GO:0071819 DUBm complex: Components, Assembly and Research Methods, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• The DUBm complex (GO:0071819) is a four-protein deubiquitinating module within SAGA and SLIK complexes that removes ubiquitin from histone H2B.
• Its core subunits in S. cerevisiae are Ubp8p, Sgf11p, Sus1p, and Sgf73p; metazoan orthologs include USP22, ATXN7L3, ENY2, and ATXN7.
• DUBm activity is essential for proper H2Bub homeostasis, transcriptional regulation, and maintenance of replicative lifespan.
• The module is linked to circadian clock regulation, neurodegeneration (spinocerebellar ataxia type 7), and cancer biology.
• CRISPR knockout, point mutation, knock-in, and overexpression models are key tools for dissecting DUBm subunit functions.
• Understanding DUBm structure and regulation enables targeted therapeutic strategies for diseases driven by epigenetic dysregulation.
Description
The DUBm complex (GO:0071819) is a conserved protein module that forms part of the larger SAGA and SLIK transcriptional coactivator complexes. It mediates the removal of ubiquitin from histone H2B, a critical epigenetic mark that influences transcription elongation, mRNA export, and chromatin dynamics. First identified in Saccharomyces cerevisiae, the DUBm consists of four subunits: Ubp8p (the catalytic deubiquitinase), Sgf11p, Sus1p, and Sgf73p. This module is essential for normal gene expression and has been implicated in diverse biological processes, from circadian rhythm control to aging and neurodegeneration. Researchers study the DUBm complex to understand how histone modifications are dynamically regulated and how their dysregulation contributes to human disease. The DUBm complex is a focal point for investigations into epigenetic mechanisms, as its activity directly impacts chromatin structure and gene transcription. Its evolutionary conservation from yeast to humans underscores its fundamental importance in cellular physiology.
DUBm complex At A Glance
| GO ID | GO:0071819 |
|---|---|
| GO term | DUBm complex |
| Ontology | cellular_component |
| Synonym | deubiquitinating module, deubiquitination module, SAGA DUBm complex |
| Major function | Deubiquitination of histone H2B within SAGA and SLIK complexes |
| Subunits (S. cerevisiae) | Ubp8p, Sgf11p, Sus1p, Sgf73p |
| Subunits (metazoan) | USP22, ATXN7L3, ENY2, ATXN7 |
| Associated complexes | SAGA, SLIK |
| Research relevance | Epigenetic regulation, transcription, aging, neurodegeneration, cancer |
What Is GO:0071819?
The DUBm complex is a protein complex that forms part of SAGA-type complexes SAGA and SLIK, and mediates deubiquitination of histone H2B. In S. cerevisiae, the DUBm consists of the proteins Ubp8p, Sgf11p, Sus1p, and Sgf73p.
Why Is DUBm complex Important in Cell Biology?
The DUBm complex is crucial for epigenetic regulation because it reverses histone H2B ubiquitination, a modification that controls transcription elongation and chromatin accessibility. Dysregulation of DUBm subunits is linked to diseases such as spinocerebellar ataxia type 7 and various cancers, making it a potential therapeutic target. Understanding its structure and regulation provides insights into fundamental gene expression mechanisms and offers avenues for drug discovery.
• Regulates histone H2B ubiquitination homeostasis, impacting transcription and mRNA processing.
• Essential for SAGA and SLIK complex integrity and function in gene activation.
• Modulates circadian clock gene expression through crosstalk with the molecular clock machinery.
• Influences replicative lifespan in yeast via interaction with Sir2.
• Implicated in spinocerebellar ataxia type 7 through polyQ expansions in ATXN7.
• Potential oncogenic role in cancers where USP22 is overexpressed.
• Required for proper localization and activity of the catalytic subunit Ubp8.
• Serves as a model for studying deubiquitinase complex assembly and substrate specificity.
Structure and Composition of DUBm complex
Core Subunits and Stoichiometry
In simple terms: The DUBm is made of four proteins that stick together to form a functional unit.
In Saccharomyces cerevisiae, the DUBm comprises Ubp8p (the catalytic subunit), Sgf11p, Sus1p, and Sgf73p. These subunits assemble in a defined stoichiometry, with Sgf11p and Sgf73p forming a scaffold that positions Ubp8p for catalysis. Sus1p connects the DUBm to the mRNA export machinery, linking deubiquitination to gene expression.
Assembly and Integration into SAGA/SLIK
In simple terms: The DUBm is a module that plugs into larger SAGA and SLIK complexes.
The DUBm associates with the SAGA and SLIK complexes through interactions with core subunits such as Spt7. Sgf73p mediates the attachment of the DUBm to the larger complex, and its absence disrupts DUBm integrity and activity. Proper assembly requires Sgf11p, which stabilizes the complex and enhances Ubp8p catalytic activity.
Structural Features of the Catalytic Subunit Ubp8
In simple terms: Ubp8 is the enzyme that removes ubiquitin, and its shape is critical for function.
Ubp8p contains a conserved USP domain typical of deubiquitinases, with a catalytic cysteine that attacks the ubiquitin-H2B isopeptide bond. Structural studies show that Sgf11p binding induces conformational changes in Ubp8p that are required for optimal activity. The zinc finger domain of Sgf11p also contributes to DNA binding and substrate recognition.
Metazoan Orthologs and Variations
In simple terms: Humans have similar proteins that do the same job but with some differences.
In metazoans, the DUBm consists of USP22 (Ubp8 ortholog), ATXN7L3 (Sgf11 ortholog), ENY2 (Sus1 ortholog), and ATXN7 (Sgf73 ortholog). ATXN7 contains a polyglutamine tract, and its expansion causes spinocerebellar ataxia type 7, though the expansion does not abolish DUBm activity. The plant SAGA complex also contains a DUBm with similar subunit composition, highlighting evolutionary conservation.
Key Genes Involved in GO:0071819 DUBm complex
The following genes encode the core subunits and associated factors of the DUBm complex, with their roles and research relevance.
| Gene | Major Role | Research Relevance |
|---|---|---|
| Ubp8p (USP22) | Catalytic deubiquitinase that removes ubiquitin from H2B | Target for cancer therapy; knockout reduces H2Bub levels |
| Sgf11p (ATXN7L3) | Scaffold subunit essential for DUBm assembly and activity | Mutations affect complex stability and H2B deubiquitination |
| Sus1p (ENY2) | Links DUBm to mRNA export and transcription | Implicated in mRNA export defects and gene expression |
| Sgf73p (ATXN7) | Mediates DUBm attachment to SAGA/SLIK | PolyQ expansion causes spinocerebellar ataxia type 7 |
| Spt7 | Core SAGA subunit required for Ubp8 localization | Knockout mislocalizes Ubp8 and reduces deubiquitinase activity |
| Spt-Ada-Gcn5 | Histone acetyltransferase module of SAGA | Cooperates with DUBm in transcription activation |
| Sir2 | NAD-dependent deacetylase that interacts with DUBm | Modulates replicative lifespan in yeast |
| DET1 | Mediates degradation of a SAGA-like DUBm in plants | Controls H2Bub homeostasis in Arabidopsis |
| ATXN7L3 | Human ortholog of Sgf11 | Involved in DUBm assembly and cancer progression |
| ENY2 | Human ortholog of Sus1 | Component of SAGA and TREX-2 complexes |
| USP22 | Human catalytic subunit | Overexpressed in multiple cancers; potential drug target |
| ATXN7 | Human ortholog of Sgf73 | PolyQ expansion linked to neurodegeneration |
| Ubp8 | Yeast catalytic subunit | Model for studying DUBm function and regulation |
| Sgf11 | Yeast scaffold subunit | Required for Ubp8 activity and DNA binding |
| Sus1 | Yeast mRNA export factor | Couples DUBm to nuclear pore complex |
| Sgf73 | Yeast DUBm attachment factor | Essential for SAGA integrity and lifespan regulation |
How Is DUBm complex Regulated?
The DUBm complex is regulated at multiple levels. Its assembly and activity depend on core SAGA subunits such as Spt7, which ensures correct localization of Ubp8. Post-translational modifications and interactions with Sir2 modulate its role in replicative lifespan. In plants, DET1 mediates degradation of a SAGA-like DUBm to control H2Bub homeostasis. Additionally, the DUBm exhibits bidirectional crosstalk with the molecular circadian clock, influencing clock gene expression.
DUBm complex and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| ATXN7 | Spinocerebellar ataxia type 7 | Knock-in mouse with polyQ expansion; patient iPSC-derived neurons |
| USP22 | Cancer (e.g., breast, colon) | Knockout cancer cell lines; xenograft models |
| ENY2 | mRNA export defects | Yeast sus1 mutants; human cell lines with ENY2 knockdown |
| Sgf73 | Aging and lifespan regulation | Yeast replicative lifespan assays; SGF73 deletion strains |
| Spt7 | Transcription dysregulation | Yeast spt7 mutants; CRISPR knockout in human cells |
Spinocerebellar Ataxia Type 7
Polyglutamine expansions in ATXN7, the human ortholog of Sgf73, cause spinocerebellar ataxia type 7. These expansions affect ATXN7 solubility but do not abolish DUBm activity, suggesting that altered protein interactions contribute to pathogenesis.
Cancer
USP22, the catalytic subunit of the human DUBm, is overexpressed in various cancers and is associated with poor prognosis. Its deubiquitinase activity promotes oncogenic gene expression programs, making it a potential therapeutic target.
Circadian Rhythm Disorders
The DUBm complex shows bidirectional crosstalk with the molecular circadian clock, and its disruption can alter clock gene expression, potentially contributing to circadian rhythm disorders.
Aging and Neurodegeneration
In yeast, the DUBm controls replicative lifespan via interaction with Sir2. In humans, DUBm dysfunction may contribute to age-related neurodegenerative diseases through epigenetic dysregulation.
From DUBm complex-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| What is the catalytic role of Ubp8/USP22 in H2B deubiquitination? | Knockout cell lines (CRISPR/Cas9) and in vitro deubiquitination assays |
| How do point mutations in ATXN7 affect DUBm assembly? | Point-mutation knock-in models (e.g., polyQ expansion) in cell lines or mice |
| Does DUBm subunit overexpression drive oncogenesis? | Overexpression models in cancer cell lines and xenografts |
| How does Sgf11 DNA binding regulate DUBm activity? | Tagged knock-in of Sgf11 mutants; ChIP-seq and deubiquitination assays |
| What is the impact of DUBm on circadian clock genes? | Knockout of DUBm subunits in circadian reporter cell lines; RNA-seq |
| Can DUBm be targeted therapeutically? | Knock-in of tagged USP22 for drug screening; patient-derived organoids |
How to Study the DUBm complex Process
| Method | What It Measures | Typical Application |
|---|---|---|
| RNA-seq | Transcriptome changes | Assessing gene expression upon DUBm knockout |
| ChIP-seq | Histone modification and factor binding | Mapping H2Bub and DUBm occupancy |
| Co-IP / Mass spectrometry | Protein-protein interactions | Identifying DUBm subunits and interactors |
| Deubiquitination assay | Catalytic activity | Measuring Ubp8/USP22 activity in vitro |
| CRISPR knockout | Gene function loss | Studying DUBm subunit roles in cells |
| CRISPR knock-in | Tagged or mutant protein expression | Localization and interaction studies |
| Yeast replicative lifespan assay | Aging phenotype | Evaluating DUBm role in lifespan |
| Circadian reporter assays | Clock gene oscillation | Investigating DUBm-clock crosstalk |
Genomic and Transcriptomic Approaches
RNA-seq and ChIP-seq are used to assess changes in gene expression and histone modifications upon DUBm perturbation. For example, knockout of Ubp8 leads to altered H2Bub levels and transcriptional changes.
Proteomic and Biochemical Assays
Mass spectrometry and co-immunoprecipitation can identify DUBm interactors and subunit stoichiometry. Deubiquitination assays using recombinant proteins or cell lysates measure catalytic activity.
Imaging and Localization Studies
Fluorescence microscopy of tagged DUBm subunits reveals their nuclear localization and association with chromatin. Live-cell imaging can track DUBm dynamics during transcription.
CRISPR-Based Functional Genomics
CRISPR knockout screens and point-mutation knock-ins enable systematic dissection of DUBm gene functions. These approaches can identify synthetic lethal interactions and drug targets.
How CRISPR Can Be Used to Study GO:0071819 DUBm complex
Knockout
CRISPR knockout of DUBm subunits such as USP22 or ATXN7L3 in cell lines abolishes deubiquitinase activity, leading to H2Bub accumulation and altered transcription. These models are used to study loss-of-function phenotypes and identify compensatory pathways.
Point Mutation
Point mutations in the catalytic cysteine of Ubp8 or in the zinc finger of Sgf11 can be introduced via CRISPR to dissect catalytic versus structural roles. Such models help distinguish deubiquitination-dependent and independent functions.
Knock-in
Knock-in of epitope tags (e.g., FLAG, HA) into endogenous DUBm genes enables precise localization and interaction studies. Knock-in of disease-associated mutations, such as ATXN7 polyQ expansions, models spinocerebellar ataxia type 7.
Overexpression
CRISPR activation or cDNA overexpression of DUBm subunits like USP22 can model oncogenic roles and identify downstream targets. Overexpression models are valuable for drug screening and resistance studies.
How EDITGENE Supports DUBm complex Research
Researchers studying DUBm complex-related genes often need to determine whether a candidate gene is causally involved in epigenetic regulation, disease progression, or therapeutic response. EDITGENE provides comprehensive CRISPR-based services to accelerate this discovery process.
Contact EDITGENE today to design your custom CRISPR model for DUBm complex research.
Frequently Asked Questions About DUBm complex
What is the DUBm complex?
The DUBm complex (GO:0071819) is a four-protein deubiquitinating module within SAGA and SLIK complexes that removes ubiquitin from histone H2B.
What genes are involved in the DUBm complex?
Core genes include Ubp8p/USP22, Sgf11p/ATXN7L3, Sus1p/ENY2, and Sgf73p/ATXN7 in yeast and humans.
What is the function of GO:0071819?
It mediates deubiquitination of histone H2B, regulating transcription, mRNA export, and chromatin dynamics.
Which diseases are associated with DUBm complex mutations?
Spinocerebellar ataxia type 7 (ATXN7 polyQ), cancers (USP22 overexpression), and circadian rhythm disorders.
How is the DUBm complex regulated?
Through assembly with SAGA core subunits like Spt7, interaction with Sir2, and degradation mediated by DET1 in plants.
What model systems are used to study DUBm?
Yeast (S. cerevisiae) and human cell lines with CRISPR knockouts, knock-ins, and overexpression.
What is the role of USP22 in cancer?
USP22 is overexpressed in several cancers and promotes oncogenic gene expression, making it a therapeutic target.
How does DUBm affect circadian rhythms?
The DUBm shows bidirectional crosstalk with the molecular circadian clock, influencing clock gene expression.
Can DUBm subunits be targeted by drugs?
Yes, small molecule inhibitors of USP22 are being explored, and CRISPR models aid in target validation.
What CRISPR services are available for DUBm research?
EDITGENE offers knockout, point mutation, knock-in, overexpression, library screening, and bioinformatics for DUBm genes.
Conclusion
The DUBm complex (GO:0071819) is a critical epigenetic regulator that controls histone H2B deubiquitination within SAGA and SLIK complexes. Its subunits are conserved from yeast to humans and are implicated in diverse processes including transcription, aging, circadian rhythms, and disease. Understanding its structure, regulation, and function provides a foundation for developing targeted therapies for cancer and neurodegeneration. Continued research using advanced CRISPR models will further elucidate its mechanistic roles and therapeutic potential.
References
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- 2. Costanzo KM et al.. 2025. Bidirectional Crosstalk Between the SAGA Complex Deubiquitinase Module and the Molecular Circadian Clock.. bioRxiv PMID: 41446136
- 3. Nassrallah A et al.. 2018. DET1-mediated degradation of a SAGA-like deubiquitination module controls H2Bub homeostasis.. Elife 7 PMID: 30192741
- 4. Lan X et al.. 2015. Poly(Q) Expansions in ATXN7 Affect Solubility but Not Activity of the SAGA Deubiquitinating Module.. Mol Cell Biol 35(10):1777-87 PMID: 25755283
- 5. Yan M et al.. 2015. Uncovering the role of Sgf73 in maintaining SAGA deubiquitinating module structure and activity.. J Mol Biol 427(8):1765-78 PMID: 25526805
- 6. Koehler C et al.. 2014. DNA binding by Sgf11 protein affects histone H2B deubiquitination by Spt-Ada-Gcn5-acetyltransferase (SAGA).. J Biol Chem 289(13):8989-99 PMID: 24509845
- 7. McCormick MA et al.. 2014. The SAGA histone deubiquitinase module controls yeast replicative lifespan via Sir2 interaction.. Cell Rep 8(2):477-86 PMID: 25043177
- 8. Nuño-Cabanes C et al.. 2020. SAGA-CORE subunit Spt7 is required for correct Ubp8 localization, chromatin association and deubiquitinase activity.. Epigenetics Chromatin 13(1):46 PMID: 33115507
