GO:1903094 negative regulation of protein K48-linked deubiquitination: Mechanism, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:1903094 describes any process that stops, prevents or reduces the removal of K48-linked polyubiquitin chains from target proteins.
• K48-linked deubiquitination is catalyzed by deubiquitinating enzymes (DUBs) such as USP29, USP15, OTUD5, USP8, USP33, PSMD14 and USP43, which stabilize substrates by reversing K48-linked ubiquitination.
• Negative regulation of this process can occur through inhibition of DUB activity, degradation of the DUB, or sequestration of the DUB from its substrate, thereby promoting substrate degradation or altering signaling.
• The term is critical in cancer biology, where DUBs that remove K48 chains stabilize oncoproteins or tumor suppressors, influencing immunotherapy response, ferroptosis, autophagy and drug sensitivity.
• Dysregulation of K48-linked deubiquitination is implicated in metabolic dysfunction-associated steatotic liver disease (MASLD), antiviral innate immunity and melanoma progression.
• Experimental dissection of GO:1903094 requires combining CRISPR knockout/knock-in models with ubiquitination assays, proteomics and functional readouts.
Description
Protein ubiquitination is a reversible post-translational modification that controls protein stability, localization and interactions. K48-linked polyubiquitin chains typically target proteins for proteasomal degradation, and their removal by deubiquitinating enzymes (DUBs) is a key regulatory step. The Gene Ontology term GO:1903094, negative regulation of protein K48-linked deubiquitination, captures any process that reduces the frequency, rate or extent of K48-linked deubiquitination, thereby indirectly promoting K48-linked ubiquitination and its downstream consequences. This term is essential for understanding how cells fine-tune protein turnover in response to stress, immune signals and oncogenic cues. DUBs such as USP29, USP15, OTUD5, USP8, USP33, PSMD14 and USP43 remove K48-linked chains from specific substrates, and their negative regulation can occur at multiple levels, including inhibition of catalytic activity, altered complex formation or changes in DUB abundance. For example, USP29 stabilizes ACSL5 via K48 deubiquitination to alleviate MASLD progression, while USP15-mediated K48 deubiquitination of VGLL4 enhances tumor immunotherapy efficacy in triple-negative breast cancer. Conversely, processes that block these DUB activities fall under GO:1903094 and can shift the balance toward substrate degradation. Understanding GO:1903094 is therefore central to cancer research, immunology and metabolism, as it directly impacts the stability of key regulatory proteins and the efficacy of therapeutic interventions. Researchers studying this term need robust experimental models to manipulate DUB activity and measure K48-linked ubiquitination in a physiological context.
negative regulation of protein K48-linked deubiquitination At A Glance
| GO ID | GO:1903094 |
|---|---|
| GO term | negative regulation of protein K48-linked deubiquitination |
| Ontology | biological_process |
| Synonym | down regulation of protein K48-linked deubiquitination; down-regulation of protein K48-linked deubiquitination; downregulation of protein K48-linked deubiquitination; inhibition of protein K48-linked deubiquitination |
| Major function | Reduces the removal of K48-linked ubiquitin chains from target proteins, thereby promoting K48-linked ubiquitination and its downstream effects such as proteasomal degradation or signaling modulation. |
| Related DUBs | USP29, USP15, OTUD5, USP8, USP33, PSMD14, USP43 |
| Associated diseases | Triple-negative breast cancer, MASLD, melanoma, antiviral innate immunity disorders |
| Research methods | CRISPR knockout/knock-in, ubiquitination assays, proteomics, RNA-seq, functional assays |
What Is GO:1903094?
GO:1903094, negative regulation of protein K48-linked deubiquitination, is a biological process that stops, prevents or reduces the frequency, rate or extent of the removal of K48-linked polyubiquitin chains from a target protein. In practice, this means any cellular mechanism that inhibits a DUB from cleaving K48 linkages, leading to sustained or enhanced K48-linked ubiquitination and often increased proteasomal degradation of the substrate.
Why Is negative regulation of protein K48-linked deubiquitination Important in Cell Biology?
GO:1903094 is important because it governs the stability of numerous regulatory proteins by controlling the reverse reaction of K48-linked ubiquitination. DUBs that remove K48 chains can stabilize oncoproteins or tumor suppressors, and their negative regulation can either promote or suppress disease depending on context. For instance, USP15-mediated K48 deubiquitination of VGLL4 enhances immunotherapy efficacy in triple-negative breast cancer, while OTUD5 stabilizes SLC7A11 to reduce paclitaxel sensitivity. In metabolic disease, USP29 stabilizes ACSL5 through K48 deubiquitination to alleviate MASLD progression. In antiviral immunity, the USP43/RNF2 axis negatively regulates TBK1 by promoting its ubiquitination and degradation, highlighting how blocking K48 deubiquitination can modulate immune responses. Thus, understanding this process offers therapeutic opportunities across oncology, immunology and metabolism.
• Controls protein stability by regulating the removal of K48-linked ubiquitin chains, which are canonical degradation signals.
• Modulates cancer progression and immunotherapy response, as seen with USP15 in triple-negative breast cancer.
• Influences metabolic diseases such as MASLD through USP29-mediated stabilization of ACSL5.
• Regulates ferroptosis and autophagy in cancer cells, as shown for USP33 and TAP63 in TNBC.
• Impacts antiviral innate immunity via the USP43/RNF2 axis and TBK1 degradation.
• Affects drug sensitivity, including paclitaxel response through OTUD5-mediated SLC7A11 stabilization.
• Plays a role in melanoma progression through the PSMD14-SP1-GYS1 axis.
• Provides a mechanism for feedback regulation, such as the USP8-Hippo/YAP positive feedback loop in TNBC.
• Offers targets for therapeutic intervention by modulating DUB activity or abundance.
• Requires integrated experimental approaches to dissect DUB-substrate relationships and their regulation.
What Happens During negative regulation of protein K48-linked deubiquitination?
Recognition of K48-linked ubiquitinated substrates by DUBs
In simple terms: DUBs find and bind proteins carrying K48-linked ubiquitin chains.
Deubiquitinating enzymes (DUBs) such as USP29, USP15, OTUD5, USP8, USP33, PSMD14 and USP43 recognize specific substrates bearing K48-linked polyubiquitin chains. This recognition often involves interactions between the DUB and structural features of the substrate or its ubiquitin chains. For example, USP29 binds and stabilizes ACSL5 by removing K48-linked chains, while USP15 deubiquitinates VGLL4 in a K48-linked manner. The specificity of these interactions determines which proteins are protected from degradation.
Catalytic removal of K48-linked ubiquitin chains
In simple terms: The DUB cuts the ubiquitin chain off the target protein.
Once bound, DUBs catalyze the hydrolysis of the isopeptide bond between the C-terminal glycine of ubiquitin and lysine residues on the substrate or on the proximal ubiquitin, thereby disassembling K48-linked chains. This activity can rescue substrates from proteasomal degradation, as shown for SLC7A11 stabilization by OTUD5 and for VGLL4 by USP15. The catalytic efficiency and processivity of DUBs influence the extent of deubiquitination and downstream signaling.
Negative regulation of DUB activity or availability
In simple terms: Something blocks the DUB from doing its job.
Negative regulation of K48-linked deubiquitination can occur through multiple mechanisms, including inhibition of DUB catalytic activity, degradation of the DUB itself, or sequestration of the DUB away from its substrate. For instance, the USP43/RNF2 axis promotes TBK1 ubiquitination and degradation, effectively reducing K48 deubiquitination of TBK1. Additionally, polyubiquitin architecture editing on collided ribosomes can maintain persistent ribosome quality control activity, indirectly affecting deubiquitination processes. These regulatory layers ensure that K48-linked deubiquitination is tightly controlled in response to cellular cues.
Downstream consequences for substrate fate
In simple terms: Blocking deubiquitination changes what happens to the target protein.
When K48-linked deubiquitination is negatively regulated, substrates remain ubiquitinated and are often targeted for proteasomal degradation or redirected to other pathways. This can alter signaling cascades, such as the Hippo/YAP axis in triple-negative breast cancer where USP8 and YAP form a positive feedback loop, or affect ferroptosis and autophagy through USP33 and TAP63. In melanoma, the PSMD14-SP1-GYS1 axis reveals how deubiquitination-related processes influence metabolic vulnerabilities. Thus, negative regulation of K48-linked deubiquitination has broad impacts on cell fate and disease progression.
Key Genes Involved in GO:1903094 negative regulation of protein K48-linked deubiquitination
The following genes and proteins are experimentally implicated in K48-linked deubiquitination or its negative regulation, based on the verified literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| USP29 | Deubiquitinates ACSL5 via K48 linkages, stabilizing it | Alleviates MASLD progression; potential metabolic target |
| USP15 | K48-linked deubiquitination of VGLL4 | Enhances tumor immunotherapy efficacy in triple-negative breast cancer |
| OTUD5 | Stabilizes SLC7A11 by K48 deubiquitination | Promotes progression and reduces paclitaxel sensitivity in TNBC |
| USP8 | Positive feedback with Hippo/YAP axis | Drives triple-negative breast cancer progression |
| USP33 | Synergizes with TAP63 to activate autophagy and ferroptosis | Inhibits TNBC through autophagy and ferroptosis |
| PSMD14 | Part of PSMD14-SP1-GYS1 axis | Reveals therapeutic vulnerabilities in melanoma |
| USP43 | Negatively regulates antiviral innate immunity via TBK1 ubiquitination | Promotes TBK1 degradation through RNF2 axis |
| RNF2 | E3 ligase promoting TBK1 ubiquitination | Part of USP43/RNF2 axis in antiviral immunity |
| TBK1 | Substrate of USP43/RNF2 axis | Degraded upon ubiquitination, affecting innate immunity |
| ACSL5 | Substrate of USP29 | Stabilized by K48 deubiquitination, alleviates MASLD |
| VGLL4 | Substrate of USP15 | K48 deubiquitination enhances immunotherapy in TNBC |
| SLC7A11 | Substrate of OTUD5 | Stabilized by K48 deubiquitination, reduces paclitaxel sensitivity |
| YAP | Component of Hippo/YAP axis | Feedback loop with USP8 in TNBC |
| TAP63 | Synergizes with USP33 | Activates autophagy and ferroptosis in TNBC |
| SP1 | Transcription factor in PSMD14-SP1-GYS1 axis | Influences melanoma metabolism |
| GYS1 | Glycogen synthase in PSMD14-SP1-GYS1 axis | Metabolic vulnerability in melanoma |
How Is negative regulation of protein K48-linked deubiquitination Regulated?
The process of negative regulation of protein K48-linked deubiquitination is itself regulated at multiple levels. DUB abundance can be controlled by transcription, translation or degradation, as seen with USP8 and YAP forming a positive feedback loop in triple-negative breast cancer. Post-translational modifications of DUBs, such as ubiquitination or phosphorylation, can alter their activity or localization. Additionally, the availability of substrates and the presence of competing interactors influence the efficiency of K48-linked deubiquitination. In antiviral immunity, the USP43/RNF2 axis exemplifies how E3 ligases and DUBs can antagonize each other to regulate TBK1 stability. These regulatory mechanisms ensure that K48-linked deubiquitination is dynamically tuned to cellular conditions.
negative regulation of protein K48-linked deubiquitination and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| USP29 | MASLD | Knockout or overexpression in hepatocytes; MASLD mouse models |
| USP15 | Triple-negative breast cancer | Knockout or overexpression in TNBC cell lines; xenograft models |
| OTUD5 | Triple-negative breast cancer | Knockout or overexpression in TNBC cell lines; paclitaxel sensitivity assays |
| USP8 | Triple-negative breast cancer | Knockout or overexpression in TNBC cell lines; Hippo/YAP reporter assays |
| USP43 | Antiviral innate immunity | Knockout or overexpression in immune cells; viral infection models |
Triple-negative breast cancer (TNBC)
Multiple DUBs are implicated in TNBC through K48-linked deubiquitination. USP15-mediated K48 deubiquitination of VGLL4 enhances tumor immunotherapy efficacy, while OTUD5 stabilizes SLC7A11 to promote progression and reduce paclitaxel sensitivity. USP8 forms a positive feedback loop with the Hippo/YAP axis to drive TNBC progression, and USP33 synergizes with TAP63 to activate autophagy and ferroptosis, inhibiting TNBC. These findings highlight the diverse roles of K48-linked deubiquitination and its negative regulation in TNBC biology.
Metabolic dysfunction-associated steatotic liver disease (MASLD)
USP29 alleviates MASLD progression by stabilizing ACSL5 through K48 deubiquitination. This suggests that enhancing K48-linked deubiquitination of specific substrates can be protective in metabolic liver disease, and negative regulation of this process could exacerbate lipid accumulation. Targeting the USP29-ACSL5 axis may offer therapeutic strategies for MASLD.
Melanoma
A metabolism-driven prognostic model and the PSMD14-SP1-GYS1 axis reveal therapeutic vulnerabilities in melanoma. PSMD14, a component of the 19S proteasome, is involved in deubiquitination, and its interplay with SP1 and GYS1 affects melanoma metabolism. This underscores the importance of K48-linked deubiquitination and its regulation in melanoma progression and potential treatment.
Antiviral innate immunity
The USP43/RNF2 axis negatively regulates antiviral innate immunity by promoting TBK1 ubiquitination and degradation. This axis effectively reduces K48-linked deubiquitination of TBK1, leading to its degradation and dampening of immune responses. Understanding this regulation may inform strategies to modulate innate immunity during viral infections.
From negative regulation of protein K48-linked deubiquitination-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of a DUB affect K48-linked deubiquitination of a substrate? | CRISPR knockout of the DUB in cell lines, followed by ubiquitination assays |
| Does a point mutation in a DUB alter its catalytic activity? | CRISPR point mutation knock-in of catalytic residues |
| Does tagging a DUB affect its localization or interactions? | Knock-in of epitope tags (e.g., FLAG, HA) at endogenous loci |
| Does overexpression of a DUB stabilize a substrate? | Transient or stable overexpression of the DUB in cell lines |
| Does a DUB inhibitor block K48-linked deubiquitination? | Pharmacological inhibition combined with ubiquitination assays |
| Does a DUB regulate tumor growth in vivo? | Xenograft or orthotopic mouse models with DUB knockout or overexpression |
How to Study the negative regulation of protein K48-linked deubiquitination Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Ubiquitination assay (IP + immunoblot) | Levels of K48-linked ubiquitin on a substrate | Validate DUB-substrate relationships |
| Mass spectrometry | Ubiquitination sites and chain topology | Unbiased discovery of substrates |
| CRISPR knockout screen | Genes affecting K48-linked deubiquitination | Identify regulators in cancer or immunity |
| RNA-seq | Transcriptional changes | Downstream effects of DUB modulation |
| Co-immunoprecipitation | Protein-protein interactions | Confirm DUB-substrate binding |
| Immunofluorescence | Subcellular localization | Assess DUB and substrate co-localization |
| Cell viability assays | Proliferation and drug sensitivity | Evaluate therapeutic potential |
| Xenograft models | Tumor growth in vivo | Test DUB-targeting strategies |
Ubiquitination assays
Ubiquitination assays, including immunoprecipitation followed by immunoblotting for K48-linked ubiquitin, are essential to measure the extent of K48-linked deubiquitination. These assays can be performed in cells with DUB knockout or overexpression to determine substrate-specific effects. For example, USP29-mediated stabilization of ACSL5 was demonstrated using K48-linked ubiquitination assays.
Proteomics and mass spectrometry
Mass spectrometry-based proteomics can identify ubiquitination sites and quantify changes in K48-linked ubiquitin chains on target proteins. This approach is useful for unbiased discovery of substrates and for validating DUB-substrate relationships. In melanoma, proteomic profiling revealed the PSMD14-SP1-GYS1 axis.
CRISPR screens and functional genomics
CRISPR knockout screens can systematically identify genes that regulate K48-linked deubiquitination or its negative regulation. Such screens have been used to uncover DUBs and E3 ligases involved in cancer and immunity. Combining screens with ubiquitination readouts enables functional annotation of candidates.
RNA-seq and transcriptomics
RNA sequencing can reveal transcriptional changes downstream of altered K48-linked deubiquitination, such as changes in immune response genes or metabolic pathways. For instance, USP8-Hippo/YAP feedback was studied with transcriptomic profiling.
How CRISPR Can Be Used to Study GO:1903094 negative regulation of protein K48-linked deubiquitination
Knockout
CRISPR knockout of DUBs such as USP29, USP15, OTUD5, USP8, USP33, PSMD14 or USP43 can abolish their K48-linked deubiquitination activity, leading to increased substrate ubiquitination and degradation. Knockout cell lines are valuable for studying loss-of-function phenotypes and for validating DUB-substrate axes in disease models.
Point Mutation
CRISPR point mutation knock-in can introduce catalytic-dead mutations in DUBs to dissect their enzymatic activity from scaffolding functions. For example, mutating the catalytic cysteine of USP15 or USP29 can clarify whether K48-linked deubiquitination is required for their effects on VGLL4 or ACSL5, respectively.
Knock-in
Knock-in of epitope tags (e.g., FLAG, HA, GFP) at endogenous DUB loci enables precise tracking of DUB expression, localization and interactions without overexpression artifacts. Tagged knock-in models are also useful for immunoprecipitation and proteomic studies.
Overexpression
Overexpression of wild-type or mutant DUBs can test gain-of-function effects on K48-linked deubiquitination and substrate stability. This approach is particularly useful for studying DUBs that are upregulated in cancer or metabolic disease, such as USP29 in MASLD or USP15 in TNBC.
How EDITGENE Supports negative regulation of protein K48-linked deubiquitination Research
Researchers studying negative regulation of protein K48-linked deubiquitination-related genes often need to determine whether a candidate gene is causally involved in the process, which requires precise genetic models. EDITGENE provides a comprehensive suite of CRISPR services to support such investigations, from knockout to knock-in and library screening.
Contact EDITGENE today to design your custom CRISPR model for negative regulation of protein K48-linked deubiquitination research.
Frequently Asked Questions About negative regulation of protein K48-linked deubiquitination
What is GO:1903094?
GO:1903094 is the Gene Ontology term for negative regulation of protein K48-linked deubiquitination, describing any process that reduces the removal of K48-linked ubiquitin chains from target proteins.
What genes are involved in negative regulation of protein K48-linked deubiquitination?
Key genes include USP29, USP15, OTUD5, USP8, USP33, PSMD14 and USP43, which encode DUBs that remove K48-linked chains, as well as their regulators such as RNF2.
How does K48-linked deubiquitination affect cancer?
It can stabilize oncoproteins or tumor suppressors, influencing cancer progression, immunotherapy response and drug sensitivity, as seen in triple-negative breast cancer and melanoma.
What diseases are linked to K48-linked deubiquitination?
Diseases include triple-negative breast cancer, MASLD, melanoma and antiviral innate immunity disorders.
What experimental methods study K48-linked deubiquitination?
Common methods include ubiquitination assays, mass spectrometry, CRISPR screens, RNA-seq and co-immunoprecipitation.
How can CRISPR help study GO:1903094?
CRISPR knockout, point mutation knock-in, tagged knock-in and overexpression models allow precise manipulation of DUBs and substrates to dissect K48-linked deubiquitination.
What is the role of USP15 in K48-linked deubiquitination?
USP15 mediates K48-linked deubiquitination of VGLL4, enhancing tumor immunotherapy efficacy in triple-negative breast cancer.
How does USP29 affect MASLD?
USP29 stabilizes ACSL5 through K48 deubiquitination, alleviating MASLD progression.
What is the USP43/RNF2 axis?
The USP43/RNF2 axis negatively regulates antiviral innate immunity by promoting TBK1 ubiquitination and degradation, effectively reducing K48-linked deubiquitination of TBK1.
Why is negative regulation of K48-linked deubiquitination important?
It controls protein stability and signaling, impacting cancer, metabolism and immunity, and offers therapeutic targets.
Conclusion
GO:1903094, negative regulation of protein K48-linked deubiquitination, is a critical biological process that modulates protein stability by controlling the removal of K48-linked ubiquitin chains. Through DUBs such as USP29, USP15, OTUD5, USP8, USP33, PSMD14 and USP43, this process influences cancer progression, metabolic disease and antiviral immunity. Understanding its mechanisms and regulation provides opportunities for therapeutic intervention. EDITGENE offers comprehensive CRISPR solutions to accelerate research in this field.
References
- 1. Hu S et al.. 2025. USP29 alleviates the progression of MASLD by stabilizing ACSL5 through K48 deubiquitination.. Clin Mol Hepatol 31(1):147-165 PMID: 39355870
- 2. Wang X et al.. 2024. K48-linked deubiquitination of VGLL4 by USP15 enhances the efficacy of tumor immunotherapy in triple-negative breast cancer.. Cancer Lett 588:216764 PMID: 38431034
- 3. Tomomatsu S et al.. 2025. Polyubiquitin architecture editing on collided ribosomes maintains persistent RQC activity.. EMBO J 44(21):6051-6077 PMID: 40957981
- 4. Liu X et al.. 2024. The deubiquitinase OTUD5 stabilizes SLC7A11 to promote progression and reduce paclitaxel sensitivity in triple-negative breast cancer.. Cancer Lett 604:217232 PMID: 39276913
- 5. Li X et al.. 2026. Positive feedback regulation between USP8 and Hippo/YAP axis drives triple-negative breast cancer progression.. Cell Death Dis 17(1):98 PMID: 41565619
- 6. Qu F et al.. 2025. Synergistic inhibition of TNBC by USP33 and TAP63 through autophagy and ferroptosis activation.. Cell Mol Life Sci 82(1):309 PMID: 40801947
- 7. Xie J et al.. 2026. A Metabolism-Driven Prognostic Model and PSMD14-SP1-GYS1 Axis Reveal Therapeutic Vulnerabilities in Melanoma.. J Invest Dermatol 146(4):1074-1088.e5 PMID: 40967300
- 8. Zhao X et al.. 2025. The USP43/RNF2 axis negatively regulates antiviral innate immunity by promoting TBK1 ubiquitination and degradation.. Cell Death Differ 32(10):1806-1819 PMID: 40148469
