":"Approved"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in many","driving_tissues":[],"url":"https://www.proteinatlas.org/search/NOXA1"},"hgnc":{"alias_symbol":["NY-CO-31","FLJ25475"],"prev_symbol":["SDCCAG31"]},"alphafold":{"accession":"Q86UR1","domains":[{"cath_id":"1.25.40.10","chopping":"5-170","consensus_level":"high","plddt":91.8895,"start":5,"end":170},{"cath_id":"3.10.20.90","chopping":"314-394","consensus_level":"medium","plddt":72.6526,"start":314,"end":394},{"cath_id":"2.30.30.40","chopping":"403-456","consensus_level":"medium","plddt":86.9607,"start":403,"end":456}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q86UR1","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q86UR1-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q86UR1-F1-predicted_aligned_error_v6.png","plddt_mean":72.06},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=NOXA1","jax_strain_url":"https://www.jax.org/strain/search?query=NOXA1"},"sequence":{"accession":"Q86UR1","fasta_url":"https://rest.uniprot.org/uniprotkb/Q86UR1.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q86UR1/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q86UR1"}},"corpus_meta":[{"pmid":"20943948","id":"PMC_20943948","title":"c-Src-mediated phosphorylation of NoxA1 and Tks4 induces the reactive oxygen species (ROS)-dependent formation of functional invadopodia in human colon cancer cells.","date":"2010","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/20943948","citation_count":92,"is_preprint":false},{"pmid":"17913709","id":"PMC_17913709","title":"Regulation of Nox1 activity via protein kinase A-mediated phosphorylation of NoxA1 and 14-3-3 binding.","date":"2007","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/17913709","citation_count":85,"is_preprint":false},{"pmid":"16814099","id":"PMC_16814099","title":"Noxa1 is a central component of the smooth muscle NADPH oxidase in mice.","date":"2006","source":"Free radical biology & medicine","url":"https://pubmed.ncbi.nlm.nih.gov/16814099","citation_count":75,"is_preprint":false},{"pmid":"24187133","id":"PMC_24187133","title":"Selective recapitulation of conserved and nonconserved regions of putative NOXA1 protein activation domain confers isoform-specific inhibition of Nox1 oxidase and attenuation of endothelial cell migration.","date":"2013","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/24187133","citation_count":65,"is_preprint":false},{"pmid":"30576919","id":"PMC_30576919","title":"NOXA1-dependent NADPH oxidase regulates redox signaling and phenotype of vascular smooth muscle cell during atherogenesis.","date":"2018","source":"Redox biology","url":"https://pubmed.ncbi.nlm.nih.gov/30576919","citation_count":58,"is_preprint":false},{"pmid":"20110267","id":"PMC_20110267","title":"Phosphorylation of NADPH oxidase activator 1 (NOXA1) on serine 282 by MAP kinases and on serine 172 by protein kinase C and protein kinase A prevents NOX1 hyperactivation.","date":"2010","source":"FASEB journal : official publication of the Federation of American Societies for Experimental Biology","url":"https://pubmed.ncbi.nlm.nih.gov/20110267","citation_count":52,"is_preprint":false},{"pmid":"20454568","id":"PMC_20454568","title":"Regulation of NOXO1 activity through reversible interactions with p22 and NOXA1.","date":"2010","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/20454568","citation_count":51,"is_preprint":false},{"pmid":"18568954","id":"PMC_18568954","title":"Essential role of NOXA1 in generation of reactive oxygen species induced by oxidized low-density lipoprotein in human vascular endothelial cells.","date":"2008","source":"Endothelium : journal of endothelial cell research","url":"https://pubmed.ncbi.nlm.nih.gov/18568954","citation_count":39,"is_preprint":false},{"pmid":"18606821","id":"PMC_18606821","title":"Inhibitory action of NoxA1 on dual oxidase activity in airway cells.","date":"2008","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/18606821","citation_count":35,"is_preprint":false},{"pmid":"25228390","id":"PMC_25228390","title":"Phosphorylation of Nox1 regulates association with NoxA1 activation domain.","date":"2014","source":"Circulation research","url":"https://pubmed.ncbi.nlm.nih.gov/25228390","citation_count":30,"is_preprint":false},{"pmid":"23957209","id":"PMC_23957209","title":"Phosphorylation of Noxo1 at threonine 341 regulates its interaction with Noxa1 and the superoxide-producing activity of Nox1.","date":"2013","source":"The FEBS journal","url":"https://pubmed.ncbi.nlm.nih.gov/23957209","citation_count":28,"is_preprint":false},{"pmid":"34714114","id":"PMC_34714114","title":"Renal NOXA1/NOX1 Signaling Regulates Epithelial Sodium Channel and Sodium Retention in Angiotensin II-induced Hypertension.","date":"2022","source":"Antioxidants & redox signaling","url":"https://pubmed.ncbi.nlm.nih.gov/34714114","citation_count":25,"is_preprint":false},{"pmid":"17602954","id":"PMC_17602954","title":"NOX1 NADPH oxidase regulation by the NOXA1 SH3 domain.","date":"2007","source":"Free radical biology & medicine","url":"https://pubmed.ncbi.nlm.nih.gov/17602954","citation_count":18,"is_preprint":false},{"pmid":"22244833","id":"PMC_22244833","title":"Noxa1 as a moderate activator of Nox2-based NADPH oxidase.","date":"2012","source":"Archives of biochemistry and biophysics","url":"https://pubmed.ncbi.nlm.nih.gov/22244833","citation_count":16,"is_preprint":false},{"pmid":"36759130","id":"PMC_36759130","title":"Reactivity of renal and mesenteric resistance vessels to angiotensin II is mediated by NOXA1/NOX1 and superoxide signaling.","date":"2023","source":"American journal of physiology. Renal physiology","url":"https://pubmed.ncbi.nlm.nih.gov/36759130","citation_count":7,"is_preprint":false},{"pmid":"36201326","id":"PMC_36201326","title":"NOXA1-dependent NADPH oxidase 1 signaling mediates angiotensin II activation of the epithelial sodium channel.","date":"2022","source":"American journal of physiology. Renal physiology","url":"https://pubmed.ncbi.nlm.nih.gov/36201326","citation_count":7,"is_preprint":false},{"pmid":"33708473","id":"PMC_33708473","title":"MiR-155 acts as an inhibitory factor in atherosclerosis-associated arterial pathogenesis by down-regulating NoxA1 related signaling pathway in ApoE-/- mouse.","date":"2021","source":"Cardiovascular diagnosis and therapy","url":"https://pubmed.ncbi.nlm.nih.gov/33708473","citation_count":7,"is_preprint":false},{"pmid":"40419114","id":"PMC_40419114","title":"Human endogenous retrovirus W family envelope protein (ERVWE1) regulates macroautophagy activation and micromitophagy inhibition via NOXA1 in schizophrenia.","date":"2025","source":"Virologica Sinica","url":"https://pubmed.ncbi.nlm.nih.gov/40419114","citation_count":3,"is_preprint":false},{"pmid":"40084254","id":"PMC_40084254","title":"NADPH oxidase activator 1 (NOXA1) suppresses ferroptosis and radiosensitization in colorectal cancer.","date":"2025","source":"International journal of medical sciences","url":"https://pubmed.ncbi.nlm.nih.gov/40084254","citation_count":1,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":13747,"output_tokens":4982,"usd":0.057986,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":13100,"output_tokens":5268,"usd":0.0986,"stage2_stop_reason":"end_turn"},"total_usd":0.156586,"stage1_batch_id":"msgbatch_013a8chtv3AWyTqv4z4sEF4C","stage2_batch_id":"msgbatch_01AHsuW63vinsvuTgzmQ3n62","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2007,\n      \"finding\": \"PKA phosphorylates NoxA1 at Ser172 and Ser461, which enhances NoxA1 binding to 14-3-3 proteins (specifically 14-3-3ζ) and induces dissociation of NoxA1 from the Nox1 complex at the plasma membrane, thereby inhibiting Nox1-dependent ROS production. Elevation of cAMP inhibits, and PKA inhibition enhances, Nox1-dependent ROS production through effects on NoxA1.\",\n      \"method\": \"Site-directed mutagenesis, transfected HEK293 cell model, endogenous Nox1 in colon cell lines, co-immunoprecipitation, cAMP manipulation\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP, site-directed mutagenesis at defined phosphorylation sites, validated in both transfected and endogenous cell systems, two orthogonal functional readouts\",\n      \"pmids\": [\"17913709\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"MAP kinases phosphorylate NoxA1 at Ser282, and PKC and PKA phosphorylate NoxA1 at Ser172. These phosphorylations occur basally and down-regulate constitutive NOX1 activity. Single mutants S172A and S282A up-regulate NOX1-derived ROS, and double mutant S172A/S282A further increases ROS. Phosphorylation at these sites decreases NoxA1 binding to both NOX1 and Rac1.\",\n      \"method\": \"In vitro kinase assays, site-directed mutagenesis, phosphopeptide mapping, transfected HEK293 cell model, ROS measurement\",\n      \"journal\": \"FASEB journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro kinase assay with mutagenesis, phosphopeptide mapping, functional ROS readout, and binding assays; multiple orthogonal methods in one study\",\n      \"pmids\": [\"20110267\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"c-Src phosphorylates NoxA1 at Tyr110 and Tks4 at Tyr508; abolishing these phosphorylations blocks the NoxA1–Tks4 interaction and decreases Nox1-dependent ROS generation. Phosphomimetic mutants of both NoxA1 and Tks4 rescue SrcYF-induced invadopodia formation and ECM degradation, while unphosphorylatable mutants block it. NoxA1 interaction with Tks4 and Tks5 scaffold proteins is Src-activity dependent.\",\n      \"method\": \"Site-directed mutagenesis (phosphomimetic and unphosphorylatable mutants), co-immunoprecipitation, ROS measurement, invadopodia/ECM degradation assays in human colon cancer cells\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP, phosphomimetic/unphosphorylatable rescue experiments, functional invadopodia assay; multiple orthogonal methods\",\n      \"pmids\": [\"20943948\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"Noxa1 (the p67phox homologue) is expressed in the cytosolic fraction of mouse vascular smooth muscle cells (VSMC) and co-localizes to the membrane when co-expressed with Noxo1. Antisense knockdown of Noxa1 attenuates basal and agonist (bFGF, EGF)-induced ROS production in mouse VSMC, establishing Noxa1 as the central activator subunit of the smooth muscle NADPH oxidase.\",\n      \"method\": \"Western blot, immunohistochemistry, fluorescent fusion protein localization, antisense knockdown, L012 chemiluminescence ROS assay\",\n      \"journal\": \"Free radical biology & medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct localization with functional consequence (antisense KD + ROS readout), single lab, two orthogonal methods\",\n      \"pmids\": [\"16814099\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"A peptide mimicking the putative activation domain of NOXA1 (NoxA1ds) potently and selectively inhibits Nox1-derived superoxide production in a reconstituted cell-free system and in whole cells, with no effect on Nox2, Nox4, Nox5, or xanthine oxidase. FRET experiments show NoxA1ds disrupts the direct binding interaction between Nox1 and NOXA1, identifying the NOXA1 activation domain as the critical interface for NOX1 complex assembly.\",\n      \"method\": \"Cell-free reconstituted Nox1 system, cytochrome c reduction, Amplex Red fluorescence, EPR, FRET (Nox1-YFP/NOXA1-CFP), ELISA, FRAP, confocal microscopy with FITC-labeled peptide\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — reconstituted cell-free system, direct FRET binding disruption assay, multiple orthogonal ROS measurement methods, validated in intact cells\",\n      \"pmids\": [\"24187133\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"The isolated tandem SH3 domains of NOXO1 bind p22phox with high affinity, likely in a superSH3 conformation, and the C-terminal tail of NOXO1 competes for p22phox binding, thereby contributing to NOX1 regulation. The NOXO1–NOXA1 interaction differs molecularly from the p47phox–p67phox interaction of the phagocytic oxidase, suggesting functional differences between the two systems.\",\n      \"method\": \"Isothermal titration calorimetry (ITC), quantitative characterization of protein-protein interactions in vitro\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — quantitative ITC binding assay with isolated domains, single lab, rigorous in vitro method but no mutagenesis/functional validation\",\n      \"pmids\": [\"20454568\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"The NOXA1 SH3 domain is not required for NOX1 activation but modulates the kinetics of active complex formation: truncated NOXA1 lacking SH3 activates NOX1 at an accelerated rate compared to wild-type. A heptapeptide insertion into the SH3 domain (from the NOXA1(inhib) splice variant) inhibits NOXA1 activity by ~90%, acts as a transdominant inhibitor, and abrogates SH3 domain binding to NOXO1 and p47phox.\",\n      \"method\": \"Transfection into K562 cells stably expressing NOX1/NOXO1, kinetic superoxide generation assays, deletion and insertion mutagenesis, pulldown binding assays\",\n      \"journal\": \"Free radical biology & medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — mutagenesis with functional reconstitution in cell model, pulldown binding assay, single lab with multiple constructs\",\n      \"pmids\": [\"17602954\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"In airway epithelial cells, Noxa1 associates with plasma membrane-bound Duox (Duox1) and acts as an inhibitory regulator of Duox activity. Calcium flux promotes Duox activation by causing dissociation of Noxa1 from Duox. Knockdown of Noxa1 increases basal H2O2 generation. Mutation of a proline-rich domain in the Duox C-terminus (a potential Noxa1-SH3 interaction motif) up-regulates H2O2 production, and the Noxa1 activation domain is not required for Duox regulation.\",\n      \"method\": \"siRNA knockdown, Duox1 reconstitution in model cell lines, mutagenesis of Noxa1 and Duox1, H2O2 measurement, mucociliary airway epithelium model\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — loss-of-function knockdown with defined phenotype, mutagenesis of interaction domain, reconstitution system; single lab\",\n      \"pmids\": [\"18606821\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"PKC-mediated phosphorylation of Noxo1 at Thr341 (directly phosphorylated by PKC in vitro) facilitates Noxo1 interaction with Noxa1, and this interaction is required for PMA-dependent enhancement of Nox1 superoxide production. Alanine substitution at Thr341 reduces both Noxo1 phosphorylation and Nox1-catalyzed superoxide production.\",\n      \"method\": \"In vitro PKC kinase assay, site-directed mutagenesis (T341A), pulldown binding assay between Noxo1 and Noxa1, superoxide production assay\",\n      \"journal\": \"The FEBS journal\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1-2 / Moderate — in vitro kinase assay plus mutagenesis plus pulldown plus functional assay; single lab\",\n      \"pmids\": [\"23957209\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"PKCβ1 phosphorylates Nox1 at Thr429 in response to TNFα, and this phosphorylation facilitates association of Nox1 with the NoxA1 activation domain. This Nox1-NoxA1 interaction is necessary for NADPH oxidase complex assembly, ROS production, and vascular smooth muscle cell migration.\",\n      \"method\": \"Mass spectrometry (phosphosite identification), pharmacological PKC inhibition, siRNA silencing of PKCβ1, site-directed mutagenesis (T429), isothermal titration calorimetry (NoxA1ds binding), VSMC migration assay, ROS measurement\",\n      \"journal\": \"Circulation research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — mass spectrometry phosphosite identification, mutagenesis, ITC binding measurement, siRNA knockdown with defined cellular phenotype; multiple orthogonal methods in one study\",\n      \"pmids\": [\"25228390\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"siRNA-mediated knockdown of NOXA1 in human vascular endothelial cells potently decreases ROS generation induced by oxidized LDL and angiotensin II, establishing NOXA1 as essential for NAD(P)H oxidase-dependent ROS production in endothelial cells downstream of LOX-1 signaling.\",\n      \"method\": \"siRNA knockdown, dihydroethidium ROS assay, RT-PCR\",\n      \"journal\": \"Endothelium\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct loss-of-function with defined ROS phenotype, validated for two stimuli (ox-LDL and Ang II); single lab\",\n      \"pmids\": [\"18568954\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"In a pure reconstituted cell-free system using purified cytochrome b558 (Nox2+p22phox), Rac(Q61L), and Noxo1, Noxa1 activates Nox2 with lower efficiency than p67phox: higher EC50, one-third Vmax, lower FAD affinity, and reduced stability of the active complex. These kinetic differences distinguish Noxa1 from the canonical Nox2 activator p67phox.\",\n      \"method\": \"In vitro reconstituted cell-free NADPH oxidase system with purified proteins, kinetic analysis, FAD affinity measurement\",\n      \"journal\": \"Archives of biochemistry and biophysics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — purified protein reconstitution with quantitative kinetics, FAD affinity and complex stability measurements; single lab but rigorous in vitro approach\",\n      \"pmids\": [\"22244833\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"SMC-specific genetic deletion of Noxa1 in Apoe-/- mice reduces vascular ROS, attenuates TNFα-induced VSMC proliferation and migration, and decreases expression of KLF4 transcription factor and its downstream targets VCAM1, CCL2, and MMP2 in atherosclerotic lesions, placing NOXA1-dependent NOX1 activity upstream of KLF4-mediated VSMC phenotypic switching to macrophage-like cells.\",\n      \"method\": \"Conditional SMC-specific Noxa1 knockout mouse, endovascular injury model, Western diet atherosclerosis model, immunofluorescence, ROS measurement, VSMC proliferation/migration assays\",\n      \"journal\": \"Redox biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — conditional KO with cell-type specific deletion, multiple disease models, defined molecular pathway (NOXA1→NOX1→ROS→KLF4→downstream targets), replicated across multiple readouts\",\n      \"pmids\": [\"30576919\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Principal cell-specific Noxa1 knockout mice fail to increase ENaC activity in response to angiotensin II, and pharmacological NOX1 inhibition (ML171) abolishes ANG II-dependent ENaC stimulation, establishing that NOXA1/NOX1 signaling mediates ANG II-dependent activation of the epithelial sodium channel in renal principal cells of the distal nephron.\",\n      \"method\": \"Principal cell-specific Noxa1 conditional knockout mice, patch-clamp electrophysiology on freshly isolated split-open tubules, ML171 pharmacological inhibition, losartan AT1R blockade\",\n      \"journal\": \"American journal of physiology. Renal physiology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — cell-type specific conditional KO with electrophysiological functional readout, pharmacological validation with selective NOX1 inhibitor and AT1R blocker; multiple orthogonal approaches\",\n      \"pmids\": [\"36201326\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"NOXA1 is present in Henle's thick ascending limb and distal nephron epithelial cells. Systemic Noxa1 deletion reduces basal systolic blood pressure and attenuates ANG II-induced increases in renal ENaC levels, ENaC activation in collecting duct principal cells, and sodium retention, with sex-specific differences (males more affected than females).\",\n      \"method\": \"Noxa1 global knockout mice, telemetry blood pressure measurement, ANG II infusion, immunofluorescence, siRNA knockdown of Noxa1 in renal epithelial cell line, ENaC activity assay\",\n      \"journal\": \"Antioxidants & redox signaling\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — global KO with telemetry and functional ENaC assay, siRNA validation in cell line; single lab\",\n      \"pmids\": [\"34714114\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Knockdown of Noxa1 in radiotherapy-resistant colorectal cancer cells decreases expression of SLC7A11 and GPX4, increases cellular ROS levels, induces ferroptosis, and sensitizes cells to radiotherapy, placing NOXA1 upstream of the glutathione metabolic pathway (SLC7A11/GPX4 axis) as a suppressor of ferroptosis.\",\n      \"method\": \"siRNA knockdown of Noxa1 in CRC cell lines, Western blot for SLC7A11 and GPX4, ROS measurement, ferroptosis assay, radiotherapy sensitivity assay, GSVA pathway analysis\",\n      \"journal\": \"International journal of medical sciences\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, single knockdown approach, no mechanistic dissection of how NOXA1 regulates SLC7A11/GPX4\",\n      \"pmids\": [\"40084254\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"ERVWE1 (human endogenous retrovirus W envelope protein) upregulates USF2 transcription factor, which enhances NOXA1 transcription. NOXA1 in turn promotes macroautophagy (increased LC3B II/I ratio, enhanced autophagosome formation, reduced SQSTM1) and inhibits micromitophagy by suppressing PINK1, Parkin, and PDHA1 expression in the context of schizophrenia-related pathology.\",\n      \"method\": \"Cellular and molecular experiments in neuronal context, LC3B assay, autophagosome formation assay, SQSTM1/PINK1/Parkin/PDHA1 expression, bioinformatics (GSE53987), clinical serum measurements\",\n      \"journal\": \"Virologica Sinica\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, mixed bioinformatics and cellular methods, limited mechanistic dissection of NOXA1's direct role in autophagy versus upstream regulatory context\",\n      \"pmids\": [\"40419114\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"NOXA1 is the activator subunit (p67phox homologue) of the NOX1 NADPH oxidase complex that directly binds NOX1 through its activation domain to drive superoxide production; its activity is regulated by multi-site phosphorylation (PKA at Ser172/Ser461, PKC/MAPK at Ser172/Ser282, c-Src at Tyr110) that controls its interactions with 14-3-3 proteins, Rac1, NOX1, and scaffold proteins (Tks4/Tks5), thereby governing ROS-dependent processes including VSMC migration/phenotypic switching, invadopodia formation in colon cancer, and renal ENaC-mediated sodium homeostasis; NOXA1 also acts as an inhibitory regulator of Duox in airway cells, where calcium-induced conformational change of Duox relieves Noxa1-mediated constraint.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"NOXA1 is the cytosolic activator subunit (p67phox homologue) of the NOX1 NADPH oxidase complex, where it serves as the central driver of regulated superoxide production across vascular, renal, and epithelial tissues [#3]. NOXA1 directly engages NOX1 through its activation domain, and a peptide mimicking this domain (NoxA1ds) selectively disrupts the NOX1–NOXA1 interface and blocks NOX1-derived superoxide without affecting NOX2, NOX4, NOX5, or xanthine oxidase [#4]. Complex assembly is gated by phosphorylation of the catalytic subunit itself: PKCβ1 phosphorylates NOX1 at Thr429 to promote its association with the NOXA1 activation domain, an interaction required for oxidase assembly and ROS-dependent vascular smooth muscle cell migration [#9]. Conversely, multi-site phosphorylation of NOXA1 restrains activity—PKA phosphorylates Ser172/Ser461 to drive 14-3-3ζ binding and dissociation of NOXA1 from the NOX1 complex, while MAPK (Ser282) and PKC/PKA (Ser172) phosphorylation reduce NOXA1 binding to both NOX1 and Rac1, basally suppressing constitutive activity [#0, #1]. The NOXO1–NOXA1 module is recruited by PKC phosphorylation of NOXO1 at Thr341, and NOXA1's SH3 domain modulates the kinetics of active complex formation [#8, #6]. c-Src phosphorylation of NOXA1 at Tyr110 (and of Tks4 at Tyr508) couples the oxidase to the Tks4/Tks5 invadopodial scaffolds, driving ROS-dependent invadopodia formation and ECM degradation in colon cancer [#2]. Physiologically, NOXA1-dependent NOX1 activity drives KLF4-mediated VSMC phenotypic switching during atherosclerosis [#12] and mediates angiotensin II–dependent activation of the renal epithelial sodium channel (ENaC), contributing to sodium handling and blood pressure control [#13, #14]. In airway epithelium NOXA1 instead acts as an inhibitory regulator of DUOX1, with calcium-induced conformational change relieving this constraint [#7].\",\n  \"teleology\": [\n    {\n      \"year\": 2006,\n      \"claim\": \"Established NOXA1 as the functional activator subunit of the smooth muscle NADPH oxidase, answering whether the p67phox homologue drives ROS in non-phagocytic cells.\",\n      \"evidence\": \"Antisense knockdown and fluorescent fusion localization with ROS chemiluminescence in mouse VSMC\",\n      \"pmids\": [\"16814099\"],\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"Did not define the molecular interface with NOX1\", \"Single lab, antisense rather than genetic deletion\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Defined a negative-regulatory mechanism whereby PKA phosphorylation of NOXA1 recruits 14-3-3 and dissociates it from NOX1, linking cAMP signaling to oxidase shutdown.\",\n      \"evidence\": \"Site-directed mutagenesis of Ser172/Ser461, co-IP, and cAMP manipulation in HEK293 and colon cell lines\",\n      \"pmids\": [\"17913709\"],\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"Did not map which interface region 14-3-3 occludes\", \"Physiological cAMP-elevating stimulus not identified\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Resolved the role of the NOXA1 SH3 domain, showing it is dispensable for activation but tunes assembly kinetics and is the target of a transdominant inhibitory splice variant.\",\n      \"evidence\": \"Deletion/insertion mutagenesis and kinetic superoxide assays in K562 cells expressing NOX1/NOXO1, with pulldowns\",\n      \"pmids\": [\"17602954\"],\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"In vivo relevance of the NOXA1(inhib) splice variant unknown\", \"Single cell model\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Revealed a context-specific inhibitory role: NOXA1 constrains DUOX1 in airway epithelium, with calcium relieving the constraint, distinguishing it from its NOX1-activating function.\",\n      \"evidence\": \"siRNA knockdown, DUOX1 reconstitution, and domain mutagenesis with H2O2 measurement in airway epithelial models\",\n      \"pmids\": [\"18606821\"],\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"Structural basis of NOXA1–DUOX1 constraint not defined\", \"How calcium triggers dissociation mechanistically unresolved\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Extended NOXA1's requirement for stimulus-induced ROS to endothelial cells downstream of LOX-1 signaling.\",\n      \"evidence\": \"siRNA knockdown with DHE ROS assay in human vascular endothelial cells under ox-LDL and angiotensin II\",\n      \"pmids\": [\"18568954\"],\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"Did not establish the NOX isoform partner in endothelium\", \"No reciprocal validation of pathway\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Mapped basal inhibitory phosphorylation of NOXA1 by MAPK and PKC/PKA and tied it to reduced NOX1 and Rac1 binding, defining how constitutive oxidase output is held in check.\",\n      \"evidence\": \"In vitro kinase assays, phosphopeptide mapping, mutagenesis (S172A/S282A), and binding/ROS assays in HEK293\",\n      \"pmids\": [\"20110267\"],\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"Did not resolve whether these sites act sequentially or independently in vivo\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Connected NOXA1 to invadopodia by showing c-Src phosphorylation at Tyr110 couples it to Tks4/Tks5 scaffolds to drive localized ROS and ECM degradation in colon cancer.\",\n      \"evidence\": \"Phosphomimetic/unphosphorylatable mutant rescue, co-IP, and invadopodia/ECM degradation assays in colon cancer cells\",\n      \"pmids\": [\"20943948\"],\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"In vivo tumor relevance not tested\", \"Spatial coupling of ROS to ECM proteases not mechanistically resolved\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Quantified the NOXO1–p22phox interaction biophysically and showed the NOXO1–NOXA1 module differs molecularly from the phagocytic p47phox–p67phox pair.\",\n      \"evidence\": \"Isothermal titration calorimetry with isolated SH3 domains and C-terminal tail\",\n      \"pmids\": [\"20454568\"],\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"No functional or mutational validation in cells\", \"Full-length complex architecture not determined\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Distinguished NOXA1 from p67phox kinetically, showing it activates NOX2 less efficiently in a purified system.\",\n      \"evidence\": \"Reconstituted cell-free system with purified cytochrome b558, Rac(Q61L), NOXO1, and kinetic/FAD-affinity analysis\",\n      \"pmids\": [\"22244833\"],\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"Physiological significance of NOXA1–NOX2 cross-activation unclear\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Showed PKC phosphorylation of the NOXO1 partner at Thr341 promotes NOXO1–NOXA1 assembly required for PMA-stimulated NOX1 superoxide.\",\n      \"evidence\": \"In vitro PKC kinase assay, T341A mutagenesis, pulldown, and superoxide assay\",\n      \"pmids\": [\"23957209\"],\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"Cell-type and stimulus generality not established\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Identified the NOXA1 activation domain as the critical, NOX1-selective assembly interface using a disrupting peptide.\",\n      \"evidence\": \"Cell-free reconstitution, FRET binding disruption, and multiple ROS readouts with the NoxA1ds peptide\",\n      \"pmids\": [\"24187133\"],\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"Atomic-resolution structure of the interface not solved\", \"Therapeutic delivery of NoxA1ds not addressed\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Demonstrated that PKCβ1 phosphorylation of NOX1 at Thr429 promotes NOX1–NOXA1 association required for assembly and VSMC migration, providing a TNFα-responsive activation switch on the catalytic subunit.\",\n      \"evidence\": \"Mass spectrometry phosphosite mapping, T429 mutagenesis, ITC, PKCβ1 siRNA, and VSMC migration/ROS assays\",\n      \"pmids\": [\"25228390\"],\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"Interplay between NOX1 Thr429 phosphorylation and inhibitory NOXA1 phosphorylation not integrated\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Placed NOXA1-dependent NOX1 activity upstream of KLF4-driven VSMC phenotypic switching in atherosclerosis using cell-type-specific genetics.\",\n      \"evidence\": \"SMC-specific Noxa1 knockout in Apoe-/- mice, injury and Western-diet models, ROS, and KLF4/VCAM1/CCL2/MMP2 readouts\",\n      \"pmids\": [\"30576919\"],\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"Mechanism linking ROS to KLF4 induction not dissected\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Established NOXA1/NOX1 as the mediator of angiotensin II–dependent ENaC activation in renal principal cells, defining a physiological sodium-handling role.\",\n      \"evidence\": \"Principal-cell-specific Noxa1 conditional KO, patch-clamp on split-open tubules, and ML171/losartan pharmacology\",\n      \"pmids\": [\"36201326\"],\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"Molecular link between ROS and ENaC gating not resolved\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Connected NOXA1 to systemic blood pressure and sex-specific sodium retention through effects on renal ENaC.\",\n      \"evidence\": \"Global Noxa1 knockout with telemetry, ANG II infusion, immunofluorescence, and renal-cell siRNA ENaC assays\",\n      \"pmids\": [\"34714114\"],\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"Basis of sex-specific difference unexplained\", \"Global KO confounds tissue-specific contributions\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Proposed NOXA1 as a ferroptosis suppressor in radiotherapy-resistant colorectal cancer via the SLC7A11/GPX4 axis.\",\n      \"evidence\": \"siRNA knockdown in CRC lines with ROS, ferroptosis, and radiosensitivity assays plus GSVA\",\n      \"pmids\": [\"40084254\"],\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"No mechanistic link between NOXA1 and SLC7A11/GPX4 regulation\", \"Single lab, single knockdown approach\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Proposed a transcriptional and autophagy-regulatory role for NOXA1 downstream of ERVWE1/USF2 in schizophrenia-related neuronal pathology.\",\n      \"evidence\": \"Neuronal cellular assays for LC3B/SQSTM1/PINK1/Parkin/PDHA1 with bioinformatics and clinical serum measures\",\n      \"pmids\": [\"40419114\"],\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"Direct role of NOXA1 in autophagy versus upstream regulatory context not dissected\", \"Mixed bioinformatic/cellular evidence, single lab\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How the multiple phosphorylation switches on NOXA1, NOX1, and NOXO1 are integrated in space and time to set oxidase output in a given tissue remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"No atomic structure of the assembled NOX1–NOXO1–NOXA1–Rac complex\", \"Crosstalk between activating (NOX1 Thr429) and inhibitory (NOXA1 Ser172/282/461) phosphorylation not integrated\", \"Mechanism linking localized ROS to downstream effectors (KLF4, ENaC, SLC7A11) undefined\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [0, 1, 3, 4, 7]},\n      {\"term_id\": \"GO:0060089\", \"supporting_discovery_ids\": [3, 4, 9]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [3]},\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [0, 3, 7]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [9, 12, 13]},\n      {\"term_id\": \"R-HSA-8953897\", \"supporting_discovery_ids\": [0, 1]}\n    ],\n    \"complexes\": [\"NOX1 NADPH oxidase complex\"],\n    \"partners\": [\"NOX1\", \"NOXO1\", \"RAC1\", \"YWHAZ\", \"TKS4\", \"TKS5\", \"DUOX1\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":7,"faith_total":7,"faith_pct":100.0}}