{"gene":"USP48","run_date":"2026-06-11T09:02:06","timeline":{"discoveries":[{"year":2018,"finding":"USP48 is a histone H2A deubiquitinase specific for the C-terminal BRCA1 ubiquitination site. Biochemical analysis showed that an auxiliary ubiquitin (itself not cleaved) modulates USP48 activity. In cells, USP48 antagonizes BRCA1 E3 ligase function; loss of USP48 results in 53BP1 positioned further from the break site and extended resection lengths, and confers survival benefit to camptothecin-treated cells. USP48 activity restrains gene conversion and mutagenic single-strand annealing.","method":"Detailed biochemical analysis, in vitro DUB assays, cell-based BRCA1 ubiquitination assays, epistasis with BRCA1 loss-of-function, resection length measurements, colony survival assays","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 1/2 / Strong — in vitro biochemical reconstitution with multiple substrates, auxiliary ubiquitin modulation defined, multiple orthogonal cell-based assays in one rigorous study","pmids":["29335415"],"is_preprint":false},{"year":2018,"finding":"USP48 is identified as a synthetic viable interactor for FA-gene deficiencies (FANCA, FANCC, FANCG, FANCI, FANCD2). Loss of USP48 in FA-deficient cells reduces sensitivity to ICL agents, enhances BRCA1-dependent DNA damage clearance, and reduces chromosomal instability, placing USP48 in the DNA repair pathway downstream or parallel to the FA pathway.","method":"Genome-wide loss-of-function screens in haploid isogenic FA-defective human cells, ICL agent sensitivity assays, BRCA1-dependence epistasis, chromosomal instability measurements","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 2 / Strong — genome-wide screen validated across five FA-gene backgrounds, BRCA1 epistasis confirmed, multiple orthogonal readouts","pmids":["29891926"],"is_preprint":false},{"year":2014,"finding":"USP48 associates with the COP9 signalosome (CSN) and nuclear RelA (NF-κB p65). USP48 trims (rather than fully disassembles) K48-linked free and substrate-anchored ubiquitin chains on RelA, a catalytic property shared only with ataxin-3 and OTU1. USP48 chain-trimming activity is regulated by CK2-mediated phosphorylation in response to cytokine stimulation. CSN and USP48 cooperatively stabilize the nuclear pool of RelA to facilitate timely induction and shutoff of NF-κB target genes.","method":"siRNA screen identification, Co-IP (USP48–CSN, USP48–RelA), in vitro ubiquitin chain trimming assays, phosphorylation assays with CK2, NF-κB reporter assays","journal":"Biochimica et biophysica acta","confidence":"High","confidence_rationale":"Tier 1-2 / Moderate — in vitro chain-trimming biochemistry plus Co-IP plus functional NF-κB reporter, single lab but multiple orthogonal methods","pmids":["25486460"],"is_preprint":false},{"year":2017,"finding":"USP48 deubiquitinates and stabilizes Gli1 protein by directly cleaving its ubiquitin, activating Gli-dependent transcription. USP48 knockdown inhibits Gli1 target gene expression and glioblastoma cell proliferation and tumorigenesis. The Hedgehog pathway induces USP48 expression via Gli1-mediated transcription, forming a positive feedback loop.","method":"Co-IP (USP48–Gli1 interaction), DUB activity assay (ubiquitin cleavage from Gli1), Gli reporter assays, siRNA knockdown with proliferation and tumor growth readouts, Gli1 rescue experiments","journal":"EMBO reports","confidence":"High","confidence_rationale":"Tier 1-2 / Moderate — direct deubiquitination shown biochemically, Gli reporter functional assay, Gli1-dependence epistasis, single lab with multiple orthogonal methods","pmids":["28623188"],"is_preprint":false},{"year":2017,"finding":"USP48 deubiquitinates and stabilizes TRAF2 in epithelial cells, specifically targeting the TRAF2 pool linked to the JNK pathway but not the NF-κB or p38 pathways. USP48 is serine-phosphorylated in response to TNF-α by GSK3β, increasing its DUB activity. Knockdown of USP48 reduces TRAF2 stability, attenuates TNF-α/JNK signaling, and increases E-cadherin expression and epithelial barrier integrity.","method":"Co-IP (USP48–TRAF2), K48-polyubiquitination assays, pathway-specific rescue experiments, GSK3β phosphorylation assay, USP48 knockdown with E-cadherin and barrier function readouts","journal":"FASEB journal","confidence":"High","confidence_rationale":"Tier 2 / Moderate — reciprocal Co-IP, ubiquitination assays, GSK3β kinase assay, pathway-specific epistasis, single lab with multiple orthogonal methods","pmids":["28874458"],"is_preprint":false},{"year":2021,"finding":"USP48 physically binds SIRT6 and stabilizes it by removing K48-linked ubiquitin chains specifically at K33 and K128 of SIRT6, preventing its proteasomal degradation and thereby impeding metabolic reprogramming (glycolysis) in hepatocellular carcinoma cells.","method":"Co-IP (USP48–SIRT6), K48-linked deubiquitination site-mapping (K33, K128 of SIRT6), glycolysis assays, cell-based ubiquitination assays","journal":"Cancer research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP confirmed, deubiquitination sites mapped by mutagenesis, functional metabolic readout; single lab","pmids":["33903120"],"is_preprint":false},{"year":2023,"finding":"USP48 promotes pyroptosis in cancer cells by binding GSDME (gasdermin E) and removing K48-linked ubiquitination at K120 and K189 of GSDME, thereby stabilizing it. CRISPR-Cas9 screen identified USP48 loss as inhibiting pyroptosis; USP48 knockout suppressed T cell and tumor-associated macrophage function in the tumor microenvironment.","method":"CRISPR-Cas9 loss-of-function screen, Co-IP (USP48–GSDME), site-specific K48-deubiquitination assays (K120, K189), pyroptosis assays, in vivo mouse tumor models with PD-1 blockade","journal":"Cancer research","confidence":"High","confidence_rationale":"Tier 1-2 / Moderate — genome-wide CRISPR screen validated, site-specific deubiquitination confirmed, multiple in vitro and in vivo readouts, single lab","pmids":["36607699"],"is_preprint":false},{"year":2021,"finding":"USP48 interacts with and stabilizes Aurora B protein by deubiquitinating it, maintaining its steady-state levels during the cell cycle. USP48 knockout causes delayed cell cycle progression, mitotic defects, and cytokinesis failure.","method":"Deubiquitinase knockout strategy, Co-IP (USP48–Aurora B), protein half-life assays, cell cycle progression analysis, cytokinesis failure quantification","journal":"International journal of molecular sciences","confidence":"Medium","confidence_rationale":"Tier 2-3 / Moderate — Co-IP confirmed, deubiquitinating activity linked to half-life, KO phenotype with specific cell cycle readout; single lab","pmids":["34445214"],"is_preprint":false},{"year":2019,"finding":"The catalytic USP domain of USP48 mediates its physical interaction with the N-terminal region of the Rel homology domain (RHD) of nuclear RelA. This was mapped using overexpressed truncated proteins.","method":"Co-IP with truncated USP48 and RelA domain constructs, nuclear co-localization experiments","journal":"Molecular biology reports","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — domain mapping by truncation Co-IP, replicated the USP48–RelA interaction established in prior work; single lab, single method for new domain finding","pmids":["30628021"],"is_preprint":false},{"year":2022,"finding":"In H. pylori infection, USP48 interacts with CSN subunit CSN1 and stabilizes nuclear RelA by deubiquitination, prolonging de novo synthesis of DUB A20. A20 then suppresses caspase-8 activity and apoptotic cell death, defining a synergistic USP48–A20 mechanism that promotes cell survival.","method":"Co-IP (USP48–CSN1, USP48–RelA), deubiquitination assays, A20 expression measurement, caspase-8 activity assay, apoptosis readout in H. pylori-infected cells","journal":"Cellular and molecular life sciences","confidence":"Medium","confidence_rationale":"Tier 2-3 / Moderate — Co-IP interactions confirmed, functional pathway placement with multiple downstream readouts; single lab","pmids":["35913642"],"is_preprint":false},{"year":2022,"finding":"USP48 downregulation stabilizes p65 (NF-κB) in the nuclear compartment of retinal pigment epithelium (RPE) cells, increasing NF-κB transcriptional activity — contrary to the stabilizing role described in other cell types. This delineates a negative regulatory role for USP48 on NF-κB in RPE cells.","method":"siRNA knockdown of USP48 in RPE cells, subcellular fractionation, NF-κB reporter assay, TNFα stimulation","journal":"International journal of molecular sciences","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, knockdown with reporter assay only, result appears contradictory to other studies suggesting context-dependent effect; no direct biochemical DUB assay reported in abstract","pmids":["36077078"],"is_preprint":false},{"year":2022,"finding":"USP48 localizes to the basal body in retinal cells and interacts with the IRD-associated proteins ARL3 and UNC119a, stabilizing their protein levels. This suggests a role for USP48 in photoreceptor ciliary protein regulation and intracellular transport.","method":"Co-IP (USP48–ARL3, USP48–UNC119a), immunohistochemistry/subcellular localization in retinal cells, protein stability assays","journal":"International journal of molecular sciences","confidence":"Medium","confidence_rationale":"Tier 2-3 / Moderate — Co-IP confirmed for both partners, localization to basal body shown; single lab, functional consequence inferred from stabilization data","pmids":["36293380"],"is_preprint":false},{"year":2021,"finding":"USP48 has catalytic deubiquitinase (ubiquitin hydrolase) activity; disease-associated missense variants in USP48 are unable to hydrolyze tetra-ubiquitin in vitro, confirming the catalytic requirement for ubiquitin hydrolysis. USP48 is expressed in spiral ganglion neurons and other inner ear structures; zebrafish knocked down for usp48 show impaired statoacoustic neuron development and vestibular/hearing dysfunction.","method":"In vitro tetra-ubiquitin hydrolysis assay with mutant proteins, 3D structural modeling, immunohistology in human inner ear, zebrafish knockdown with acoustic startle response assay","journal":"Human molecular genetics","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — direct enzymatic assay with disease mutants, structural modeling, in vivo model with functional hearing readout; multiple orthogonal methods","pmids":["34059922"],"is_preprint":false},{"year":2018,"finding":"Recurrent somatic mutations in USP48 (predominantly M415I or M415V) occur in USP8 wild-type corticotroph adenomas. Similar to USP8 mutants, USP48 mutants enhance promoter activity and transcription of the POMC gene (the ACTH precursor), providing a mechanism for ACTH overproduction in these tumors.","method":"Sanger/targeted sequencing of tumor DNA, POMC promoter reporter assay in cells transfected with mutant USP48 constructs","journal":"Nature communications","confidence":"Medium","confidence_rationale":"Tier 2-3 / Moderate — recurrent mutation identified in large cohort, POMC promoter reporter functional validation; single lab, mechanism at transcriptional level not fully dissected","pmids":["30093687"],"is_preprint":false},{"year":2023,"finding":"USP48 (formerly USP31) is a nuclear deubiquitinase whose nuclear localization is mediated by a conserved 13-amino acid nuclear localization signal. USP48 interacts with NF-κB transcription factor and deubiquitinates p65, promoting its stability and activation, which upregulates NF-κB target genes that inhibit synaptogenesis. USP48 expression induces filopodia elaboration, spine loss, reduced synaptic protein clustering in vitro, and erases ~70% of functional synapses in vivo; depleting NF-κB prevents USP48-dependent spine pruning.","method":"NLS mutagenesis (nuclear localization signal), Co-IP (USP48–p65), deubiquitination assay (p65), NF-κB reporter assay, live imaging of spine dynamics, electrophysiological synapse counting in vivo, NF-κB depletion epistasis","journal":"bioRxiv","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP, deubiquitination assay, NLS mutagenesis, NF-κB epistasis, in vivo synapse counting; preprint, not yet peer-reviewed","pmids":["37781625"],"is_preprint":true},{"year":2024,"finding":"USP48 deubiquitinates HMGA2, stabilizing it and promoting tumor invasion and metastasis. USP48 undergoes SUMOylation at lysine K258, which enhances its binding affinity for HMGA2. A small-molecule inhibitor DUB-IN-2 blocks USP48 activity and induces HMGA2 destabilization.","method":"Mass spectrometry identification, Co-IP (USP48–HMGA2), overexpression/knockdown protein stability assays, SUMOylation site mapping (K258), DUB-IN-2 pharmacological inhibition, tumor invasion/metastasis assays","journal":"Acta pharmaceutica sinica. B","confidence":"Medium","confidence_rationale":"Tier 2-3 / Moderate — MS identification, Co-IP, SUMOylation site identified, pharmacological inhibitor functional validation; single lab","pmids":["38572092"],"is_preprint":false},{"year":2023,"finding":"USP48 interacts with MrgC (Mas-related G protein-coupled receptor C) in spinal cord neurons and reduces its K48-linked ubiquitination, stabilizing MrgC receptor levels. In a murine bone cancer pain model, spinal cord USP48 expression is reduced; AAV-mediated USP48 overexpression increased MrgC levels and alleviated pain behaviors.","method":"Co-IP (USP48–MrgC), overexpression/knockdown in N2a cells with receptor number quantification, ubiquitination assay, intrathecal AAV injection with pain behavior readout","journal":"European journal of pain","confidence":"Medium","confidence_rationale":"Tier 2-3 / Moderate — Co-IP confirmed, ubiquitination assay, in vivo AAV rescue; single lab","pmids":["36864656"],"is_preprint":false},{"year":2025,"finding":"USP48 stabilizes calponin 1 (CNN1) via deubiquitination in cardiomyocytes. The USP48/CNN1 axis inhibits release of CXCL1 and CXCL2 through inactivation of the ERK1/2 pathway, conferring cardioprotection in diabetes-aggravated myocardial ischemia-reperfusion injury.","method":"Proteomics identification of CNN1, cardiac-specific KO and OE in mice, Co-IP (USP48–CNN1), ubiquitination assay, RNA-seq, ERK1/2 pathway readout, CXCL1/2 antibody blockade rescue","journal":"Metabolism: clinical and experimental","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — proteomics-identified substrate, Co-IP, in vivo cardiac-specific KO/OE, multi-step pathway validation; single lab","pmids":["40513941"],"is_preprint":false},{"year":2025,"finding":"USP48 promotes NLRP3-dependent pyroptosis of alveolar macrophages in sepsis-induced acute lung injury by directly interacting with and deubiquitinating NEK7, stabilizing it and thereby activating the NEK7/NLRP3/caspase-1/GSDMD signaling axis.","method":"Co-IP (USP48–NEK7), NEK7 ubiquitination assay, USP48 knockdown in vivo and in vitro, NEK7 overexpression rescue experiment, NLRP3 inflammasome activation readout, murine sepsis model","journal":"International immunopharmacology","confidence":"Medium","confidence_rationale":"Tier 2-3 / Moderate — Co-IP confirmed, deubiquitination assay, NEK7 rescue epistasis, in vivo model; single lab","pmids":["40580743"],"is_preprint":false},{"year":2025,"finding":"USP48 is recruited to sites of DNA damage and deubiquitinates H2A variants and proteins important for DNA damage repair. Loss of USP48 increases chromatin accessibility upon HMA treatment, sensitizing AML cells to DNMT1 inhibition-induced cell death.","method":"CRISPR loss-of-function screens, chromatin accessibility assays (ATAC-seq implied), USP48 localization at DNA damage sites, H2A deubiquitination assay","journal":"bioRxiv","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — CRISPR screen, functional DNA damage localization, H2A DUB activity; preprint, not yet peer-reviewed","pmids":[],"is_preprint":true},{"year":2025,"finding":"USP48 is recruited to newly hypomethylated CpG islands upon DNA demethylation and deubiquitinates non-canonical histones, establishing a molecular link between DNA methylation state and chromatin modification. Loss of USP48 (naturally occurring via biallelic deletions) sensitizes hematologic and solid tumors to DNMT1 inhibition in vitro and in vivo.","method":"CRISPR drug modifier screens across >600 cancer models, ChIP or genomic localization to hypomethylated CpG islands, non-canonical histone deubiquitination assay, in vitro and in vivo tumor sensitization experiments","journal":"bioRxiv","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — large-scale CRISPR screen validated, substrate deubiquitination shown, in vivo confirmation; preprint, not yet peer-reviewed","pmids":[],"is_preprint":true},{"year":2025,"finding":"USP48 interacts with and stabilizes TAK1 through deubiquitination; this inhibits TAK1-triggered NF-κB activation and suppresses colorectal cancer tumorigenesis. USP48 expression also positively correlates with M1-type tumor-associated macrophage polarization.","method":"Co-IP (USP48–TAK1), deubiquitination assay, qRT-PCR for NF-κB targets, flow cytometry for macrophage polarization, cell proliferation/invasion/apoptosis assays","journal":"Experimental cell research","confidence":"Medium","confidence_rationale":"Tier 2-3 / Moderate — Co-IP and deubiquitination assay confirmed, NF-κB pathway downstream readout; single lab","pmids":["39971179"],"is_preprint":false},{"year":2026,"finding":"USP48 interacts with and stabilizes DBF4 by modulating its ubiquitination. USP48 knockdown reduces DBF4 protein levels and inhibits ccRCC cell proliferation, migration, invasion, and causes cell cycle arrest and apoptosis. DBF4 overexpression rescues USP48-deficiency phenotypes in ccRCC cells.","method":"Luciferase-tagged DBF4 USP screen (40 USPs), Co-IP (USP48–DBF4), ubiquitination assay, KD + rescue experiments, xenograft in vivo assay","journal":"Cancer cell international","confidence":"Medium","confidence_rationale":"Tier 2-3 / Moderate — substrate identified by functional screen, Co-IP and ubiquitination assay validated, rescue epistasis, in vivo xenograft; single lab","pmids":["42163235"],"is_preprint":false},{"year":2026,"finding":"USP48 associates with YBX1 and removes K48-linked polyubiquitin chains from it, preventing proteasomal degradation. YBX1 stabilization by USP48 drives transcriptional activation of PTK7 and Wnt/β-catenin signaling, forming a positive feedback loop (TCF7L2 directly upregulates USP48 transcription) that sustains stem-like osimertinib resistance in EGFR-mutant NSCLC.","method":"CRISPR-Cas9 dropout screening in patient-derived organoids, Co-IP (USP48–YBX1), K48-ubiquitination removal assay, TCF7L2 ChIP/promoter assay, USP48 inhibition with glycyrrhizic acid, orthotopic and PDX mouse models","journal":"Cancer letters","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — CRISPR screen, Co-IP, deubiquitination assay, promoter feedback loop, in vivo models; single lab","pmids":["42142703"],"is_preprint":false},{"year":2025,"finding":"USP48 directly interacts with and stabilizes HEG1 by removing K48-linked polyubiquitin chains, preventing its proteasomal degradation and sustaining AKT1 stabilization and AKT signaling in gastric cancer.","method":"Co-IP (USP48–HEG1), K48-ubiquitination assay, RNA-seq, pharmacogenomic data analysis, in vivo and in vitro proliferation/clonogenicity assays","journal":"European journal of medical research","confidence":"Low","confidence_rationale":"Tier 3 / Weak — Co-IP and ubiquitination assay reported; single lab, limited mechanistic depth in abstract","pmids":["41013721"],"is_preprint":false},{"year":2024,"finding":"USP48 deubiquitinates and stabilizes SLC1A5, protecting retinal pigment epithelial cells from high-glucose-induced apoptosis, inflammation, ferroptosis, and oxidative stress.","method":"Co-IP (USP48–SLC1A5), overexpression/knockdown stability assays, SLC1A5 rescue experiment, ferroptosis and oxidative stress biochemical assays","journal":"Journal of bioenergetics and biomembranes","confidence":"Low","confidence_rationale":"Tier 3 / Weak — Co-IP and overexpression/knockdown, single lab, limited mechanistic depth reported in abstract","pmids":["38427128"],"is_preprint":false}],"current_model":"USP48 is a nuclear-enriched deubiquitinating enzyme (ubiquitin-specific protease) that stabilizes a broad range of substrates—including histone H2A (at the BRCA1 ubiquitination site), NF-κB/RelA, SIRT6, TRAF2, Gli1, Aurora B, GSDME, NEK7, HMGA2, DBF4, YBX1, HEG1, CNN1, ARL3, UNC119a, MrgC, and SLC1A5—by removing K48-linked polyubiquitin chains to prevent proteasomal degradation; its catalytic activity and substrate selectivity are regulated by post-translational modifications (phosphorylation by CK2 or GSK3β, SUMOylation at K258), by an auxiliary (non-cleaved) ubiquitin that allosterically modulates activity, and by nuclear localization via a defined NLS signal, collectively placing USP48 at the intersection of DNA damage repair (antagonizing BRCA1–H2A ubiquitination and acting as a synthetic viable target in Fanconi anemia), NF-κB-driven inflammation and cell survival, Hedgehog/Gli1 signaling, cell cycle progression, and pyroptosis."},"narrative":{"mechanistic_narrative":"USP48 is a nuclear-enriched ubiquitin-specific protease that removes K48-linked polyubiquitin from a diverse set of substrates to prevent their proteasomal degradation, positioning it at the intersection of DNA damage repair, NF-κB signaling, cell cycle control, and pyroptosis [PMID:29335415, PMID:25486460, PMID:34059922]. Its catalytic ubiquitin-hydrolase activity is essential for function: disease-associated missense variants fail to cleave tetra-ubiquitin in vitro, and an auxiliary, non-cleaved ubiquitin allosterically modulates its activity [PMID:29335415, PMID:34059922]. In the DNA damage response USP48 acts as a histone H2A deubiquitinase that antagonizes BRCA1-mediated ubiquitination at the C-terminal site, thereby restraining end resection and homology-directed repair pathway choice; loss of USP48 is synthetic viable in Fanconi anemia-deficient cells by enhancing BRCA1-dependent damage clearance [PMID:29335415, PMID:29891926]. A second major axis is NF-κB: USP48 associates with the COP9 signalosome and trims K48 chains on nuclear RelA/p65 to stabilize it and tune induction and shutoff of NF-κB target genes, with activity gated by CK2-mediated phosphorylation [PMID:25486460, PMID:30628021, PMID:35913642]. USP48 stabilizes additional substrates including Gli1 in Hedgehog signaling, TRAF2 in the TNFα/JNK pathway, Aurora B during mitosis, GSDME and NEK7 in pyroptosis, and SIRT6, HMGA2, DBF4, and YBX1 in cancer contexts [PMID:28623188, PMID:28874458, PMID:33903120, PMID:36607699, PMID:34445214, PMID:38572092, PMID:40580743, PMID:42163235, PMID:42142703]. Its substrate selectivity is further regulated by GSK3β phosphorylation, SUMOylation at K258, and nuclear targeting via a defined nuclear localization signal [PMID:28874458, PMID:37781625, PMID:38572092]. USP48 is recurrently mutated (M415I/M415V) in USP8 wild-type corticotroph adenomas, where mutants enhance POMC promoter activity, and recessive variants disrupt inner ear neuronal development with hearing and vestibular dysfunction [PMID:34059922, PMID:30093687].","teleology":[{"year":2014,"claim":"Established USP48's first defined cellular substrate and an unusual catalytic mode—chain trimming rather than full disassembly—linking it to NF-κB signaling.","evidence":"siRNA screen, Co-IP with CSN and RelA, in vitro K48 chain-trimming assays, NF-κB reporters","pmids":["25486460"],"confidence":"High","gaps":["Did not resolve structural basis of chain trimming","CK2 phosphosite not mapped"]},{"year":2017,"claim":"Extended USP48 beyond NF-κB by showing it directly deubiquitinates and stabilizes Gli1 (Hedgehog) and TRAF2 (TNFα/JNK), revealing substrate breadth and pathway-specific targeting.","evidence":"Co-IP, DUB/ubiquitination assays, Gli reporter, pathway-specific rescue, GSK3β phosphorylation assay","pmids":["28623188","28874458"],"confidence":"High","gaps":["Mechanism of pathway-specific TRAF2 pool selection unresolved","Generality of feedback loops across tissues untested"]},{"year":2018,"claim":"Defined USP48 as the histone H2A deubiquitinase antagonizing BRCA1 and a synthetic viable target in Fanconi anemia, placing it in DNA repair pathway choice.","evidence":"In vitro DUB assays with auxiliary ubiquitin, cell-based BRCA1 ubiquitination, resection measurements, genome-wide screens across five FA backgrounds","pmids":["29335415","29891926"],"confidence":"High","gaps":["Recruitment mechanism to damage sites not defined","Auxiliary ubiquitin binding site structurally uncharacterized"]},{"year":2018,"claim":"Identified recurrent USP48 mutations in corticotroph adenomas driving POMC transcription, the first disease-associated coding variants.","evidence":"Tumor DNA sequencing, POMC promoter reporter with mutant constructs","pmids":["30093687"],"confidence":"Medium","gaps":["Mechanism connecting M415 mutation to POMC activation not dissected","DUB activity change of mutants not measured"]},{"year":2019,"claim":"Mapped the USP48–RelA interaction interface, localizing binding to the catalytic USP domain and the RHD N-terminus.","evidence":"Truncation Co-IP and nuclear co-localization","pmids":["30628021"],"confidence":"Medium","gaps":["Domain mapping by overexpression only","No structural model of the interface"]},{"year":2021,"claim":"Broadened the substrate set to SIRT6 and Aurora B with site-mapped K48 deubiquitination, connecting USP48 to metabolism and mitotic progression.","evidence":"Co-IP, deubiquitination site mutagenesis, glycolysis assays, KO cell cycle and cytokinesis readouts","pmids":["33903120","34445214"],"confidence":"Medium","gaps":["Single-lab findings without reciprocal independent validation","Regulation of substrate choice between contexts unknown"]},{"year":2021,"claim":"Confirmed catalytic ubiquitin-hydrolase requirement using disease mutants and tied USP48 to a Mendelian hearing/vestibular phenotype via an in vivo model.","evidence":"In vitro tetra-ubiquitin hydrolysis with mutants, structural modeling, human inner ear immunohistology, zebrafish knockdown","pmids":["34059922"],"confidence":"High","gaps":["Relevant inner ear substrate not identified","Human genetics causality limited to candidate variants"]},{"year":2022,"claim":"Revealed context-dependent NF-κB regulation and a non-canonical ciliary/basal body role, complicating the uniform stabilizer model.","evidence":"siRNA + fractionation + reporter in RPE cells; Co-IP and basal body localization with ARL3/UNC119a; CSN1–RelA–A20 axis in H. pylori infection","pmids":["36077078","36293380","35913642"],"confidence":"Medium","gaps":["RPE negative regulation lacks direct DUB assay (Low confidence)","Mechanism distinguishing stabilizing vs destabilizing RelA effects unknown"]},{"year":2023,"claim":"Linked USP48 to pyroptosis by stabilizing GSDME at mapped K48 sites, with tumor microenvironment and immunotherapy relevance.","evidence":"CRISPR screen, Co-IP, site-specific deubiquitination, pyroptosis assays, in vivo PD-1 blockade models","pmids":["36607699"],"confidence":"High","gaps":["Direct regulation of USP48 activity in tumor immune context unclear"]},{"year":2024,"claim":"Defined SUMOylation at K258 as a regulator of substrate affinity (HMGA2) and demonstrated pharmacological tractability.","evidence":"MS, Co-IP, SUMOylation site mapping, DUB-IN-2 inhibition, invasion/metastasis assays","pmids":["38572092"],"confidence":"Medium","gaps":["SUMO E3 ligase for K258 not identified","Selectivity of DUB-IN-2 not established"]},{"year":2025,"claim":"Expanded USP48 into chromatin–methylation crosstalk and DNMT1-inhibitor sensitization, plus multiple new disease-context substrates (NEK7, CNN1, MrgC, SLC1A5).","evidence":"CRISPR drug-modifier screens across >600 models, genomic localization to hypomethylated CpG islands, non-canonical histone DUB assays (preprints); Co-IP/DUB and in vivo models for NEK7, CNN1, MrgC, SLC1A5","pmids":["40580743","40513941","36864656","38427128"],"confidence":"Medium","gaps":["Chromatin/methylation link from preprints not peer-reviewed","Recruitment to hypomethylated CpG islands mechanistically undefined"]},{"year":2026,"claim":"Implicated USP48 in cancer survival circuits by stabilizing DBF4, YBX1, and TAK1, including transcriptional feedback loops sustaining drug resistance.","evidence":"Functional USP screens, organoid CRISPR dropout, Co-IP, ubiquitination assays, promoter/ChIP feedback loop, xenograft and PDX models","pmids":["42163235","42142703","39971179"],"confidence":"Medium","gaps":["Opposing NF-κB outcomes (TAK1 suppression vs RelA stabilization) not reconciled","Single-lab findings each"]},{"year":null,"claim":"How USP48 achieves substrate selectivity across such a broad target set, and what determines its context-dependent positive versus negative regulation of NF-κB, remain unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structural model of substrate engagement across targets","PTM code (CK2/GSK3β/SUMO) governing context-specific activity incompletely defined","Mechanism of recruitment to damage sites and hypomethylated chromatin unknown"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[0,2,3,4,5,6,12]},{"term_id":"GO:0016787","term_label":"hydrolase activity","supporting_discovery_ids":[0,12]}],"localization":[{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[2,8,14]},{"term_id":"GO:0005815","term_label":"microtubule organizing center","supporting_discovery_ids":[11]},{"term_id":"GO:0000228","term_label":"nuclear chromosome","supporting_discovery_ids":[0,19]}],"pathway":[{"term_id":"R-HSA-73894","term_label":"DNA Repair","supporting_discovery_ids":[0,1]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[2,3,4,9]},{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[2,6,18]},{"term_id":"R-HSA-5357801","term_label":"Programmed Cell Death","supporting_discovery_ids":[6,18]},{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[7]}],"complexes":["COP9 signalosome (CSN)"],"partners":["RELA","GLI1","TRAF2","SIRT6","GSDME","AURKB","HMGA2","NEK7"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q86UV5","full_name":"Ubiquitin carboxyl-terminal hydrolase 48","aliases":["Deubiquitinating enzyme 48","Ubiquitin thioesterase 48","Ubiquitin-specific peptidase 48","Ubiquitin-specific protease 48","Ubiquitin-specific-processing protease 48"],"length_aa":1035,"mass_kda":119.0,"function":"Deubiquitinase that recognizes and hydrolyzes the peptide bond at the C-terminal Gly of ubiquitin. Involved in the processing of polyubiquitin precursors as well as that of ubiquitinated proteins (PubMed:16214042, PubMed:34059922). Plays a role in the regulation of NF-kappa-B activation by TNF receptor superfamily via its interactions with RELA and TRAF2. May also play a regulatory role at postsynaptic sites. Plays an important role in cell cycle progression by deubiquitinating Aurora B/AURKB and thereby extending its stability (PubMed:34445214). In the context of H.pylori infection, stabilizes nuclear RELA through deubiquitination, thereby promoting the transcriptional activity of RELA to prolong TNFAIP3 de novo synthesis. Consequently, TNFAIP3 suppresses caspase activity and apoptotic cell death (PubMed:35913642). Also functions in the modulation of the ciliary and synaptic transport as well as cytoskeleton organization, which are key for photoreceptor function and homeostasis. To achieve this, stabilizes the levels of the retinal degeneration-associated proteins ARL3 and UNC119 using distinct mechanisms (PubMed:36293380). Plays a positive role in pyroptosis by stabilizing gasdermin E/GSDME through removal of its 'Lys-48'-linked ubiquitination (PubMed:36607699)","subcellular_location":"Cytoplasm; Nucleus; Cell projection, cilium","url":"https://www.uniprot.org/uniprotkb/Q86UV5/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/USP48","classification":"Not Classified","n_dependent_lines":11,"n_total_lines":1208,"dependency_fraction":0.009105960264900662},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/USP48","total_profiled":1310},"omim":[{"mim_id":"620227","title":"DEAFNESS, AUTOSOMAL DOMINANT 85; DFNA85","url":"https://www.omim.org/entry/620227"},{"mim_id":"619536","title":"UBIQUITIN-SPECIFIC PEPTIDASE 31; USP31","url":"https://www.omim.org/entry/619536"},{"mim_id":"617445","title":"UBIQUITIN-SPECIFIC PEPTIDASE 48; USP48","url":"https://www.omim.org/entry/617445"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Nucleoplasm","reliability":"Supported"},{"location":"Mitochondria","reliability":"Additional"},{"location":"Cytosol","reliability":"Additional"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/USP48"},"hgnc":{"alias_symbol":["FLJ23277","FLJ11328","FLJ20103","FLJ23054","MGC14879"],"prev_symbol":["USP31"]},"alphafold":{"accession":"Q86UV5","domains":[{"cath_id":"3.90.70.10","chopping":"79-125_139-203_430-459","consensus_level":"medium","plddt":90.7632,"start":79,"end":459},{"cath_id":"3.90.70.10","chopping":"205-385_404-421","consensus_level":"medium","plddt":92.0854,"start":205,"end":421},{"cath_id":"3.30.2230.10","chopping":"698-852","consensus_level":"high","plddt":87.0052,"start":698,"end":852},{"cath_id":"3.10.20.90","chopping":"945-1005","consensus_level":"medium","plddt":88.0397,"start":945,"end":1005}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q86UV5","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q86UV5-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q86UV5-F1-predicted_aligned_error_v6.png","plddt_mean":81.06},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=USP48","jax_strain_url":"https://www.jax.org/strain/search?query=USP48"},"sequence":{"accession":"Q86UV5","fasta_url":"https://rest.uniprot.org/uniprotkb/Q86UV5.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q86UV5/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q86UV5"}},"corpus_meta":[{"pmid":"33903120","id":"PMC_33903120","title":"USP48 Is Upregulated by Mettl14 to Attenuate Hepatocellular Carcinoma via Regulating SIRT6 Stabilization.","date":"2021","source":"Cancer research","url":"https://pubmed.ncbi.nlm.nih.gov/33903120","citation_count":124,"is_preprint":false},{"pmid":"30093687","id":"PMC_30093687","title":"Identification of recurrent USP48 and BRAF mutations in Cushing's disease.","date":"2018","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/30093687","citation_count":115,"is_preprint":false},{"pmid":"29335415","id":"PMC_29335415","title":"USP48 restrains resection by site-specific cleavage of the BRCA1 ubiquitin mark from H2A.","date":"2018","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/29335415","citation_count":87,"is_preprint":false},{"pmid":"28623188","id":"PMC_28623188","title":"Gli1-induced deubiquitinase USP48 aids glioblastoma tumorigenesis by stabilizing Gli1.","date":"2017","source":"EMBO 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stabilizes TRAF2 and reduces E-cadherin-mediated adherens junctions.","date":"2017","source":"FASEB journal : official publication of the Federation of American Societies for Experimental Biology","url":"https://pubmed.ncbi.nlm.nih.gov/28874458","citation_count":36,"is_preprint":false},{"pmid":"34664215","id":"PMC_34664215","title":"USP8, USP48, and BRAF mutations differ in their genotype-phenotype correlation in Asian Indian patients with Cushing's disease.","date":"2021","source":"Endocrine","url":"https://pubmed.ncbi.nlm.nih.gov/34664215","citation_count":22,"is_preprint":false},{"pmid":"35913642","id":"PMC_35913642","title":"USP48 and A20 synergistically promote cell survival in Helicobacter pylori infection.","date":"2022","source":"Cellular and molecular life sciences : CMLS","url":"https://pubmed.ncbi.nlm.nih.gov/35913642","citation_count":21,"is_preprint":false},{"pmid":"35413838","id":"PMC_35413838","title":"miR-489-3p promotes malignant progression of non-small cell lung cancer through the inactivation of Wnt/β-catenin signaling pathway via regulating USP48.","date":"2022","source":"Respiratory research","url":"https://pubmed.ncbi.nlm.nih.gov/35413838","citation_count":19,"is_preprint":false},{"pmid":"38572092","id":"PMC_38572092","title":"Blockade of the deubiquitinating enzyme USP48 degrades oncogenic HMGA2 and inhibits colorectal cancer invasion and metastasis.","date":"2024","source":"Acta pharmaceutica Sinica. B","url":"https://pubmed.ncbi.nlm.nih.gov/38572092","citation_count":16,"is_preprint":false},{"pmid":"34445214","id":"PMC_34445214","title":"USP48 Governs Cell Cycle Progression by Regulating the Protein Level of Aurora B.","date":"2021","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/34445214","citation_count":16,"is_preprint":false},{"pmid":"36077078","id":"PMC_36077078","title":"Ubiquitin Specific Protease USP48 Destabilizes NF-κB/p65 in Retinal Pigment Epithelium Cells.","date":"2022","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/36077078","citation_count":16,"is_preprint":false},{"pmid":"32359336","id":"PMC_32359336","title":"USP48 Sustains Chemoresistance and Metastasis in Ovarian Cancer.","date":"2020","source":"Current cancer drug targets","url":"https://pubmed.ncbi.nlm.nih.gov/32359336","citation_count":15,"is_preprint":false},{"pmid":"30628021","id":"PMC_30628021","title":"Catalytic domain of deubiquitinylase USP48 directs interaction with Rel homology domain of nuclear factor kappaB transcription factor RelA.","date":"2019","source":"Molecular biology reports","url":"https://pubmed.ncbi.nlm.nih.gov/30628021","citation_count":14,"is_preprint":false},{"pmid":"29901102","id":"PMC_29901102","title":"Deubiquitinase USP48 promotes ATRA-induced granulocytic differentiation of acute promyelocytic leukemia cells.","date":"2018","source":"International journal of oncology","url":"https://pubmed.ncbi.nlm.nih.gov/29901102","citation_count":13,"is_preprint":false},{"pmid":"36293380","id":"PMC_36293380","title":"The Deubiquitinating Enzyme USP48 Interacts with the Retinal Degeneration-Associated Proteins UNC119a and ARL3.","date":"2022","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/36293380","citation_count":8,"is_preprint":false},{"pmid":"38427128","id":"PMC_38427128","title":"USP48 deubiquitination stabilizes SLC1A5 to inhibit retinal pigment epithelium cell inflammation, oxidative stress and ferroptosis in the progression of diabetic retinopathy.","date":"2024","source":"Journal of bioenergetics and biomembranes","url":"https://pubmed.ncbi.nlm.nih.gov/38427128","citation_count":8,"is_preprint":false},{"pmid":"34059922","id":"PMC_34059922","title":"Variants in USP48 encoding ubiquitin hydrolase are associated with autosomal dominant non-syndromic hereditary hearing loss.","date":"2021","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/34059922","citation_count":8,"is_preprint":false},{"pmid":"38245760","id":"PMC_38245760","title":"Baicalin enhances proliferation and reduces inflammatory-oxidative stress effect in H2O2-induced granulosa cells apoptosis via USP48 protein regulation.","date":"2024","source":"BMC complementary medicine and therapies","url":"https://pubmed.ncbi.nlm.nih.gov/38245760","citation_count":6,"is_preprint":false},{"pmid":"38505871","id":"PMC_38505871","title":"miR-26b-5p Affects the Progression of Acute Myeloid Leukemia by Regulating the USP48-Mediated Wnt/β-Catenin Pathway.","date":"2024","source":"Critical reviews in eukaryotic gene expression","url":"https://pubmed.ncbi.nlm.nih.gov/38505871","citation_count":3,"is_preprint":false},{"pmid":"37781625","id":"PMC_37781625","title":"USP48/USP31 Is a Nuclear Deubiquitinase that Potently Regulates Synapse Remodeling.","date":"2023","source":"bioRxiv : the preprint server for biology","url":"https://pubmed.ncbi.nlm.nih.gov/37781625","citation_count":3,"is_preprint":false},{"pmid":"40513941","id":"PMC_40513941","title":"USP48 protects against myocardial ischemia-reperfusion injury by stabilizing and upregulating CNN1 in type 1 diabetes mice.","date":"2025","source":"Metabolism: clinical and experimental","url":"https://pubmed.ncbi.nlm.nih.gov/40513941","citation_count":2,"is_preprint":false},{"pmid":"40580743","id":"PMC_40580743","title":"USP48 promotes NLRP3-dependent pyroptosis of alveolar macrophages to exacerbate sepsis-induced acute lung injury.","date":"2025","source":"International immunopharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/40580743","citation_count":2,"is_preprint":false},{"pmid":"36864656","id":"PMC_36864656","title":"USP48 alleviates bone cancer pain and regulates MrgC stabilization in spinal cord neurons of male mice.","date":"2023","source":"European journal of pain (London, England)","url":"https://pubmed.ncbi.nlm.nih.gov/36864656","citation_count":2,"is_preprint":false},{"pmid":"39971179","id":"PMC_39971179","title":"USP48 inhibits colorectal cancer progression and promotes M1-like macrophage polarization by stabilizing TAK1.","date":"2025","source":"Experimental cell research","url":"https://pubmed.ncbi.nlm.nih.gov/39971179","citation_count":1,"is_preprint":false},{"pmid":"41047423","id":"PMC_41047423","title":"USP8, USP48, BRAF and TP53 mutations in crooke cell adenoma.","date":"2025","source":"Pituitary","url":"https://pubmed.ncbi.nlm.nih.gov/41047423","citation_count":1,"is_preprint":false},{"pmid":"42142703","id":"PMC_42142703","title":"USP48 stabilizes YBX1 to enforce a Wnt-driven stemness circuit and osimertinib resistance in EGFR-mutant NSCLC.","date":"2026","source":"Cancer letters","url":"https://pubmed.ncbi.nlm.nih.gov/42142703","citation_count":0,"is_preprint":false},{"pmid":"41013721","id":"PMC_41013721","title":"HEG1 promotes gastric cancer progression by stabilizing AKT1 and is functionally regulated by the deubiquitinase USP48.","date":"2025","source":"European journal of medical research","url":"https://pubmed.ncbi.nlm.nih.gov/41013721","citation_count":0,"is_preprint":false},{"pmid":"42163235","id":"PMC_42163235","title":"USP48 promotes tumour progression through the deubiquitination and stabilization of DBF4 in clear cell renal carcinoma.","date":"2026","source":"Cancer cell international","url":"https://pubmed.ncbi.nlm.nih.gov/42163235","citation_count":0,"is_preprint":false},{"pmid":"42045809","id":"PMC_42045809","title":"Prevalence of germline variants in USP8, USP48, CABLES1 and PAM in patients with pituitary adenomas.","date":"2026","source":"European journal of endocrinology","url":"https://pubmed.ncbi.nlm.nih.gov/42045809","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.07.28.666975","title":"Chromatin Perturbation Promotes Susceptibility to Hypomethylating Agents","date":"2025-07-31","source":"bioRxiv","url":"https://doi.org/10.1101/2025.07.28.666975","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.07.29.664810","title":"Discovery of chromatin-based determinants of azacytidine and decitabine anti-cancer activity","date":"2025-08-01","source":"bioRxiv","url":"https://doi.org/10.1101/2025.07.29.664810","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":19203,"output_tokens":7075,"usd":0.081867,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":16311,"output_tokens":4207,"usd":0.093365,"stage2_stop_reason":"end_turn"},"total_usd":0.175232,"stage1_batch_id":"msgbatch_01UT1AahFPCAyn2uVweS7A9z","stage2_batch_id":"msgbatch_01HuKWtKNT4Pqj1bc8eEP5RV","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2018,\n      \"finding\": \"USP48 is a histone H2A deubiquitinase specific for the C-terminal BRCA1 ubiquitination site. Biochemical analysis showed that an auxiliary ubiquitin (itself not cleaved) modulates USP48 activity. In cells, USP48 antagonizes BRCA1 E3 ligase function; loss of USP48 results in 53BP1 positioned further from the break site and extended resection lengths, and confers survival benefit to camptothecin-treated cells. USP48 activity restrains gene conversion and mutagenic single-strand annealing.\",\n      \"method\": \"Detailed biochemical analysis, in vitro DUB assays, cell-based BRCA1 ubiquitination assays, epistasis with BRCA1 loss-of-function, resection length measurements, colony survival assays\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1/2 / Strong — in vitro biochemical reconstitution with multiple substrates, auxiliary ubiquitin modulation defined, multiple orthogonal cell-based assays in one rigorous study\",\n      \"pmids\": [\"29335415\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"USP48 is identified as a synthetic viable interactor for FA-gene deficiencies (FANCA, FANCC, FANCG, FANCI, FANCD2). Loss of USP48 in FA-deficient cells reduces sensitivity to ICL agents, enhances BRCA1-dependent DNA damage clearance, and reduces chromosomal instability, placing USP48 in the DNA repair pathway downstream or parallel to the FA pathway.\",\n      \"method\": \"Genome-wide loss-of-function screens in haploid isogenic FA-defective human cells, ICL agent sensitivity assays, BRCA1-dependence epistasis, chromosomal instability measurements\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genome-wide screen validated across five FA-gene backgrounds, BRCA1 epistasis confirmed, multiple orthogonal readouts\",\n      \"pmids\": [\"29891926\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"USP48 associates with the COP9 signalosome (CSN) and nuclear RelA (NF-κB p65). USP48 trims (rather than fully disassembles) K48-linked free and substrate-anchored ubiquitin chains on RelA, a catalytic property shared only with ataxin-3 and OTU1. USP48 chain-trimming activity is regulated by CK2-mediated phosphorylation in response to cytokine stimulation. CSN and USP48 cooperatively stabilize the nuclear pool of RelA to facilitate timely induction and shutoff of NF-κB target genes.\",\n      \"method\": \"siRNA screen identification, Co-IP (USP48–CSN, USP48–RelA), in vitro ubiquitin chain trimming assays, phosphorylation assays with CK2, NF-κB reporter assays\",\n      \"journal\": \"Biochimica et biophysica acta\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Moderate — in vitro chain-trimming biochemistry plus Co-IP plus functional NF-κB reporter, single lab but multiple orthogonal methods\",\n      \"pmids\": [\"25486460\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"USP48 deubiquitinates and stabilizes Gli1 protein by directly cleaving its ubiquitin, activating Gli-dependent transcription. USP48 knockdown inhibits Gli1 target gene expression and glioblastoma cell proliferation and tumorigenesis. The Hedgehog pathway induces USP48 expression via Gli1-mediated transcription, forming a positive feedback loop.\",\n      \"method\": \"Co-IP (USP48–Gli1 interaction), DUB activity assay (ubiquitin cleavage from Gli1), Gli reporter assays, siRNA knockdown with proliferation and tumor growth readouts, Gli1 rescue experiments\",\n      \"journal\": \"EMBO reports\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Moderate — direct deubiquitination shown biochemically, Gli reporter functional assay, Gli1-dependence epistasis, single lab with multiple orthogonal methods\",\n      \"pmids\": [\"28623188\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"USP48 deubiquitinates and stabilizes TRAF2 in epithelial cells, specifically targeting the TRAF2 pool linked to the JNK pathway but not the NF-κB or p38 pathways. USP48 is serine-phosphorylated in response to TNF-α by GSK3β, increasing its DUB activity. Knockdown of USP48 reduces TRAF2 stability, attenuates TNF-α/JNK signaling, and increases E-cadherin expression and epithelial barrier integrity.\",\n      \"method\": \"Co-IP (USP48–TRAF2), K48-polyubiquitination assays, pathway-specific rescue experiments, GSK3β phosphorylation assay, USP48 knockdown with E-cadherin and barrier function readouts\",\n      \"journal\": \"FASEB journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal Co-IP, ubiquitination assays, GSK3β kinase assay, pathway-specific epistasis, single lab with multiple orthogonal methods\",\n      \"pmids\": [\"28874458\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"USP48 physically binds SIRT6 and stabilizes it by removing K48-linked ubiquitin chains specifically at K33 and K128 of SIRT6, preventing its proteasomal degradation and thereby impeding metabolic reprogramming (glycolysis) in hepatocellular carcinoma cells.\",\n      \"method\": \"Co-IP (USP48–SIRT6), K48-linked deubiquitination site-mapping (K33, K128 of SIRT6), glycolysis assays, cell-based ubiquitination assays\",\n      \"journal\": \"Cancer research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP confirmed, deubiquitination sites mapped by mutagenesis, functional metabolic readout; single lab\",\n      \"pmids\": [\"33903120\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"USP48 promotes pyroptosis in cancer cells by binding GSDME (gasdermin E) and removing K48-linked ubiquitination at K120 and K189 of GSDME, thereby stabilizing it. CRISPR-Cas9 screen identified USP48 loss as inhibiting pyroptosis; USP48 knockout suppressed T cell and tumor-associated macrophage function in the tumor microenvironment.\",\n      \"method\": \"CRISPR-Cas9 loss-of-function screen, Co-IP (USP48–GSDME), site-specific K48-deubiquitination assays (K120, K189), pyroptosis assays, in vivo mouse tumor models with PD-1 blockade\",\n      \"journal\": \"Cancer research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Moderate — genome-wide CRISPR screen validated, site-specific deubiquitination confirmed, multiple in vitro and in vivo readouts, single lab\",\n      \"pmids\": [\"36607699\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"USP48 interacts with and stabilizes Aurora B protein by deubiquitinating it, maintaining its steady-state levels during the cell cycle. USP48 knockout causes delayed cell cycle progression, mitotic defects, and cytokinesis failure.\",\n      \"method\": \"Deubiquitinase knockout strategy, Co-IP (USP48–Aurora B), protein half-life assays, cell cycle progression analysis, cytokinesis failure quantification\",\n      \"journal\": \"International journal of molecular sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 / Moderate — Co-IP confirmed, deubiquitinating activity linked to half-life, KO phenotype with specific cell cycle readout; single lab\",\n      \"pmids\": [\"34445214\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"The catalytic USP domain of USP48 mediates its physical interaction with the N-terminal region of the Rel homology domain (RHD) of nuclear RelA. This was mapped using overexpressed truncated proteins.\",\n      \"method\": \"Co-IP with truncated USP48 and RelA domain constructs, nuclear co-localization experiments\",\n      \"journal\": \"Molecular biology reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — domain mapping by truncation Co-IP, replicated the USP48–RelA interaction established in prior work; single lab, single method for new domain finding\",\n      \"pmids\": [\"30628021\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"In H. pylori infection, USP48 interacts with CSN subunit CSN1 and stabilizes nuclear RelA by deubiquitination, prolonging de novo synthesis of DUB A20. A20 then suppresses caspase-8 activity and apoptotic cell death, defining a synergistic USP48–A20 mechanism that promotes cell survival.\",\n      \"method\": \"Co-IP (USP48–CSN1, USP48–RelA), deubiquitination assays, A20 expression measurement, caspase-8 activity assay, apoptosis readout in H. pylori-infected cells\",\n      \"journal\": \"Cellular and molecular life sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 / Moderate — Co-IP interactions confirmed, functional pathway placement with multiple downstream readouts; single lab\",\n      \"pmids\": [\"35913642\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"USP48 downregulation stabilizes p65 (NF-κB) in the nuclear compartment of retinal pigment epithelium (RPE) cells, increasing NF-κB transcriptional activity — contrary to the stabilizing role described in other cell types. This delineates a negative regulatory role for USP48 on NF-κB in RPE cells.\",\n      \"method\": \"siRNA knockdown of USP48 in RPE cells, subcellular fractionation, NF-κB reporter assay, TNFα stimulation\",\n      \"journal\": \"International journal of molecular sciences\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, knockdown with reporter assay only, result appears contradictory to other studies suggesting context-dependent effect; no direct biochemical DUB assay reported in abstract\",\n      \"pmids\": [\"36077078\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"USP48 localizes to the basal body in retinal cells and interacts with the IRD-associated proteins ARL3 and UNC119a, stabilizing their protein levels. This suggests a role for USP48 in photoreceptor ciliary protein regulation and intracellular transport.\",\n      \"method\": \"Co-IP (USP48–ARL3, USP48–UNC119a), immunohistochemistry/subcellular localization in retinal cells, protein stability assays\",\n      \"journal\": \"International journal of molecular sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 / Moderate — Co-IP confirmed for both partners, localization to basal body shown; single lab, functional consequence inferred from stabilization data\",\n      \"pmids\": [\"36293380\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"USP48 has catalytic deubiquitinase (ubiquitin hydrolase) activity; disease-associated missense variants in USP48 are unable to hydrolyze tetra-ubiquitin in vitro, confirming the catalytic requirement for ubiquitin hydrolysis. USP48 is expressed in spiral ganglion neurons and other inner ear structures; zebrafish knocked down for usp48 show impaired statoacoustic neuron development and vestibular/hearing dysfunction.\",\n      \"method\": \"In vitro tetra-ubiquitin hydrolysis assay with mutant proteins, 3D structural modeling, immunohistology in human inner ear, zebrafish knockdown with acoustic startle response assay\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — direct enzymatic assay with disease mutants, structural modeling, in vivo model with functional hearing readout; multiple orthogonal methods\",\n      \"pmids\": [\"34059922\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"Recurrent somatic mutations in USP48 (predominantly M415I or M415V) occur in USP8 wild-type corticotroph adenomas. Similar to USP8 mutants, USP48 mutants enhance promoter activity and transcription of the POMC gene (the ACTH precursor), providing a mechanism for ACTH overproduction in these tumors.\",\n      \"method\": \"Sanger/targeted sequencing of tumor DNA, POMC promoter reporter assay in cells transfected with mutant USP48 constructs\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 / Moderate — recurrent mutation identified in large cohort, POMC promoter reporter functional validation; single lab, mechanism at transcriptional level not fully dissected\",\n      \"pmids\": [\"30093687\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"USP48 (formerly USP31) is a nuclear deubiquitinase whose nuclear localization is mediated by a conserved 13-amino acid nuclear localization signal. USP48 interacts with NF-κB transcription factor and deubiquitinates p65, promoting its stability and activation, which upregulates NF-κB target genes that inhibit synaptogenesis. USP48 expression induces filopodia elaboration, spine loss, reduced synaptic protein clustering in vitro, and erases ~70% of functional synapses in vivo; depleting NF-κB prevents USP48-dependent spine pruning.\",\n      \"method\": \"NLS mutagenesis (nuclear localization signal), Co-IP (USP48–p65), deubiquitination assay (p65), NF-κB reporter assay, live imaging of spine dynamics, electrophysiological synapse counting in vivo, NF-κB depletion epistasis\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP, deubiquitination assay, NLS mutagenesis, NF-κB epistasis, in vivo synapse counting; preprint, not yet peer-reviewed\",\n      \"pmids\": [\"37781625\"],\n      \"is_preprint\": true\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"USP48 deubiquitinates HMGA2, stabilizing it and promoting tumor invasion and metastasis. USP48 undergoes SUMOylation at lysine K258, which enhances its binding affinity for HMGA2. A small-molecule inhibitor DUB-IN-2 blocks USP48 activity and induces HMGA2 destabilization.\",\n      \"method\": \"Mass spectrometry identification, Co-IP (USP48–HMGA2), overexpression/knockdown protein stability assays, SUMOylation site mapping (K258), DUB-IN-2 pharmacological inhibition, tumor invasion/metastasis assays\",\n      \"journal\": \"Acta pharmaceutica sinica. B\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 / Moderate — MS identification, Co-IP, SUMOylation site identified, pharmacological inhibitor functional validation; single lab\",\n      \"pmids\": [\"38572092\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"USP48 interacts with MrgC (Mas-related G protein-coupled receptor C) in spinal cord neurons and reduces its K48-linked ubiquitination, stabilizing MrgC receptor levels. In a murine bone cancer pain model, spinal cord USP48 expression is reduced; AAV-mediated USP48 overexpression increased MrgC levels and alleviated pain behaviors.\",\n      \"method\": \"Co-IP (USP48–MrgC), overexpression/knockdown in N2a cells with receptor number quantification, ubiquitination assay, intrathecal AAV injection with pain behavior readout\",\n      \"journal\": \"European journal of pain\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 / Moderate — Co-IP confirmed, ubiquitination assay, in vivo AAV rescue; single lab\",\n      \"pmids\": [\"36864656\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"USP48 stabilizes calponin 1 (CNN1) via deubiquitination in cardiomyocytes. The USP48/CNN1 axis inhibits release of CXCL1 and CXCL2 through inactivation of the ERK1/2 pathway, conferring cardioprotection in diabetes-aggravated myocardial ischemia-reperfusion injury.\",\n      \"method\": \"Proteomics identification of CNN1, cardiac-specific KO and OE in mice, Co-IP (USP48–CNN1), ubiquitination assay, RNA-seq, ERK1/2 pathway readout, CXCL1/2 antibody blockade rescue\",\n      \"journal\": \"Metabolism: clinical and experimental\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — proteomics-identified substrate, Co-IP, in vivo cardiac-specific KO/OE, multi-step pathway validation; single lab\",\n      \"pmids\": [\"40513941\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"USP48 promotes NLRP3-dependent pyroptosis of alveolar macrophages in sepsis-induced acute lung injury by directly interacting with and deubiquitinating NEK7, stabilizing it and thereby activating the NEK7/NLRP3/caspase-1/GSDMD signaling axis.\",\n      \"method\": \"Co-IP (USP48–NEK7), NEK7 ubiquitination assay, USP48 knockdown in vivo and in vitro, NEK7 overexpression rescue experiment, NLRP3 inflammasome activation readout, murine sepsis model\",\n      \"journal\": \"International immunopharmacology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 / Moderate — Co-IP confirmed, deubiquitination assay, NEK7 rescue epistasis, in vivo model; single lab\",\n      \"pmids\": [\"40580743\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"USP48 is recruited to sites of DNA damage and deubiquitinates H2A variants and proteins important for DNA damage repair. Loss of USP48 increases chromatin accessibility upon HMA treatment, sensitizing AML cells to DNMT1 inhibition-induced cell death.\",\n      \"method\": \"CRISPR loss-of-function screens, chromatin accessibility assays (ATAC-seq implied), USP48 localization at DNA damage sites, H2A deubiquitination assay\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — CRISPR screen, functional DNA damage localization, H2A DUB activity; preprint, not yet peer-reviewed\",\n      \"pmids\": [],\n      \"is_preprint\": true\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"USP48 is recruited to newly hypomethylated CpG islands upon DNA demethylation and deubiquitinates non-canonical histones, establishing a molecular link between DNA methylation state and chromatin modification. Loss of USP48 (naturally occurring via biallelic deletions) sensitizes hematologic and solid tumors to DNMT1 inhibition in vitro and in vivo.\",\n      \"method\": \"CRISPR drug modifier screens across >600 cancer models, ChIP or genomic localization to hypomethylated CpG islands, non-canonical histone deubiquitination assay, in vitro and in vivo tumor sensitization experiments\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — large-scale CRISPR screen validated, substrate deubiquitination shown, in vivo confirmation; preprint, not yet peer-reviewed\",\n      \"pmids\": [],\n      \"is_preprint\": true\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"USP48 interacts with and stabilizes TAK1 through deubiquitination; this inhibits TAK1-triggered NF-κB activation and suppresses colorectal cancer tumorigenesis. USP48 expression also positively correlates with M1-type tumor-associated macrophage polarization.\",\n      \"method\": \"Co-IP (USP48–TAK1), deubiquitination assay, qRT-PCR for NF-κB targets, flow cytometry for macrophage polarization, cell proliferation/invasion/apoptosis assays\",\n      \"journal\": \"Experimental cell research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 / Moderate — Co-IP and deubiquitination assay confirmed, NF-κB pathway downstream readout; single lab\",\n      \"pmids\": [\"39971179\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"USP48 interacts with and stabilizes DBF4 by modulating its ubiquitination. USP48 knockdown reduces DBF4 protein levels and inhibits ccRCC cell proliferation, migration, invasion, and causes cell cycle arrest and apoptosis. DBF4 overexpression rescues USP48-deficiency phenotypes in ccRCC cells.\",\n      \"method\": \"Luciferase-tagged DBF4 USP screen (40 USPs), Co-IP (USP48–DBF4), ubiquitination assay, KD + rescue experiments, xenograft in vivo assay\",\n      \"journal\": \"Cancer cell international\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 / Moderate — substrate identified by functional screen, Co-IP and ubiquitination assay validated, rescue epistasis, in vivo xenograft; single lab\",\n      \"pmids\": [\"42163235\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"USP48 associates with YBX1 and removes K48-linked polyubiquitin chains from it, preventing proteasomal degradation. YBX1 stabilization by USP48 drives transcriptional activation of PTK7 and Wnt/β-catenin signaling, forming a positive feedback loop (TCF7L2 directly upregulates USP48 transcription) that sustains stem-like osimertinib resistance in EGFR-mutant NSCLC.\",\n      \"method\": \"CRISPR-Cas9 dropout screening in patient-derived organoids, Co-IP (USP48–YBX1), K48-ubiquitination removal assay, TCF7L2 ChIP/promoter assay, USP48 inhibition with glycyrrhizic acid, orthotopic and PDX mouse models\",\n      \"journal\": \"Cancer letters\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — CRISPR screen, Co-IP, deubiquitination assay, promoter feedback loop, in vivo models; single lab\",\n      \"pmids\": [\"42142703\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"USP48 directly interacts with and stabilizes HEG1 by removing K48-linked polyubiquitin chains, preventing its proteasomal degradation and sustaining AKT1 stabilization and AKT signaling in gastric cancer.\",\n      \"method\": \"Co-IP (USP48–HEG1), K48-ubiquitination assay, RNA-seq, pharmacogenomic data analysis, in vivo and in vitro proliferation/clonogenicity assays\",\n      \"journal\": \"European journal of medical research\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — Co-IP and ubiquitination assay reported; single lab, limited mechanistic depth in abstract\",\n      \"pmids\": [\"41013721\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"USP48 deubiquitinates and stabilizes SLC1A5, protecting retinal pigment epithelial cells from high-glucose-induced apoptosis, inflammation, ferroptosis, and oxidative stress.\",\n      \"method\": \"Co-IP (USP48–SLC1A5), overexpression/knockdown stability assays, SLC1A5 rescue experiment, ferroptosis and oxidative stress biochemical assays\",\n      \"journal\": \"Journal of bioenergetics and biomembranes\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — Co-IP and overexpression/knockdown, single lab, limited mechanistic depth reported in abstract\",\n      \"pmids\": [\"38427128\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"USP48 is a nuclear-enriched deubiquitinating enzyme (ubiquitin-specific protease) that stabilizes a broad range of substrates—including histone H2A (at the BRCA1 ubiquitination site), NF-κB/RelA, SIRT6, TRAF2, Gli1, Aurora B, GSDME, NEK7, HMGA2, DBF4, YBX1, HEG1, CNN1, ARL3, UNC119a, MrgC, and SLC1A5—by removing K48-linked polyubiquitin chains to prevent proteasomal degradation; its catalytic activity and substrate selectivity are regulated by post-translational modifications (phosphorylation by CK2 or GSK3β, SUMOylation at K258), by an auxiliary (non-cleaved) ubiquitin that allosterically modulates activity, and by nuclear localization via a defined NLS signal, collectively placing USP48 at the intersection of DNA damage repair (antagonizing BRCA1–H2A ubiquitination and acting as a synthetic viable target in Fanconi anemia), NF-κB-driven inflammation and cell survival, Hedgehog/Gli1 signaling, cell cycle progression, and pyroptosis.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"USP48 is a nuclear-enriched ubiquitin-specific protease that removes K48-linked polyubiquitin from a diverse set of substrates to prevent their proteasomal degradation, positioning it at the intersection of DNA damage repair, NF-\\u03baB signaling, cell cycle control, and pyroptosis [#0, #2, #12]. Its catalytic ubiquitin-hydrolase activity is essential for function: disease-associated missense variants fail to cleave tetra-ubiquitin in vitro, and an auxiliary, non-cleaved ubiquitin allosterically modulates its activity [#0, #12]. In the DNA damage response USP48 acts as a histone H2A deubiquitinase that antagonizes BRCA1-mediated ubiquitination at the C-terminal site, thereby restraining end resection and homology-directed repair pathway choice; loss of USP48 is synthetic viable in Fanconi anemia-deficient cells by enhancing BRCA1-dependent damage clearance [#0, #1]. A second major axis is NF-\\u03baB: USP48 associates with the COP9 signalosome and trims K48 chains on nuclear RelA/p65 to stabilize it and tune induction and shutoff of NF-\\u03baB target genes, with activity gated by CK2-mediated phosphorylation [#2, #8, #9]. USP48 stabilizes additional substrates including Gli1 in Hedgehog signaling, TRAF2 in the TNF\\u03b1/JNK pathway, Aurora B during mitosis, GSDME and NEK7 in pyroptosis, and SIRT6, HMGA2, DBF4, and YBX1 in cancer contexts [#3, #4, #5, #6, #7, #15, #18, #22, #23]. Its substrate selectivity is further regulated by GSK3\\u03b2 phosphorylation, SUMOylation at K258, and nuclear targeting via a defined nuclear localization signal [#4, #14, #15]. USP48 is recurrently mutated (M415I/M415V) in USP8 wild-type corticotroph adenomas, where mutants enhance POMC promoter activity, and recessive variants disrupt inner ear neuronal development with hearing and vestibular dysfunction [#12, #13].\",\n  \"teleology\": [\n    {\n      \"year\": 2014,\n      \"claim\": \"Established USP48's first defined cellular substrate and an unusual catalytic mode\\u2014chain trimming rather than full disassembly\\u2014linking it to NF-\\u03baB signaling.\",\n      \"evidence\": \"siRNA screen, Co-IP with CSN and RelA, in vitro K48 chain-trimming assays, NF-\\u03baB reporters\",\n      \"pmids\": [\"25486460\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not resolve structural basis of chain trimming\", \"CK2 phosphosite not mapped\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Extended USP48 beyond NF-\\u03baB by showing it directly deubiquitinates and stabilizes Gli1 (Hedgehog) and TRAF2 (TNF\\u03b1/JNK), revealing substrate breadth and pathway-specific targeting.\",\n      \"evidence\": \"Co-IP, DUB/ubiquitination assays, Gli reporter, pathway-specific rescue, GSK3\\u03b2 phosphorylation assay\",\n      \"pmids\": [\"28623188\", \"28874458\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism of pathway-specific TRAF2 pool selection unresolved\", \"Generality of feedback loops across tissues untested\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Defined USP48 as the histone H2A deubiquitinase antagonizing BRCA1 and a synthetic viable target in Fanconi anemia, placing it in DNA repair pathway choice.\",\n      \"evidence\": \"In vitro DUB assays with auxiliary ubiquitin, cell-based BRCA1 ubiquitination, resection measurements, genome-wide screens across five FA backgrounds\",\n      \"pmids\": [\"29335415\", \"29891926\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Recruitment mechanism to damage sites not defined\", \"Auxiliary ubiquitin binding site structurally uncharacterized\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Identified recurrent USP48 mutations in corticotroph adenomas driving POMC transcription, the first disease-associated coding variants.\",\n      \"evidence\": \"Tumor DNA sequencing, POMC promoter reporter with mutant constructs\",\n      \"pmids\": [\"30093687\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism connecting M415 mutation to POMC activation not dissected\", \"DUB activity change of mutants not measured\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Mapped the USP48\\u2013RelA interaction interface, localizing binding to the catalytic USP domain and the RHD N-terminus.\",\n      \"evidence\": \"Truncation Co-IP and nuclear co-localization\",\n      \"pmids\": [\"30628021\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Domain mapping by overexpression only\", \"No structural model of the interface\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Broadened the substrate set to SIRT6 and Aurora B with site-mapped K48 deubiquitination, connecting USP48 to metabolism and mitotic progression.\",\n      \"evidence\": \"Co-IP, deubiquitination site mutagenesis, glycolysis assays, KO cell cycle and cytokinesis readouts\",\n      \"pmids\": [\"33903120\", \"34445214\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single-lab findings without reciprocal independent validation\", \"Regulation of substrate choice between contexts unknown\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Confirmed catalytic ubiquitin-hydrolase requirement using disease mutants and tied USP48 to a Mendelian hearing/vestibular phenotype via an in vivo model.\",\n      \"evidence\": \"In vitro tetra-ubiquitin hydrolysis with mutants, structural modeling, human inner ear immunohistology, zebrafish knockdown\",\n      \"pmids\": [\"34059922\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Relevant inner ear substrate not identified\", \"Human genetics causality limited to candidate variants\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Revealed context-dependent NF-\\u03baB regulation and a non-canonical ciliary/basal body role, complicating the uniform stabilizer model.\",\n      \"evidence\": \"siRNA + fractionation + reporter in RPE cells; Co-IP and basal body localization with ARL3/UNC119a; CSN1\\u2013RelA\\u2013A20 axis in H. pylori infection\",\n      \"pmids\": [\"36077078\", \"36293380\", \"35913642\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"RPE negative regulation lacks direct DUB assay (Low confidence)\", \"Mechanism distinguishing stabilizing vs destabilizing RelA effects unknown\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Linked USP48 to pyroptosis by stabilizing GSDME at mapped K48 sites, with tumor microenvironment and immunotherapy relevance.\",\n      \"evidence\": \"CRISPR screen, Co-IP, site-specific deubiquitination, pyroptosis assays, in vivo PD-1 blockade models\",\n      \"pmids\": [\"36607699\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct regulation of USP48 activity in tumor immune context unclear\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Defined SUMOylation at K258 as a regulator of substrate affinity (HMGA2) and demonstrated pharmacological tractability.\",\n      \"evidence\": \"MS, Co-IP, SUMOylation site mapping, DUB-IN-2 inhibition, invasion/metastasis assays\",\n      \"pmids\": [\"38572092\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"SUMO E3 ligase for K258 not identified\", \"Selectivity of DUB-IN-2 not established\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Expanded USP48 into chromatin\\u2013methylation crosstalk and DNMT1-inhibitor sensitization, plus multiple new disease-context substrates (NEK7, CNN1, MrgC, SLC1A5).\",\n      \"evidence\": \"CRISPR drug-modifier screens across >600 models, genomic localization to hypomethylated CpG islands, non-canonical histone DUB assays (preprints); Co-IP/DUB and in vivo models for NEK7, CNN1, MrgC, SLC1A5\",\n      \"pmids\": [\"40580743\", \"40513941\", \"36864656\", \"38427128\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Chromatin/methylation link from preprints not peer-reviewed\", \"Recruitment to hypomethylated CpG islands mechanistically undefined\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Implicated USP48 in cancer survival circuits by stabilizing DBF4, YBX1, and TAK1, including transcriptional feedback loops sustaining drug resistance.\",\n      \"evidence\": \"Functional USP screens, organoid CRISPR dropout, Co-IP, ubiquitination assays, promoter/ChIP feedback loop, xenograft and PDX models\",\n      \"pmids\": [\"42163235\", \"42142703\", \"39971179\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Opposing NF-\\u03baB outcomes (TAK1 suppression vs RelA stabilization) not reconciled\", \"Single-lab findings each\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How USP48 achieves substrate selectivity across such a broad target set, and what determines its context-dependent positive versus negative regulation of NF-\\u03baB, remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No structural model of substrate engagement across targets\", \"PTM code (CK2/GSK3\\u03b2/SUMO) governing context-specific activity incompletely defined\", \"Mechanism of recruitment to damage sites and hypomethylated chromatin unknown\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [0, 2, 3, 4, 5, 6, 12]},\n      {\"term_id\": \"GO:0016787\", \"supporting_discovery_ids\": [0, 12]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [2, 8, 14]},\n      {\"term_id\": \"GO:0005815\", \"supporting_discovery_ids\": [11]},\n      {\"term_id\": \"GO:0000228\", \"supporting_discovery_ids\": [0, 19]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-73894\", \"supporting_discovery_ids\": [0, 1]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [2, 3, 4, 9]},\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [2, 6, 18]},\n      {\"term_id\": \"R-HSA-5357801\", \"supporting_discovery_ids\": [6, 18]},\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [7]}\n    ],\n    \"complexes\": [\"COP9 signalosome (CSN)\"],\n    \"partners\": [\"RELA\", \"GLI1\", \"TRAF2\", \"SIRT6\", \"GSDME\", \"AURKB\", \"HMGA2\", \"NEK7\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":7,"faith_total":7,"faith_pct":100.0}}