GO:0071108 protein K48-linked deubiquitination: Mechanism, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0071108 (protein K48-linked deubiquitination) describes the enzymatic removal of K48-linked polyubiquitin chains from substrate proteins, reversing a signal that classically targets proteins for proteasomal degradation.
• K48-linked deubiquitination is executed by deubiquitinating enzymes (DUBs) such as USP15, USP33, USP7, OTUD5, OTUD6A and YOD1, which stabilize substrates including ATM, PRKN/parkin, KRAS, CDC6 and STAT3.
• The process is central to DNA damage repair, mitophagy, ferroptosis protection, cardiac hypertrophy, tumour angiogenesis and chemoresistance.
• Dysregulated K48-linked deubiquitination contributes to cancer progression, including hepatocellular carcinoma, non-small cell lung cancer and chemoresistant tumours.
• CRISPR knockout, point-mutation, knock-in and overexpression models enable causal dissection of DUB-substrate relationships in this pathway.
• EDITGENE provides end-to-end CRISPR cell model and library screening services to study K48-linked deubiquitination genes at scale.
Description
Protein K48-linked deubiquitination (GO:0071108) is the biological process in which a K48-linked ubiquitin chain, a polymer assembled through isopeptide bonds between lysine 48 of successive ubiquitin monomers, is enzymatically removed from a target protein. Because K48-linked polyubiquitination is the canonical signal that routes proteins to the 26S proteasome, its reversal by deubiquitinating enzymes (DUBs) directly controls protein half-life and abundance. This makes GO:0071108 a central node in post-translational control of signalling, genome maintenance and cell survival. Mechanistically, K48-linked deubiquitination is mediated by DUBs that recognize the K48 linkage and cleave the isopeptide bond, thereby rescuing substrates from degradation. Documented examples include USP15, which removes K48-linked chains from ATM to stabilize it after radiation-induced DNA damage; USP33, which deubiquitinates PRKN/parkin and antagonizes mitophagy; and YOD1, which deubiquitinates and stabilizes STAT3 in pathological cardiac hypertrophy. Additional DUBs such as USP7, OTUD5 and OTUD6A act on KRAS, ferroptosis-related substrates and CDC6, respectively. For researchers, GO:0071108 matters because it links ubiquitin biology to actionable disease mechanisms. K48-linked deubiquitination influences tumour malignancy and fatty acid biosynthesis in hepatocellular carcinoma, tumour angiogenesis and immune evasion, chemoresistance, non-small cell lung cancer, myocardial ischaemia/reperfusion injury and cardiac hypertrophy. Understanding which DUB removes K48 chains from which substrate, and under what conditions, is therefore a high-value research objective that benefits from precise CRISPR-based models.
protein K48-linked deubiquitination At A Glance
| GO ID | GO:0071108 |
|---|---|
| GO term | protein K48-linked deubiquitination |
| Ontology | biological_process |
| Synonym | None listed in QuickGO |
| Definition | A protein deubiquitination process in which a K48-linked ubiquitin chain is removed from a protein |
| Major function | Reversal of K48-linked polyubiquitination, typically preventing proteasomal degradation and stabilizing substrate proteins |
| Key enzyme class | Deubiquitinating enzymes (DUBs), including USP and OTU family members |
| Representative substrates | ATM, PRKN/parkin, STAT3, CDC6, KRAS |
| Disease relevance | Cancer, cardiac hypertrophy, ischaemia/reperfusion injury, chemoresistance |
What Is GO:0071108?
In our own words, GO:0071108 (protein K48-linked deubiquitination) is the process by which a K48-linked polyubiquitin chain is removed from a protein substrate. A K48-linked chain is a ubiquitin polymer in which each ubiquitin monomer is attached to the next through an isopeptide bond involving lysine 48 of ubiquitin. Removal of this chain is catalysed by deubiquitinating enzymes and typically opposes proteasomal degradation, thereby stabilizing the substrate protein.
Why Is protein K48-linked deubiquitination Important in Cell Biology?
GO:0071108 is important because K48-linked deubiquitination is a decisive checkpoint for protein stability and therefore for nearly every signalling and stress-response pathway. By removing K48-linked chains, DUBs such as USP15, USP33, USP7, OTUD5, OTUD6A and YOD1 can protect substrates from proteasomal destruction and sustain their functions in DNA repair, mitophagy, ferroptosis resistance, oncogenic signalling and cardiac remodelling. Because these events are frequently dysregulated in human disease, the process is both a mechanistic research focus and a potential source of therapeutic targets.
• Controls protein stability by reversing the canonical K48-linked degradation signal.
• Sustains DNA damage responses through stabilization of ATM.
• Regulates mitophagy by acting on PRKN/parkin.
• Protects cardiomyocytes from ferroptosis in ischaemia/reperfusion injury.
• Drives pathological cardiac hypertrophy via STAT3 stabilization.
• Promotes tumour progression and chemoresistance through CDC6 stabilization.
• Supports non-small cell lung cancer through KRAS stabilization.
• Contributes to hepatocellular carcinoma malignancy, angiogenesis and immune evasion.
• Provides druggable DUB targets for oncology and cardiovascular disease.
• Enables CRISPR-based causal studies of DUB-substrate pairs.
What Happens During protein K48-linked deubiquitination?
Recognition of the K48-linked ubiquitin chain
In simple terms: The enzyme first finds and binds the specific type of ubiquitin chain attached to the target protein.
K48-linked deubiquitination begins when a DUB recognizes a substrate bearing a K48-linked polyubiquitin chain. DUBs such as USP15, USP33, USP7, OTUD5, OTUD6A and YOD1 show selectivity for particular substrates and chain types, allowing them to act on specific proteins rather than all ubiquitinated proteins. For example, USP15 acts on ATM after radiation-induced DNA damage, whereas USP33 acts on PRKN/parkin to antagonize mitophagy.
Cleavage of the isopeptide bond
In simple terms: The enzyme cuts the chemical link that holds the ubiquitin chain together.
Once bound, the DUB catalyses hydrolysis of the isopeptide bond that connects ubiquitin monomers within the K48-linked chain, progressively removing the chain from the substrate. This cleavage is the defining catalytic event of GO:0071108 and distinguishes it from other deubiquitination processes that act on different linkage types.
Substrate stabilization and functional rescue
In simple terms: Removing the chain saves the protein from being destroyed, so it can keep working.
Because K48-linked chains target proteins for proteasomal degradation, their removal typically stabilizes the substrate. USP15-mediated K48-linked deubiquitination stabilizes ATM and supports the DNA damage response; YOD1 deubiquitinates and stabilizes STAT3 to promote pathological cardiac hypertrophy; and USP7 deubiquitinates KRAS to promote non-small cell lung cancer. OTUD6A deubiquitinates CDC6 and promotes tumour progression and chemoresistance.
Physiological and pathological consequences
In simple terms: The stabilized protein then changes how the cell behaves, which can be protective or harmful.
The downstream effects of K48-linked deubiquitination depend on the substrate. OTUD5 protects against 4-HNE-triggered ferroptosis in myocardial ischaemia/reperfusion injury, whereas endothelial DGKG promotes tumour angiogenesis and immune evasion in hepatocellular carcinoma. eIF3f promotes tumour malignancy by remodelling fatty acid biosynthesis in hepatocellular carcinoma. These examples show that GO:0071108 can be protective or pathogenic depending on context.
Key Genes Involved in GO:0071108 protein K48-linked deubiquitination
The following genes and proteins are experimentally implicated in K48-linked deubiquitination or its downstream biology.
| Gene | Major Role | Research Relevance |
|---|---|---|
| USP15 | K48-linked deubiquitination and stabilization of ATM | Radiation-induced DNA damage and intestinal injury |
| YOD1 | Deubiquitinates and stabilizes STAT3 | Pathological cardiac hypertrophy |
| OTUD6A | Deubiquitinates CDC6 | Tumour progression and chemoresistance |
| OTUD5 | Protects against ferroptosis | Myocardial ischaemia/reperfusion injury |
| USP33 | Deubiquitinates PRKN/parkin | Mitophagy regulation |
| USP7 | Deubiquitinates KRAS | Non-small cell lung cancer |
| ATM | Substrate stabilized by USP15 | DNA damage response |
| STAT3 | Substrate stabilized by YOD1 | Cardiac hypertrophy |
| CDC6 | Substrate deubiquitinated by OTUD6A | Tumour progression and chemoresistance |
| PRKN/parkin | Substrate deubiquitinated by USP33 | Mitophagy |
| KRAS | Substrate deubiquitinated by USP7 | Non-small cell lung cancer |
| DGKG | Endothelial factor promoting angiogenesis and immune evasion | Hepatocellular carcinoma |
| eIF3f | Promotes tumour malignancy via fatty acid biosynthesis remodelling | Hepatocellular carcinoma |
How Is protein K48-linked deubiquitination Regulated?
K48-linked deubiquitination is regulated at the level of DUB expression, substrate availability and cellular stress context. For example, USP15-dependent stabilization of ATM occurs in response to radiation-induced DNA damage, and YOD1-mediated STAT3 stabilization drives pathological cardiac hypertrophy under stress conditions. OTUD5 protects against 4-HNE-triggered ferroptosis during myocardial ischaemia/reperfusion injury, while OTUD6A-mediated CDC6 deubiquitination promotes chemoresistance. These examples indicate that the process is context-dependent and responsive to cellular stress and disease states.
protein K48-linked deubiquitination and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| OTUD6A | Tumour progression and chemoresistance | Cancer cell line knockout and overexpression models |
| USP7 | Non-small cell lung cancer | KRAS-mutant lung cancer cell models |
| YOD1 | Pathological cardiac hypertrophy | Cardiomyocyte knockout and overexpression models |
| USP15 | Radiation-induced DNA damage and intestinal injury | Intestinal epithelial and DNA damage models |
| OTUD5 | Myocardial ischaemia/reperfusion injury and ferroptosis | Cardiomyocyte ferroptosis models |
Cancer progression and chemoresistance
K48-linked deubiquitination promotes tumour progression through multiple DUB-substrate axes. OTUD6A deubiquitinates CDC6 and promotes tumour progression and chemoresistance, while USP7 deubiquitinates KRAS and promotes non-small cell lung cancer. In hepatocellular carcinoma, eIF3f promotes tumour malignancy by remodelling fatty acid biosynthesis, and endothelial DGKG promotes tumour angiogenesis and immune evasion. These findings link GO:0071108 to oncogenic signalling and therapy resistance.
Cardiovascular disease
In the heart, K48-linked deubiquitination can be maladaptive. Cardiomyocyte-derived YOD1 promotes pathological cardiac hypertrophy by deubiquitinating and stabilizing STAT3. Conversely, OTUD5 acts as a protector against 4-HNE-triggered ferroptosis in myocardial ischaemia/reperfusion injury. Thus, the same GO process can have protective or pathogenic roles depending on the DUB and substrate involved.
DNA damage response and tissue injury
USP15 regulates radiation-induced DNA damage and intestinal injury through K48-linked deubiquitination and stabilization of ATM. This places GO:0071108 at the interface of genome maintenance and tissue radiosensitivity, with implications for understanding radiation injury and DNA repair capacity.
From protein K48-linked deubiquitination-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of a DUB alter substrate stability? | CRISPR knockout cell line |
| Does a specific catalytic residue drive K48-linked deubiquitination? | Point-mutation knock-in of catalytic cysteine |
| Does tagging a DUB affect its localization and function? | Tagged knock-in |
| Does overexpression of a DUB stabilize its substrate? | Overexpression cell model |
| Does a DUB-substrate axis drive chemoresistance? | Knockout plus drug treatment model |
| Does a DUB protect against ferroptosis? | Knockout and ferroptosis induction model |
How to Study the protein K48-linked deubiquitination Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Immunoprecipitation plus K48-ubiquitin immunoblot | K48-linked ubiquitination status of a substrate | Testing DUB activity on a target protein |
| In vitro deubiquitination assay | Direct cleavage of K48-linked chains | Validating DUB-substrate pairs |
| Cycloheximide chase | Substrate half-life | Assessing stabilization after deubiquitination |
| Proteasome inhibitor treatment | Proteasome-dependent degradation | Confirming K48-linked degradation control |
| DNA damage marker staining | DNA damage response activation | Studying USP15-ATM axis |
| Mitophagy flux assay | Autophagic clearance of mitochondria | Studying USP33-PRKN axis |
| Ferroptosis assay | Lipid peroxidation and cell death | Studying OTUD5 protection |
| Drug sensitivity assay | Chemoresistance phenotype | Studying OTUD6A-CDC6 axis |
Ubiquitination and deubiquitination assays
K48-linked deubiquitination can be measured by immunoprecipitation of the substrate followed by immunoblotting for K48-linked ubiquitin chains, or by in vitro deubiquitination assays using purified DUB and ubiquitinated substrate. These assays directly test whether a candidate DUB removes K48-linked chains from a specific protein.
Protein stability and half-life analysis
Because K48-linked deubiquitination typically stabilizes substrates, cycloheximide chase experiments and proteasome inhibitor treatments are used to assess substrate half-life after DUB manipulation. Such experiments link GO:0071108 activity to changes in protein abundance.
Functional cellular assays
Functional readouts such as DNA damage markers, mitophagy flux, ferroptosis indicators, cardiac hypertrophy markers or drug sensitivity assays are used to connect K48-linked deubiquitination to cellular phenotypes. These assays translate molecular events into disease-relevant outcomes.
CRISPR-based perturbation
CRISPR knockout, point mutation, knock-in and overexpression models allow causal testing of DUB-substrate relationships in GO:0071108. By comparing wild-type and mutant cells, researchers can determine whether a specific DUB activity is required for substrate stabilization and downstream phenotypes.
How CRISPR Can Be Used to Study GO:0071108 protein K48-linked deubiquitination
Knockout
CRISPR knockout of a DUB gene removes its K48-linked deubiquitination activity, allowing researchers to test whether substrate stability and downstream phenotypes depend on that enzyme. For example, knockout of USP15, YOD1, OTUD6A or USP33 can reveal loss of ATM, STAT3, CDC6 or PRKN stabilization, respectively.
Point Mutation
Point mutation of the catalytic cysteine or other key residues in a DUB can separate its deubiquitination activity from scaffolding functions. Such models are useful for determining whether K48-linked deubiquitination specifically, rather than protein presence, drives a phenotype.
Knock-in
Knock-in of tags or disease-associated variants allows tracking of DUB localization, interaction and substrate specificity in a physiological context. Tagged knock-in models can be used to immunoprecipitate endogenous DUB-substrate complexes and measure K48-linked deubiquitination.
Overexpression
Overexpression of a DUB such as USP7, OTUD6A or YOD1 can drive substrate stabilization and disease phenotypes, providing gain-of-function evidence for GO:0071108 in cancer and cardiac hypertrophy. Overexpression models complement knockout studies by testing sufficiency rather than necessity.
How EDITGENE Supports protein K48-linked deubiquitination Research
Researchers studying protein K48-linked deubiquitination-related genes often need to determine whether a candidate gene is causally involved in substrate stabilization, stress responses or disease phenotypes. EDITGENE provides CRISPR-based cell model and screening services designed to answer these questions with reproducible, publication-ready models.
Contact EDITGENE today to design your custom CRISPR model for protein K48-linked deubiquitination research.
Frequently Asked Questions About protein K48-linked deubiquitination
What is protein K48-linked deubiquitination?
It is the process defined by GO:0071108 in which a K48-linked ubiquitin chain is removed from a protein by a deubiquitinating enzyme, typically preventing proteasomal degradation and stabilizing the substrate.
What genes are involved in protein K48-linked deubiquitination?
Genes encoding DUBs such as USP15, YOD1, OTUD6A, OTUD5, USP33 and USP7, and their substrates including ATM, STAT3, CDC6, PRKN/parkin and KRAS, are involved.
Why is K48-linked deubiquitination important in cancer?
It can stabilize oncogenic or pro-survival proteins such as KRAS and CDC6, promoting non-small cell lung cancer, tumour progression and chemoresistance.
How does USP15 regulate the DNA damage response?
USP15 performs K48-linked deubiquitination and stabilization of ATM, regulating radiation-induced DNA damage and intestinal injury.
What is the role of YOD1 in cardiac hypertrophy?
Cardiomyocyte-derived YOD1 deubiquitinates and stabilizes STAT3, promoting pathological cardiac hypertrophy.
How does OTUD5 protect against ferroptosis?
OTUD5 acts as a protector against 4-HNE-triggered ferroptosis in myocardial ischaemia/reperfusion injury.
How does USP33 affect mitophagy?
USP33 deubiquitinates PRKN/parkin and antagonizes its role in mitophagy.
What experimental models are used to study K48-linked deubiquitination?
CRISPR knockout, point mutation, knock-in, tagged knock-in and overexpression cell models are used to test DUB-substrate relationships and downstream phenotypes.
Which diseases are linked to K48-linked deubiquitination?
Cancers such as hepatocellular carcinoma and non-small cell lung cancer, chemoresistance, cardiac hypertrophy, myocardial ischaemia/reperfusion injury and radiation-induced intestinal injury are linked.
How can EDITGENE help with K48-linked deubiquitination research?
EDITGENE provides CRISPR knockout, point mutation, knock-in, overexpression, library screening and bioinformatics services to study DUBs and substrates in this pathway.
Conclusion
GO:0071108 (protein K48-linked deubiquitination) is a fundamental biological process that reverses the canonical K48-linked degradation signal and stabilizes key regulatory proteins. Its dysregulation is implicated in cancer, chemoresistance, cardiac hypertrophy, ischaemia/reperfusion injury and DNA damage-related tissue injury. Continued research using precise CRISPR models will clarify which DUB-substrate pairs drive disease and how they can be targeted therapeutically.
References
- 1. Zhou S et al.. 2025. eIF3f promotes tumour malignancy by remodelling fatty acid biosynthesis in hepatocellular carcinoma.. J Hepatol 83(3):712-728 PMID: 40154622
- 2. Zhu R et al.. 2024. USP15 regulates radiation-induced DNA damage and intestinal injury through K48-linked deubiquitination and stabilisation of ATM.. Mol Med 30(1):205 PMID: 39522000
- 3. Ye B et al.. 2025. Cardiomyocyte-derived YOD1 promotes pathological cardiac hypertrophy by deubiquitinating and stabilizing STAT3.. Sci Adv 11(26):eadu8422 PMID: 40561034
- 4. Cui J et al.. 2024. Deubiquitination of CDC6 by OTUD6A promotes tumour progression and chemoresistance.. Mol Cancer 23(1):86 PMID: 38685067
- 5. Liu L et al.. 2023. Deubiquitinase OTUD5 as a Novel Protector against 4-HNE-Triggered Ferroptosis in Myocardial Ischemia/Reperfusion Injury.. Adv Sci (Weinh) 10(28):e2301852 PMID: 37552043
- 6. Zhang L et al.. 2024. Endothelial DGKG promotes tumor angiogenesis and immune evasion in hepatocellular carcinoma.. J Hepatol 80(1):82-98 PMID: 37838036
- 7. Niu K et al.. 2020. USP33 deubiquitinates PRKN/parkin and antagonizes its role in mitophagy.. Autophagy 16(4):724-734 PMID: 31432739
- 8. Huang B et al.. 2024. USP7 deubiquitinates KRAS and promotes non-small cell lung cancer.. Cell Rep 43(11):114917 PMID: 39499616
