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Replication Fork Reversal during DNA Interstrand Crosslink Repair Requires CMG Unloading

DNA interstrand crosslinks (ICLs) are extremely cytotoxic, but the mechanism of their repair remains incompletely understood. Using Xenopus egg extracts, we previously showed that repair of a cisplatin ICL is triggered when two replication forks converge on the lesion. After CDC45/MCM2-7/GINS (CMG)...

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Autores principales: Amunugama, Ravindra, Willcox, Smaranda, Wu, R. Alex, Abdullah, Ummi B., El-Sagheer, Afaf H., Brown, Tom, McHugh, Peter J., Griffith, Jack D., Walter, Johannes C.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6086610/
https://www.ncbi.nlm.nih.gov/pubmed/29924986
http://dx.doi.org/10.1016/j.celrep.2018.05.061
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author Amunugama, Ravindra
Willcox, Smaranda
Wu, R. Alex
Abdullah, Ummi B.
El-Sagheer, Afaf H.
Brown, Tom
McHugh, Peter J.
Griffith, Jack D.
Walter, Johannes C.
author_facet Amunugama, Ravindra
Willcox, Smaranda
Wu, R. Alex
Abdullah, Ummi B.
El-Sagheer, Afaf H.
Brown, Tom
McHugh, Peter J.
Griffith, Jack D.
Walter, Johannes C.
author_sort Amunugama, Ravindra
collection PubMed
description DNA interstrand crosslinks (ICLs) are extremely cytotoxic, but the mechanism of their repair remains incompletely understood. Using Xenopus egg extracts, we previously showed that repair of a cisplatin ICL is triggered when two replication forks converge on the lesion. After CDC45/MCM2-7/GINS (CMG) ubiquitylation and unloading by the p97 segregase, FANCI-FANCD2 promotes DNA incisions by XPF-ERCC1, leading to ICL unhooking. Here, we report that, during this cell-free ICL repair reaction, one of the two converged forks undergoes reversal. Fork reversal fails when CMG unloading is inhibited, but it does not require FANCI-FANCD2. After one fork has undergone reversal, the opposing fork that still abuts the ICL undergoes incisions. Our data show that replication fork reversal at an ICL requires replisome disassembly. We present a revised model of ICL repair that involves a reversed fork intermediate.
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spelling pubmed-60866102018-08-10 Replication Fork Reversal during DNA Interstrand Crosslink Repair Requires CMG Unloading Amunugama, Ravindra Willcox, Smaranda Wu, R. Alex Abdullah, Ummi B. El-Sagheer, Afaf H. Brown, Tom McHugh, Peter J. Griffith, Jack D. Walter, Johannes C. Cell Rep Article DNA interstrand crosslinks (ICLs) are extremely cytotoxic, but the mechanism of their repair remains incompletely understood. Using Xenopus egg extracts, we previously showed that repair of a cisplatin ICL is triggered when two replication forks converge on the lesion. After CDC45/MCM2-7/GINS (CMG) ubiquitylation and unloading by the p97 segregase, FANCI-FANCD2 promotes DNA incisions by XPF-ERCC1, leading to ICL unhooking. Here, we report that, during this cell-free ICL repair reaction, one of the two converged forks undergoes reversal. Fork reversal fails when CMG unloading is inhibited, but it does not require FANCI-FANCD2. After one fork has undergone reversal, the opposing fork that still abuts the ICL undergoes incisions. Our data show that replication fork reversal at an ICL requires replisome disassembly. We present a revised model of ICL repair that involves a reversed fork intermediate. 2018-06-19 /pmc/articles/PMC6086610/ /pubmed/29924986 http://dx.doi.org/10.1016/j.celrep.2018.05.061 Text en http://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
spellingShingle Article
Amunugama, Ravindra
Willcox, Smaranda
Wu, R. Alex
Abdullah, Ummi B.
El-Sagheer, Afaf H.
Brown, Tom
McHugh, Peter J.
Griffith, Jack D.
Walter, Johannes C.
Replication Fork Reversal during DNA Interstrand Crosslink Repair Requires CMG Unloading
title Replication Fork Reversal during DNA Interstrand Crosslink Repair Requires CMG Unloading
title_full Replication Fork Reversal during DNA Interstrand Crosslink Repair Requires CMG Unloading
title_fullStr Replication Fork Reversal during DNA Interstrand Crosslink Repair Requires CMG Unloading
title_full_unstemmed Replication Fork Reversal during DNA Interstrand Crosslink Repair Requires CMG Unloading
title_short Replication Fork Reversal during DNA Interstrand Crosslink Repair Requires CMG Unloading
title_sort replication fork reversal during dna interstrand crosslink repair requires cmg unloading
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6086610/
https://www.ncbi.nlm.nih.gov/pubmed/29924986
http://dx.doi.org/10.1016/j.celrep.2018.05.061
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