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Updated: Oct 29, 2025
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Single-Molecule Fluorescence Visualization of DNA Polymerase Dynamics at G-Quadruplexes
Published on: April 4, 2025
922
DNA G-quadruplex structures: more than simple roadblocks to transcription?
Jenna Robinson1,2, Federica Raguseo1,2, Sabrina Pia Nuccio1,2
1Imperial College London, Chemistry Department, Molecular Sciences Research Hub, 82 Wood Lane, London W12 0BZ, UK.
Nucleic Acids Research
|July 13, 2021
Summary
G-quadruplexes (G4s) in gene promoters are more than just transcriptional roadblocks. This review challenges the simplistic
Area of Science:
- Molecular Biology
- Genetics
- Epigenetics
Background:
- G-quadruplex (G4) DNA structures in gene promoters have been studied for over 20 years for their role in gene expression regulation.
- Small molecules targeting G4s have advanced understanding of their role in transcription.
- A prevailing model viewed G4s as simple repressors of transcription by blocking polymerase movement.
Purpose of the Study:
- To challenge the simplistic model of G4s as mere transcriptional roadblocks or 'off switches'.
- To present evidence that G4 formation regulates gene expression at multiple levels.
- To highlight G4s as key regulatory elements influencing epigenetic marks and chromatin architecture.
Main Methods:
- Review of existing scientific literature on G-quadruplex structures and gene expression.
- Analysis of studies investigating the role of G4s in transcription regulation.
- Synthesis of evidence regarding G4s' impact on epigenetic modifications and chromatin.
Main Results:
- Recent studies provide substantial evidence against the simplistic model of G4s as solely transcriptional repressors.
- G4 formation can influence gene expression through mechanisms beyond blocking polymerase processivity.
- G4s act as regulatory elements that can alter epigenetic landscapes and chromatin organization.
Conclusions:
- The role of G-quadruplexes in gene regulation is complex and multifaceted, not limited to transcriptional repression.
- G4s are crucial regulatory elements that interact with epigenetic machinery and chromatin structure.
- Revisiting the understanding of G4s is essential for a comprehensive view of gene expression control.
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