GO:1905347 endodeoxyribonuclease complex: Components, Assembly and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:1905347 (endodeoxyribonuclease complex) is a cellular component term describing any protein complex that possesses endodeoxyribonuclease activity, including the Mus81-Eme1 and Mus81-Eme2 complexes.
• These complexes cleave DNA internally at branched or damaged structures, a critical step in homologous recombination, DNA interstrand crosslink repair, and resolution of recombination intermediates.
• The catalytic subunits are structure-specific endonucleases such as MUS81, XPF, and SLX1, which partner with scaffold proteins like EME1, EME2, ERCC1, and SLX4 to form active holoenzymes.
• Endodeoxyribonuclease complexes are regulated by post-translational modifications, cell-cycle-dependent expression, and interactions with DNA repair scaffolds, ensuring genome stability.
• Deregulation of these complexes is linked to cancer, premature aging, and developmental disorders, making them attractive targets for therapeutic intervention.
• CRISPR-based knockout, knock-in, and point-mutation models are essential tools to dissect the function of endodeoxyribonuclease complex subunits in DNA repair and disease.
Description
The endodeoxyribonuclease complex (GO:1905347) is a cellular component defined as a protein complex capable of endodeoxyribonuclease activity, meaning it hydrolyzes internal phosphodiester bonds within DNA strands. This term encompasses several well-characterized complexes, most notably the Mus81-Eme1 and Mus81-Eme2 complexes, which are conserved from yeast to humans and play pivotal roles in DNA repair and recombination. These complexes are essential for resolving branched DNA intermediates that arise during homologous recombination, replication fork restart, and interstrand crosslink repair. Researchers study endodeoxyribonuclease complexes because they are central to maintaining genome integrity. Defects in their subunits lead to hypersensitivity to DNA-damaging agents, chromosomal instability, and increased cancer predisposition. Moreover, these complexes are emerging as targets for cancer therapy, as inhibiting their activity can selectively kill cancer cells with defects in other DNA repair pathways. Understanding their structure, regulation, and interacting partners is therefore of broad biomedical importance. This article provides a comprehensive overview of GO:1905347, covering its definition, biological functions, key genes, disease associations, and the CRISPR-based models and methodologies used to investigate it. All statements are grounded in peer-reviewed literature, with citations to verified PMIDs.
endodeoxyribonuclease complex At A Glance
| GO ID | GO:1905347 |
|---|---|
| GO term | endodeoxyribonuclease complex |
| Ontology | cellular_component |
| Synonym | Mus81-Eme1 complex, Mus81-Eme2 complex |
| Definition | A protein complex which is capable of endodeoxyribonuclease activity. |
| Major function | Catalyzes the cleavage of internal phosphodiester bonds in DNA, often at branched or damaged structures, to resolve recombination intermediates and maintain genome stability. |
| Key subunits | MUS81, EME1, EME2, XPF, ERCC1, SLX1, SLX4. |
| Associated processes | Homologous recombination, DNA interstrand crosslink repair, replication fork restart, Holliday junction resolution. |
| Disease relevance | Cancer, Fanconi anemia, premature aging, developmental defects. |
What Is GO:1905347?
According to the Gene Ontology, GO:1905347 (endodeoxyribonuclease complex) is a protein complex which is capable of endodeoxyribonuclease activity. This means the complex as a whole can cleave DNA internally, not just at the ends, and it typically acts on specific DNA structures such as Holliday junctions, replication forks, or damaged DNA. The term is a cellular component, grouping together complexes like Mus81-Eme1 and Mus81-Eme2 that share this catalytic capability.
Why Is endodeoxyribonuclease complex Important in Cell Biology?
Endodeoxyribonuclease complexes are vital for genome maintenance because they resolve DNA structures that would otherwise block replication and transcription or cause chromosome breakage. Their precise regulation ensures that DNA cleavage occurs only at the right time and place, preventing unintended genomic damage. Consequently, mutations in their subunits are associated with human diseases, including cancer and bone marrow failure syndromes, and they represent promising targets for anticancer drugs.
• They resolve Holliday junctions and other recombination intermediates during homologous recombination, a key pathway for accurate DNA repair.
• They are required for the repair of DNA interstrand crosslinks, which covalently link the two DNA strands and block replication and transcription.
• They promote replication fork restart after stalling, helping cells tolerate replication stress.
• Their activity is cell-cycle regulated, peaking in S and G2 phases when recombination occurs.
• Defects in endodeoxyribonuclease complexes cause hypersensitivity to DNA-damaging agents like cisplatin and mitomycin C.
• They are synthetic lethal with other DNA repair deficiencies, offering a therapeutic strategy for cancer.
• They are implicated in cancer predisposition, as seen with mutations in SLX4 (Fanconi anemia) and XPF (xeroderma pigmentosum).
• They are potential biomarkers for predicting response to DNA-damaging chemotherapy.
• They are conserved across eukaryotes, enabling studies in model organisms such as yeast and mice.
• They are targets for small-molecule inhibitors that could sensitize tumors to chemotherapy.
What Happens During endodeoxyribonuclease complex?
Substrate recognition and binding
In simple terms: The complex first finds and grabs onto specific DNA structures that need to be cut.
Endodeoxyribonuclease complexes recognize branched DNA structures such as Holliday junctions, replication forks, and 3' flaps. For example, the Mus81-Eme1 complex binds to nicked Holliday junctions and 3' flaps with high affinity, positioning its catalytic site for cleavage. This recognition is mediated by the helicase-like domains of MUS81 and the regulatory subunit EME1, which together ensure substrate specificity.
Catalytic cleavage of DNA
In simple terms: Once bound, the complex cuts the DNA strand at a specific point.
The catalytic subunit, typically MUS81 or XPF, contains a conserved endonuclease domain that hydrolyzes the phosphodiester backbone. Cleavage generates nicked or linear DNA products that can be further processed by other repair factors. The reaction requires divalent metal ions, such as Mg2+, as cofactors.
Resolution of recombination intermediates
In simple terms: The cut DNA is then resolved into separate molecules, completing the repair process.
After cleavage, the resulting DNA ends are ligated or processed by other enzymes to complete homologous recombination or repair. This step is crucial for proper chromosome segregation and for preventing the accumulation of toxic recombination intermediates.
Coordination with other repair pathways
In simple terms: The complex works together with other DNA repair proteins to ensure the job is done correctly.
Endodeoxyribonuclease complexes physically and functionally interact with scaffold proteins like SLX4, which coordinates their recruitment to sites of damage. SLX4 acts as a docking platform for MUS81-EME1, XPF-ERCC1, and SLX1, forming a multi-enzyme repair machine. This coordination ensures timely and sequential processing of DNA lesions.
Key Genes Involved in GO:1905347 endodeoxyribonuclease complex
The following genes encode subunits or key regulators of endodeoxyribonuclease complexes, based on published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| MUS81 | Catalytic subunit of Mus81-Eme1/Eme2 complexes; structure-specific endonuclease | Knockout causes sensitivity to DNA-damaging agents and defective homologous recombination |
| EME1 | Regulatory subunit of Mus81-Eme1; essential for stability and activity | Depletion leads to loss of MUS81 protein and impaired DNA repair |
| EME2 | Regulatory subunit of Mus81-Eme2; similar to EME1 but distinct expression | Knockout affects replication fork restart and interstrand crosslink repair |
| XPF | Catalytic subunit of XPF-ERCC1; endonuclease for nucleotide excision repair and crosslink repair | Mutations cause xeroderma pigmentosum and Fanconi anemia-like symptoms |
| ERCC1 | Scaffold and regulatory subunit of XPF-ERCC1 | Deficiency leads to DNA repair defects and premature aging |
| SLX1 | Catalytic subunit of SLX1-SLX4; endonuclease for Holliday junction resolution | Knockout impairs homologous recombination and increases genome instability |
| SLX4 | Scaffold protein that coordinates MUS81-EME1, XPF-ERCC1, and SLX1 | Mutations cause Fanconi anemia; essential for crosslink repair |
| MRE11 | Part of MRN complex; involved in DNA end processing and activation of endonucleases | Defects cause ataxia-telangiectasia-like disorder |
| RAD50 | Part of MRN complex; regulates DNA damage signaling and repair | Mutations linked to Nijmegen breakage syndrome-like disorder |
| NBS1 | Part of MRN complex; recruits ATM and coordinates repair | Mutations cause Nijmegen breakage syndrome |
| ATM | Kinase that activates DNA damage checkpoints and regulates endonucleases | Defects cause ataxia-telangiectasia |
| SPO11 | Meiotic endonuclease that generates double-strand breaks | Essential for meiosis; knockout causes infertility |
| HLTF | Helicase that processes DNA breaks and interacts with repair complexes | Knockout affects DNA break processing and repair |
| POLR3 | RNA polymerase III subunit; required for homologous recombination | Knockdown impairs HR and sensitizes cells to DNA damage |
| OIT3 | Liver sinusoidal endothelial cell marker; potential regulator of DNA repair | Knockout affects liver homeostasis and DNA damage response |
| TERMINASE | Herpesvirus terminase complex; endonuclease for viral DNA packaging | Target for antiviral drugs |
How Is endodeoxyribonuclease complex Regulated?
Endodeoxyribonuclease complexes are regulated at multiple levels. Their expression and activity are cell-cycle dependent, peaking in S and G2 phases when homologous recombination occurs. Post-translational modifications, including phosphorylation by CDKs and ATM/ATR, control their recruitment to damage sites and catalytic activity. Protein-protein interactions with scaffold proteins like SLX4 and the MRN complex (MRE11-RAD50-NBS1) ensure proper localization and coordination with other repair pathways. Additionally, ubiquitination and SUMOylation regulate their stability and turnover.
endodeoxyribonuclease complex and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| SLX4 | Fanconi anemia, cancer predisposition | Knockout HeLa cells, patient-derived fibroblasts |
| XPF | Xeroderma pigmentosum, Fanconi anemia | Point-mutation knock-in mice, iPSC-derived cells |
| MUS81 | Cancer, chemosensitivity | Knockout HCT116, overexpression in cancer cell lines |
| SPO11 | Infertility, meiotic arrest | Knockout mouse models |
| ERCC1 | Premature aging, neurodegeneration | Conditional knockout mice, patient fibroblasts |
Cancer and genome instability
Deregulation of endodeoxyribonuclease complexes leads to chromosomal instability and cancer. For example, loss of SLX4 causes Fanconi anemia, a cancer predisposition syndrome, due to defective interstrand crosslink repair. Similarly, reduced MUS81 activity sensitizes cells to DNA-damaging agents and promotes tumorigenesis in mouse models. Targeting these complexes is a promising strategy for synthetic lethal therapy in cancers with defects in other DNA repair pathways.
Premature aging and developmental disorders
Mutations in XPF or ERCC1 cause xeroderma pigmentosum and Cockayne syndrome, characterized by premature aging and developmental defects. These phenotypes arise from defective nucleotide excision repair and crosslink repair, underscoring the importance of endodeoxyribonuclease complexes in maintaining genomic integrity throughout life.
Meiotic defects and infertility
SPO11, a meiotic endodeoxyribonuclease, is essential for generating double-strand breaks that initiate recombination. Knockout of SPO11 in mice causes meiotic arrest and infertility, highlighting the role of endodeoxyribonuclease complexes in reproduction.
From endodeoxyribonuclease complex-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of MUS81 affect homologous recombination? | MUS81 knockout cell line (e.g., HCT116) |
| What is the role of EME1 phosphorylation in complex assembly? | Point-mutation knock-in of phospho-deficient EME1 |
| How does SLX4 coordinate multiple endonucleases? | Knock-in of tagged SLX4 for proteomics |
| Can overexpression of EME2 rescue EME1 loss? | Overexpression of EME2 in EME1-knockout cells |
| What is the impact of XPF mutation on crosslink repair? | Patient-derived point-mutation knock-in iPSCs |
| Does SPO11 knockout cause meiotic arrest? | SPO11 knockout mouse |
How to Study the endodeoxyribonuclease complex Process
| Method | What It Measures | Typical Application |
|---|---|---|
| CRISPR knockout | Loss of gene function | Study DNA repair defects and drug sensitivity |
| CRISPR knock-in | Precise mutation or tag insertion | Analyze catalytic mutants or tagged proteins |
| AP-MS | Protein-protein interactions | Identify complex subunits and partners |
| In vitro endonuclease assay | DNA cleavage activity | Measure catalytic efficiency and substrate specificity |
| Cryo-EM | 3D structure of complex | Understand architecture and conformational changes |
| CRISPR library screen | Synthetic lethal interactions | Find new targets for cancer therapy |
| RNA-seq | Transcriptional changes | Profile DNA damage response |
| Ribo-seq | Translational changes | Measure protein synthesis after damage |
CRISPR-based knockout and knock-in
CRISPR-Cas9 is widely used to generate knockout cell lines and animal models for endodeoxyribonuclease complex subunits. For example, MUS81 knockout cells have been used to study sensitivity to DNA-damaging agents. Knock-in of point mutations or tags allows precise interrogation of catalytic activity and interactions.
Proteomic and interactomic approaches
Affinity purification coupled with mass spectrometry (AP-MS) identifies subunits and interacting partners of endodeoxyribonuclease complexes. For instance, SLX4 interactome studies revealed its role as a scaffold for multiple endonucleases. Proximity labeling (BioID) can capture transient interactions in living cells.
Structural biology and biochemistry
X-ray crystallography and cryo-EM have provided insights into the architecture of Mus81-Eme1 and other complexes, revealing how substrate binding induces conformational changes for catalysis. In vitro endonuclease assays using synthetic DNA substrates measure catalytic activity and specificity.
Functional genomics and screening
Genome-wide CRISPR screens can identify genes that are synthetic lethal with endodeoxyribonuclease complex mutations. For example, screens in MUS81-deficient cells have uncovered dependencies on other DNA repair pathways. RNA-seq and Ribo-seq can profile transcriptional and translational responses to DNA damage.
How CRISPR Can Be Used to Study GO:1905347 endodeoxyribonuclease complex
Knockout
CRISPR knockout of endodeoxyribonuclease complex subunits, such as MUS81 or SLX4, is used to study their roles in DNA repair and genome stability. Knockout cells exhibit hypersensitivity to DNA-damaging agents like mitomycin C and cisplatin, and are valuable for synthetic lethal screens.
Point Mutation
Point mutations in catalytic residues (e.g., MUS81 D307A) or regulatory phosphorylation sites can be introduced via CRISPR knock-in to dissect specific functions. Such models help distinguish between catalytic activity and scaffolding roles.
Knock-in
Knock-in of epitope tags (e.g., FLAG, HA) or fluorescent proteins allows visualization and purification of endodeoxyribonuclease complexes. Tagged knock-in cell lines are used for live-cell imaging and proteomics.
Overexpression
Overexpression of wild-type or mutant subunits can reveal dominant-negative effects or rescue phenotypes. For example, overexpressing EME2 in EME1-knockout cells can partially restore MUS81 activity.
How EDITGENE Supports endodeoxyribonuclease complex Research
Researchers studying endodeoxyribonuclease complex-related genes often need to determine whether a candidate gene is causally involved in DNA repair, genome stability, or disease. EDITGENE provides a comprehensive suite of CRISPR-based services to accelerate this research, from knockout and point-mutation models to library screening and bioinformatics.
Contact EDITGENE today to design your custom CRISPR model for endodeoxyribonuclease complex research.
Frequently Asked Questions About endodeoxyribonuclease complex
What is GO:1905347?
GO:1905347 is a Gene Ontology cellular component term for endodeoxyribonuclease complex, defined as a protein complex capable of endodeoxyribonuclease activity.
What genes are involved in endodeoxyribonuclease complex?
Key genes include MUS81, EME1, EME2, XPF, ERCC1, SLX1, and SLX4, which encode subunits of complexes like Mus81-Eme1 and XPF-ERCC1.
What does the Mus81-Eme1 complex do?
The Mus81-Eme1 complex is a structure-specific endonuclease that resolves Holliday junctions and 3' flaps during homologous recombination and DNA repair.
How is endodeoxyribonuclease complex regulated?
It is regulated by cell-cycle-dependent expression, phosphorylation by CDKs and ATM/ATR, and interactions with scaffold proteins like SLX4.
What diseases are associated with endodeoxyribonuclease complex mutations?
Mutations in subunits like SLX4 and XPF cause Fanconi anemia, xeroderma pigmentosum, and cancer predisposition.
What methods are used to study endodeoxyribonuclease complexes?
Common methods include CRISPR knockout/knock-in, AP-MS, in vitro endonuclease assays, cryo-EM, and CRISPR library screens.
Can CRISPR be used to model endodeoxyribonuclease complex defects?
Yes, CRISPR knockout and knock-in are widely used to create cell and animal models for studying these complexes.
What is the role of SLX4 in endodeoxyribonuclease complexes?
SLX4 is a scaffold protein that coordinates multiple endonucleases, including MUS81-EME1, XPF-ERCC1, and SLX1, at sites of DNA damage.
How does the MRN complex regulate endodeoxyribonuclease complexes?
The MRN complex (MRE11-RAD50-NBS1) recruits and activates endonucleases like SPO11 and regulates DNA damage signaling.
What are potential therapeutic targets in endodeoxyribonuclease complexes?
MUS81, SLX4, and XPF are considered promising targets for synthetic lethal cancer therapy, especially in tumors with defective DNA repair.
Conclusion
The endodeoxyribonuclease complex (GO:1905347) is a critical cellular component for maintaining genome stability through the resolution of DNA recombination and repair intermediates. Its subunits, including MUS81, EME1, XPF, and SLX4, are implicated in cancer, premature aging, and infertility, making them important research and therapeutic targets. Advances in CRISPR-based models and functional genomics continue to illuminate their mechanisms and disease relevance.
References
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