GO:0051865 protein autoubiquitination: Mechanism, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0051865 protein autoubiquitination is the process by which a ubiquitin ligase attaches ubiquitin to its own lysine residues or to residues on an identical protein, forming an isopeptide bond.
• Autoubiquitination is a self-regulatory mechanism that controls ligase abundance, activity, and localization, and it can trigger protein retrotranslocation in ERAD.
• Key autoubiquitinating enzymes include Hrd1, FBXW7β, DDB1 (within CRL4), TRIM23, TRAF6, RNF125, and UBR5 [1,2,3,4,6,7,8].
• Dysregulated autoubiquitination contributes to cancer, neurodevelopmental disorders, and antiviral immunity [1,2,4,7,8].
• CRISPR knockout, point-mutation, knock-in, and overexpression models are essential to dissect the causal roles of autoubiquitination in disease [2,5,8].
• EDITGENE provides end-to-end CRISPR services, including library screening and bioinformatics, to study protein autoubiquitination in any cell model.
Description
Protein autoubiquitination (GO:0051865) is a specialized form of ubiquitination in which a ubiquitin-protein ligase (E3) catalyzes the covalent attachment of ubiquitin to one or more of its own amino acid residues, or to residues on an identical protein molecule. This self-modification occurs on lysine residues via an isopeptide crosslink and is a fundamental regulatory mechanism in eukaryotes. Autoubiquitination is best understood in the context of E3 ligases, where it often serves as a self-regulatory switch that controls protein stability, localization, and catalytic activity. For researchers, GO:0051865 represents a critical node in ubiquitin signaling, with implications for protein quality control, immune signaling, and cancer biology [1,2,4,7,8]. The process is experimentally tractable and is frequently studied using in vitro ubiquitination assays, mass spectrometry, and CRISPR-based genetic models [2,5,8].
protein autoubiquitination At A Glance
| GO ID | GO:0051865 |
|---|---|
| GO term | protein autoubiquitination |
| Ontology | biological_process |
| Synonym | protein auto-ubiquitination; protein auto-ubiquitinylation; protein autoubiquitinylation; protein self-ubiquitination; protein self-ubiquitinylation |
| Major function | Self-attachment of ubiquitin to a ligase or identical protein, regulating stability, activity, and interactions |
| Cellular context | Occurs in the cytosol, nucleus, and endoplasmic reticulum membrane |
| Key enzymes | E3 ubiquitin ligases such as Hrd1, FBXW7β, DDB1, TRIM23, TRAF6, RNF125, UBR5 [1,2,3,4,6,7,8] |
| Biological impact | Controls protein quality control, immune signaling, and cell growth [1,2,4,5,7,8] |
What Is GO:0051865?
According to the Gene Ontology, protein autoubiquitination (GO:0051865) is defined as the ubiquitination by a protein of one or more of its own amino acid residues, or residues on an identical protein. Ubiquitination occurs on the lysine residue by formation of an isopeptide crosslink. In simpler terms, it is the self-tagging of a ubiquitin ligase with ubiquitin, a modification that can alter the ligase's fate or function.
Why Is protein autoubiquitination Important in Cell Biology?
Protein autoubiquitination is a central self-regulatory mechanism in ubiquitin biology, enabling E3 ligases to control their own abundance and activity. This process is critical for endoplasmic reticulum-associated degradation (ERAD), where autoubiquitination of Hrd1 triggers protein retrotranslocation. It also modulates immune responses, as seen with RNF125 autoubiquitination enhancing RIG-I-like receptor signaling and TRIM23 mediating cGAS-induced autophagy. Dysregulation of autoubiquitination is linked to cancer, where FBXW7β loss promotes lipogenesis and TRAF6-IL-6-STAT3 signaling drives tumorigenesis, and to neurodevelopmental disorders caused by UBR5 variants. Understanding GO:0051865 is therefore essential for both basic research and therapeutic development.
• Regulates E3 ligase stability and activity through self-ubiquitination.
• Essential for ERAD and protein quality control in the secretory pathway.
• Modulates innate immune signaling, including RIG-I-like receptor and cGAS pathways [1,4].
• Influences cancer cell proliferation and metabolism via FBXW7β and TRAF6 [2,6].
• Contributes to antiviral defense mechanisms, such as anti-HSV autophagy.
• Linked to neurodevelopmental syndromes with autism and intellectual disability through UBR5 variants.
• Provides a mechanism for feedback regulation of ubiquitin ligase abundance.
• Serves as a target for therapeutic intervention in cancers and immune disorders [2,7].
• Can be studied using CRISPR knockout, point mutation, and knock-in models [2,5,8].
• Offers a paradigm for understanding self-modifying enzymes in cell signaling.
What Happens During protein autoubiquitination?
Recognition and Activation of the E3 Ligase
In simple terms: The ligase first needs to be in an active state to tag itself with ubiquitin.
Autoubiquitination begins with the activation of an E3 ubiquitin ligase, often through dimerization or conformational changes. For example, the Hrd1 ligase autoubiquitinates in response to ERAD substrates, a step that is required for its function in retrotranslocation. Similarly, TRIM23 autoubiquitination is triggered during cGAS-induced autophagy, indicating that cellular signals can activate the ligase for self-modification.
Transfer of Ubiquitin to the Ligase
In simple terms: The ligase attaches ubiquitin to itself, usually on a lysine residue.
The activated E3 ligase catalyzes the formation of an isopeptide bond between the C-terminal glycine of ubiquitin and a lysine residue on its own sequence or on an identical protein. This reaction can occur in cis (intramolecular) or in trans (intermolecular between identical molecules). In the CRL4 complex, DDB1 autoubiquitination occurs upon deneddylation inhibition, demonstrating that the modification can be regulated by the neddylation cycle.
Consequences of Autoubiquitination
In simple terms: Self-tagging can change the ligase's fate, such as degradation or altered function.
Autoubiquitination can lead to proteasomal degradation of the ligase, thereby limiting its activity, as observed for FBXW7β where loss-of-function mutations prevent autoubiquitination and enhance lipogenesis. Alternatively, autoubiquitination can serve non-degradative roles, such as triggering retrotranslocation of ERAD substrates by Hrd1 or promoting autophagy through TRIM23. In immune signaling, RNF125 autoubiquitination enhances RIG-I-like receptor signaling, highlighting a positive regulatory role.
Regulation by Associated Factors
In simple terms: Other proteins can influence whether and how a ligase autoubiquitinates.
Autoubiquitination is often modulated by interacting proteins or post-translational modifications. For instance, histone lactylation inhibits RARγ expression, which in turn affects TRAF6-IL-6-STAT3 signaling, suggesting that metabolic states can influence TRAF6 autoubiquitination. TXNIP suppresses lung cancer progression by inhibiting TRAF6-mediated NF-κB activation and autophagy, potentially by interfering with TRAF6 autoubiquitination. These examples illustrate that autoubiquitination is integrated into broader cellular signaling networks.
Key Genes Involved in GO:0051865 protein autoubiquitination
The following genes and proteins are experimentally validated to undergo or regulate protein autoubiquitination (GO:0051865) in human and viral contexts.
| Gene | Major Role | Research Relevance |
|---|---|---|
| HRD1 (SYVN1) | E3 ligase that autoubiquitinates to trigger ERAD retrotranslocation | ERAD and protein quality control |
| FBXW7 | F-box protein; FBXW7β isoform autoubiquitination regulates lipogenesis | Colorectal cancer metabolism |
| DDB1 | CRL4 adaptor; autoubiquitinates upon deneddylation inhibition | Ubiquitin-proteasome system regulation |
| TRIM23 | E3 ligase that autoubiquitinates to mediate cGAS-induced autophagy | Antiviral innate immunity |
| TRAF6 | E3 ligase; autoubiquitination linked to NF-κB and tumorigenesis [6,7] | Cancer and inflammation |
| RNF125 | E3 ligase; autoubiquitination enhances RIG-I-like receptor signaling | Antiviral signaling |
| UBR5 | HECT E3 ligase; variants affect neurodevelopment | Neurodevelopmental disorders |
| RARγ | Nuclear receptor; its expression is inhibited by histone lactylation, affecting TRAF6 signaling | Colorectal cancer |
| TXNIP | Inhibits TRAF6-mediated NF-κB activation and autophagy | Lung cancer suppression |
| cGAS | DNA sensor; TRIM23 autoubiquitination mediates cGAS-induced autophagy | Anti-HSV defense |
| RIG-I | RNA sensor; RNF125 autoubiquitination enhances signaling | Antiviral immunity |
| MDA5 | RNA sensor; part of RIG-I-like receptor signaling | Antiviral immunity |
| pMGF505-9R | African swine fever virus protein; promotes RNF125 autoubiquitination | Viral immune evasion |
| FASN | Fatty acid synthase; FBXW7β loss enhances FASN-mediated lipogenesis | Cancer metabolism |
| IL-6 | Cytokine; TRAF6-IL-6-STAT3 signaling promotes tumorigenesis | Colorectal cancer |
| STAT3 | Transcription factor; activated by TRAF6-IL-6 signaling | Cancer signaling |
| NF-κB | Transcription factor; regulated by TRAF6 autoubiquitination | Inflammation and cancer |
| NEDD8 | Ubiquitin-like protein; deneddylation inhibition triggers DDB1 autoubiquitination | CRL regulation |
How Is protein autoubiquitination Regulated?
Protein autoubiquitination is regulated at multiple levels. The neddylation cycle controls CRL4-mediated DDB1 autoubiquitination, as inhibition of deneddylation promotes this modification. Cellular metabolic states, such as histone lactylation, can indirectly influence TRAF6 signaling and potentially its autoubiquitination. Viral proteins like African swine fever virus pMGF505-9R enhance RNF125 autoubiquitination to modulate immune signaling. Additionally, interacting proteins such as TXNIP can suppress TRAF6-mediated pathways, suggesting a regulatory role. These examples highlight that autoubiquitination is not a constitutive process but is tightly controlled by upstream signals and protein-protein interactions.
protein autoubiquitination and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| FBXW7 | Colorectal cancer | Knockout of FBXW7β in HCT116 cells |
| TRAF6 | Colorectal cancer, lung cancer | Point mutation of TRAF6 autoubiquitination site [6,7] |
| UBR5 | Neurodevelopmental syndrome | Knock-in of patient variants in iPSCs |
| TRIM23 | Herpes simplex virus defense | Knockout in macrophages |
| RNF125 | Antiviral signaling | Overexpression in HEK293T cells |
Cancer
Dysregulated autoubiquitination is implicated in multiple cancers. FBXW7β loss-of-function prevents autoubiquitination, leading to enhanced FASN-mediated lipogenesis and colorectal cancer growth. TRAF6-IL-6-STAT3 signaling, which involves TRAF6 autoubiquitination, promotes colorectal tumorigenesis. In lung cancer, TXNIP suppresses progression by inhibiting TRAF6-mediated NF-κB activation and autophagy, highlighting the therapeutic potential of targeting TRAF6 autoubiquitination.
Neurodevelopmental Disorders
Heterozygous variants in UBR5, an E3 ligase that undergoes autoubiquitination, cause a neurodevelopmental syndrome characterized by developmental delay, autism, and intellectual disability. This underscores the critical role of autoubiquitination in brain development and function.
Antiviral Immunity
Autoubiquitination is a key regulatory mechanism in antiviral defense. RNF125 autoubiquitination enhances RIG-I-like receptor signaling, and the African swine fever virus protein pMGF505-9R promotes this process to modulate immune responses. TRIM23 autoubiquitination mediates cGAS-induced autophagy, which is essential for anti-HSV defense.
From protein autoubiquitination-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of FBXW7β autoubiquitination promote lipogenesis? | FBXW7β knockout colorectal cancer cell line |
| Is Hrd1 autoubiquitination required for ERAD? | Hrd1 point mutant (lysine to arginine) knock-in |
| Does TRIM23 autoubiquitination mediate autophagy? | TRIM23 knockout macrophages |
| Do UBR5 variants cause neurodevelopmental defects? | Patient-derived iPSCs with knock-in variants |
| Does RNF125 autoubiquitination enhance antiviral signaling? | RNF125 overexpression in reporter cells |
| Does DDB1 autoubiquitination affect CRL4 function? | DDB1 knockout with deneddylation inhibitor treatment |
How to Study the protein autoubiquitination Process
| Method | What It Measures | Typical Application |
|---|---|---|
| In vitro ubiquitination assay | Autoubiquitination activity | Purified E3 ligase with E1/E2 |
| Mass spectrometry | Ubiquitination sites | Mapping diGly remnants on ligases |
| Western blot | Ubiquitin conjugates | Detecting autoubiquitination in cell lysates |
| CRISPR knockout screen | Genes regulating autoubiquitination | Cancer cell lines |
| Live-cell imaging | Real-time autoubiquitination | Fluorescently tagged ligases |
| Co-immunoprecipitation | Protein interactions | Identifying regulators of autoubiquitination |
| RNA-seq | Transcriptional changes | Downstream effects of autoubiquitination |
| Proteasome inhibition assay | Degradation of autoubiquitinated ligase | MG132 treatment followed by western blot |
In Vitro Ubiquitination Assays
In vitro ubiquitination assays using purified E1, E2, and E3 enzymes, along with ubiquitin and ATP, are the gold standard to detect autoubiquitination. These assays can be coupled with western blotting for ubiquitin or mass spectrometry to identify modification sites.
Mass Spectrometry-Based Proteomics
Mass spectrometry can map autoubiquitination sites on ligases by detecting ubiquitin remnants (diGly) after trypsin digestion. This approach has been used to identify autoubiquitination of DDB1 and other CRL components.
CRISPR-Based Genetic Screens
Genome-wide CRISPR knockout or activation screens can identify genes that regulate autoubiquitination. For example, screens in cancer cells have revealed FBXW7β as a regulator of lipogenesis.
Live-Cell Imaging
Fluorescently tagged ubiquitin and ligases can be used to visualize autoubiquitination dynamics in live cells. This method has been applied to study TRIM23-mediated autophagy.
How CRISPR Can Be Used to Study GO:0051865 protein autoubiquitination
Knockout
CRISPR knockout of autoubiquitinating ligases such as FBXW7β or TRIM23 can reveal their roles in cancer metabolism and antiviral immunity. For example, FBXW7β knockout in colorectal cancer cells enhances lipogenesis and tumor growth. Knockout of TRIM23 impairs cGAS-induced autophagy and anti-HSV defense.
Point Mutation
Point mutations that substitute the acceptor lysine in the ligase with arginine can prevent autoubiquitination while preserving other functions. Such models are invaluable to dissect the specific contribution of autoubiquitination to ERAD, as shown for Hrd1.
Knock-in
Knock-in of patient-derived variants, such as UBR5 mutations, into cell lines or iPSCs can model neurodevelopmental disorders and test genotype-phenotype relationships.
Overexpression
Overexpression of ligases like RNF125 or TRAF6 can enhance autoubiquitination and downstream signaling, enabling gain-of-function studies in immune and cancer pathways [1,6].
How EDITGENE Supports protein autoubiquitination Research
Researchers studying protein autoubiquitination-related genes often need to determine whether a candidate gene is causally involved in a specific biological process or disease. This requires precise genetic models that can isolate the contribution of autoubiquitination from other functions of the ligase. EDITGENE provides a comprehensive suite of CRISPR services to generate such models efficiently and reliably.
Contact EDITGENE today to design your custom CRISPR model for protein autoubiquitination research.
Frequently Asked Questions About protein autoubiquitination
What is protein autoubiquitination?
Protein autoubiquitination (GO:0051865) is the process by which a ubiquitin ligase attaches ubiquitin to its own lysine residues or to residues on an identical protein, forming an isopeptide bond.
What genes are involved in protein autoubiquitination?
Key genes include HRD1, FBXW7, DDB1, TRIM23, TRAF6, RNF125, and UBR5, all of which encode E3 ligases or associated proteins that undergo autoubiquitination [1,2,3,4,5,6,7,8].
How does autoubiquitination regulate protein function?
Autoubiquitination can lead to proteasomal degradation, alter protein localization, or trigger non-degradative functions such as retrotranslocation and autophagy [4,5].
What diseases are associated with defective autoubiquitination?
Defective autoubiquitination is linked to colorectal cancer, lung cancer, neurodevelopmental disorders, and impaired antiviral immunity [1,2,4,6,7,8].
What is the role of Hrd1 autoubiquitination in ERAD?
Hrd1 autoubiquitination triggers protein retrotranslocation from the endoplasmic reticulum to the cytosol for degradation, a critical step in ERAD.
How is autoubiquitination detected experimentally?
Common methods include in vitro ubiquitination assays, mass spectrometry, western blotting, and live-cell imaging with fluorescently tagged ubiquitin [3,4,5].
Can CRISPR be used to study autoubiquitination?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models are widely used to dissect the roles of autoubiquitination in cells and disease models [2,5,8].
What is the difference between autoubiquitination and ubiquitination?
Ubiquitination generally refers to the attachment of ubiquitin to a substrate protein, while autoubiquitination specifically refers to a ligase modifying itself or an identical protein.
Which E3 ligases are known to autoubiquitinate?
Examples include Hrd1, FBXW7β, DDB1 (in CRL4), TRIM23, TRAF6, RNF125, and UBR5 [1,2,3,4,5,6,7,8].
How does autoubiquitination affect cancer?
Autoubiquitination can either promote or suppress cancer. For instance, FBXW7β autoubiquitination limits lipogenesis and tumor growth, while TRAF6 autoubiquitination promotes tumorigenesis [2,6].
Conclusion
Protein autoubiquitination (GO:0051865) is a fundamental self-regulatory mechanism in ubiquitin signaling, with critical roles in protein quality control, immunity, and cancer. The diversity of E3 ligases that undergo autoubiquitination, from Hrd1 to UBR5, underscores its broad biological importance. Dysregulation of this process contributes to human diseases, making it a promising target for therapeutic intervention. Continued research using advanced CRISPR models and proteomic tools will further illuminate the molecular details and disease relevance of autoubiquitination.
References
- 1. Zhao J et al.. 2025. African swine fever virus pMGF505-9R enhances RIG-I-like receptor signaling by promoting RING finger protein 125 autoubiquitination.. J Biol Chem 301(10):110669 PMID: 40889680
- 2. Wei W et al.. 2023. FBXW7β loss-of-function enhances FASN-mediated lipogenesis and promotes colorectal cancer growth.. Signal Transduct Target Ther 8(1):187 PMID: 37202390
- 3. Kim YM et al.. 2025. CRL4 mediates autoubiquitination of DDB1 upon deneddylation inhibition.. Biochem Biophys Res Commun 786:152772 PMID: 41066978
- 4. Acharya D et al.. 2025. TRIM23 mediates cGAS-induced autophagy in anti-HSV defense.. Nat Commun 16(1):4418 PMID: 40360474
- 5. Baldridge RD et al.. 2016. Autoubiquitination of the Hrd1 Ligase Triggers Protein Retrotranslocation in ERAD.. Cell 166(2):394-407 PMID: 27321670
- 6. Li XM et al.. 2024. Histone lactylation inhibits RARγ expression in macrophages to promote colorectal tumorigenesis through activation of TRAF6-IL-6-STAT3 signaling.. Cell Rep 43(2):113688 PMID: 38245869
- 7. Kim JY et al.. 2025. TXNIP Suppresses Lung Cancer Progression by Inhibiting TRAF6-Mediated NF-κB Activation and Autophagy.. Immune Netw 25(5):e33 PMID: 41220844
- 8. Sabeh P et al.. 2025. Heterozygous UBR5 variants result in a neurodevelopmental syndrome with developmental delay, autism, and intellectual disability.. Am J Hum Genet 112(1):75-86 PMID: 39721588
