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Updated: May 12, 2026
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Electrophoretic Analysis of Replication Through Structure-Prone DNA Repeats Within the SV40-Based Human Episome
Published on: September 13, 2024
ATM and ATR activities maintain replication fork integrity during SV40 chromatin replication
Gregory A Sowd1, Nancy Yan Li, Ellen Fanning
1Department of Biological Sciences, Vanderbilt University, Vanderbilt Ingram Comprehensive Cancer Center, Nashville, Tennessee, United States of America.
Plos Pathogens
|April 18, 2013
Summary
DNA damage kinases ataxia telangiectasia-mutated (ATM) and ATM- and Rad3-related (ATR) are crucial for genomic stability. This study reveals ATM repairs replication-associated breaks, while ATR prevents fork breakage during DNA replication.
Area of Science:
- Molecular Biology
- Genetics
- Cellular Biology
Background:
- Mutations in DNA damage checkpoint kinases ataxia telangiectasia-mutated (ATM) and ATM- and Rad3-related (ATR) lead to genomic instability.
- The precise relationship between genomic instability, DNA replication/repair defects, and failed cell cycle checkpoint control in these syndromes remains unclear.
Purpose of the Study:
- To investigate the roles of ATM and ATR in maintaining genome stability during DNA replication.
- To elucidate how ATM and ATR signaling pathways respond to replication stress in a model system.
Main Methods:
- Utilized SV40 chromatin replication as a model system in infected cells.
- Employed inhibitors to block ATM and ATR activities.
- Analyzed replication products using two-dimensional gel electrophoresis and southern blotting.
Main Results:
- ATM activity was found to prevent the accumulation of unidirectional replication products, suggesting a role in repairing replication-associated double-strand breaks.
- ATR activity was shown to alleviate breakage at converging replication forks.
- Endogenous replication stress during SV40 chromatin replication activates ATM and ATR signaling.
Conclusions:
- ATM and ATR play distinct but essential roles in maintaining genome integrity during DNA replication.
- These kinases orchestrate the recruitment of genome maintenance machinery to viral replication intermediates in response to replication stress.
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