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Author Spotlight: Characterizing DNA G-Quadruplex by Bis-3-Chloropiperidine Based Chemical Mapping
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Pif1 is essential for efficient replisome progression through lagging strand G-quadruplex DNA secondary structures
Danielle Dahan1, Ioannis Tsirkas1, Daniel Dovrat1
1Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Be'er Sheva 84105, Israel.
Nucleic Acids Research
|November 6, 2018
Summary
The Pif1 DNA helicase is crucial for efficient DNA replication through G-quadruplex (G4) structures, particularly on the lagging strand. Its interaction with PCNA ensures smooth replisome progression, maintaining genome stability in yeast.
Area of Science:
- Molecular Biology
- Genetics
- Biochemistry
Background:
- G-quadruplex (G4) structures pose challenges to DNA replication.
- Pif1 DNA helicase is known to unwind G4 structures in vitro.
- Maintaining genome stability at G4 sequences is vital.
Purpose of the Study:
- To quantitatively measure replication fork progression through G4 sequences in vivo.
- To determine the role of Pif1 in replication fork progression through G4s.
- To investigate the importance of the Pif1-PCNA interaction in G4 replication.
Main Methods:
- Live-cell imaging to track single replication forks.
- Quantitative measurement of replication fork progression rates.
- Analysis of replication rates in wild-type and Pif1-deficient yeast strains.
Main Results:
- Replication rates through lagging strand G4s significantly decreased without Pif1.
- Replication rates through leading strand G4s were unaffected by the absence of Pif1.
- Pif1-PCNA interaction is essential for efficient replication through G4s in vitro and in vivo.
Conclusions:
- Pif1 is essential for efficient replication fork progression through lagging strand G4s.
- The interaction between Pif1 and PCNA is critical for optimal replisome progression at G4 sequences.
- Coupling Pif1 activity with replisome progression is important for yeast genome replication.
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