scholarly journals USP39 promotes non-homologous end-joining repair by poly(ADP-ribose)-induced liquid demixing

2021 ◽  
Author(s):  
Jae Jin Kim ◽  
Seo Yun Lee ◽  
Yiseul Hwang ◽  
Soyeon Kim ◽  
Jee Min Chung ◽  
...  
Keyword(s):  
Dna Repair ◽  
Conclusive Evidence ◽  
Dna Lesions ◽  
Dependent Manner ◽  
Deubiquitinating Enzymes ◽  
End Joining ◽  
Independent Manner ◽  
Recombination Repair ◽  
Non Homologous End Joining

Abstract Mutual crosstalk among poly(ADP-ribose) (PAR), activated PAR polymerase 1 (PARP1) metabolites, and DNA repair machinery has emerged as a key regulatory mechanism of the DNA damage response (DDR). However, there is no conclusive evidence of how PAR precisely controls DDR. Herein, six deubiquitinating enzymes (DUBs) associated with PAR-coupled DDR were identified, and the role of USP39, an inactive DUB involved in spliceosome assembly, was characterized. USP39 rapidly localizes to DNA lesions in a PAR-dependent manner, where it regulates non-homologous end-joining (NHEJ) via a tripartite RG motif located in the N-terminus comprising 46 amino acids (N46). Furthermore, USP39 acts as a molecular trigger for liquid demixing in a PAR-coupled N46-dependent manner, thereby directly interacting with the XRCC4/LIG4 complex during NHEJ. In parallel, the USP39-associated spliceosome complex controls homologous recombination repair in a PAR-independent manner. These findings provide mechanistic insights into how PAR chains precisely control DNA repair processes in the DDR.

141 INDICATIONS FOR DNA DOUBLE-STRAND BREAK REPAIR IN EARLY BOVINE EMBRYOS

2007 ◽  
Vol 19 (1) ◽  
pp. 188
Author(s):  
A. Brero ◽  
D. Koehler ◽  
T. Cremer ◽  
E. Wolf ◽  
V. Zakhartchenko
Keyword(s):  
Dna Repair ◽  
Homologous Recombination ◽  
Strand Break ◽  
Dna Lesions ◽  
Homologous Recombination Repair ◽  
Dna Double Strand Breaks ◽  
End Joining ◽  
Male And Female ◽  
Γh2ax Foci ◽  
Recombination Repair

DNA double-strand breaks (DSBs) are considered the most severe type of DNA lesions, because such lesions, if unrepaired, lead to a loss of genome integrity. Soon after induction of DSBs, chromatin surrounding the damage is modified by phosphorylation of the histone variant H2AX, generating so-called γH2AX, which is a hallmark of DSBs (Takahashi et al. 2005 Cancer Lett. 229, 171–179). γH2AX appears to be a signal for the recruitment of proteins constituting the DNA repair machinery. Depending on the type of damage and the cell cycle stage of the affected cell, DSBs are repaired either by nonhomologous end joining or by homologous recombination using the sister chromatid DNA as template (Hoeijmakers 2001 Nature 411, 366–374). We used immunofluorescence to analyze chromatin composition during bovine development and found γH2AX foci in both male and female pronuclei of IVF embryos. The number and size of foci varied considerably between embryos and between the male and female pronuclei. To test whether the observed γH2AX foci represented sites of active DNA repair, we co-stained IVF zygotes for γH2AX and 3 different proteins involved in homologous recombination repair of DSBs: NBS1 (phosphorylated at amino acid serine 343), 53BP1, and Rad51. We found co-localization of γH2AX foci with phosphorylated NBS1 as well as with Rad51 but did not observe the presence of 53BP1 at γH2AX foci in IVF zygotes. Our finding shows the presence of DSBs in IVF zygotes and suggests the capability of homologous recombination repair. The lack of 53BP1, a component of homologous recombination repair, which usually co-localizes with γH2AX foci at exogenously induced DSBs (Schultz et al. 2000 J. Cell. Biol. 151, 1381–1390) poses the possibility that the mechanism present in early embryos differs substantially from that involved in DNA repair of DSBs in somatic cells.

scholarly journals Beta Human Papillomavirus 8E6 Attenuates Non-Homologous End Joining by Hindering DNA-PKcs Activity

Cancers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2356
Author(s):  
Changkun Hu ◽  
Taylor Bugbee ◽  
Monica Gamez ◽  
Nicholas A. Wallace
Keyword(s):  
Dna Repair ◽  
Viral Infections ◽  
Dna Lesions ◽  
Human Papillomaviruses ◽  
Molecular Evidence ◽  
Repair Pathway ◽  
End Joining ◽  
Dsb Repair ◽  
Dependent Protein ◽  
Non Homologous End Joining

Cutaneous viral infections occur in a background of near continual exposure to environmental genotoxins, like UV radiation in sunlight. Failure to repair damaged DNA is an established driver of tumorigenesis and substantial cellular resources are devoted to repairing DNA lesions. Beta-human papillomaviruses (β-HPVs) attenuate DNA repair signaling. However, their role in human disease is unclear. Some have proposed that β-HPV promotes tumorigenesis, while others suggest that β-HPV protects against skin cancer. Most of the molecular evidence that β-HPV impairs DNA repair has been gained via characterization of the E6 protein from β-HPV 8 (β-HPV 8E6). Moreover, β-HPV 8E6 hinders DNA repair by binding and destabilizing p300, a transcription factor for multiple DNA repair genes. By reducing p300 availability, β-HPV 8E6 attenuates a major double strand DNA break (DSB) repair pathway, homologous recombination. Here, β-HPV 8E6 impairs another DSB repair pathway, non-homologous end joining (NHEJ). Specifically, β-HPV 8E6 acts by attenuating DNA-dependent protein kinase (DNA-PK) activity, a critical NHEJ kinase. This includes DNA-PK activation and the downstream of steps in the pathway associated with DNA-PK activity. Notably, β-HPV 8E6 inhibits NHEJ through p300 dependent and independent means. Together, these data expand the known genome destabilizing capabilities of β-HPV 8E6.

scholarly journals ATM antagonizes NHEJ proteins assembly and DNA-ends synapsis at single-ended DNA double strand breaks

2020 ◽  
Vol 48 (17) ◽  
pp. 9710-9723
Author(s):  
Sébastien Britton ◽  
Pauline Chanut ◽  
Christine Delteil ◽  
Nadia Barboule ◽  
Philippe Frit ◽  
...  
Keyword(s):  
Dna Repair ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
End Joining ◽  
Strand Breaks ◽  
Repair Pathways ◽  
Non Homologous End Joining ◽  
Dna Strand ◽  
Dna Ends

Abstract Two DNA repair pathways operate at DNA double strand breaks (DSBs): non-homologous end-joining (NHEJ), that requires two adjacent DNA ends for ligation, and homologous recombination (HR), that resects one DNA strand for invasion of a homologous duplex. Faithful repair of replicative single-ended DSBs (seDSBs) is mediated by HR, due to the lack of a second DNA end for end-joining. ATM stimulates resection at such breaks through multiple mechanisms including CtIP phosphorylation, which also promotes removal of the DNA-ends sensor and NHEJ protein Ku. Here, using a new method for imaging the recruitment of the Ku partner DNA-PKcs at DSBs, we uncover an unanticipated role of ATM in removing DNA-PKcs from seDSBs in human cells. Phosphorylation of DNA-PKcs on the ABCDE cluster is necessary not only for DNA-PKcs clearance but also for the subsequent MRE11/CtIP-dependent release of Ku from these breaks. We propose that at seDSBs, ATM activity is necessary for the release of both Ku and DNA-PKcs components of the NHEJ apparatus, and thereby prevents subsequent aberrant interactions between seDSBs accompanied by DNA-PKcs autophosphorylation and detrimental commitment to Lig4-dependent end-joining.

scholarly journals Mechanisms of double-strand break repair in somatic mammalian cells

2009 ◽  
Vol 423 (2) ◽  
pp. 157-168 ◽  
Author(s):  
Andrea J. Hartlerode ◽  
Ralph Scully
Keyword(s):  
Genetic Information ◽  
Mammalian Cells ◽  
Current Knowledge ◽  
Strand Break ◽  
Dna Lesions ◽  
Double Strand Breaks ◽  
End Joining ◽  
Strand Breaks ◽  
Non Homologous End Joining

DNA chromosomal DSBs (double-strand breaks) are potentially hazardous DNA lesions, and their accurate repair is essential for the successful maintenance and propagation of genetic information. Two major pathways have evolved to repair DSBs: HR (homologous recombination) and NHEJ (non-homologous end-joining). Depending on the context in which the break is encountered, HR and NHEJ may either compete or co-operate to fix DSBs in eukaryotic cells. Defects in either pathway are strongly associated with human disease, including immunodeficiency and cancer predisposition. Here we review the current knowledge of how NHEJ and HR are controlled in somatic mammalian cells, and discuss the role of the chromatin context in regulating each pathway. We also review evidence for both co-operation and competition between the two pathways.

scholarly journals The Intermediate Filament Synemin Regulates Non-Homologous End Joining in an ATM-Dependent Manner

Cancers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1717 ◽  
Author(s):  
Sara Sofia Deville ◽  
Anne Vehlow ◽  
Sarah Förster ◽  
Ellen Dickreuter ◽  
Kerstin Borgmann ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Dna Damage Response ◽  
Intermediate Filament ◽  
Intermediate Filament Protein ◽  
Dependent Manner ◽  
End Joining ◽  
Damage Response ◽  
Non Homologous End Joining ◽  
Filament Protein

The treatment resistance of cancer cells is a multifaceted process in which DNA repair emerged as a potential therapeutic target. DNA repair is predominantly conducted by nuclear events; yet, how extra-nuclear cues impact the DNA damage response is largely unknown. Here, using a high-throughput RNAi-based screen in three-dimensionally-grown cell cultures of head and neck squamous cell carcinoma (HNSCC), we identified novel focal adhesion proteins controlling DNA repair, including the intermediate filament protein, synemin. We demonstrate that synemin critically regulates the DNA damage response by non-homologous end joining repair. Mechanistically, synemin forms a protein complex with DNA-PKcs through its C-terminal tail domain for determining DNA repair processes upstream of this enzyme in an ATM-dependent manner. Our study discovers a critical function of the intermediate filament protein, synemin in the DNA damage response, fundamentally supporting the concept of cytoarchitectural elements as co-regulators of nuclear events.

scholarly journals HPF1-dependent histone ADP-ribosylation triggers chromatin relaxation to promote the recruitment of repair factors at sites of DNA damage

2021 ◽  
Author(s):  
Rebecca Smith ◽  
Siham Zentout ◽  
Catherine Chapuis ◽  
Gyula Timinszky ◽  
Sebastien Huet
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Dna Damage Response ◽  
Dna Lesions ◽  
End Joining ◽  
Adp Ribosylation ◽  
Damage Response ◽  
Non Homologous End Joining ◽  
Chromatin Relaxation ◽  
The Impact

PARP1 activity is regulated by its cofactor HPF1. The binding of HPF1 on PARP1 controls the grafting of ADP-ribose moieties on serine residues of proteins nearby the DNA lesions, mainly PARP1 and histones. However, the impact of HPF1 on DNA repair regulated by PARP1 remains unclear. Here, we show that HPF1 controls both the number and the length of the ADP-ribose chains generated by PARP1 at DNA lesions. We demonstrate that HPF1-dependent histone ADP-ribosylation, rather than auto-modification of PARP1, triggers the rapid unfolding of the chromatin structure at the DNA damage sites and promotes the recruitment of the repair factors CHD4 and CHD7. Together with the observation that HPF1 contributes to efficient repair both by homologous recombination and non-homologous end joining, our findings highlight the key roles played by this PARP1 cofactor at early stages of the DNA damage response.

scholarly journals Defective DNA damage repair leads to frequent catastrophic genomic events in murine and human tumors

2018 ◽  
Author(s):  
Manasi Ratnaparkhe ◽  
John Wong ◽  
Pei-Chi Wei ◽  
Mario Hlevnjak ◽  
Thorsten Kolb ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Genomic Rearrangements ◽  
End Joining ◽  
Catastrophic Events ◽  
Mouse Tumors ◽  
Damage Repair ◽  
Target Dna ◽  
Recombination Repair ◽  
Non Homologous End Joining

AbstractChromothripsis and chromoanasynthesis are catastrophic events leading to clustered genomic rearrangements. Whole-genome sequencing revealed frequent chromothripsis or chromoanasynthesis (n= 16/26) in brain tumors developing in mice deficient for factors involved in homologous-recombination-repair or non-homologous-end-joining. Catastrophic events were tightly linked to Myc/Mycn amplification, with increased DNA damage and inefficient apoptotic response already observable at early postnatal stages. Inhibition of repair processes and comparison of the mouse tumors with human medulloblastomas (n=68) and glioblastomas (n=32) identified chromothripsis as associated with MYC/MYCN gains and with DNA repair deficiencies, pointing towards therapeutic opportunities to target DNA repair defects in tumors with complex genomic rearrangements.

scholarly journals Functional Roles of Homologous Recombination and Non-Homologous End Joining in DNA Damage Response and Microevolution in Cryptococcus neoformans

2021 ◽  
Vol 7 (7) ◽  
pp. 566
Author(s):  
Kwang-Woo Jung ◽  
Jong-Hyun Jung ◽  
Ha-Young Park
Keyword(s):  
Dna Damage ◽  
Homologous Recombination ◽  
Cryptococcus Neoformans ◽  
Dna Damage Response ◽  
Genotoxic Stress ◽  
Dna Lesions ◽  
Dependent Manner ◽  
End Joining ◽  
Damage Response ◽  
Non Homologous End Joining

DNA double-strand breaks (DSBs) are the most deleterious type of DNA lesions because they cause loss of genetic information if not properly repaired. In eukaryotes, homologous recombination (HR) and non-homologous end joining (NHEJ) are required for DSB repair. However, the relationship of HR and NHEJ in DNA damage stress is unknown in the radiation-resistant fungus Cryptococcus neoformans. In this study, we found that the expression levels of HR- and NHEJ-related genes were highly induced in a Rad53–Bdr1 pathway-dependent manner under genotoxic stress. Deletion of RAD51, which is one of the main components in the HR, resulted in growth under diverse types of DNA damage stress, whereas perturbations of KU70 and KU80, which belong to the NHEJ system, did not affect the genotoxic stresses except when bleomycin was used for treatment. Furthermore, deletion of both RAD51 and KU70/80 renders cells susceptible to oxidative stress. Notably, we found that deletion of RAD51 induced a hypermutator phenotype in the fluctuation assay. In contrast to the fluctuation assay, perturbation of KU70 or KU80 induced rapid microevolution similar to that induced by the deletion of RAD51. Collectively, Rad51-mediated HR and Ku70/Ku80-mediated NHEJ regulate the DNA damage response and maintain genome stability.

scholarly journals Role of the yeast DNA repair protein Nej1 in end processing during the repair of DNA double strand breaks by non-homologous end joining

DNA Repair ◽  
2015 ◽  
Vol 31 ◽  
pp. 1-10 ◽  
Author(s):  
Hui Yang ◽  
Yoshihiro Matsumoto ◽  
Kelly M. Trujillo ◽  
Susan P. Lees-Miller ◽  
Mary Ann Osley ◽  
...  
Keyword(s):  
Dna Repair ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
End Joining ◽  
Strand Breaks ◽  
Repair Protein ◽  
Dna Repair Protein ◽  
Non Homologous End Joining
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