MOF Suppresses Replication Stress and Contributes to Resolution of Stalled Replication Forks

ABSTRACT The human MOF (hMOF) protein belongs to the MYST family of histone acetyltransferases and plays a critical role in transcription and the DNA damage response. MOF is essential for cell proliferation; however, its role during replication and replicative stress is unknown. Here we demonstrate that cells depleted of MOF and under replicative stress induced by cisplatin, hydroxyurea, or camptothecin have reduced survival, a higher frequency of S-phase-specific chromosome damage, and increased R-loop formation. MOF depletion decreased replication fork speed and, when combined with replicative stress, also increased stalled replication forks as well as new origin firing. MOF interacted with PCNA, a key coordinator of replication and repair machinery at replication forks, and affected its ubiquitination and recruitment to the DNA damage site. Depletion of MOF, therefore, compromised the DNA damage repair response as evidenced by decreased Mre11, RPA70, Rad51, and PCNA focus formation, reduced DNA end resection, and decreased CHK1 phosphorylation in cells after exposure to hydroxyurea or cisplatin. These results support the argument that MOF plays an important role in suppressing replication stress induced by genotoxic agents at several stages during the DNA damage response.

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Regulation of Rtt107 Recruitment to Stalled DNA Replication Forks by the Cullin Rtt101 and the Rtt109 Acetyltransferase

Molecular Biology of the Cell ◽

10.1091/mbc.e07-09-0961 ◽

2008 ◽

Vol 19 (1) ◽

pp. 171-180 ◽

Cited By ~ 45

Author(s):

Tania M. Roberts ◽

Iram Waris Zaidi ◽

Jessica A. Vaisica ◽

Matthias Peter ◽

Grant W. Brown

Keyword(s):

Dna Damage ◽

Dna Damage Response ◽

Replication Forks ◽

Chromatin Binding ◽

Direct Role ◽

Repair Enzymes ◽

Damage Response ◽

Stalled Replication Forks

RTT107 (ESC4, YHR154W) encodes a BRCA1 C-terminal domain protein that is important for recovery from DNA damage during S phase. Rtt107 is a substrate of the checkpoint kinase Mec1, and it forms complexes with DNA repair enzymes, including the nuclease subunit Slx4, but the role of Rtt107 in the DNA damage response remains unclear. We find that Rtt107 interacts with chromatin when cells are treated with compounds that cause replication forks to arrest. This damage-dependent chromatin binding requires the acetyltransferase Rtt109, but it does not require acetylation of the known Rtt109 target, histone H3-K56. Chromatin binding of Rtt107 also requires the cullin Rtt101, which seems to play a direct role in Rtt107 recruitment, because the two proteins are found in complex with each other. Finally, we provide evidence that Rtt107 is bound at or near stalled replication forks in vivo. Together, these results indicate that Rtt109, Rtt101, and Rtt107, which genetic evidence suggests are functionally related, form a DNA damage response pathway that recruits Rtt107 complexes to damaged or stalled replication forks.

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Chemical strategies for development of ATR inhibitors

Expert Reviews in Molecular Medicine ◽

10.1017/erm.2014.10 ◽

2014 ◽

Vol 16 ◽

Cited By ~ 15

Author(s):

Sabin Llona-Minguez ◽

Andreas Höglund ◽

Sylvain A. Jacques ◽

Tobias Koolmeister ◽

Thomas Helleday

Keyword(s):

Dna Damage ◽

Dna Damage Response ◽

Checkpoint Inhibitors ◽

Genome Integrity ◽

Signalling Pathways ◽

Replication Forks ◽

Damage Response ◽

Key Players ◽

Chemical Strategies ◽

Stalled Replication Forks

ATR protein kinase is one of the key players in maintaining genome integrity and coordinating of the DNA damage response and repair signalling pathways. Inhibition of ATR prevents signalling from stalled replication forks and enhances the formation of DNA damage, particularly under conditions of replication stress present in cancers. For this reason ATR/CHK1 checkpoint inhibitors can potentiate the effect of DNA cross-linking agents, as evidenced by ATR inhibitors recently entering human clinical trials. This review aims to compile the existing literature on small molecule inhibitors of ATR, both from academia and the pharmaceutical industry, and will provide the reader with a comprehensive summary of this promising oncology target.

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A model of DNA damage response activation at stalled replication forks by SPRTN

Nature Communications ◽

10.1038/s41467-019-13610-7 ◽

2019 ◽

Vol 10 (1) ◽

Cited By ~ 1

Author(s):

Christopher Bruhn ◽

Marco Foiani

Keyword(s):

Dna Damage ◽

Dna Damage Response ◽

Replication Forks ◽

Damage Response ◽

Stalled Replication Forks ◽

Response Activation

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DNA-PKcs promotes chromatin decondensation to facilitate initiation of the DNA damage response

Nucleic Acids Research ◽

10.1093/nar/gkz694 ◽

2019 ◽

Vol 47 (18) ◽

pp. 9467-9479 ◽

Cited By ~ 10

Author(s):

Huiming Lu ◽

Janapriya Saha ◽

Pauline J Beckmann ◽

Eric A Hendrickson ◽

Anthony J Davis

Keyword(s):

Dna Damage ◽

Dna Damage Response ◽

Ataxia Telangiectasia ◽

Cellular Response ◽

Kinase Activity ◽

Human Cell Line ◽

Cell Cycle Checkpoint ◽

Chromatin Decondensation ◽

Damage Site ◽

Damage Response

Abstract The DNA damage response (DDR) encompasses the cellular response to DNA double-stranded breaks (DSBs), and includes recognition of the DSB, recruitment of numerous factors to the DNA damage site, initiation of signaling cascades, chromatin remodeling, cell-cycle checkpoint activation, and repair of the DSB. Key drivers of the DDR are multiple members of the phosphatidylinositol 3-kinase-related kinase family, including ataxia telangiectasia mutated (ATM), ataxia telangiectasia and Rad3-related (ATR), and the DNA-dependent protein kinase catalytic subunit (DNA-PKcs). ATM and ATR modulate multiple portions of the DDR, but DNA-PKcs is believed to primarily function in the DSB repair pathway, non-homologous end joining. Utilizing a human cell line in which the kinase domain of DNA-PKcs is inactivated, we show here that DNA-PKcs kinase activity is required for the cellular response to DSBs immediately after their induction. Specifically, DNA-PKcs kinase activity initiates phosphorylation of the chromatin factors H2AX and KAP1 following ionizing radiation exposure and drives local chromatin decondensation near the DSB site. Furthermore, loss of DNA-PKcs kinase activity results in a marked decrease in the recruitment of numerous members of the DDR machinery to DSBs. Collectively, these results provide clear evidence that DNA-PKcs activity is pivotal for the initiation of the DDR.

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Analysis of spatial correlations between patterns of DNA damage response and DNA replication in nuclei of cells subjected to replication stress or oxidative damage

Cytometry Part A ◽

10.1002/cyto.a.22325 ◽

2013 ◽

pp. n/a-n/a

Author(s):

Tytus Bernas ◽

Krzysztof Berniak ◽

Paulina Rybak ◽

Mirosław Zarębski ◽

Hong Zhao ◽

...

Keyword(s):

Dna Damage ◽

Dna Replication ◽

Oxidative Damage ◽

Dna Damage Response ◽

Replication Stress ◽

Spatial Correlations ◽

Damage Response

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Faculty Opinions recommendation of ATM orchestrates the DNA-damage response to counter toxic non-homologous end-joining at broken replication forks.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.734831207.793557672 ◽

2019 ◽

Author(s):

Susan Lees-Miller

Keyword(s):

Dna Damage ◽

Dna Damage Response ◽

Replication Forks ◽

End Joining ◽

Damage Response ◽

Non Homologous End Joining

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Faculty Opinions recommendation of ATM orchestrates the DNA-damage response to counter toxic non-homologous end-joining at broken replication forks.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.734831207.793557450 ◽

2019 ◽

Author(s):

Antony Carr

Keyword(s):

Dna Damage ◽

Dna Damage Response ◽

Replication Forks ◽

End Joining ◽

Damage Response ◽

Non Homologous End Joining

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Inhibition of RNA Polymerase I Transcription Activates Targeted DNA Damage Response and Enhances the Efficacy of PARP Inhibitors in High-Grade Serous Ovarian Cancer

10.1101/621623 ◽

2019 ◽

Cited By ~ 2

Author(s):

Elaine Sanij ◽

Katherine M. Hannan ◽

Shunfei Yan ◽

Jiachen Xuan ◽

Jessica E. Ahern ◽

...

Keyword(s):

Ovarian Cancer ◽

Dna Damage ◽

Dna Damage Response ◽

Parp Inhibitors ◽

Rna Polymerase I ◽

High Grade ◽

Replication Forks ◽

Serous Ovarian Cancer ◽

Damage Response ◽

Polymerase I

AbstractHigh-grade serous ovarian cancer (HGSOC) accounts for the majority of ovarian cancer and has a dismal prognosis. PARP inhibitors (PARPi) have revolutionized disease management of patients with homologous recombination (HR) DNA repair-deficient HGSOC. However, acquired resistance to PARPi by complex mechanisms including HR restoration and stabilisation of replication forks is a major challenge in the clinic. Here, we demonstrate CX-5461, an inhibitor of RNA polymerase I transcription of ribosomal RNA genes (rDNA), induces replication stress at rDNA leading to activation of DNA damage response and DNA damage involving MRE11-dependent degradation of replication forks. CX-5461 cooperates with PARPi in exacerbating DNA damage and enhances synthetic lethal interactions of PARPi with HR deficiency in HGSOC-patient-derived xenograft (PDX)in vivo. We demonstrate CX-5461 has a different sensitivity spectrum to PARPi and destabilises replication forks irrespective of HR pathway status, overcoming two well-known mechanisms of resistance to PARPi. Importantly, CX-5461 exhibits single agent efficacy in PARPi-resistant HGSOC-PDX. Further, we identify CX-5461-sensitivity gene expression signatures in primary and relapsed HGSOC. Therefore, CX-5461 is a promising therapy alone and in combination therapy with PARPi in HR-deficient HGSOC. CX-5461 is also an exciting treatment option for patients with relapsed HGSOC tumors that have poor clinical outcome.

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