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Detection of Homologous Recombination Intermediates via Proximity Ligation and Quantitative PCR in Saccharomyces cerevisiae
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Break-induced replication promotes formation of lethal joint molecules dissolved by Srs2
Rajula Elango1, Ziwei Sheng2, Jessica Jackson3
1Department of Biology, University of Iowa, Iowa City, IA, 52242, USA.
Nature Communications
|November 28, 2017
Summary
Break-induced replication (BIR) repair can cause genomic instability. The protein Srs2 prevents toxic DNA structures by controlling Rad51 binding to single-stranded DNA (ssDNA) during BIR.
Area of Science:
- Molecular Biology
- Genetics
- DNA Repair
Background:
- Break-induced replication (BIR) is a DNA repair pathway.
- BIR can lead to genomic instability, similar to cancer.
- Uncontrolled single-stranded DNA (ssDNA) interactions during BIR pose a risk.
Purpose of the Study:
- Investigate the role of Srs2 in managing ssDNA during BIR.
- Determine how cells prevent toxic DNA structures arising from BIR.
- Elucidate the mechanisms preventing unscheduled DNA pairing during BIR.
Main Methods:
- Investigated the function of Srs2 in controlling Rad51 binding to ssDNA.
- Analyzed the role of structure-specific endonucleases (Mus81, Yen1) in BIR survivors.
- Studied the formation and resolution of toxic joint molecules during BIR.
Main Results:
- Srs2 dislodges Rad51 from ssDNA, preventing promiscuous strand invasions.
- Srs2 dismantles toxic DNA intermediates formed during BIR.
- Mus81 and Yen1 resolve toxic joint molecules in Srs2-deficient cells.
Conclusions:
- Tight control of ssDNA during BIR is essential for cell viability.
- Srs2 plays a crucial role in preventing genomic instability during BIR.
- Uncontrolled Rad51 binding to ssDNA can lead to toxic structures that threaten cells.
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