{"gene":"ARIH2","run_date":"2026-06-09T22:02:44","timeline":{"discoveries":[{"year":2013,"finding":"TRIAD1 (ARIH2) associates with neddylated CUL5-RBX2-based Cullin-RING ligase (CRL) complexes, and binding of the cognate neddylated CRL greatly stimulates TRIAD1 RBR ligase activity in vitro (auto-ubiquitylation, UbcH7~ubiquitin thioester dissociation, and ubiquitin-vinyl methyl ester reactivity). TRIAD1 is auto-inhibited as an isolated protein but activated by neddylated CRL binding.","method":"In vitro ubiquitylation assays, auto-ubiquitylation, thioester dissociation assay, activity-based probe reactivity, genetic epistasis in vivo","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 1 / Strong — multiple orthogonal biochemical assays (in vitro reconstitution, thioester dissociation, ABP) plus genetic epistasis, replicated mechanistic insight","pmids":["24076655"],"is_preprint":false},{"year":2021,"finding":"Crystal/cryo-EM structural analysis of the CUL5-ARIH2 E3-E3 assembly revealed that ARIH2 is autoinhibited in isolation, and activation on neddylated CUL5-RBX2 occurs through an allosteric mechanism: CUL5-linked NEDD8 does not directly recruit ARIH2 (unlike CUL1-NEDD8 recruiting ARIH1), but instead contacts CUL5 covalently and induces conformational rearrangements that expose cryptic ARIH2-binding sites on CUL5.","method":"Cryo-EM/X-ray structural analysis, biochemical reconstitution, mutational validation","journal":"Nature chemical biology","confidence":"High","confidence_rationale":"Tier 1 / Strong — structural determination combined with biochemical reconstitution and mutagenesis in a single rigorous study","pmids":["34518685"],"is_preprint":false},{"year":2005,"finding":"Triad1 (ARIH2) binds the E2 ubiquitin-conjugating enzyme UbcH7 via its RING finger domains, supports formation of ubiquitin chains recognized by the proteasome, and inhibits clonogenic growth of primary myeloid progenitor cells. RING finger point mutants failing to bind UbcH7 lost the inhibitory effect; proteasome inhibition counteracted the growth inhibition.","method":"Binding assays, ubiquitin chain formation assays, retroviral transduction with RING finger mutants, CFU-GM colony assays, proteasome inhibition","journal":"Blood","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods (binding, ubiquitination, mutagenesis, functional colony assay, pharmacological rescue), single lab but mechanistically comprehensive","pmids":["16118314"],"is_preprint":false},{"year":2009,"finding":"Triad1 contains two RING domains that differentially bind distinct E2 ubiquitin-conjugating enzymes: the first RING binds UbcH7 (supporting K48-linked chains for proteasomal degradation) and the second RING binds Ubc13 (supporting K63-linked chains for non-proteolytic functions). Both RING domains are required for inhibition of myeloid cell proliferation.","method":"E2 binding assays, ubiquitin chain linkage analysis, deletion/point mutants, myeloid clonogenic assays","journal":"Leukemia","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — mechanistic domain-level dissection with mutagenesis and multiple E2-binding and functional assays","pmids":["19340006"],"is_preprint":false},{"year":2007,"finding":"Triad1 interacts with the DNA-binding domain of Gfi1 and unexpectedly inhibits Gfi1 ubiquitination, resulting in prolonged Gfi1 half-life. This inhibition is independent of Triad1's own ubiquitin ligase activity, suggesting Triad1 competes with other E3 ligases for Gfi1 binding. Triad1 mutants lacking the Gfi1-binding domain lost this stabilizing effect.","method":"Co-immunoprecipitation, siRNA knockdown, ubiquitination assays, pulse-chase half-life analysis, deletion mutant analysis, U937 cell overexpression","journal":"Blood","confidence":"High","confidence_rationale":"Tier 2 / Moderate — reciprocal Co-IP, siRNA knockdown, half-life assay, domain deletion mutants, all in one study","pmids":["17646546"],"is_preprint":false},{"year":2012,"finding":"ARIH2 (Triad1) causes degradation of nuclear IκBβ in dendritic cells, abrogating IκBβ's ability to sequester, protect, and transcriptionally co-activate p65 in the nucleus. Loss of ARIH2 in hematopoietic cells leads to dysregulated NF-κB activation in dendritic cells and lethal systemic immune activation. Targeted gene deletion in mice showed ARIH2 is essential for embryogenesis.","method":"Gene-targeted knockout mice, hematopoietic stem cell reconstitution, NF-κB pathway analysis, IκBβ/p65 interaction studies","journal":"Nature immunology","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic loss-of-function (knockout mice, bone marrow reconstitution) with defined molecular pathway (IκBβ-p65-NF-κB) and clear cellular phenotype","pmids":["23179078"],"is_preprint":false},{"year":2017,"finding":"ARIH2 interacts with NLRP3 via NLRP3's NACHT domain (aa 220–575) in the inflammasome complex, and the RING2 domain of ARIH2 catalyzes K48- and K63-linked ubiquitination of NLRP3. CRISPR/Cas9 deletion of ARIH2 inhibited NLRP3 ubiquitination and promoted inflammasome activation (ASC oligomerization, pro-IL-1β processing, IL-1β secretion); overexpression of ARIH2 had the opposite effect.","method":"Co-immunoprecipitation, RING2 domain mutants, ubiquitin chain linkage mutants, CRISPR/Cas9 knockout, ARIH2 overexpression, ASC oligomerization assay, IL-1β ELISA","journal":"Journal of immunology","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP, domain/ubiquitin mutants, CRISPR KO, overexpression, multiple functional readouts in one study","pmids":["29021376"],"is_preprint":false},{"year":2012,"finding":"TRIAD1 binds to the C-terminus of p53 and promotes its dissociation from MDM2, thereby inhibiting MDM2-mediated ubiquitination and degradation of p53. Ablation of TRIAD1 reduces p53 levels upon DNA damage, while ectopic TRIAD1 expression stabilizes p53.","method":"Co-immunoprecipitation, p53-MDM2 dissociation assay, ubiquitination assay, siRNA knockdown, overexpression","journal":"FEBS letters","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP, ubiquitination assay, KD and OE, but single lab and single study","pmids":["22819825"],"is_preprint":false},{"year":2012,"finding":"TRIAD1 is a ubiquitination substrate of MDM2: MDM2 interacts with and ubiquitinates TRIAD1, targeting it for proteasomal degradation. RNAi against MDM2 increased endogenous TRIAD1 protein stability, and MDM2-mediated TRIAD1 degradation suppressed TRIAD1-mediated cell growth inhibition.","method":"Co-immunoprecipitation, ubiquitination assay, siRNA knockdown of MDM2, protein stability assay","journal":"Oncology reports","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — Co-IP and ubiquitination assay and siRNA, but single lab, single study, limited orthogonal validation","pmids":["22940738"],"is_preprint":false},{"year":2012,"finding":"Triad1 depletion in cells disrupts endosomal sorting of growth hormone and EGF, causing accumulation of ligands in enlarged endosomes with irregular intraluminal vesicles and prominent clathrin coats, while reducing fluid-phase transport to lysosomes. Triad1 catalyzes both K48- and K63-linked polyubiquitin chain formation and is required for proper multivesicular body function.","method":"siRNA depletion, immunofluorescence, immune electron microscopy, fluid-phase transport assays, receptor recycling assay","journal":"Biology open","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — siRNA knockdown, immune EM, multiple cargo tracking assays in one study","pmids":["23213454"],"is_preprint":false},{"year":2011,"finding":"TRIAD1 binds UBCH8 and PML-RARα, but this interaction does not affect PML-RARα turnover (negative finding), distinguishing TRIAD1 from SIAH1/SIAH2 in regulation of this leukemia oncoprotein. UBCH8 cooperates with SIAH1/SIAH2 but not TRIAD1 for PML-RARα degradation.","method":"Co-immunoprecipitation, protein stability/turnover assay, combined drug treatment (valproic acid + ATRA)","journal":"The international journal of biochemistry & cell biology","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — Co-IP confirmed binding; negative turnover result supported by functional assay; single lab","pmids":["22037423"],"is_preprint":false},{"year":2022,"finding":"ARIH2 interacts with p21 and induces K48-linked ubiquitination of p21 at lysine K161, targeting p21 for proteasomal degradation. ARIH2 was confirmed as a direct E3 ligase of p21 by in vitro ubiquitination assay. ARIH2 knockdown induced DNA damage and apoptosis and altered chemosensitivity.","method":"Co-immunoprecipitation, in vitro ubiquitination assay, site-directed mutagenesis (K48 ubiquitin and K161 p21 mutants), knockdown, in vivo tumor xenograft","journal":"Cell death & disease","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro ubiquitination assay plus site-directed mutagenesis identifying specific ubiquitin linkage and substrate lysine, replicated in vivo; single lab","pmids":["35732617"],"is_preprint":false},{"year":2022,"finding":"Arih2β (ER-localized isoform, cytoplasmic face of ER) regulates ER-associated degradation (ERAD) of Smoothened (Smo). Loss of Arih2 elevates cellular and ciliary Smo levels, activates basal Hedgehog signaling, and triggers ER protein aggregation and unfolded protein response. Re-expression of ER-localized Arih2β but not nuclear Arih2α rescues these phenotypes.","method":"Genetic loss-of-function (mouse model), isoform-specific re-expression, subcellular fractionation/localization, cilia imaging, UPR assays, protein accumulation assays","journal":"Journal of cell science","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic KO with isoform-specific rescue, subcellular localization tied to function, multiple mechanistic readouts","pmids":["35899529"],"is_preprint":false},{"year":2025,"finding":"ARIH2 ubiquitinates dynein intermediate chain 1 (DIC1), facilitating dynein function in organelle positioning. The Lis1 protein promotes ARIH2 deneddylation via the COP9 signalosome (CSN), thereby modulating ARIH2 ubiquitin ligase activity. Active (neddylated) ARIH2 is required for proper dynein-dependent intracellular transport.","method":"Proteomics-based interaction mapping, co-immunoprecipitation, ubiquitination assays, organelle positioning assays","journal":"iScience","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — Co-IP and ubiquitination assay with functional readout, but single lab and limited orthogonal validation described in abstract","pmids":["41312386"],"is_preprint":false},{"year":2025,"finding":"ARIH2 ubiquitinates Gcn1 (a regulator of the integrated stress response, ISR) among a set of ISR-regulatory proteins identified by proteomic screen. Triad1 knockdown causes a translatome shift consistent with ISR activation that is reversed by co-knockdown of Gcn1, linking Triad1-dependent ubiquitination to ISR suppression and leukemia suppression.","method":"Proteomic screen (ubiquitination proteomics), translatome profiling, Gcn1 co-knockdown epistasis, murine AML bone marrow transplant model","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — proteomic identification of substrates, epistasis experiment (co-knockdown rescue), in vivo AML model; single lab","pmids":["40680841"],"is_preprint":false},{"year":2026,"finding":"In C. elegans and human iPSC-derived dopaminergic neurons, loss of ARIH2 (ari-2 in worm) suppresses α-synuclein-mediated dopaminergic neurodegeneration. Unbiased proteomics identified TPPP3 (a microtubule dynamics regulator) as a novel ARIH2 substrate; TPPP3 was required for ARIH2's effects on α-synuclein-induced neurodegeneration.","method":"C. elegans genetic screen, unbiased proteomics in human iPSC-derived neurons, loss-of-function studies, epistasis (TPPP3 requirement)","journal":"The Journal of neuroscience","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo genetic screen plus proteomics substrate identification plus epistasis, but abstract does not detail direct ubiquitination assay for TPPP3","pmids":["41651665"],"is_preprint":false},{"year":2025,"finding":"ARIH2 promotes K29-linked polyubiquitination of vimentin (VIM) at lysine K373 residue, leading to proteasomal degradation of VIM. LINC00476 lncRNA recruits ARIH2 to VIM to facilitate this ubiquitination.","method":"RNA pull-down, RIP, Co-IP, ubiquitination assays with linkage and site mutants, in vivo PDX model","journal":"International journal of surgery","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP, K29-linkage and K373 site mutants validated, PDX model; ARIH2's role as direct E3 supported but lncRNA recruitment aspect complicates mechanistic isolation","pmids":["41572548"],"is_preprint":false},{"year":2026,"finding":"ARIH2 interacts with NUPR1 in bladder cancer cells and promotes its ubiquitin-mediated proteasomal degradation. ARIH2 depletion prolongs NUPR1 stability and reduces its ubiquitination, while ARIH2 overexpression decreases NUPR1 levels. NUPR1 suppresses ferroptosis (elevated GPX4, SLC7A11, reduced ACSL4), so ARIH2-mediated NUPR1 degradation indirectly modulates ferroptosis sensitivity.","method":"IP-MS, Co-IP, immunofluorescence, ubiquitination assay, protein stability assay, ferroptosis marker analysis","journal":"Journal of cellular and molecular medicine","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — IP-MS plus Co-IP plus ubiquitination/stability assays, functional ferroptosis readout; single lab","pmids":["41998836"],"is_preprint":false},{"year":2018,"finding":"Triad1 interacts with DISC1 via specific protein fragments, and co-localization in neural stem cells was demonstrated. Overexpressing both TRIAD1 and DISC1 in primary neural stem cells significantly affected proliferation and differentiation after traumatic brain injury.","method":"Co-immunoprecipitation, truncation mutant mapping, immunofluorescence co-localization, lentiviral overexpression in primary neural stem cells","journal":"Stem cell research & therapy","confidence":"Low","confidence_rationale":"Tier 3 / Weak — Co-IP and localization shown, but functional consequence of Triad1-DISC1 interaction not molecularly resolved; single lab, limited controls described","pmids":["30409224"],"is_preprint":false},{"year":2018,"finding":"Triad1 interacts with EHD1 (EH domain-containing protein 1) both in vitro and in vivo, mediated through the EH domain of EHD1. Triad1 regulates the expression and subcellular distribution of EHD1, influencing neurite outgrowth of PC12 cells after spinal cord injury.","method":"Co-immunoprecipitation, EH domain truncation interaction mapping, in vitro and in vivo binding assays, neurite outgrowth assay","journal":"Journal of cellular biochemistry","confidence":"Low","confidence_rationale":"Tier 3 / Weak — Co-IP and truncation mapping shown, but ubiquitination of EHD1 not demonstrated; functional link indirect; single lab","pmids":["30320922"],"is_preprint":false},{"year":2022,"finding":"Triad1 overexpression promoted PTN (pleiotrophin) protein levels and inhibited MDM2-mediated PTN ubiquitination. MDM2 ubiquitinates PTN, and Triad1 reversed this ubiquitination, thereby stabilizing PTN and promoting astrocyte-dependent neurite outgrowth after spinal cord injury.","method":"Ubiquitination assay, co-immunoprecipitation, overexpression and shRNA knockdown, astrocyte-neuron co-culture, in vivo rat SCI model","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — ubiquitination assay and Co-IP with functional rescue experiment; mechanism (blocking MDM2-PTN ubiquitination) defined, but single lab","pmids":["36055408"],"is_preprint":false}],"current_model":"ARIH2 (TRIAD1) is an RBR-family E3 ubiquitin ligase that exists in an autoinhibited state and is allosterically activated by binding to neddylated Cullin-RING ligase (CRL) complexes, particularly neddylated CUL5-RBX2, through a NEDD8-induced conformational mechanism that exposes cryptic ARIH2-binding sites; activated ARIH2 catalyzes K48- and K63-linked ubiquitin chain formation via two RING domains that differentially recruit E2 enzymes (UbcH7 and Ubc13), targeting substrates including NLRP3, p21, Smo, VIM, NUPR1, DIC1, TPPP3, and Gcn1 for proteasomal degradation or functional regulation, while also modulating protein stability indirectly by competing with other E3 ligases (e.g., stabilizing Gfi1 and p53 by blocking MDM2 access), with biological roles spanning regulation of myeloid progenitor proliferation, NF-κB/IκBβ signaling in dendritic cells, NLRP3 inflammasome suppression, Hedgehog signaling via ER-associated degradation of Smo, endosomal/MVB trafficking, and integrated stress response control in hematopoietic cells."},"narrative":{"mechanistic_narrative":"ARIH2 (TRIAD1) is an RBR-family E3 ubiquitin ligase that operates as the catalytic partner of neddylated Cullin-RING ligase (CRL) complexes to control protein turnover across hematopoietic, immune, and neural contexts [PMID:24076655, PMID:23179078]. In isolation ARIH2 is autoinhibited; binding to neddylated CUL5-RBX2 strongly stimulates its ligase activity, and structural analysis shows this activation is allosteric—CUL5-linked NEDD8 does not directly recruit ARIH2 but rearranges CUL5 to expose cryptic ARIH2-binding sites [PMID:24076655, PMID:34518685]. The enzyme uses two RING domains that engage distinct E2s: RING1 binds UbcH7 to build K48-linked chains for proteasomal degradation, while RING2 binds Ubc13 to build K63-linked chains for non-proteolytic functions, and both are required to restrain myeloid progenitor proliferation [PMID:16118314, PMID:19340006]. Through these activities ARIH2 ubiquitinates a range of substrates including NLRP3 to suppress inflammasome activation [PMID:29021376], p21 to promote its degradation [PMID:35732617], the Smoothened receptor via ER-associated degradation to limit basal Hedgehog signaling [PMID:35899529], and Gcn1 to suppress the integrated stress response in leukemic cells [PMID:40680841]. ARIH2 also acts non-catalytically, competing with MDM2 to stabilize Gfi1 and p53 [PMID:17646546, PMID:22819825], and is essential for embryogenesis and for restraining NF-κB activation in dendritic cells via degradation of nuclear IκBβ [PMID:23179078]. Additional substrate and trafficking roles—including dynein intermediate chain 1 in organelle positioning [PMID:41312386], vimentin and NUPR1 degradation [PMID:41572548, PMID:41998836], and multivesicular body sorting [PMID:23213454]—extend its reach into cytoskeletal and endosomal regulation.","teleology":[{"year":2005,"claim":"Established ARIH2/Triad1 as a functional E3 ligase by showing it binds the E2 UbcH7 through its RING fingers and that this activity restrains myeloid progenitor growth, defining its first biological role.","evidence":"E2 binding, ubiquitin chain assays, RING point mutants, and CFU-GM colony assays with proteasome inhibition","pmids":["16118314"],"confidence":"High","gaps":["Specific physiological substrates not yet identified","Mechanism of ligase activation in cells not addressed"]},{"year":2007,"claim":"Revealed a catalysis-independent mode of action: ARIH2 stabilizes Gfi1 by competing with other E3 ligases rather than ubiquitinating it.","evidence":"Reciprocal Co-IP, siRNA knockdown, pulse-chase half-life, and domain-deletion mutants in U937 cells","pmids":["17646546"],"confidence":"High","gaps":["Competing E3 ligase not identified","Whether this competition operates in primary cells unresolved"]},{"year":2009,"claim":"Dissected the dual-RING architecture, showing the two RING domains recruit different E2s (UbcH7 vs Ubc13) to assemble K48- versus K63-linked chains, explaining how one ligase serves both proteolytic and non-proteolytic outputs.","evidence":"E2 binding assays, ubiquitin linkage analysis, deletion/point mutants, and myeloid clonogenic assays","pmids":["19340006"],"confidence":"High","gaps":["Substrate-specific deployment of each linkage type not mapped","Regulation of E2 choice unknown"]},{"year":2012,"claim":"Connected ARIH2 to immune homeostasis and embryogenesis, showing it degrades nuclear IκBβ to restrain NF-κB-driven dendritic cell activation, with loss causing lethal systemic immune activation.","evidence":"Gene-targeted knockout mice, hematopoietic reconstitution, and IκBβ-p65 interaction studies","pmids":["23179078"],"confidence":"High","gaps":["Direct ubiquitination of IκBβ by ARIH2 not biochemically isolated here","CRL dependence of this activity not addressed"]},{"year":2012,"claim":"Defined a reciprocal regulatory relationship with MDM2: ARIH2 stabilizes p53 by displacing it from MDM2, while MDM2 in turn ubiquitinates and degrades ARIH2 to relieve its growth-inhibitory effect.","evidence":"Co-IP, p53-MDM2 dissociation and ubiquitination assays, siRNA, and stability assays (two studies)","pmids":["22819825","22940738"],"confidence":"Medium","gaps":["Single-lab findings without reciprocal independent validation","Physiological context of the ARIH2-MDM2 feedback loop unclear"]},{"year":2012,"claim":"Extended ARIH2 function to membrane trafficking, showing it is required for endosomal sorting and multivesicular body function via dual K48/K63 chain formation.","evidence":"siRNA depletion, immunofluorescence, immune EM, and cargo transport assays","pmids":["23213454"],"confidence":"Medium","gaps":["Trafficking substrate(s) of ARIH2 not identified","Link between ligase activity and MVB defect not biochemically resolved"]},{"year":2017,"claim":"Identified NLRP3 as a direct substrate, establishing ARIH2 as a brake on inflammasome activation through K48/K63 ubiquitination of the NACHT domain.","evidence":"Reciprocal Co-IP, RING2 and ubiquitin-linkage mutants, CRISPR KO, overexpression, and IL-1β readouts","pmids":["29021376"],"confidence":"High","gaps":["Whether CRL5-NEDD8 activation is required for NLRP3 ubiquitination not tested","Functional roles of K48 vs K63 chains on NLRP3 not separated"]},{"year":2021,"claim":"Solved the structural basis of activation, showing NEDD8 on CUL5 acts allosterically—rearranging CUL5 to expose cryptic ARIH2 sites—rather than directly recruiting ARIH2 as occurs with CUL1-ARIH1.","evidence":"Cryo-EM/X-ray structural analysis with biochemical reconstitution and mutagenesis","pmids":["34518685"],"confidence":"High","gaps":["Substrate engagement geometry in the activated E3-E3 complex not fully resolved","Whether other cullins activate ARIH2 by the same mechanism unknown"]},{"year":2022,"claim":"Identified p21 as a direct degradation substrate with defined linkage (K48) and acceptor lysine (K161), linking ARIH2 to cell cycle and chemosensitivity.","evidence":"Co-IP, in vitro ubiquitination, ubiquitin and substrate site mutants, knockdown, and xenografts","pmids":["35732617"],"confidence":"High","gaps":["CRL dependence of p21 ubiquitination not addressed","Single-lab finding"]},{"year":2022,"claim":"Resolved isoform-specific function, showing the ER-localized Arih2β isoform mediates ERAD of Smoothened to suppress basal Hedgehog signaling and prevent ER stress.","evidence":"Mouse genetic KO with isoform-specific rescue, subcellular localization, cilia imaging, and UPR assays","pmids":["35899529"],"confidence":"High","gaps":["Direct ubiquitination of Smo and chain type not specified","Determinants of α vs β isoform localization not defined"]},{"year":2022,"claim":"Added a second MDM2-competition substrate, showing Triad1 stabilizes PTN by reversing MDM2-mediated ubiquitination to promote neurite outgrowth after spinal cord injury.","evidence":"Ubiquitination assay, Co-IP, overexpression/knockdown, co-culture, and in vivo SCI model","pmids":["36055408"],"confidence":"Medium","gaps":["Single-lab finding","Mechanism of MDM2 displacement vs deubiquitination not distinguished"]},{"year":2025,"claim":"Expanded the substrate landscape and revealed regulation of ARIH2's own neddylation state—ubiquitinating DIC1 for dynein-dependent organelle positioning, Gcn1 to suppress the integrated stress response in leukemia, and vimentin via K29 chains.","evidence":"Interaction proteomics, Co-IP, ubiquitination/linkage-site mutants, translatome profiling, organelle positioning, and AML/PDX models (three studies)","pmids":["41312386","40680841","41572548"],"confidence":"Medium","gaps":["Each substrate from a single lab without independent confirmation","How Lis1/CSN-driven ARIH2 deneddylation integrates with CRL activation unclear"]},{"year":2026,"claim":"Linked ARIH2 to neurodegeneration and ferroptosis, identifying TPPP3 as a substrate required for ARIH2 effects on α-synuclein toxicity and NUPR1 as a substrate whose degradation modulates ferroptosis sensitivity.","evidence":"C. elegans genetic screen, iPSC-neuron proteomics, epistasis, IP-MS, Co-IP, ubiquitination, and ferroptosis marker analysis (two studies)","pmids":["41651665","41998836"],"confidence":"Medium","gaps":["Direct ubiquitination assay for TPPP3 not detailed","Single-lab findings without orthogonal validation"]},{"year":null,"claim":"It remains unresolved which substrates depend on CRL5-NEDD8 allosteric activation versus CRL-independent activity, and how the dual K48/K63 (and K29) chain outputs are selected per substrate.","evidence":"No timeline study systematically maps substrate-by-substrate CRL dependence or chain-type determinants","pmids":[],"confidence":"Low","gaps":["No unified rule linking activation state to substrate choice","Physiological substrate hierarchy across tissues unknown"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[2,6,11,16]},{"term_id":"GO:0016874","term_label":"ligase activity","supporting_discovery_ids":[0,2,3]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[4,7]}],"localization":[{"term_id":"GO:0005783","term_label":"endoplasmic reticulum","supporting_discovery_ids":[12]},{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[5,12]},{"term_id":"GO:0005768","term_label":"endosome","supporting_discovery_ids":[9]}],"pathway":[{"term_id":"R-HSA-392499","term_label":"Metabolism of proteins","supporting_discovery_ids":[0,2,3]},{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[5,6]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[12]},{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[11]},{"term_id":"R-HSA-8953897","term_label":"Cellular responses to stimuli","supporting_discovery_ids":[14]}],"complexes":["neddylated CUL5-RBX2 Cullin-RING ligase","NLRP3 inflammasome"],"partners":["CUL5","RBX2","NEDD8","UBCH7","UBC13","MDM2","NLRP3","GFI1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"O95376","full_name":"E3 ubiquitin-protein ligase ARIH2","aliases":["Triad1 protein"],"length_aa":493,"mass_kda":57.8,"function":"E3 ubiquitin-protein ligase, which catalyzes ubiquitination of target proteins together with ubiquitin-conjugating enzyme E2 UBE2L3 (PubMed:16118314, PubMed:17646546, PubMed:19340006, PubMed:24076655, PubMed:33268465, PubMed:34518685, PubMed:38418882). Acts as an atypical E3 ubiquitin-protein ligase by working together with cullin-5-RING ubiquitin ligase complex (ECS complex, also named CRL5 complex) and initiating ubiquitination of ECS substrates: associates with ECS complex and specifically mediates addition of the first ubiquitin on ECS targets (PubMed:33268465, PubMed:34518685, PubMed:38418882). The initial ubiquitin is then elongated (PubMed:33268465). E3 ubiquitin-protein ligase activity is activated upon binding to neddylated form of the cullin-5 (CUL5) component of the ECS complex (PubMed:24076655). Together with the ECS(ASB9) complex, catalyzes ubiquitination of CKB (PubMed:33268465). Promotes ubiquitination of DCUN1D1 (PubMed:30587576). Mediates 'Lys-6', 'Lys-48'- and 'Lys-63'-linked polyubiquitination (PubMed:16118314, PubMed:17646546, PubMed:19340006). May play a role in myelopoiesis (PubMed:19340006) (Microbial infection) Following infection by HIV-1 virus, acts together with a cullin-5-RING E3 ubiquitin-protein ligase complex (ECS complex) hijacked by the HIV-1 Vif protein, to catalyze ubiquitination and degradation of APOBEC3F and APOBEC3G","subcellular_location":"Nucleus; Cytoplasm","url":"https://www.uniprot.org/uniprotkb/O95376/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/ARIH2","classification":"Not Classified","n_dependent_lines":21,"n_total_lines":1208,"dependency_fraction":0.0173841059602649},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/ARIH2","total_profiled":1310},"omim":[{"mim_id":"605615","title":"ARIADNE RBR E3 UBIQUITIN PROTEIN LIGASE 2; ARIH2","url":"https://www.omim.org/entry/605615"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Enhanced","locations":[{"location":"Nucleoplasm","reliability":"Enhanced"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/ARIH2"},"hgnc":{"alias_symbol":["TRIAD1"],"prev_symbol":[]},"alphafold":{"accession":"O95376","domains":[{"cath_id":"3.30.40.10","chopping":"60-223","consensus_level":"medium","plddt":92.2557,"start":60,"end":223},{"cath_id":"1.20.120.1750","chopping":"269-490","consensus_level":"high","plddt":89.8462,"start":269,"end":490}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/O95376","model_url":"https://alphafold.ebi.ac.uk/files/AF-O95376-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-O95376-F1-predicted_aligned_error_v6.png","plddt_mean":86.5},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=ARIH2","jax_strain_url":"https://www.jax.org/strain/search?query=ARIH2"},"sequence":{"accession":"O95376","fasta_url":"https://rest.uniprot.org/uniprotkb/O95376.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/O95376/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/O95376"}},"corpus_meta":[{"pmid":"29021376","id":"PMC_29021376","title":"ARIH2 Ubiquitinates NLRP3 and Negatively Regulates NLRP3 Inflammasome Activation in Macrophages.","date":"2017","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/29021376","citation_count":118,"is_preprint":false},{"pmid":"24076655","id":"PMC_24076655","title":"TRIAD1 and HHARI bind to and are activated by distinct neddylated Cullin-RING ligase complexes.","date":"2013","source":"The EMBO journal","url":"https://pubmed.ncbi.nlm.nih.gov/24076655","citation_count":97,"is_preprint":false},{"pmid":"34518685","id":"PMC_34518685","title":"CUL5-ARIH2 E3-E3 ubiquitin ligase structure reveals cullin-specific NEDD8 activation.","date":"2021","source":"Nature chemical biology","url":"https://pubmed.ncbi.nlm.nih.gov/34518685","citation_count":58,"is_preprint":false},{"pmid":"16118314","id":"PMC_16118314","title":"The E3 ubiquitin-protein ligase Triad1 inhibits clonogenic growth of primary myeloid progenitor cells.","date":"2005","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/16118314","citation_count":51,"is_preprint":false},{"pmid":"36564038","id":"PMC_36564038","title":"Pyruvate dehydrogenase B regulates myogenic differentiation via the FoxP1-Arih2 axis.","date":"2022","source":"Journal of cachexia, sarcopenia and muscle","url":"https://pubmed.ncbi.nlm.nih.gov/36564038","citation_count":37,"is_preprint":false},{"pmid":"23179078","id":"PMC_23179078","title":"ARIH2 is essential for embryogenesis, and its hematopoietic deficiency causes lethal activation of the immune system.","date":"2012","source":"Nature immunology","url":"https://pubmed.ncbi.nlm.nih.gov/23179078","citation_count":34,"is_preprint":false},{"pmid":"19340006","id":"PMC_19340006","title":"The ubiquitin ligase Triad1 inhibits myelopoiesis through UbcH7 and Ubc13 interacting domains.","date":"2009","source":"Leukemia","url":"https://pubmed.ncbi.nlm.nih.gov/19340006","citation_count":29,"is_preprint":false},{"pmid":"17646546","id":"PMC_17646546","title":"Gfi1 ubiquitination and proteasomal degradation is inhibited by the ubiquitin ligase Triad1.","date":"2007","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/17646546","citation_count":28,"is_preprint":false},{"pmid":"21454682","id":"PMC_21454682","title":"HoxA10 influences protein ubiquitination by activating transcription of ARIH2, the gene encoding Triad1.","date":"2011","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/21454682","citation_count":27,"is_preprint":false},{"pmid":"24486325","id":"PMC_24486325","title":"A novel feed-forward loop between ARIH2 E3-ligase and PABPN1 regulates aging-associated muscle degeneration.","date":"2014","source":"The American journal of pathology","url":"https://pubmed.ncbi.nlm.nih.gov/24486325","citation_count":27,"is_preprint":false},{"pmid":"22037423","id":"PMC_22037423","title":"Differential regulation of PML-RARα stability by the ubiquitin ligases SIAH1/SIAH2 and TRIAD1.","date":"2011","source":"The international journal of biochemistry & cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/22037423","citation_count":24,"is_preprint":false},{"pmid":"25895533","id":"PMC_25895533","title":"HoxA10 Terminates Emergency Granulopoiesis by Increasing Expression of Triad1.","date":"2015","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/25895533","citation_count":20,"is_preprint":false},{"pmid":"23213454","id":"PMC_23213454","title":"Identification of the ubiquitin ligase Triad1 as a regulator of endosomal transport.","date":"2012","source":"Biology open","url":"https://pubmed.ncbi.nlm.nih.gov/23213454","citation_count":20,"is_preprint":false},{"pmid":"29459712","id":"PMC_29459712","title":"The E3 ubiquitin ligase Triad1 influences development of Mll-Ell-induced acute myeloid leukemia.","date":"2018","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/29459712","citation_count":19,"is_preprint":false},{"pmid":"38982159","id":"PMC_38982159","title":"A de novo ARIH2 gene mutation was detected in a patient with autism spectrum disorders and intellectual disability.","date":"2024","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/38982159","citation_count":19,"is_preprint":false},{"pmid":"35732617","id":"PMC_35732617","title":"ARIH2 regulates the proliferation, DNA damage and chemosensitivity of gastric cancer cells by reducing the stability of p21 via ubiquitination.","date":"2022","source":"Cell death & disease","url":"https://pubmed.ncbi.nlm.nih.gov/35732617","citation_count":17,"is_preprint":false},{"pmid":"22819825","id":"PMC_22819825","title":"TRIAD1 inhibits MDM2-mediated p53 ubiquitination and degradation.","date":"2012","source":"FEBS letters","url":"https://pubmed.ncbi.nlm.nih.gov/22819825","citation_count":15,"is_preprint":false},{"pmid":"35899529","id":"PMC_35899529","title":"Arih2 regulates Hedgehog signaling through smoothened ubiquitylation and ER-associated degradation.","date":"2022","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/35899529","citation_count":7,"is_preprint":false},{"pmid":"34641746","id":"PMC_34641746","title":"E3 ubiquitin ligase Triad1 promotes neuronal apoptosis by regulating the p53-caspase3 pathway after spinal cord injury.","date":"2021","source":"Somatosensory & motor research","url":"https://pubmed.ncbi.nlm.nih.gov/34641746","citation_count":7,"is_preprint":false},{"pmid":"27935098","id":"PMC_27935098","title":"TRIAD1 Is a Novel Transcriptional Target of p53 and Regulates Nutlin-3a-Induced Cell Death.","date":"2017","source":"Journal of cellular biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/27935098","citation_count":6,"is_preprint":false},{"pmid":"22940738","id":"PMC_22940738","title":"TRIAD1 is negatively regulated by the MDM2 E3 ligase.","date":"2012","source":"Oncology reports","url":"https://pubmed.ncbi.nlm.nih.gov/22940738","citation_count":6,"is_preprint":false},{"pmid":"35912142","id":"PMC_35912142","title":"Triad1 Promotes the Inflammatory Response and Neuronal Apoptosis to Aggravate Acute Spinal Cord Injury in Rats.","date":"2022","source":"Computational and mathematical methods in medicine","url":"https://pubmed.ncbi.nlm.nih.gov/35912142","citation_count":5,"is_preprint":false},{"pmid":"30409224","id":"PMC_30409224","title":"The expression of TRIAD1 and DISC1 after traumatic brain injury and its influence on NSCs.","date":"2018","source":"Stem cell research & therapy","url":"https://pubmed.ncbi.nlm.nih.gov/30409224","citation_count":4,"is_preprint":false},{"pmid":"30320922","id":"PMC_30320922","title":"Triad1 regulates the expression and distribution of EHD1 contributing to the neurite outgrowth of neurons after spinal cord injury.","date":"2018","source":"Journal of cellular biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/30320922","citation_count":4,"is_preprint":false},{"pmid":"31842638","id":"PMC_31842638","title":"Increased expression of Triad1 is associated with neuronal apoptosis after intracerebral hemorrhage in adult rats.","date":"2020","source":"The International journal of neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/31842638","citation_count":4,"is_preprint":false},{"pmid":"31551339","id":"PMC_31551339","title":"Arih2 gene influences immune response and tissue development in chicken.","date":"2019","source":"Bioscience reports","url":"https://pubmed.ncbi.nlm.nih.gov/31551339","citation_count":3,"is_preprint":false},{"pmid":"36055408","id":"PMC_36055408","title":"Ubiquitin ligase Triad1 promotes neurite outgrowth by inhibiting MDM2-mediated ubiquitination of the neuroprotective factor pleiotrophin.","date":"2022","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/36055408","citation_count":3,"is_preprint":false},{"pmid":"40680841","id":"PMC_40680841","title":"The ubiquitin ligase Triad1 influences myeloid leukemogenesis by regulating the integrated stress response.","date":"2025","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/40680841","citation_count":2,"is_preprint":false},{"pmid":"41312386","id":"PMC_41312386","title":"A LisH-domain protein interaction map reveals a Lis1-ARIH2-dynein regulatory axis.","date":"2025","source":"iScience","url":"https://pubmed.ncbi.nlm.nih.gov/41312386","citation_count":2,"is_preprint":false},{"pmid":"41572548","id":"PMC_41572548","title":"LINC00476 cooperates with ARIH2 and suppresses pancreatic cancer progression by inducing VIM ubiquitination.","date":"2025","source":"International journal of surgery (London, England)","url":"https://pubmed.ncbi.nlm.nih.gov/41572548","citation_count":1,"is_preprint":false},{"pmid":"41998836","id":"PMC_41998836","title":"ARIH2 Ubiquitination Regulates NUPR1 to Inhibit Ferroptosis in Bladder Cancer.","date":"2026","source":"Journal of cellular and molecular medicine","url":"https://pubmed.ncbi.nlm.nih.gov/41998836","citation_count":0,"is_preprint":false},{"pmid":"41651665","id":"PMC_41651665","title":"In Vivo Screen of Parkinson's Disease GWAS Risk Genes Identifies ARIH2 as a Novel Regulator of α-Synuclein Toxicity in Dopaminergic Neurons.","date":"2026","source":"The Journal of neuroscience : the official journal of the Society for Neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/41651665","citation_count":0,"is_preprint":false},{"pmid":"42217341","id":"PMC_42217341","title":"Cepharanthine inhibits NLRP3 inflammasome-induced pyroptosis through ARIH2-mediated degradation of NLRP3.","date":"2026","source":"International immunopharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/42217341","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.05.21.655409","title":"The Mechanism of Histone Ubiquitylation by the ASB9-CUL5 Ubiquitin Ligase","date":"2025-05-26","source":"bioRxiv","url":"https://doi.org/10.1101/2025.05.21.655409","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":18892,"output_tokens":5754,"usd":0.071493,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":14264,"output_tokens":4555,"usd":0.092597,"stage2_stop_reason":"end_turn"},"total_usd":0.16409,"stage1_batch_id":"msgbatch_0179Z2pxRYBsXi2xADneafRw","stage2_batch_id":"msgbatch_01LaY9ZaVdgjWArcZo9eqQE5","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2013,\n      \"finding\": \"TRIAD1 (ARIH2) associates with neddylated CUL5-RBX2-based Cullin-RING ligase (CRL) complexes, and binding of the cognate neddylated CRL greatly stimulates TRIAD1 RBR ligase activity in vitro (auto-ubiquitylation, UbcH7~ubiquitin thioester dissociation, and ubiquitin-vinyl methyl ester reactivity). TRIAD1 is auto-inhibited as an isolated protein but activated by neddylated CRL binding.\",\n      \"method\": \"In vitro ubiquitylation assays, auto-ubiquitylation, thioester dissociation assay, activity-based probe reactivity, genetic epistasis in vivo\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — multiple orthogonal biochemical assays (in vitro reconstitution, thioester dissociation, ABP) plus genetic epistasis, replicated mechanistic insight\",\n      \"pmids\": [\"24076655\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"Crystal/cryo-EM structural analysis of the CUL5-ARIH2 E3-E3 assembly revealed that ARIH2 is autoinhibited in isolation, and activation on neddylated CUL5-RBX2 occurs through an allosteric mechanism: CUL5-linked NEDD8 does not directly recruit ARIH2 (unlike CUL1-NEDD8 recruiting ARIH1), but instead contacts CUL5 covalently and induces conformational rearrangements that expose cryptic ARIH2-binding sites on CUL5.\",\n      \"method\": \"Cryo-EM/X-ray structural analysis, biochemical reconstitution, mutational validation\",\n      \"journal\": \"Nature chemical biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — structural determination combined with biochemical reconstitution and mutagenesis in a single rigorous study\",\n      \"pmids\": [\"34518685\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"Triad1 (ARIH2) binds the E2 ubiquitin-conjugating enzyme UbcH7 via its RING finger domains, supports formation of ubiquitin chains recognized by the proteasome, and inhibits clonogenic growth of primary myeloid progenitor cells. RING finger point mutants failing to bind UbcH7 lost the inhibitory effect; proteasome inhibition counteracted the growth inhibition.\",\n      \"method\": \"Binding assays, ubiquitin chain formation assays, retroviral transduction with RING finger mutants, CFU-GM colony assays, proteasome inhibition\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods (binding, ubiquitination, mutagenesis, functional colony assay, pharmacological rescue), single lab but mechanistically comprehensive\",\n      \"pmids\": [\"16118314\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"Triad1 contains two RING domains that differentially bind distinct E2 ubiquitin-conjugating enzymes: the first RING binds UbcH7 (supporting K48-linked chains for proteasomal degradation) and the second RING binds Ubc13 (supporting K63-linked chains for non-proteolytic functions). Both RING domains are required for inhibition of myeloid cell proliferation.\",\n      \"method\": \"E2 binding assays, ubiquitin chain linkage analysis, deletion/point mutants, myeloid clonogenic assays\",\n      \"journal\": \"Leukemia\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — mechanistic domain-level dissection with mutagenesis and multiple E2-binding and functional assays\",\n      \"pmids\": [\"19340006\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"Triad1 interacts with the DNA-binding domain of Gfi1 and unexpectedly inhibits Gfi1 ubiquitination, resulting in prolonged Gfi1 half-life. This inhibition is independent of Triad1's own ubiquitin ligase activity, suggesting Triad1 competes with other E3 ligases for Gfi1 binding. Triad1 mutants lacking the Gfi1-binding domain lost this stabilizing effect.\",\n      \"method\": \"Co-immunoprecipitation, siRNA knockdown, ubiquitination assays, pulse-chase half-life analysis, deletion mutant analysis, U937 cell overexpression\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal Co-IP, siRNA knockdown, half-life assay, domain deletion mutants, all in one study\",\n      \"pmids\": [\"17646546\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"ARIH2 (Triad1) causes degradation of nuclear IκBβ in dendritic cells, abrogating IκBβ's ability to sequester, protect, and transcriptionally co-activate p65 in the nucleus. Loss of ARIH2 in hematopoietic cells leads to dysregulated NF-κB activation in dendritic cells and lethal systemic immune activation. Targeted gene deletion in mice showed ARIH2 is essential for embryogenesis.\",\n      \"method\": \"Gene-targeted knockout mice, hematopoietic stem cell reconstitution, NF-κB pathway analysis, IκBβ/p65 interaction studies\",\n      \"journal\": \"Nature immunology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic loss-of-function (knockout mice, bone marrow reconstitution) with defined molecular pathway (IκBβ-p65-NF-κB) and clear cellular phenotype\",\n      \"pmids\": [\"23179078\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"ARIH2 interacts with NLRP3 via NLRP3's NACHT domain (aa 220–575) in the inflammasome complex, and the RING2 domain of ARIH2 catalyzes K48- and K63-linked ubiquitination of NLRP3. CRISPR/Cas9 deletion of ARIH2 inhibited NLRP3 ubiquitination and promoted inflammasome activation (ASC oligomerization, pro-IL-1β processing, IL-1β secretion); overexpression of ARIH2 had the opposite effect.\",\n      \"method\": \"Co-immunoprecipitation, RING2 domain mutants, ubiquitin chain linkage mutants, CRISPR/Cas9 knockout, ARIH2 overexpression, ASC oligomerization assay, IL-1β ELISA\",\n      \"journal\": \"Journal of immunology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP, domain/ubiquitin mutants, CRISPR KO, overexpression, multiple functional readouts in one study\",\n      \"pmids\": [\"29021376\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"TRIAD1 binds to the C-terminus of p53 and promotes its dissociation from MDM2, thereby inhibiting MDM2-mediated ubiquitination and degradation of p53. Ablation of TRIAD1 reduces p53 levels upon DNA damage, while ectopic TRIAD1 expression stabilizes p53.\",\n      \"method\": \"Co-immunoprecipitation, p53-MDM2 dissociation assay, ubiquitination assay, siRNA knockdown, overexpression\",\n      \"journal\": \"FEBS letters\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP, ubiquitination assay, KD and OE, but single lab and single study\",\n      \"pmids\": [\"22819825\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"TRIAD1 is a ubiquitination substrate of MDM2: MDM2 interacts with and ubiquitinates TRIAD1, targeting it for proteasomal degradation. RNAi against MDM2 increased endogenous TRIAD1 protein stability, and MDM2-mediated TRIAD1 degradation suppressed TRIAD1-mediated cell growth inhibition.\",\n      \"method\": \"Co-immunoprecipitation, ubiquitination assay, siRNA knockdown of MDM2, protein stability assay\",\n      \"journal\": \"Oncology reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — Co-IP and ubiquitination assay and siRNA, but single lab, single study, limited orthogonal validation\",\n      \"pmids\": [\"22940738\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Triad1 depletion in cells disrupts endosomal sorting of growth hormone and EGF, causing accumulation of ligands in enlarged endosomes with irregular intraluminal vesicles and prominent clathrin coats, while reducing fluid-phase transport to lysosomes. Triad1 catalyzes both K48- and K63-linked polyubiquitin chain formation and is required for proper multivesicular body function.\",\n      \"method\": \"siRNA depletion, immunofluorescence, immune electron microscopy, fluid-phase transport assays, receptor recycling assay\",\n      \"journal\": \"Biology open\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — siRNA knockdown, immune EM, multiple cargo tracking assays in one study\",\n      \"pmids\": [\"23213454\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"TRIAD1 binds UBCH8 and PML-RARα, but this interaction does not affect PML-RARα turnover (negative finding), distinguishing TRIAD1 from SIAH1/SIAH2 in regulation of this leukemia oncoprotein. UBCH8 cooperates with SIAH1/SIAH2 but not TRIAD1 for PML-RARα degradation.\",\n      \"method\": \"Co-immunoprecipitation, protein stability/turnover assay, combined drug treatment (valproic acid + ATRA)\",\n      \"journal\": \"The international journal of biochemistry & cell biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — Co-IP confirmed binding; negative turnover result supported by functional assay; single lab\",\n      \"pmids\": [\"22037423\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"ARIH2 interacts with p21 and induces K48-linked ubiquitination of p21 at lysine K161, targeting p21 for proteasomal degradation. ARIH2 was confirmed as a direct E3 ligase of p21 by in vitro ubiquitination assay. ARIH2 knockdown induced DNA damage and apoptosis and altered chemosensitivity.\",\n      \"method\": \"Co-immunoprecipitation, in vitro ubiquitination assay, site-directed mutagenesis (K48 ubiquitin and K161 p21 mutants), knockdown, in vivo tumor xenograft\",\n      \"journal\": \"Cell death & disease\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro ubiquitination assay plus site-directed mutagenesis identifying specific ubiquitin linkage and substrate lysine, replicated in vivo; single lab\",\n      \"pmids\": [\"35732617\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Arih2β (ER-localized isoform, cytoplasmic face of ER) regulates ER-associated degradation (ERAD) of Smoothened (Smo). Loss of Arih2 elevates cellular and ciliary Smo levels, activates basal Hedgehog signaling, and triggers ER protein aggregation and unfolded protein response. Re-expression of ER-localized Arih2β but not nuclear Arih2α rescues these phenotypes.\",\n      \"method\": \"Genetic loss-of-function (mouse model), isoform-specific re-expression, subcellular fractionation/localization, cilia imaging, UPR assays, protein accumulation assays\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic KO with isoform-specific rescue, subcellular localization tied to function, multiple mechanistic readouts\",\n      \"pmids\": [\"35899529\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"ARIH2 ubiquitinates dynein intermediate chain 1 (DIC1), facilitating dynein function in organelle positioning. The Lis1 protein promotes ARIH2 deneddylation via the COP9 signalosome (CSN), thereby modulating ARIH2 ubiquitin ligase activity. Active (neddylated) ARIH2 is required for proper dynein-dependent intracellular transport.\",\n      \"method\": \"Proteomics-based interaction mapping, co-immunoprecipitation, ubiquitination assays, organelle positioning assays\",\n      \"journal\": \"iScience\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — Co-IP and ubiquitination assay with functional readout, but single lab and limited orthogonal validation described in abstract\",\n      \"pmids\": [\"41312386\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"ARIH2 ubiquitinates Gcn1 (a regulator of the integrated stress response, ISR) among a set of ISR-regulatory proteins identified by proteomic screen. Triad1 knockdown causes a translatome shift consistent with ISR activation that is reversed by co-knockdown of Gcn1, linking Triad1-dependent ubiquitination to ISR suppression and leukemia suppression.\",\n      \"method\": \"Proteomic screen (ubiquitination proteomics), translatome profiling, Gcn1 co-knockdown epistasis, murine AML bone marrow transplant model\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — proteomic identification of substrates, epistasis experiment (co-knockdown rescue), in vivo AML model; single lab\",\n      \"pmids\": [\"40680841\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"In C. elegans and human iPSC-derived dopaminergic neurons, loss of ARIH2 (ari-2 in worm) suppresses α-synuclein-mediated dopaminergic neurodegeneration. Unbiased proteomics identified TPPP3 (a microtubule dynamics regulator) as a novel ARIH2 substrate; TPPP3 was required for ARIH2's effects on α-synuclein-induced neurodegeneration.\",\n      \"method\": \"C. elegans genetic screen, unbiased proteomics in human iPSC-derived neurons, loss-of-function studies, epistasis (TPPP3 requirement)\",\n      \"journal\": \"The Journal of neuroscience\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo genetic screen plus proteomics substrate identification plus epistasis, but abstract does not detail direct ubiquitination assay for TPPP3\",\n      \"pmids\": [\"41651665\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"ARIH2 promotes K29-linked polyubiquitination of vimentin (VIM) at lysine K373 residue, leading to proteasomal degradation of VIM. LINC00476 lncRNA recruits ARIH2 to VIM to facilitate this ubiquitination.\",\n      \"method\": \"RNA pull-down, RIP, Co-IP, ubiquitination assays with linkage and site mutants, in vivo PDX model\",\n      \"journal\": \"International journal of surgery\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP, K29-linkage and K373 site mutants validated, PDX model; ARIH2's role as direct E3 supported but lncRNA recruitment aspect complicates mechanistic isolation\",\n      \"pmids\": [\"41572548\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"ARIH2 interacts with NUPR1 in bladder cancer cells and promotes its ubiquitin-mediated proteasomal degradation. ARIH2 depletion prolongs NUPR1 stability and reduces its ubiquitination, while ARIH2 overexpression decreases NUPR1 levels. NUPR1 suppresses ferroptosis (elevated GPX4, SLC7A11, reduced ACSL4), so ARIH2-mediated NUPR1 degradation indirectly modulates ferroptosis sensitivity.\",\n      \"method\": \"IP-MS, Co-IP, immunofluorescence, ubiquitination assay, protein stability assay, ferroptosis marker analysis\",\n      \"journal\": \"Journal of cellular and molecular medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — IP-MS plus Co-IP plus ubiquitination/stability assays, functional ferroptosis readout; single lab\",\n      \"pmids\": [\"41998836\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"Triad1 interacts with DISC1 via specific protein fragments, and co-localization in neural stem cells was demonstrated. Overexpressing both TRIAD1 and DISC1 in primary neural stem cells significantly affected proliferation and differentiation after traumatic brain injury.\",\n      \"method\": \"Co-immunoprecipitation, truncation mutant mapping, immunofluorescence co-localization, lentiviral overexpression in primary neural stem cells\",\n      \"journal\": \"Stem cell research & therapy\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — Co-IP and localization shown, but functional consequence of Triad1-DISC1 interaction not molecularly resolved; single lab, limited controls described\",\n      \"pmids\": [\"30409224\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"Triad1 interacts with EHD1 (EH domain-containing protein 1) both in vitro and in vivo, mediated through the EH domain of EHD1. Triad1 regulates the expression and subcellular distribution of EHD1, influencing neurite outgrowth of PC12 cells after spinal cord injury.\",\n      \"method\": \"Co-immunoprecipitation, EH domain truncation interaction mapping, in vitro and in vivo binding assays, neurite outgrowth assay\",\n      \"journal\": \"Journal of cellular biochemistry\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — Co-IP and truncation mapping shown, but ubiquitination of EHD1 not demonstrated; functional link indirect; single lab\",\n      \"pmids\": [\"30320922\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Triad1 overexpression promoted PTN (pleiotrophin) protein levels and inhibited MDM2-mediated PTN ubiquitination. MDM2 ubiquitinates PTN, and Triad1 reversed this ubiquitination, thereby stabilizing PTN and promoting astrocyte-dependent neurite outgrowth after spinal cord injury.\",\n      \"method\": \"Ubiquitination assay, co-immunoprecipitation, overexpression and shRNA knockdown, astrocyte-neuron co-culture, in vivo rat SCI model\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — ubiquitination assay and Co-IP with functional rescue experiment; mechanism (blocking MDM2-PTN ubiquitination) defined, but single lab\",\n      \"pmids\": [\"36055408\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"ARIH2 (TRIAD1) is an RBR-family E3 ubiquitin ligase that exists in an autoinhibited state and is allosterically activated by binding to neddylated Cullin-RING ligase (CRL) complexes, particularly neddylated CUL5-RBX2, through a NEDD8-induced conformational mechanism that exposes cryptic ARIH2-binding sites; activated ARIH2 catalyzes K48- and K63-linked ubiquitin chain formation via two RING domains that differentially recruit E2 enzymes (UbcH7 and Ubc13), targeting substrates including NLRP3, p21, Smo, VIM, NUPR1, DIC1, TPPP3, and Gcn1 for proteasomal degradation or functional regulation, while also modulating protein stability indirectly by competing with other E3 ligases (e.g., stabilizing Gfi1 and p53 by blocking MDM2 access), with biological roles spanning regulation of myeloid progenitor proliferation, NF-κB/IκBβ signaling in dendritic cells, NLRP3 inflammasome suppression, Hedgehog signaling via ER-associated degradation of Smo, endosomal/MVB trafficking, and integrated stress response control in hematopoietic cells.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"ARIH2 (TRIAD1) is an RBR-family E3 ubiquitin ligase that operates as the catalytic partner of neddylated Cullin-RING ligase (CRL) complexes to control protein turnover across hematopoietic, immune, and neural contexts [#0, #5]. In isolation ARIH2 is autoinhibited; binding to neddylated CUL5-RBX2 strongly stimulates its ligase activity, and structural analysis shows this activation is allosteric—CUL5-linked NEDD8 does not directly recruit ARIH2 but rearranges CUL5 to expose cryptic ARIH2-binding sites [#0, #1]. The enzyme uses two RING domains that engage distinct E2s: RING1 binds UbcH7 to build K48-linked chains for proteasomal degradation, while RING2 binds Ubc13 to build K63-linked chains for non-proteolytic functions, and both are required to restrain myeloid progenitor proliferation [#2, #3]. Through these activities ARIH2 ubiquitinates a range of substrates including NLRP3 to suppress inflammasome activation [#6], p21 to promote its degradation [#11], the Smoothened receptor via ER-associated degradation to limit basal Hedgehog signaling [#12], and Gcn1 to suppress the integrated stress response in leukemic cells [#14]. ARIH2 also acts non-catalytically, competing with MDM2 to stabilize Gfi1 and p53 [#4, #7], and is essential for embryogenesis and for restraining NF-\\u03baB activation in dendritic cells via degradation of nuclear I\\u03baB\\u03b2 [#5]. Additional substrate and trafficking roles—including dynein intermediate chain 1 in organelle positioning [#13], vimentin and NUPR1 degradation [#16, #17], and multivesicular body sorting [#9]—extend its reach into cytoskeletal and endosomal regulation.\",\n  \"teleology\": [\n    {\n      \"year\": 2005,\n      \"claim\": \"Established ARIH2/Triad1 as a functional E3 ligase by showing it binds the E2 UbcH7 through its RING fingers and that this activity restrains myeloid progenitor growth, defining its first biological role.\",\n      \"evidence\": \"E2 binding, ubiquitin chain assays, RING point mutants, and CFU-GM colony assays with proteasome inhibition\",\n      \"pmids\": [\"16118314\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Specific physiological substrates not yet identified\", \"Mechanism of ligase activation in cells not addressed\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Revealed a catalysis-independent mode of action: ARIH2 stabilizes Gfi1 by competing with other E3 ligases rather than ubiquitinating it.\",\n      \"evidence\": \"Reciprocal Co-IP, siRNA knockdown, pulse-chase half-life, and domain-deletion mutants in U937 cells\",\n      \"pmids\": [\"17646546\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Competing E3 ligase not identified\", \"Whether this competition operates in primary cells unresolved\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Dissected the dual-RING architecture, showing the two RING domains recruit different E2s (UbcH7 vs Ubc13) to assemble K48- versus K63-linked chains, explaining how one ligase serves both proteolytic and non-proteolytic outputs.\",\n      \"evidence\": \"E2 binding assays, ubiquitin linkage analysis, deletion/point mutants, and myeloid clonogenic assays\",\n      \"pmids\": [\"19340006\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Substrate-specific deployment of each linkage type not mapped\", \"Regulation of E2 choice unknown\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Connected ARIH2 to immune homeostasis and embryogenesis, showing it degrades nuclear I\\u03baB\\u03b2 to restrain NF-\\u03baB-driven dendritic cell activation, with loss causing lethal systemic immune activation.\",\n      \"evidence\": \"Gene-targeted knockout mice, hematopoietic reconstitution, and I\\u03baB\\u03b2-p65 interaction studies\",\n      \"pmids\": [\"23179078\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct ubiquitination of I\\u03baB\\u03b2 by ARIH2 not biochemically isolated here\", \"CRL dependence of this activity not addressed\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Defined a reciprocal regulatory relationship with MDM2: ARIH2 stabilizes p53 by displacing it from MDM2, while MDM2 in turn ubiquitinates and degrades ARIH2 to relieve its growth-inhibitory effect.\",\n      \"evidence\": \"Co-IP, p53-MDM2 dissociation and ubiquitination assays, siRNA, and stability assays (two studies)\",\n      \"pmids\": [\"22819825\", \"22940738\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single-lab findings without reciprocal independent validation\", \"Physiological context of the ARIH2-MDM2 feedback loop unclear\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Extended ARIH2 function to membrane trafficking, showing it is required for endosomal sorting and multivesicular body function via dual K48/K63 chain formation.\",\n      \"evidence\": \"siRNA depletion, immunofluorescence, immune EM, and cargo transport assays\",\n      \"pmids\": [\"23213454\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Trafficking substrate(s) of ARIH2 not identified\", \"Link between ligase activity and MVB defect not biochemically resolved\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Identified NLRP3 as a direct substrate, establishing ARIH2 as a brake on inflammasome activation through K48/K63 ubiquitination of the NACHT domain.\",\n      \"evidence\": \"Reciprocal Co-IP, RING2 and ubiquitin-linkage mutants, CRISPR KO, overexpression, and IL-1\\u03b2 readouts\",\n      \"pmids\": [\"29021376\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether CRL5-NEDD8 activation is required for NLRP3 ubiquitination not tested\", \"Functional roles of K48 vs K63 chains on NLRP3 not separated\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Solved the structural basis of activation, showing NEDD8 on CUL5 acts allosterically—rearranging CUL5 to expose cryptic ARIH2 sites—rather than directly recruiting ARIH2 as occurs with CUL1-ARIH1.\",\n      \"evidence\": \"Cryo-EM/X-ray structural analysis with biochemical reconstitution and mutagenesis\",\n      \"pmids\": [\"34518685\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Substrate engagement geometry in the activated E3-E3 complex not fully resolved\", \"Whether other cullins activate ARIH2 by the same mechanism unknown\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Identified p21 as a direct degradation substrate with defined linkage (K48) and acceptor lysine (K161), linking ARIH2 to cell cycle and chemosensitivity.\",\n      \"evidence\": \"Co-IP, in vitro ubiquitination, ubiquitin and substrate site mutants, knockdown, and xenografts\",\n      \"pmids\": [\"35732617\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"CRL dependence of p21 ubiquitination not addressed\", \"Single-lab finding\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Resolved isoform-specific function, showing the ER-localized Arih2\\u03b2 isoform mediates ERAD of Smoothened to suppress basal Hedgehog signaling and prevent ER stress.\",\n      \"evidence\": \"Mouse genetic KO with isoform-specific rescue, subcellular localization, cilia imaging, and UPR assays\",\n      \"pmids\": [\"35899529\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct ubiquitination of Smo and chain type not specified\", \"Determinants of \\u03b1 vs \\u03b2 isoform localization not defined\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Added a second MDM2-competition substrate, showing Triad1 stabilizes PTN by reversing MDM2-mediated ubiquitination to promote neurite outgrowth after spinal cord injury.\",\n      \"evidence\": \"Ubiquitination assay, Co-IP, overexpression/knockdown, co-culture, and in vivo SCI model\",\n      \"pmids\": [\"36055408\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single-lab finding\", \"Mechanism of MDM2 displacement vs deubiquitination not distinguished\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Expanded the substrate landscape and revealed regulation of ARIH2's own neddylation state—ubiquitinating DIC1 for dynein-dependent organelle positioning, Gcn1 to suppress the integrated stress response in leukemia, and vimentin via K29 chains.\",\n      \"evidence\": \"Interaction proteomics, Co-IP, ubiquitination/linkage-site mutants, translatome profiling, organelle positioning, and AML/PDX models (three studies)\",\n      \"pmids\": [\"41312386\", \"40680841\", \"41572548\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Each substrate from a single lab without independent confirmation\", \"How Lis1/CSN-driven ARIH2 deneddylation integrates with CRL activation unclear\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Linked ARIH2 to neurodegeneration and ferroptosis, identifying TPPP3 as a substrate required for ARIH2 effects on \\u03b1-synuclein toxicity and NUPR1 as a substrate whose degradation modulates ferroptosis sensitivity.\",\n      \"evidence\": \"C. elegans genetic screen, iPSC-neuron proteomics, epistasis, IP-MS, Co-IP, ubiquitination, and ferroptosis marker analysis (two studies)\",\n      \"pmids\": [\"41651665\", \"41998836\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct ubiquitination assay for TPPP3 not detailed\", \"Single-lab findings without orthogonal validation\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"It remains unresolved which substrates depend on CRL5-NEDD8 allosteric activation versus CRL-independent activity, and how the dual K48/K63 (and K29) chain outputs are selected per substrate.\",\n      \"evidence\": \"No timeline study systematically maps substrate-by-substrate CRL dependence or chain-type determinants\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No unified rule linking activation state to substrate choice\", \"Physiological substrate hierarchy across tissues unknown\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0061630\", \"supporting_discovery_ids\": [0, 2, 3, 6, 11]},\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [2, 6, 11, 16]},\n      {\"term_id\": \"GO:0016874\", \"supporting_discovery_ids\": [0, 2, 3]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [4, 7]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005783\", \"supporting_discovery_ids\": [12]},\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [5, 12]},\n      {\"term_id\": \"GO:0005768\", \"supporting_discovery_ids\": [9]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-392499\", \"supporting_discovery_ids\": [0, 2, 3]},\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [5, 6]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [12]},\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [11]},\n      {\"term_id\": \"R-HSA-8953897\", \"supporting_discovery_ids\": [14]}\n    ],\n    \"complexes\": [\"neddylated CUL5-RBX2 Cullin-RING ligase\", \"NLRP3 inflammasome\"],\n    \"partners\": [\"CUL5\", \"RBX2\", \"NEDD8\", \"UbcH7\", \"Ubc13\", \"MDM2\", \"NLRP3\", \"Gfi1\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":6,"faith_pct":100.0}}