GO:0061654 NEDD8 conjugating enzyme activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0061654 (NEDD8 conjugating enzyme activity) describes the E2-catalyzed isopeptide transfer of NEDD8 from a thioester-linked E2 to a substrate lysine, a central step in protein neddylation.
• The two principal human NEDD8-conjugating enzymes are UBE2M (UBC12) and UBE2F, which cooperate with distinct E3 ligases to determine substrate specificity.
• Neddylation regulates cullin-RING ligases, autophagy, DNA repair, and cell survival, making this activity essential for proteostasis and stress responses.
• Dysregulated NEDD8 conjugation is implicated in multiple cancers, ischemic brain injury, vascular calcification, and platinum resistance.
• Small-molecule inhibitors such as MLN4924 (pevonedistat) and orlistat target the neddylation cascade and show preclinical efficacy.
• CRISPR knockout, point-mutation, knock-in, and overexpression models enable precise interrogation of UBE2M/UBE2F function in disease contexts.
Description
NEDD8 conjugating enzyme activity (GO:0061654) is a molecular function that catalyzes the transfer of the ubiquitin-like protein NEDD8 from a thioester-linked E2 enzyme to a target protein, forming a covalent isopeptide bond. This reaction is the second enzymatic step in the neddylation cascade, following NEDD8 activation by the heterodimeric E1 enzyme (NAE1-UBA3) and preceding E3-mediated substrate recognition. The activity is essential for the modification of cullin family proteins and many non-cullin substrates, thereby influencing protein stability, localization, and function. Researchers study this term because neddylation controls fundamental processes such as cell cycle progression, DNA damage repair, autophagy, and immune signaling, and its dysregulation is linked to cancer, neurodegeneration, and metabolic disorders. Understanding the precise biochemical mechanism and regulation of NEDD8 conjugating enzymes provides a foundation for therapeutic targeting of the neddylation pathway.
NEDD8 conjugating enzyme activity At A Glance
| GO ID | GO:0061654 |
|---|---|
| GO term | NEDD8 conjugating enzyme activity |
| Ontology | molecular_function |
| Synonym | E2 |
| Major function | Catalyzes the transfer of NEDD8 from a thioester-linked E2 to a substrate lysine, forming an isopeptide bond. |
| Cellular context | Cytoplasm and nucleus; associated with cullin-RING ligases and other E3 complexes. |
| Key enzymes | UBE2M (UBC12) and UBE2F are the primary NEDD8-conjugating E2 enzymes in humans. |
| Pathway | Neddylation cascade: E1 (NAE1-UBA3) activates NEDD8, E2 (UBE2M/UBE2F) conjugates it, E3 ligases provide substrate specificity. |
| Inhibitors | MLN4924 (pevonedistat) targets NAE1; orlistat has been reported to target UBC12. |
What Is GO:0061654?
GO:0061654 defines the isoenzymatic transfer of NEDD8 from one protein to another via the reaction X-NEDD8 + Y = Y-NEDD8 + X, where both the X-NEDD8 and Y-NEDD8 linkages are thioester bonds between the C-terminal amino acid of NEDD8 and a sulfhydryl side group of a cysteine residue. In simpler terms, it is the E2 enzyme activity that moves NEDD8 from a carrier protein to a substrate, forming a stable covalent bond.
Why Is NEDD8 conjugating enzyme activity Important in Cell Biology?
NEDD8 conjugating enzyme activity is critical because it determines the specificity and efficiency of protein neddylation, a post-translational modification that regulates the stability and activity of hundreds of proteins. This activity is required for the function of cullin-RING ligases, which control the turnover of key cell cycle and signaling proteins. Dysregulation of NEDD8 conjugation contributes to cancer progression, ischemic injury, vascular calcification, and chemoresistance, making it a promising therapeutic target.
• Controls cullin-RING ligase activity and thereby regulates protein degradation.
• Modulates autophagy by stabilizing LC3B and promoting autophagosome formation.
• Regulates DNA repair and apoptosis through neddylation of PARP-1 and other substrates.
• Is essential for cell cycle progression and genome stability.
• Its inhibition by MLN4924 reduces ischemic brain injury in mice.
• Overexpression of UBE2F confers platinum resistance in lung cancer.
• UBC12 (UBE2M) is a therapeutic target in esophageal squamous cell carcinoma.
• Orlistat targeting UBC12 shows anti-cancer activity.
• Neddylation is implicated in immune signaling and inflammation.
• Provides a druggable node for cancer and other diseases.
Molecular Mechanism of NEDD8 conjugating enzyme activity
Thioester formation between NEDD8 and E2
In simple terms: The E2 enzyme grabs NEDD8 and holds it via a high-energy bond.
The NEDD8-conjugating enzyme (E2) receives NEDD8 from the E1 enzyme through a transthioesterification reaction, forming a thioester bond between the C-terminal glycine of NEDD8 and the catalytic cysteine of the E2. This step is required for subsequent substrate modification.
E3-mediated substrate recognition
In simple terms: A helper protein (E3) brings the target protein close to the E2.
E3 ligases, such as RBX1/2 within cullin-RING ligases or DCN1, bind both the E2~NEDD8 complex and the substrate, orienting the thioester for nucleophilic attack by a substrate lysine. Different E3s dictate which proteins are neddylated, thereby providing specificity.
Isopeptide bond formation
In simple terms: NEDD8 is glued onto the target protein.
The substrate lysine attacks the thioester bond, resulting in the covalent attachment of NEDD8 to the substrate via an isopeptide bond. This modification can alter the substrate's conformation, interactions, or stability.
Deconjugation and recycling
In simple terms: Other enzymes can remove NEDD8 to reverse the modification.
NEDD8 is removed from substrates by deneddylases such as the COP9 signalosome and NEDP1, allowing dynamic regulation of neddylation. This reversibility ensures that neddylation is a tightly controlled process.
Regulation by cofactors and post-translational modifications
In simple terms: The activity of E2 enzymes can be switched on or off by other proteins and chemical changes.
The activity of UBE2M and UBE2F is regulated by their interaction with E3 ligases, by phosphorylation, and by the availability of NEDD8. For example, induction of UBE2F by platinum compounds enhances neddylation and protects lung cancer cells from apoptosis.
Key Genes Involved in GO:0061654 NEDD8 conjugating enzyme activity
The following genes encode proteins that directly participate in or regulate NEDD8 conjugating enzyme activity.
| Gene | Major Role | Research Relevance |
|---|---|---|
| UBE2M (UBC12) | Primary NEDD8-conjugating E2 enzyme; transfers NEDD8 to cullins and other substrates | Target in esophageal squamous cell carcinoma; knockout reduces neddylation |
| UBE2F | NEDD8-conjugating E2 enzyme specific for cullin-5 and other substrates | Induced by platinum; confers chemoresistance in lung cancer |
| NAE1 | Subunit of the NEDD8-activating E1 enzyme | Target of MLN4924; knockout abolishes neddylation |
| UBA3 | Catalytic subunit of the NEDD8-activating E1 enzyme | Essential for E2 charging; knockout is lethal |
| RBX1 | RING-box protein that acts as an E3 ligase for cullin neddylation | Knockout impairs cullin-RING ligase function |
| RBX2 | RING-box protein E3 ligase for cullin neddylation | Modulates neddylation of cullins |
| DCN1 (DCUN1D1) | Scaffold protein that enhances E2-E3 interaction | Overexpression promotes neddylation and tumor growth |
| CUL1 | Cullin substrate that is neddylated by UBE2M | Neddylation regulates SCF complex assembly |
| CUL5 | Cullin substrate preferentially neddylated by UBE2F | Neddylation controls CRL5 activity |
| NEDD8 | Ubiquitin-like modifier transferred by E2 enzymes | Essential for neddylation; knockout is lethal |
| NEDP1 (SENP8) | Deneddylase that removes NEDD8 from substrates | Regulates steady-state neddylation levels |
| COPS5 | Subunit of COP9 signalosome with deneddylase activity | Modulates cullin neddylation dynamics |
| PARP-1 | Substrate of neddylation; neddylation enhances its activity | Neddylation of PARP-1 promotes vascular calcification |
| LC3B | Autophagy protein stabilized by neddylation | Neddylation antagonizes ubiquitin-mediated degradation of LC3B |
| CBL-b | E3 ligase that mediates neddylation of PARP-1 | Regulates vascular calcification |
| UBC12 (UBE2M) paralog | Alternative name for UBE2M | Targeted by orlistat in cancer |
How Is NEDD8 conjugating enzyme activity Regulated?
NEDD8 conjugating enzyme activity is regulated at multiple levels. The availability of NEDD8 and the E1 enzyme controls the charging of E2 enzymes. E3 ligases such as RBX1/2 and DCN1 determine substrate specificity and enhance catalytic efficiency. Post-translational modifications, including phosphorylation, can modulate E2 activity. Additionally, deneddylases like the COP9 signalosome and NEDP1 reverse the modification, maintaining dynamic equilibrium. In disease contexts, UBE2F expression is induced by platinum-based chemotherapy, leading to increased neddylation and chemoresistance.
NEDD8 conjugating enzyme activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| UBE2M (UBC12) | Esophageal squamous cell carcinoma | Knockout in cancer cell lines; xenograft models |
| UBE2F | Platinum resistance in lung cancer | Overexpression and knockout in lung cancer cells |
| NAE1 | Cancer; ischemic brain injury | Knockout or inhibitor treatment in mouse models |
| PARP-1 | Vascular calcification | Point mutation of neddylation sites; knockout mice |
| LC3B | Autophagy in skin | Knock-in of neddylation-deficient LC3B; knockout |
Cancer
Dysregulated NEDD8 conjugating enzyme activity promotes tumorigenesis by stabilizing oncoproteins and enhancing cell survival. UBE2M (UBC12) is overexpressed in esophageal squamous cell carcinoma and its knockdown inhibits tumor growth. UBE2F induction by platinum protects lung cancer cells from apoptosis, conferring chemoresistance. Targeting UBC12 with orlistat reduces cancer cell viability. The NAE inhibitor MLN4924 shows broad anti-cancer activity in preclinical models.
Ischemic brain injury
Inhibition of NEDD8-activating enzyme with MLN4924 reduces ischemic brain injury in mice, suggesting that neddylation contributes to neuronal damage after stroke. This implies that NEDD8 conjugating enzyme activity may be a therapeutic target for neuroprotection.
Vascular calcification
CBL-b E3 ligase-mediated neddylation and activation of PARP-1 induce vascular calcification, a process dependent on NEDD8 conjugation. Modulating this activity could prevent calcification in cardiovascular disease.
Autophagy and skin homeostasis
Neddylation stabilizes LC3B by antagonizing its ubiquitin-mediated degradation, promoting autophagy in skin. This highlights the role of NEDD8 conjugating enzyme activity in maintaining tissue homeostasis.
From NEDD8 conjugating enzyme activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does UBE2M knockout reduce tumor growth? | CRISPR knockout in cancer cell lines and xenografts |
| Does UBE2F overexpression confer platinum resistance? | Overexpression in lung cancer cells |
| What is the role of NEDD8 conjugation on PARP-1 in calcification? | Point mutation of PARP-1 neddylation sites |
| How does neddylation of LC3B affect autophagy? | Knock-in of tagged LC3B and neddylation-deficient mutant |
| Can MLN4924 protect against ischemic brain injury? | Mouse middle cerebral artery occlusion model |
| Does orlistat target UBC12 in vivo? | Xenograft models treated with orlistat |
How to Study the NEDD8 conjugating enzyme activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| In vitro neddylation assay | E2-mediated transfer of NEDD8 to substrate | Enzyme kinetics and inhibitor testing |
| Mass spectrometry proteomics | Identification of neddylated proteins | Global substrate profiling |
| CRISPR knockout screen | Genes required for neddylation or resistance | Target discovery |
| Western blot with anti-NEDD8 | Levels of neddylated proteins | Validation of E2 knockout or inhibition |
| Immunoprecipitation | Interaction between E2 and E3 or substrates | Complex composition |
| Fluorescence microscopy | Subcellular localization of neddylation | Live-cell imaging |
| Cell viability assay | Effect of neddylation inhibition | Drug sensitivity |
| Xenograft tumor models | In vivo efficacy of targeting E2 | Preclinical drug testing |
Biochemical assays for E2 activity
In vitro thioester formation and substrate neddylation assays using recombinant E1, E2, E3, and substrate proteins can directly measure NEDD8 conjugating enzyme activity. These assays typically use fluorescently labeled NEDD8 and detect covalent modification by SDS-PAGE.
Proteomic profiling of neddylated substrates
Mass spectrometry-based proteomics after enrichment of neddylated peptides can identify substrates and quantify changes in neddylation upon E2 knockout or inhibition. This approach reveals global effects on cellular signaling.
CRISPR screening for modulators
Genome-wide CRISPR knockout or activation screens can identify genes that regulate NEDD8 conjugating enzyme activity or synthetic lethal interactions with neddylation inhibitors.
Imaging and cellular assays
Fluorescence microscopy with GFP-tagged NEDD8 or substrates can visualize neddylation dynamics in live cells. Autophagy flux assays and cell viability assays are used to link neddylation to phenotypes.
How CRISPR Can Be Used to Study GO:0061654 NEDD8 conjugating enzyme activity
Knockout
CRISPR knockout of UBE2M or UBE2F eliminates NEDD8 conjugating enzyme activity, leading to reduced cullin neddylation and impaired cell proliferation. Knockout cell lines are valuable for identifying substrates and pathways dependent on neddylation.
Point Mutation
Point mutation of the catalytic cysteine in UBE2M or UBE2F abolishes thioester formation, providing a catalytically dead control. Mutating substrate lysine acceptors can prevent specific neddylation events, such as PARP-1 modification in vascular calcification.
Knock-in
Knock-in of tagged NEDD8 or substrate proteins (e.g., GFP-LC3B) allows tracking of neddylation dynamics and substrate localization. Knock-in of neddylation-deficient mutants can reveal the functional significance of specific modification sites.
Overexpression
Overexpression of UBE2F or UBE2M increases global neddylation and can confer resistance to chemotherapy, as shown for UBE2F in lung cancer. Overexpression models are useful for studying gain-of-function effects and drug resistance.
How EDITGENE Supports NEDD8 conjugating enzyme activity Research
Researchers studying NEDD8 conjugating enzyme activity-related genes often need to determine whether a candidate gene is causally involved in neddylation, substrate specificity, or disease phenotypes. EDITGENE provides comprehensive CRISPR-based services to generate precisely engineered cell models for such investigations.
Contact EDITGENE today to design your custom CRISPR model for NEDD8 conjugating enzyme activity research.
Frequently Asked Questions About NEDD8 conjugating enzyme activity
What is NEDD8 conjugating enzyme activity?
It is the E2 enzyme activity that transfers NEDD8 from a thioester-linked E2 to a substrate lysine, forming an isopeptide bond, as defined by GO:0061654.
What genes are involved in NEDD8 conjugating enzyme activity?
The primary genes are UBE2M (UBC12) and UBE2F, which encode the NEDD8-conjugating E2 enzymes.
What is the difference between UBE2M and UBE2F?
UBE2M primarily neddylates cullin-1, while UBE2F preferentially modifies cullin-5; both are E2 enzymes with distinct substrate specificities.
How is NEDD8 conjugating enzyme activity regulated?
It is regulated by E3 ligases, deneddylases, NEDD8 availability, and post-translational modifications such as phosphorylation.
What diseases are associated with NEDD8 conjugating enzyme activity?
Cancer, ischemic brain injury, vascular calcification, and chemoresistance have been linked to dysregulated neddylation.
Can NEDD8 conjugating enzyme activity be inhibited?
Yes, MLN4924 inhibits the upstream E1 enzyme, and orlistat has been reported to target UBC12, reducing neddylation.
What is the role of UBE2F in cancer?
UBE2F induction by platinum protects lung cancer cells from apoptosis and confers platinum insensitivity.
How can I study NEDD8 conjugating enzyme activity in the lab?
In vitro neddylation assays, CRISPR knockout, proteomics, and imaging are common methods.
What is the clinical relevance of UBC12 (UBE2M)?
UBC12 is a therapeutic target in esophageal squamous cell carcinoma and is targeted by orlistat.
What CRISPR models are available for neddylation research?
Knockout, point mutation, knock-in, and overexpression models for UBE2M, UBE2F, and substrates can be generated.
Conclusion
NEDD8 conjugating enzyme activity (GO:0061654) is a pivotal molecular function in the neddylation cascade, controlling protein stability and signaling through the covalent attachment of NEDD8 to substrates. Its dysregulation is implicated in cancer, ischemic injury, and vascular calcification, making it a compelling therapeutic target. Advances in CRISPR-based models and biochemical assays continue to unravel the specificity and regulation of UBE2M and UBE2F, offering new opportunities for drug discovery.
References
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- 3. Yu H et al.. 2022. The NEDD8-activating enzyme inhibitor MLN4924 reduces ischemic brain injury in mice.. Proc Natl Acad Sci U S A 119(6) PMID: 35101976
- 4. Soucy TA et al.. 2009. An inhibitor of NEDD8-activating enzyme as a new approach to treat cancer.. Nature 458(7239):732-6 PMID: 19360080
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- 6. Xu L et al.. 2025. Neddylation modification stabilizes LC3B by antagonizing its ubiquitin-mediated degradation and promoting autophagy in skin.. Proc Natl Acad Sci U S A 122(15):e2411429122 PMID: 40208944
- 7. Kwon DH et al.. 2024. CBL-b E3 ligase-mediated neddylation and activation of PARP-1 induce vascular calcification.. Exp Mol Med 56(10):2246-2259 PMID: 39349831
- 8. Zhou L et al.. 2020. Induction of NEDD8-conjugating enzyme E2 UBE2F by platinum protects lung cancer cells from apoptosis and confers to platinum-insensitivity.. Cell Death Dis 11(11):975 PMID: 33184273
