Affinage

JOSD2

Josephin-2 · UniProt Q8TAC2

Length
188 aa
Mass
20.8 kDa
Annotated
2026-04-28
17 papers in source corpus 16 papers cited in narrative 16 extracted findings

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

JOSD2 is a Josephin-domain deubiquitinase that cleaves polyubiquitin chains of multiple linkage types (K6, K27, K48, K63) from a broad range of substrate proteins, thereby controlling their stability or activity in metabolic, signaling, and inflammatory pathways. Its catalytic cysteine (C24) and histidine (H125) residues are essential for hydrolysis of ubiquitin chains; removal of K48-linked chains stabilizes substrates such as Aldolase A, PFK1, YAP/TAZ, SERCA2a, SMAD7, KRAS mutants, and β-catenin against proteasomal degradation, whereas removal of K63-linked chains from SIRT7 and AKT routes them to P62-mediated autophagic degradation (PMID:33082514, PMID:35024322, PMID:39195964, PMID:39833306, PMID:40240366, PMID:40217118, PMID:41412561). JOSD2 also modulates enzyme activity non-degradatively: it removes K6-linked ubiquitin from LKB1 to restrict its kinase function, K63-linked ubiquitin from CaMKIIδ to alter its phosphorylation, K63-linked ubiquitin from IMPDH2 to suppress its enzymatic activity and NF-κB signaling, and K27-linked ubiquitin from cGAS to inhibit cGAS-STING innate immune signaling (PMID:38177135, PMID:38195959, PMID:40177575, PMID:41351298). Through these diverse substrates, JOSD2 exerts context-dependent roles in glycolysis, cardiac calcium handling and hypertrophy, Wnt and TGF-β signaling, inflammation, renal fibrosis, and tumor immune evasion.

Mechanistic history

Synthesis pass · year-by-year structured walk · 8 steps
  1. 2020 High

    The initial enzymatic function of JOSD2 was established: it directly deubiquitinates glycolytic enzymes (Aldolase A, PFK1, PHGDH), stabilizing them and enhancing glycolysis—demonstrating that JOSD2 is an active deubiquitinase with metabolic substrates.

    Evidence In vitro deubiquitination assays, catalytically inactive mutant, glycolytic rate measurement, Co-IP in cancer cell lines

    PMID:33082514

    Open questions at the time
    • Ubiquitin linkage specificity on glycolytic substrates not determined
    • No structural basis for substrate recognition
    • Whether metabolic effects are relevant in non-cancer cells unknown
  2. 2021 High

    JOSD2's substrate repertoire was extended to signaling effectors: it deubiquitinates YAP and TAZ to prevent their proteasomal degradation, establishing JOSD2 as a stabilizer of Hippo pathway transcriptional co-activators.

    Evidence Deubiquitination assay with catalytic mutant, proteasome inhibitor rescue, cholangiocarcinoma cell proliferation assays

    PMID:35024322

    Open questions at the time
    • Ubiquitin linkage type on YAP/TAZ not specified
    • E3 ligase counterpart not identified
    • In vivo validation lacking
  3. 2022 Medium

    Beyond deubiquitination-mediated stabilization, JOSD2 was found to regulate PKM2 nuclear localization by reducing its acetylation, and to stabilize β-catenin by deubiquitination—expanding its mechanisms to include non-degradative regulation and Wnt signaling.

    Evidence Mass spectrometry, Co-IP, nuclear/cytoplasmic fractionation, acetylation assays for PKM2; Co-IP and ubiquitination assays for CTNNB1 in HCC cells

    PMID:35568970 PMID:35836282

    Open questions at the time
    • Mechanism by which JOSD2 affects PKM2 acetylation is indirect and unexplained
    • Ubiquitin linkage type on β-catenin not specified
    • Both findings from single laboratories
  4. 2023 High

    JOSD2 was shown to stabilize SERCA2a in cardiomyocytes and its deficiency causes impaired calcium handling and cardiac hypertrophy, establishing a non-cancer physiological role for JOSD2 in the heart with in vivo genetic evidence.

    Evidence Proteome-wide analysis, Co-IP, deubiquitination assay, Josd2 KO mice, AAV9-mediated cardiac overexpression, calcium imaging

    PMID:39195964

    Open questions at the time
    • Ubiquitin linkage type on SERCA2a not specified
    • Whether JOSD2 cardiac effects are solely SERCA2a-dependent or involve additional substrates not resolved
  5. 2024 High

    Ubiquitin linkage specificity of JOSD2 was resolved for multiple substrates: K6-linked chains on LKB1 (restricting its kinase activity), K63-linked chains on CaMKIIδ (altering phosphorylation and calcium handling), and K63-linked chains on IMPDH2 (suppressing enzymatic activity and NF-κB), revealing that JOSD2 cleaves distinct chain types to modulate enzyme activity rather than solely protein stability.

    Evidence Linkage-specific ubiquitination assays, kinase/enzyme activity assays, active-site and site-directed mutagenesis, in vivo KO mice (myeloid-specific for IMPDH2), pharmacological rescue (KN-93 for CaMKIIδ)

    PMID:38177135 PMID:38195959 PMID:40177575

    Open questions at the time
    • How JOSD2 achieves selectivity for different linkage types on different substrates is structurally unexplained
    • Whether K63-chain removal from CaMKIIδ promotes autophagy or only alters signaling not tested
    • No crystal structure of JOSD2-substrate complex available
  6. 2025 High

    A dual-outcome model was established: JOSD2 removal of K63-linked ubiquitin from SIRT7 and AKT promotes their P62-mediated autophagic degradation, while removal of K48-linked ubiquitin from SMAD7 and KRAS mutants blocks proteasomal degradation—demonstrating that chain-type specificity dictates whether JOSD2 stabilizes or destabilizes a substrate.

    Evidence Active-site mutagenesis (C24, H125), K63- and K48-linkage-specific assays, P62/autophagy pathway analysis, renal tubular- and VSMC-specific OE in mice, PDC/PDX/PDO for KRAS, site-directed mutagenesis (K220 on SMAD7)

    PMID:39833306 PMID:40217118 PMID:40240366 PMID:41412561

    Open questions at the time
    • Determinants of whether K63-deubiquitination leads to autophagic degradation versus non-degradative signaling change are unknown
    • Whether JOSD2 acts processively or distributively on chains not tested
    • Relative contribution of each substrate to in vivo phenotypes not deconvoluted
  7. 2025 High

    JOSD2 was shown to remove K27-linked ubiquitin from cGAS, suppressing cGAS-STING innate immune signaling and enabling tumor immune evasion, extending the linkage repertoire to K27 and connecting JOSD2 to innate immunity.

    Evidence K27-linkage-specific ubiquitination assay, cGAS enzymatic activity assay, JOSD2 catalytic inhibitor (HY041004), macrophage polarization assay, in vivo CRC model

    PMID:41351298

    Open questions at the time
    • Whether JOSD2 regulation of cGAS is relevant outside of tumor microenvironment not examined
    • Structural basis for K27-linkage recognition unknown
  8. 2025 Medium

    A covalent small-molecule inhibitor targeting the JOSD2 catalytic cysteine was developed, pharmacologically validating the active site and demonstrating that JOSD2 inhibition can downregulate KRAS protein in cancer cells.

    Evidence Cyanamide-warhead covalent binding assay, structure-activity relationship, KRAS protein measurement in CRC cells

    PMID:41092805

    Open questions at the time
    • Selectivity over other Josephin-domain DUBs not comprehensively profiled
    • In vivo pharmacokinetics and efficacy not reported
    • Whether inhibitor blocks all JOSD2 substrate deubiquitination equally not tested

Open questions

Synthesis pass · forward-looking unresolved questions
  • Key unresolved questions include how JOSD2 achieves specificity for different ubiquitin linkage types (K6, K27, K48, K63) and different substrates, what structural features govern whether deubiquitination leads to substrate stabilization versus autophagic degradation, and whether a unifying physiological role integrates JOSD2's diverse substrate repertoire.
  • No crystal or cryo-EM structure of JOSD2 alone or in complex with any substrate
  • No systematic substrate profiling (e.g., ubiquitin-SILAC) performed
  • Relative physiological importance of individual substrates in vivo not ranked

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0016787 hydrolase activity 12 GO:0140096 catalytic activity, acting on a protein 12
Localization
GO:0005829 cytosol 2 GO:0005634 nucleus 1
Pathway
R-HSA-392499 Metabolism of proteins 12 R-HSA-162582 Signal Transduction 6 R-HSA-1430728 Metabolism 2 R-HSA-168256 Immune System 2 R-HSA-9612973 Autophagy 2
Partners
ALDOACGASIMPDH2KRASLKB1PFKLSERCA2ASMAD7

Evidence

Reading pass · 16 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2020 JOSD2 directly deubiquitinates and stabilizes a glycolytic enzyme complex including Aldolase A, Phosphofructokinase-1, and Phosphoglycerate dehydrogenase, enhancing their activities and the glycolytic rate; a catalytically inactive JOSD2 mutant fails to do so, demonstrating the requirement for deubiquitinase activity. In vitro and in vivo deubiquitination assays, catalytically inactive mutant analysis, glycolytic rate measurement, Co-IP Cell death and differentiation High 33082514
2021 JOSD2 deubiquitinates YAP and TAZ, cleaving their polyubiquitin chains in a deubiquitinase activity-dependent manner to prevent proteasomal degradation, thereby sustaining YAP/TAZ protein levels in cholangiocarcinoma cells. Deubiquitination assay, proteasome inhibitor rescue, JOSD2 knockdown with YAP/TAZ protein level measurement, in vitro and in vivo proliferation assays Acta pharmaceutica Sinica. B High 35024322
2022 JOSD2 interacts with PKM2 and inhibits its nuclear localization by reducing K433 acetylation of PKM2, without affecting PKM2 protein stability. Mass spectrometry, co-immunoprecipitation, co-immunofluorescence, nuclear/cytoplasmic fractionation, acetylation assays Experimental hematology & oncology Medium 35836282
2022 JOSD2 binds to and deubiquitinates CTNNB1 (β-catenin), reducing its ubiquitination level and preventing its degradation, thereby augmenting Wnt signaling in hepatocellular carcinoma cells. Co-immunoprecipitation, ubiquitination assay, rescue experiments with CTNNB1 manipulation Cell biology international Medium 35568970
2023 JOSD2 deubiquitinates and stabilizes SERCA2a (sarco/endoplasmic reticulum calcium ATPase 2a) in cardiomyocytes; JOSD2 deficiency impairs calcium handling and promotes cardiac hypertrophy, while cardiac-specific JOSD2 overexpression via AAV9 prevents angiotensin II-induced hypertrophy. Proteome-wide quantitative analysis, Co-IP, deubiquitination assay, Josd2 knockout mice, AAV9-mediated overexpression, calcium imaging Nature cardiovascular research High 39195964
2024 JOSD2 restricts the kinase activity of LKB1 by removing K6-linked polyubiquitination from LKB1, an action vital for maintaining the integrity of the LKB1-STRAD-MO25 complex in NSCLC. Co-IP, ubiquitination linkage-specific assay (K6-linked), LKB1 kinase activity assay, JOSD2 knockdown and pharmacological inhibition in cell/PDX models Signal transduction and targeted therapy High 38177135
2024 JOSD2 interacts with CaMKIIδ and directly hydrolyzes K63-linked polyubiquitin chains on CaMKIIδ, increasing its phosphorylation and thereby causing calcium mishandling, hypertrophy, and fibrosis in cardiomyocytes; these effects are reversible by the CaMKIIδ inhibitor KN-93. Mass spectrometry, Co-IP, K63-specific deubiquitination assay, CaMKIIδ phosphorylation measurement, JOSD2 KO and OE in vivo, KN-93 rescue Cellular and molecular life sciences : CMLS High 38195959
2024 JOSD2 deubiquitinates IMPDH2 by preferentially cleaving K63-linked polyubiquitin chains at the K134 site of IMPDH2, suppressing IMPDH2 activity and preventing NF-κB activation and inflammation in macrophages. Co-IP, K63-linkage-specific ubiquitination assay, site-directed mutagenesis (K134), IMPDH2 activity assay, NF-κB reporter assay, myeloid-specific JOSD2 KO mice, bone marrow transplantation Acta pharmaceutica Sinica. B High 40177575
2023 JOSD2 promotes DNA damage repair in NSCLC cells; DNA damaging agents increase nuclear localization of JOSD2, and JOSD2 depletion sensitizes NSCLC cells to DNA damaging agents. Immunofluorescence (nuclear localization), Western blotting (DDR pathway proteins), SRB cytotoxicity assay upon JOSD2 knockdown with DNA damaging drugs Journal of Zhejiang University. Medical sciences Low 37899394
2025 JOSD2 directly interacts with and stabilizes KRAS mutant proteins by reverting their proteolytic ubiquitination; reciprocally, KRAS mutants inhibit the catalytic activity of CHIP (an E3 ubiquitin ligase for JOSD2), forming a positive feedback circuit that accelerates KRAS-mutant CRC growth. DUB siRNA library screen, Co-IP, ubiquitination assay, CHIP E3 ligase activity assay, JOSD2 KD and pharmacological inhibition in PDC/PDX/PDO models Nature communications High 40240366
2025 JOSD2 specifically binds to the MH1 domain of SMAD7 and removes K48-linked ubiquitin chains from SMAD7 at lysine 220, sustaining SMAD7 stability and thereby inhibiting TGFβ-SMAD signaling in vascular smooth muscle cells. LC-MS/MS, Co-IP, K48-linkage-specific ubiquitination assay, site-directed mutagenesis (K220), SMAD7 stability assay, RNA-seq, VSMC-specific JOSD2 OE in mice Acta pharmacologica Sinica High 39833306
2025 JOSD2 removes K63-linked ubiquitination from SIRT7 via its active site C24, promoting P62-mediated autophagic degradation of SIRT7, which prevents P65 phosphorylation and nuclear translocation, thereby reducing inflammatory responses in renal tubular epithelial cells during acute kidney injury. Mass spectrometry, Co-IP, K63-linkage-specific ubiquitination assay, active-site mutagenesis (C24), P62/autophagy pathway analysis, renal tubular-specific JOSD2 OE in mice, cisplatin and IRI AKI models Acta pharmacologica Sinica High 40217118
2025 JOSD2 interacts with and stabilizes SMAD4 by removing polyubiquitin chains, thereby activating TGF-β signaling and promoting breast cancer metastasis. Co-IP, ubiquitination assay, JOSD2 RNAi, in vitro migration/invasion assays, in vivo metastasis model Biochemical pharmacology Medium 39793716
2025 JOSD2 suppresses cGAS enzymatic activity by removing K27-linked ubiquitination from cGAS, thereby inhibiting cGAS-STING signaling and promoting M2 macrophage polarization and immune evasion in colorectal cancer. Co-IP, K27-linkage-specific ubiquitination assay, cGAS enzymatic activity assay, JOSD2 catalytic inhibitor (HY041004), macrophage polarization assay, in vivo CRC model Oncoimmunology High 41351298
2025 JOSD2 deubiquitinates the K63-linked ubiquitin chain of AKT via its active site H125 and enhances P62-mediated autophagic degradation of AKT in renal tubular epithelial cells, reducing AKT levels and thereby reducing renal EMT and fibrosis. Mass spectrometry, Co-IP, K63-linkage-specific ubiquitination assay, active-site mutagenesis (H125), autophagy assay, JOSD2 KO mice, single-cell RNA-seq, TEC-specific JOSD2 OE Cellular signalling High 41412561
2025 A small-molecule covalent inhibitor of JOSD2 (compound 31) was designed with a cyanamide warhead that selectively engages the catalytic cysteine residue of JOSD2, confirming the catalytic cysteine as the active site and demonstrating that JOSD2 inhibition induces downregulation of KRAS protein in CRC cells. Covalent binding assay, structure-activity relationship, KRAS protein level measurement after inhibitor treatment Bioorganic chemistry Medium 41092805

Source papers

Stage 0 corpus · 17 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2021 Deubiquitinase JOSD2 stabilizes YAP/TAZ to promote cholangiocarcinoma progression. Acta pharmaceutica Sinica. B 38 35024322
2020 The deubiquitinase JOSD2 is a positive regulator of glucose metabolism. Cell death and differentiation 35 33082514
2023 Deubiquitinase JOSD2 improves calcium handling and attenuates cardiac hypertrophy and dysfunction by stabilizing SERCA2a in cardiomyocytes. Nature cardiovascular research 22 39195964
2022 JOSD2 regulates PKM2 nuclear translocation and reduces acute myeloid leukemia progression. Experimental hematology & oncology 19 35836282
2024 Josephin domain containing 2 (JOSD2) promotes lung cancer by inhibiting LKB1 (Liver kinase B1) activity. Signal transduction and targeted therapy 17 38177135
2022 Deubiquitinating enzyme JOSD2 promotes hepatocellular carcinoma progression through interacting with and inhibiting CTNNB1 degradation. Cell biology international 12 35568970
2024 JOSD2 mediates isoprenaline-induced heart failure by deubiquitinating CaMKIIδ in cardiomyocytes. Cellular and molecular life sciences : CMLS 10 38195959
2025 Josephin Domain Containing 2 (JOSD2) inhibition as Pan-KRAS-mutation-targeting strategy for colorectal cancer. Nature communications 6 40240366
2024 Role of deubiquitinase JOSD2 in the pathogenesis of esophageal squamous cell carcinoma. World journal of gastroenterology 4 38463028
2024 Deubiquitinase JOSD2 alleviates colitis by inhibiting inflammation via deubiquitination of IMPDH2 in macrophages. Acta pharmaceutica Sinica. B 4 40177575
2025 JOSD2 alleviates acute kidney injury through deubiquitinating SIRT7 and negativity regulating SIRT7-NF-κB inflammatory pathway in renal tubular epithelial cells. Acta pharmacologica Sinica 3 40217118
2025 JOSD2 inhibits angiotensin II-induced vascular remodeling by deubiquitinating and stabilizing SMAD7. Acta pharmacologica Sinica 2 39833306
2023 Deubiquitinating enzyme JOSD2 affects susceptibility of non-small cell lung carcinoma cells to anti-cancer drugs through DNA damage repair. Zhejiang da xue xue bao. Yi xue ban = Journal of Zhejiang University. Medical sciences 2 37899394
2025 JOSD2 promotes breast cancer metastasis by deubiquitinating and stabilizing SMAD4. Biochemical pharmacology 1 39793716
2025 Deubiquitinating enzyme JOSD2 modulates cGAS to facilitate immune evasion in colorectal cancer. Oncoimmunology 1 41351298
2025 Rational DESIGN and Structure-activity relationship study of novel JOSD2 inhibitor against colorectal cancer. Bioorganic chemistry 0 41092805
2025 JOSD2 alleviates hypertensive renal disease through deubiquitinating AKT in renal tubular epithelial cells. Cellular signalling 0 41412561