DNA-PKcs and PARP1 bind to unresected stalled DNA replication forks where they recruit XRCC1 to mediate repair

A series of critical pathways are responsible for the detection, signaling, and restart of replication forks that encounter blocks during S-phase progression. Small base lesions may obstruct replication fork progression and processing, but the link between repair of small lesions and replication for...

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Main Authors: Sing, S, Chen, Z, Medhurst, A, Neal, J, Bao, Z, Mortusewicz, O, McGouran, J, Song, X, Shen, H, Hamdy, F, Kessler, B, Meek, K, Helleday, T
Format: Journal article
Language:English
Published: American Association for Cancer Research 2016
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author Sing, S
Chen, Z
Medhurst, A
Neal, J
Bao, Z
Mortusewicz, O
McGouran, J
Song, X
Shen, H
Hamdy, F
Kessler, B
Meek, K
Helleday, T
author_facet Sing, S
Chen, Z
Medhurst, A
Neal, J
Bao, Z
Mortusewicz, O
McGouran, J
Song, X
Shen, H
Hamdy, F
Kessler, B
Meek, K
Helleday, T
author_sort Sing, S
collection OXFORD
description A series of critical pathways are responsible for the detection, signaling, and restart of replication forks that encounter blocks during S-phase progression. Small base lesions may obstruct replication fork progression and processing, but the link between repair of small lesions and replication forks is unclear. In this study, we investigated a hypothesized role for DNA-PK, an important enzyme in DNA repair, in cellular responses to DNA replication stress. The enzyme catalytic subunit DNA-PKcs was phosphorylated on S2056 at sites of stalled replication forks in response to short hydroxyurea treatment. Using DNA fiber experiments, we found that catalytically active DNA-PK was required for efficient replication restart of stalled forks. Furthermore, enzymatically active DNA-PK was also required for PARP-dependent recruitment of XRCC1 to stalled replication forks. This activity was enhanced by preventing Mre11-dependent DNA end resection, suggesting that XRCC1 must be recruited early to an unresected stalled fork. We also found that XRCC1 was required for effective restart of a subset of stalled replication forks. Overall, our work suggested that DNA-PK and PARP-dependent recruitment of XRCC1 is necessary to effectively protect, repair, and restart stalled replication forks, providing new insight into how genomic stability is preserved.
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spelling oxford-uuid:5c6eb5cc-c1d3-4ace-9821-050bb3f42ec42022-03-26T17:28:11ZDNA-PKcs and PARP1 bind to unresected stalled DNA replication forks where they recruit XRCC1 to mediate repairJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:5c6eb5cc-c1d3-4ace-9821-050bb3f42ec4EnglishSymplectic Elements at OxfordAmerican Association for Cancer Research2016Sing, SChen, ZMedhurst, ANeal, JBao, ZMortusewicz, OMcGouran, JSong, XShen, HHamdy, FKessler, BMeek, KHelleday, TA series of critical pathways are responsible for the detection, signaling, and restart of replication forks that encounter blocks during S-phase progression. Small base lesions may obstruct replication fork progression and processing, but the link between repair of small lesions and replication forks is unclear. In this study, we investigated a hypothesized role for DNA-PK, an important enzyme in DNA repair, in cellular responses to DNA replication stress. The enzyme catalytic subunit DNA-PKcs was phosphorylated on S2056 at sites of stalled replication forks in response to short hydroxyurea treatment. Using DNA fiber experiments, we found that catalytically active DNA-PK was required for efficient replication restart of stalled forks. Furthermore, enzymatically active DNA-PK was also required for PARP-dependent recruitment of XRCC1 to stalled replication forks. This activity was enhanced by preventing Mre11-dependent DNA end resection, suggesting that XRCC1 must be recruited early to an unresected stalled fork. We also found that XRCC1 was required for effective restart of a subset of stalled replication forks. Overall, our work suggested that DNA-PK and PARP-dependent recruitment of XRCC1 is necessary to effectively protect, repair, and restart stalled replication forks, providing new insight into how genomic stability is preserved.
spellingShingle Sing, S
Chen, Z
Medhurst, A
Neal, J
Bao, Z
Mortusewicz, O
McGouran, J
Song, X
Shen, H
Hamdy, F
Kessler, B
Meek, K
Helleday, T
DNA-PKcs and PARP1 bind to unresected stalled DNA replication forks where they recruit XRCC1 to mediate repair
title DNA-PKcs and PARP1 bind to unresected stalled DNA replication forks where they recruit XRCC1 to mediate repair
title_full DNA-PKcs and PARP1 bind to unresected stalled DNA replication forks where they recruit XRCC1 to mediate repair
title_fullStr DNA-PKcs and PARP1 bind to unresected stalled DNA replication forks where they recruit XRCC1 to mediate repair
title_full_unstemmed DNA-PKcs and PARP1 bind to unresected stalled DNA replication forks where they recruit XRCC1 to mediate repair
title_short DNA-PKcs and PARP1 bind to unresected stalled DNA replication forks where they recruit XRCC1 to mediate repair
title_sort dna pkcs and parp1 bind to unresected stalled dna replication forks where they recruit xrcc1 to mediate repair
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