ATR protects ongoing and newly assembled DNA replication forks through distinct mechanisms
Summary: The ATR kinase safeguards genomic integrity during S phase, but how ATR protects DNA replication forks remains incompletely understood. Here, we combine four distinct assays to analyze ATR functions at ongoing and newly assembled replication forks upon replication inhibition by hydroxyurea....
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| Format: | Article |
| Language: | English |
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Elsevier
2023-07-01
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| Series: | Cell Reports |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2211124723008033 |
| _version_ | 1797778399451676672 |
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| author | Wendy Leung Antoine Simoneau Sneha Saxena Jessica Jackson Parasvi S. Patel Mangsi Limbu Alessandro Vindigni Lee Zou |
| author_facet | Wendy Leung Antoine Simoneau Sneha Saxena Jessica Jackson Parasvi S. Patel Mangsi Limbu Alessandro Vindigni Lee Zou |
| author_sort | Wendy Leung |
| collection | DOAJ |
| description | Summary: The ATR kinase safeguards genomic integrity during S phase, but how ATR protects DNA replication forks remains incompletely understood. Here, we combine four distinct assays to analyze ATR functions at ongoing and newly assembled replication forks upon replication inhibition by hydroxyurea. At ongoing forks, ATR inhibitor (ATRi) increases MRE11- and EXO1-mediated nascent DNA degradation from PrimPol-generated, single-stranded DNA (ssDNA) gaps. ATRi also exposes template ssDNA through fork uncoupling and nascent DNA degradation. Electron microscopy reveals that ATRi reduces reversed forks by increasing gap-dependent nascent DNA degradation. At new forks, ATRi triggers MRE11- and CtIP-initiated template DNA degradation by EXO1, exposing nascent ssDNA. Upon PARP inhibition, ATRi preferentially exacerbates gap-dependent nascent DNA degradation at ongoing forks in BRCA1/2-deficient cells and disrupts the restored gap protection in BRCA1-deficient, PARP-inhibitor-resistant cells. Thus, ATR protects ongoing and new forks through distinct mechanisms, providing an extended view of ATR’s functions in stabilizing replication forks. |
| first_indexed | 2024-03-12T23:17:43Z |
| format | Article |
| id | doaj.art-cdd77a82eef24f59b9521c5d45cbc32a |
| institution | Directory Open Access Journal |
| issn | 2211-1247 |
| language | English |
| last_indexed | 2024-03-12T23:17:43Z |
| publishDate | 2023-07-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Cell Reports |
| spelling | doaj.art-cdd77a82eef24f59b9521c5d45cbc32a2023-07-17T04:07:37ZengElsevierCell Reports2211-12472023-07-01427112792ATR protects ongoing and newly assembled DNA replication forks through distinct mechanismsWendy Leung0Antoine Simoneau1Sneha Saxena2Jessica Jackson3Parasvi S. Patel4Mangsi Limbu5Alessandro Vindigni6Lee Zou7Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USAMassachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USAMassachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USADivision of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USAMassachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USADivision of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USADivision of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA; Corresponding authorMassachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA; Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02115, USA; Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC 27708, USA; Corresponding authorSummary: The ATR kinase safeguards genomic integrity during S phase, but how ATR protects DNA replication forks remains incompletely understood. Here, we combine four distinct assays to analyze ATR functions at ongoing and newly assembled replication forks upon replication inhibition by hydroxyurea. At ongoing forks, ATR inhibitor (ATRi) increases MRE11- and EXO1-mediated nascent DNA degradation from PrimPol-generated, single-stranded DNA (ssDNA) gaps. ATRi also exposes template ssDNA through fork uncoupling and nascent DNA degradation. Electron microscopy reveals that ATRi reduces reversed forks by increasing gap-dependent nascent DNA degradation. At new forks, ATRi triggers MRE11- and CtIP-initiated template DNA degradation by EXO1, exposing nascent ssDNA. Upon PARP inhibition, ATRi preferentially exacerbates gap-dependent nascent DNA degradation at ongoing forks in BRCA1/2-deficient cells and disrupts the restored gap protection in BRCA1-deficient, PARP-inhibitor-resistant cells. Thus, ATR protects ongoing and new forks through distinct mechanisms, providing an extended view of ATR’s functions in stabilizing replication forks.http://www.sciencedirect.com/science/article/pii/S2211124723008033CP: Molecular biology |
| spellingShingle | Wendy Leung Antoine Simoneau Sneha Saxena Jessica Jackson Parasvi S. Patel Mangsi Limbu Alessandro Vindigni Lee Zou ATR protects ongoing and newly assembled DNA replication forks through distinct mechanisms Cell Reports CP: Molecular biology |
| title | ATR protects ongoing and newly assembled DNA replication forks through distinct mechanisms |
| title_full | ATR protects ongoing and newly assembled DNA replication forks through distinct mechanisms |
| title_fullStr | ATR protects ongoing and newly assembled DNA replication forks through distinct mechanisms |
| title_full_unstemmed | ATR protects ongoing and newly assembled DNA replication forks through distinct mechanisms |
| title_short | ATR protects ongoing and newly assembled DNA replication forks through distinct mechanisms |
| title_sort | atr protects ongoing and newly assembled dna replication forks through distinct mechanisms |
| topic | CP: Molecular biology |
| url | http://www.sciencedirect.com/science/article/pii/S2211124723008033 |
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