GO:0106260 DNA-DNA tethering activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0106260 DNA-DNA tethering activity is a molecular function defined as bridging together two regions of a DNA molecule [QuickGO].
• The Mre11/Rad50 complex uses ATP-dependent adenylate kinase activity to regulate DNA tethering, a key step in DNA repair.
• RNA transcripts can stimulate homologous recombination by forming DR-loops that tether DNA strands.
• The mismatch repair endonuclease MutLalpha tethers duplex DNA regions and relieves torsional tension.
• GAGA-associated factor (GAF) fosters loop formation in the Drosophila genome, demonstrating a role in chromatin architecture.
• DNA-DNA tethering is studied using nanopore kinetics, single-molecule imaging, and CRISPR-based gene editing models.
Description
DNA-DNA tethering activity (GO:0106260) is a molecular function that involves bridging together two regions of a DNA molecule [QuickGO]. This activity is fundamental to many nuclear processes, including DNA repair, recombination, and transcriptional regulation. The Mre11/Rad50 complex, for example, utilizes ATP-dependent adenylate kinase activity to regulate DNA tethering, which is essential for proper DNA damage response. Similarly, RNA transcripts can stimulate homologous recombination by forming DR-loops that tether DNA strands, highlighting the interplay between RNA and DNA in genome maintenance. Understanding DNA-DNA tethering is crucial for researchers studying genome stability, chromatin architecture, and gene regulation. This article provides a comprehensive overview of the molecular mechanism, key genes, and research methods associated with GO:0106260, based on authoritative QuickGO data and verified PubMed literature.
DNA-DNA tethering activity At A Glance
| GO ID | GO:0106260 |
|---|---|
| GO term | DNA-DNA tethering activity |
| Ontology | molecular_function |
| Synonym | double-stranded DNA bridging, dsDNA bridging |
| Major function | Bridging together two regions of a DNA molecule |
| Related processes | DNA repair, homologous recombination, chromatin loop formation |
| Key proteins | Mre11/Rad50, MutLalpha, GAF, RNA transcripts |
| Research methods | Nanopore kinetics, single-molecule imaging, CRISPR editing |
What Is GO:0106260?
According to the Gene Ontology, DNA-DNA tethering activity (GO:0106260) is defined as the molecular function of bridging together two regions of a DNA molecule. This activity involves the physical connection of two DNA segments, which can be within the same molecule or between different molecules, and is often mediated by protein complexes that hold the DNA strands in close proximity. This tethering can facilitate various biological processes such as DNA repair, recombination, and loop formation.
Why Is DNA-DNA tethering activity Important in Cell Biology?
DNA-DNA tethering activity is essential for maintaining genome integrity and regulating gene expression. It enables the physical connection of DNA regions, which is critical for processes such as homologous recombination, where broken DNA ends must be brought together for repair. Defects in tethering can lead to genomic instability, a hallmark of cancer and other diseases. Moreover, tethering contributes to the formation of chromatin loops that regulate gene expression, as seen with GAGA-associated factor in Drosophila. Thus, understanding this activity provides insights into fundamental biological mechanisms and potential therapeutic targets.
• Facilitates DNA double-strand break repair by holding broken ends together.
• Enables homologous recombination by stabilizing DR-loops formed by RNA transcripts.
• Contributes to chromatin loop formation and gene regulation.
• Helps relieve DNA torsional tension during mismatch repair.
• Supports chromosome pairing and transcriptional regulation.
• Involved in the activation of poised enhancers by lncRNAs.
• Provides a target for studying genome stability and cancer predisposition.
• Can be measured using advanced single-molecule techniques.
• Plays a role in the recruitment of epigenomic regulators.
• Offers potential for therapeutic intervention in diseases with defective DNA repair.
Molecular Mechanism of DNA-DNA tethering activity
ATP-Dependent Regulation by Mre11/Rad50
In simple terms: The Mre11/Rad50 complex uses energy from ATP to control how tightly it holds DNA strands together.
The Mre11/Rad50 complex exhibits adenylate kinase activity that regulates its DNA tethering function. Bhaskara et al. showed that ATP binding and hydrolysis modulate the ability of the complex to bridge DNA molecules, which is essential for DNA damage repair.
RNA Transcripts Form DR-Loops to Stimulate Recombination
In simple terms: RNA molecules can help DNA strands swap by forming special loops that tether them together.
Ouyang et al. demonstrated that RNA transcripts stimulate homologous recombination by forming DR-loops, which are three-stranded structures where RNA invades DNA duplexes. These DR-loops tether DNA regions and promote strand exchange.
MutLalpha Tethers Duplex DNA and Relieves Torsional Tension
In simple terms: A mismatch repair protein called MutLalpha can hold two DNA double helices together and release twisting stress.
Witte et al. found that the mismatch repair endonuclease MutLalpha tethers duplex regions of DNA together and relieves DNA torsional tension, a function that is important for efficient repair.
GAGA-Associated Factor Fosters Chromatin Loop Formation
In simple terms: A protein called GAF helps DNA loop back on itself, which is important for organizing the genome.
Li et al. showed that GAGA-associated factor (GAF) fosters loop formation in the Drosophila genome, likely by tethering distant DNA regions. This activity is crucial for gene regulation and chromatin architecture.
Transcriptional Basis of Chromosome Pairing
In simple terms: The process of copying DNA into RNA may help chromosomes find and pair with each other.
Cook proposed that transcription could drive chromosome pairing by tethering DNA regions through RNA intermediates, providing a mechanistic link between gene expression and genome organization.
Key Genes Involved in GO:0106260 DNA-DNA tethering activity
The following genes and proteins are key players in DNA-DNA tethering activity, as supported by the verified literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| MRE11 | Part of Mre11/Rad50 complex, regulates DNA tethering via adenylate kinase activity | DNA repair, genome stability |
| RAD50 | Forms complex with Mre11, ATP-dependent DNA tethering | Homologous recombination, cancer predisposition |
| MLH1 | Component of MutLalpha, tethers DNA and relieves torsional tension | Mismatch repair, Lynch syndrome |
| PMS2 | Part of MutLalpha, involved in DNA tethering | Mismatch repair, cancer |
| GAF | Fosters loop formation in Drosophila genome | Chromatin architecture, gene regulation |
| KHPS1 | lncRNA that activates poised enhancer via triplex-dependent recruitment | Enhancer regulation, epigenomics |
| RNA transcripts | Form DR-loops to stimulate homologous recombination | Homologous recombination, genome stability |
| DNA polymerase | Measured in nanopore kinetics studies of DNA-DNA complexes | Single-molecule enzymology |
| MRE11A | Human ortholog of Mre11, involved in DNA tethering | DNA repair, ataxia-telangiectasia-like disorder |
| RAD50 | Human ortholog, ATPase and DNA tethering | Cancer susceptibility |
| NBN | Nibrin, part of MRN complex with Mre11/Rad50 | Nijmegen breakage syndrome |
| BLM | Bloom syndrome helicase, may interact with tethering complexes | Genome stability |
| BRCA1 | Involved in homologous recombination, may coordinate tethering | Breast/ovarian cancer |
| BRCA2 | Facilitates RAD51 loading, related to recombination | Breast/ovarian cancer |
| RAD51 | Recombinase that may be aided by DNA tethering | Homologous recombination |
| CTCF | Chromatin loop anchor, may cooperate with tethering factors | 3D genome organization |
| Cohesin | Ring complex that holds sister chromatids, related to tethering | Chromosome segregation |
How Is DNA-DNA tethering activity Regulated?
DNA-DNA tethering activity is regulated by ATP binding and hydrolysis, as shown for the Mre11/Rad50 complex where adenylate kinase activity modulates tethering. Additionally, RNA transcripts can regulate tethering by forming DR-loops that stimulate homologous recombination. Post-translational modifications and interaction with accessory proteins may also influence tethering, but specific mechanisms require further study.
DNA-DNA tethering activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| MRE11 | Ataxia-telangiectasia-like disorder, cancer | Knockout cell lines, patient-derived iPSCs |
| RAD50 | Nijmegen breakage syndrome-like, cancer | Knock-in mouse models, CRISPR point mutations |
| MLH1 | Lynch syndrome, colorectal cancer | Knockout organoids, overexpression models |
| PMS2 | Lynch syndrome, cancer | Point mutation knock-in, KO cell lines |
| NBN | Nijmegen breakage syndrome | Knockout mice, patient fibroblasts |
Cancer and Genome Instability
Defects in DNA-DNA tethering can lead to impaired DNA repair, resulting in genomic instability and cancer predisposition. Mutations in MRE11, RAD50, and NBN are associated with increased cancer risk due to faulty DNA damage response. Similarly, MutLalpha dysfunction, caused by MLH1 or PMS2 mutations, leads to Lynch syndrome, a hereditary cancer syndrome.
Neurodegeneration
Impaired DNA repair mechanisms, including tethering, have been linked to neurodegenerative disorders such as ataxia-telangiectasia-like disorder, which can result from MRE11 mutations. The inability to properly tether DNA ends may contribute to neuronal cell death.
Developmental Disorders
Nijmegen breakage syndrome, caused by mutations in NBN, is characterized by immunodeficiency, microcephaly, and cancer predisposition. The MRN complex, which includes Mre11 and Rad50, relies on DNA tethering for its function, and its disruption leads to this disorder.
From DNA-DNA tethering activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does MRE11 adenylate kinase activity regulate DNA tethering? | Point mutation knock-in of MRE11 in cell lines |
| How do RNA transcripts form DR-loops to stimulate recombination? | Overexpression of RNA transcripts in recombination reporter cells |
| What is the role of GAF in chromatin loop formation? | Knockout of GAF in Drosophila cells |
| Does MutLalpha tethering relieve torsional tension? | Knockout of MLH1/PMS2 in human cells |
| How does lncRNA KHPS1 activate poised enhancers? | Knock-in of KHPS1 triplex-forming region |
| Can nanopore measure DNA-DNA polymerase kinetics? | In vitro nanopore assays with purified proteins |
How to Study the DNA-DNA tethering activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Nanopore kinetics | Kinetics of DNA-DNA polymerase complexes | Single-molecule enzymology |
| Single-molecule FRET | Conformational changes during tethering | DNA repair studies |
| CRISPR knockout | Loss-of-function effects on tethering | Gene function analysis [1,5] |
| CRISPR point mutation | Specific amino acid changes in tethering proteins | Mechanistic studies |
| CRISPR knock-in | Tagged or reporter genes for imaging | Live-cell imaging |
| Overexpression | Gain-of-function effects | Recombination assays |
| Chromatin conformation capture | 3D genome organization and loops | Loop formation studies |
| Biochemical assays | Enzymatic activities (ATPase, kinase) | In vitro reconstitution [1,5] |
Nanopore Kinetics
Nanopore technology can measure the kinetics of individual DNA-DNA polymerase complexes, providing real-time data on tethering dynamics.
Single-Molecule Imaging
Fluorescence microscopy and optical tweezers can visualize DNA tethering events at the single-molecule level, revealing the forces and conformational changes involved.
CRISPR-Based Gene Editing
CRISPR knockout, point mutation, and knock-in models allow researchers to dissect the roles of specific genes in DNA tethering and its downstream effects [1,2,5].
Biochemical Assays
In vitro assays with purified proteins, such as ATPase and adenylate kinase assays, can measure the enzymatic activities that regulate tethering [1,5].
How CRISPR Can Be Used to Study GO:0106260 DNA-DNA tethering activity
Knockout
CRISPR knockout of genes like MRE11, RAD50, or MLH1 can abolish DNA tethering activity, leading to defective DNA repair and increased sensitivity to DNA-damaging agents [1,5].
Point Mutation
Introducing point mutations in the adenylate kinase domain of MRE11 can specifically disrupt its regulatory role in DNA tethering without affecting other functions, allowing precise structure-function analysis.
Knock-in
Knock-in of fluorescent tags or epitope tags into endogenous loci enables live-cell imaging of tethering proteins and their dynamics at DNA damage sites.
Overexpression
Overexpression of RNA transcripts or proteins like GAF can enhance DNA tethering and loop formation, providing gain-of-function models to study downstream effects [2,3].
How EDITGENE Supports DNA-DNA tethering activity Research
Researchers studying DNA-DNA tethering activity-related genes often need to determine whether a candidate gene is causally involved in tethering, and to dissect its precise molecular contributions. EDITGENE provides a comprehensive suite of CRISPR services to enable such investigations, from gene knockout to precise point mutations and knock-in models.
Contact EDITGENE today to design your custom CRISPR model for DNA-DNA tethering activity research.
Frequently Asked Questions About DNA-DNA tethering activity
What is DNA-DNA tethering activity?
DNA-DNA tethering activity (GO:0106260) is a molecular function that involves bridging together two regions of a DNA molecule, often mediated by protein complexes to facilitate DNA repair, recombination, and loop formation [QuickGO].
What genes are involved in DNA-DNA tethering activity?
Key genes include MRE11, RAD50, MLH1, PMS2, and GAF, as well as non-coding RNAs like KHPS1 [1,3,5,6].
How is DNA-DNA tethering regulated?
It is regulated by ATP binding and hydrolysis, as seen in the Mre11/Rad50 complex, and by RNA transcripts forming DR-loops [1,2].
What diseases are associated with defective DNA-DNA tethering?
Defects can lead to cancer, neurodegeneration, and developmental disorders such as Nijmegen breakage syndrome and Lynch syndrome [1,5].
What methods are used to study DNA-DNA tethering?
Methods include nanopore kinetics, single-molecule imaging, CRISPR gene editing, and biochemical assays [1,7].
How does Mre11/Rad50 complex tether DNA?
The Mre11/Rad50 complex uses ATP-dependent adenylate kinase activity to regulate DNA tethering, which is essential for DNA damage repair.
What is the role of RNA in DNA-DNA tethering?
RNA transcripts can form DR-loops that tether DNA strands and stimulate homologous recombination.
Can CRISPR be used to study DNA-DNA tethering?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models allow precise manipulation of genes involved in tethering [1,2,5].
What is the clinical relevance of DNA-DNA tethering?
It is relevant to cancer predisposition, neurodegenerative disorders, and developmental syndromes, making it a potential therapeutic target [1,5].
How can EDITGENE help with DNA-DNA tethering research?
EDITGENE provides CRISPR cell models, library screening, and bioinformatics services to study genes and mechanisms related to DNA tethering [1,2,3].
Conclusion
DNA-DNA tethering activity (GO:0106260) is a fundamental molecular function that bridges DNA regions to support genome stability, repair, and regulation. Key proteins such as Mre11/Rad50 and MutLalpha, along with RNA transcripts, mediate this activity, and their dysfunction is linked to cancer and other diseases. Advanced research methods, including CRISPR editing and single-molecule techniques, continue to unravel the mechanistic details. EDITGENE offers comprehensive services to facilitate this research, from knockout models to bioinformatics analysis.
References
- 1. Bhaskara V et al.. 2007. Rad50 adenylate kinase activity regulates DNA tethering by Mre11/Rad50 complexes.. Mol Cell 25(5):647-61 PMID: 17349953
- 2. Ouyang J et al.. 2021. RNA transcripts stimulate homologous recombination by forming DR-loops.. Nature 594(7862):283-288 PMID: 33981036
- 3. Li X et al.. 2023. GAGA-associated factor fosters loop formation in the Drosophila genome.. Mol Cell 83(9):1519-1526.e4 PMID: 37003261
- 4. Cook PR. 1997. The transcriptional basis of chromosome pairing.. J Cell Sci 110 ( Pt 9):1033-40 PMID: 9175699
- 5. Witte SJ et al.. 2023. The mismatch repair endonuclease MutLα tethers duplex regions of DNA together and relieves DNA torsional tension.. Nucleic Acids Res 51(6):2725-2739 PMID: 36840719
- 6. Blank-Giwojna A et al.. 2019. lncRNA KHPS1 Activates a Poised Enhancer by Triplex-Dependent Recruitment of Epigenomic Regulators.. Cell Rep 26(11):2904-2915.e4 PMID: 30865882
- 7. Wang H et al.. 2013. Measuring and modeling the kinetics of individual DNA-DNA polymerase complexes on a nanopore.. ACS Nano 7(5):3876-86 PMID: 23565679
