Dna2 nuclease resolves RNA:DNA hybrids at double-strand breaks

Summary: DNA double-strand breaks (DSBs) are highly detrimental to cells, as improper repair can result in inheritable genetic rearrangements or cell death. The role of RNA:DNA hybrids (RDHs) in DSB repair remains poorly understood, but their transient accumulation and subsequent resolution are cruc...

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Main Authors: Aditya Mojumdar, Courtney Granger, Martine Lunke, Ellis Evans, Jennifer A. Cobb
Format: Article
Language:English
Published: Elsevier 2025-09-01
Series:iScience
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Online Access:http://www.sciencedirect.com/science/article/pii/S2589004225014968
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author Aditya Mojumdar
Courtney Granger
Martine Lunke
Ellis Evans
Jennifer A. Cobb
author_facet Aditya Mojumdar
Courtney Granger
Martine Lunke
Ellis Evans
Jennifer A. Cobb
author_sort Aditya Mojumdar
collection DOAJ
description Summary: DNA double-strand breaks (DSBs) are highly detrimental to cells, as improper repair can result in inheritable genetic rearrangements or cell death. The role of RNA:DNA hybrids (RDHs) in DSB repair remains poorly understood, but their transient accumulation and subsequent resolution are crucial for accurate repair. The absence of the end-joining factor Nej1 at DSBs significantly reduced RDH levels, which was linked to increased activity of the Dna2 nuclease. Dna2 limits the accumulation of hybrids at DSBs, with levels rising in nuclease-dead Dna2 and deletion of RNH201. Dna2 has a heightened preference for resolving RDHs with 5′ RNA overhangs compared to duplex substrates with 5′ DNA overhangs. This selective resolution by Dna2 helps limit hybrid accumulation at DSBs and promotes DNA resection, a function not shared by Exo1. This study underscores the multifunctional roles of canonical repair factors in ensuring efficient homology-directed repair.
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spelling doaj-art-e689a5476ec1425484417e696199e2f12025-08-20T04:01:03ZengElsevieriScience2589-00422025-09-0128911323510.1016/j.isci.2025.113235Dna2 nuclease resolves RNA:DNA hybrids at double-strand breaksAditya Mojumdar0Courtney Granger1Martine Lunke2Ellis Evans3Jennifer A. Cobb4Department of Microbiology & Biochemistry, University of Victoria, Victoria, BC V8W 2Y2, CanadaDepartment of Microbiology & Biochemistry, University of Victoria, Victoria, BC V8W 2Y2, CanadaDepartment of Microbiology & Biochemistry, University of Victoria, Victoria, BC V8W 2Y2, CanadaDepartment of Microbiology & Biochemistry, University of Victoria, Victoria, BC V8W 2Y2, CanadaDepartment of Microbiology & Biochemistry, University of Victoria, Victoria, BC V8W 2Y2, Canada; Corresponding authorSummary: DNA double-strand breaks (DSBs) are highly detrimental to cells, as improper repair can result in inheritable genetic rearrangements or cell death. The role of RNA:DNA hybrids (RDHs) in DSB repair remains poorly understood, but their transient accumulation and subsequent resolution are crucial for accurate repair. The absence of the end-joining factor Nej1 at DSBs significantly reduced RDH levels, which was linked to increased activity of the Dna2 nuclease. Dna2 limits the accumulation of hybrids at DSBs, with levels rising in nuclease-dead Dna2 and deletion of RNH201. Dna2 has a heightened preference for resolving RDHs with 5′ RNA overhangs compared to duplex substrates with 5′ DNA overhangs. This selective resolution by Dna2 helps limit hybrid accumulation at DSBs and promotes DNA resection, a function not shared by Exo1. This study underscores the multifunctional roles of canonical repair factors in ensuring efficient homology-directed repair.http://www.sciencedirect.com/science/article/pii/S2589004225014968BiochemistryMolecular biology
spellingShingle Aditya Mojumdar
Courtney Granger
Martine Lunke
Ellis Evans
Jennifer A. Cobb
Dna2 nuclease resolves RNA:DNA hybrids at double-strand breaks
iScience
Biochemistry
Molecular biology
title Dna2 nuclease resolves RNA:DNA hybrids at double-strand breaks
title_full Dna2 nuclease resolves RNA:DNA hybrids at double-strand breaks
title_fullStr Dna2 nuclease resolves RNA:DNA hybrids at double-strand breaks
title_full_unstemmed Dna2 nuclease resolves RNA:DNA hybrids at double-strand breaks
title_short Dna2 nuclease resolves RNA:DNA hybrids at double-strand breaks
title_sort dna2 nuclease resolves rna dna hybrids at double strand breaks
topic Biochemistry
Molecular biology
url http://www.sciencedirect.com/science/article/pii/S2589004225014968
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