ATR protects ongoing and newly assembled DNA replication forks through distinct mechanisms

Bibliographic Details
Title: ATR protects ongoing and newly assembled DNA replication forks through distinct mechanisms
Authors: Wendy Leung, Antoine Simoneau, Sneha Saxena, Jessica Jackson, Parasvi S. Patel, Mangsi Limbu, Alessandro Vindigni, Lee Zou
Source: Cell Reports, Vol 42, Iss 7, Pp 112792- (2023)
Publisher Information: Elsevier, 2023.
Publication Year: 2023
Collection: LCC:Biology (General)
Subject Terms: CP: Molecular biology, Biology (General), QH301-705.5
More Details: 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.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 2211-1247
Relation: http://www.sciencedirect.com/science/article/pii/S2211124723008033; https://doaj.org/toc/2211-1247
DOI: 10.1016/j.celrep.2023.112792
Access URL: https://doaj.org/article/cdd77a82eef24f59b9521c5d45cbc32a
Accession Number: edsdoj.77a82eef24f59b9521c5d45cbc32a
Database: Directory of Open Access Journals
More Details
ISSN:22111247
DOI:10.1016/j.celrep.2023.112792
Published in:Cell Reports
Language:English