401: Chromatin remodelling by the p400 ATPase influences DNA double-strand breaks repair and genetic instability independently of the H2AZ histone variant incorporation

2014 ◽  
Vol 50 ◽  
pp. S96
Author(s):  
Y. Canitrot ◽  
C. Courilleau ◽  
C. Chailleux ◽  
G.C. Taty-Taty ◽  
M. Quaranta ◽  
...  
Keyword(s):  
Genetic Instability ◽  
Histone Variant ◽  
Chromatin Remodelling ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Strand Breaks

scholarly journals ATM-dependent pathways of chromatin remodelling and oxidative DNA damage responses

2017 ◽  
Vol 372 (1731) ◽  
pp. 20160283 ◽  
Author(s):  
N. Daniel Berger ◽  
Fintan K. T. Stanley ◽  
Shaun Moore ◽  
Aaron A. Goodarzi
Keyword(s):  
Dna Damage ◽  
Oxidative Dna Damage ◽  
Strand Break ◽  
Chromatin Remodelling ◽  
Double Strand Breaks ◽  
Biochemical Network ◽  
Regulatory Function ◽  
Dna Double Strand Breaks ◽  
Strand Breaks ◽  
The Impact

Ataxia-telangiectasia mutated (ATM) is a serine/threonine protein kinase with a master regulatory function in the DNA damage response. In this role, ATM commands a complex biochemical network that signals the presence of oxidative DNA damage, including the dangerous DNA double-strand break, and facilitates subsequent repair. Here, we review the current state of knowledge regarding ATM-dependent chromatin remodelling and epigenomic alterations that are required to maintain genomic integrity in the presence of DNA double-strand breaks and/or oxidative stress. We will focus particularly on the roles of ATM in adjusting nucleosome spacing at sites of unresolved DNA double-strand breaks within complex chromatin environments, and the impact of ATM on preserving the health of cells within the mammalian central nervous system. This article is part of the themed issue ‘Chromatin modifiers and remodellers in DNA repair and signalling’.

scholarly journals The role of ubiquitin-dependent segregase p97 (VCP or Cdc48) in chromatin dynamics after DNA double strand breaks

2017 ◽  
Vol 372 (1731) ◽  
pp. 20160282 ◽  
Author(s):  
Ignacio Torrecilla ◽  
Judith Oehler ◽  
Kristijan Ramadan
Keyword(s):  
Dna Repair ◽  
Current Knowledge ◽  
Dna Lesions ◽  
Chromatin Remodelling ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Dsb Repair ◽  
Chromatin Dynamics ◽  
Strand Breaks ◽  
Signalling Molecules

DNA double strand breaks (DSBs) are the most cytotoxic DNA lesions and, if not repaired, lead to chromosomal rearrangement, genomic instability and cell death. Cells have evolved a complex network of DNA repair and signalling molecules which promptly detect and repair DSBs, commonly known as the DNA damage response (DDR). The DDR is orchestrated by various post-translational modifications such as phosphorylation, methylation, ubiquitination or SUMOylation. As DSBs are located in complex chromatin structures, the repair of DSBs is engineered at two levels: (i) at sites of broken DNA and (ii) at chromatin structures that surround DNA lesions. Thus, DNA repair and chromatin remodelling machineries must work together to efficiently repair DSBs. Here, we summarize the current knowledge of the ubiquitin-dependent molecular unfoldase/segregase p97 (VCP in vertebrates and Cdc48 in worms and lower eukaryotes) in DSB repair. We identify p97 as an essential factor that regulates DSB repair. p97-dependent extraction of ubiquitinated substrates mediates spatio-temporal protein turnover at and around the sites of DSBs, thus orchestrating chromatin remodelling and DSB repair. As p97 is a druggable target, p97 inhibition in the context of DDR has great potential for cancer therapy, as shown for other DDR components such as PARP, ATR and CHK1. This article is part of the themed issue ‘Chromatin modifiers and remodellers in DNA repair and signalling’.

scholarly journals Chronic hypoxia compromises repair of DNA double-strand breaks to drive genetic instability

2012 ◽  
Vol 125 (1) ◽  
pp. 189-199 ◽  
Author(s):  
R. Kumareswaran ◽  
O. Ludkovski ◽  
A. Meng ◽  
J. Sykes ◽  
M. Pintilie ◽  
...  
Keyword(s):  
Genetic Instability ◽  
Chronic Hypoxia ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Strand Breaks

Single-molecule views on homologous recombination

2013 ◽  
Vol 46 (4) ◽  
pp. 323-348 ◽  
Author(s):  
Andrea Candelli ◽  
Mauro Modesti ◽  
Erwin J. G. Peterman ◽  
Gijs J. L. Wuite
Keyword(s):  
Homologous Recombination ◽  
Single Molecule ◽  
Genetic Instability ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Single Stranded Dna ◽  
Strand Breaks ◽  
Future Developments ◽  
Recent Developments ◽  
Human Rad51

AbstractAll organisms need homologous recombination (HR) to repair DNA double-strand breaks. Defects in recombination are linked to genetic instability and to elevated risks in developing cancers. The central catalyst of HR is a nucleoprotein filament, consisting of recombinase proteins (human RAD51 or bacterial RecA) bound around single-stranded DNA. Over the last two decades, single-molecule techniques have provided substantial new insights into the dynamics of homologous recombination. Here, we survey important recent developments in this field of research and provide an outlook on future developments.

scholarly journals Dot1L-dependent H3K79 methylation facilitates histone variant H2A.Z exchange at DNA double strand breaks and is required for high fidelity, homology-directed DNA repair

2019 ◽  
Author(s):  
Nehemiah S. Alvarez ◽  
Pavla Brachova ◽  
Timothy A. Fields ◽  
Patrick E. Fields
Keyword(s):  
Dna Repair ◽  
Genome Stability ◽  
Repair Process ◽  
Histone Variant ◽  
Double Strand Breaks ◽  
Open Chromatin ◽  
High Fidelity ◽  
Dna Double Strand Breaks ◽  
Strand Breaks ◽  
Non Homologous End Joining

AbstractIn eukaryotic cells, the homology-directed repair (HDR) and non-homologous end joining (NHEJ) pathways are required for the repair of DNA double strand breaks (DSB). The high-fidelity HDR pathway is particularly important for maintenance of genomic stability. In mammals, histone post-translational modifications and histone variant exchange into nucleosomes at sites of DSB generate an open chromatin state necessary for repair to take place. However, the specific contributions of histone modifications to histone variant exchange at DSB sites and the influence of these changes on the DNA repair process and genome stability are incompletely understood. Here we show that Dot1L-catalyzed methylation of H3 histone on lysine 79 (H3K79) is required for efficient HDR of DSB. In cells with DNA DSB either lacking Dot1L or expressing a methylation-dead Dot1L, there is altered kinetics of DNA repair factor recruitment, markedly decreased H2A.Z incorporation at DSB sites, and a specific and profound reduction in HDR, which results in significant genomic instability. These findings demonstrate a new role for Dot1L, identifying it as a critical regulator of the DNA repair process and a steward of genomic integrity.

Repair pathway choice for double-strand breaks

2020 ◽  
Vol 64 (5) ◽  
pp. 765-777 ◽  
Author(s):  
Yixi Xu ◽  
Dongyi Xu
Keyword(s):  
Cell Cycle ◽  
Double Strand Breaks ◽  
Homologous Region ◽  
Gene Repair ◽  
Repair Pathway ◽  
Dna Double Strand Breaks ◽  
Environmental Radiation ◽  
Strand Breaks ◽  
Dna End Resection ◽  
End Resection

Abstract Deoxyribonucleic acid (DNA) is at a constant risk of damage from endogenous substances, environmental radiation, and chemical stressors. DNA double-strand breaks (DSBs) pose a significant threat to genomic integrity and cell survival. There are two major pathways for DSB repair: nonhomologous end-joining (NHEJ) and homologous recombination (HR). The extent of DNA end resection, which determines the length of the 3′ single-stranded DNA (ssDNA) overhang, is the primary factor that determines whether repair is carried out via NHEJ or HR. NHEJ, which does not require a 3′ ssDNA tail, occurs throughout the cell cycle. 53BP1 and the cofactors PTIP or RIF1-shieldin protect the broken DNA end, inhibit long-range end resection and thus promote NHEJ. In contrast, HR mainly occurs during the S/G2 phase and requires DNA end processing to create a 3′ tail that can invade a homologous region, ensuring faithful gene repair. BRCA1 and the cofactors CtIP, EXO1, BLM/DNA2, and the MRE11–RAD50–NBS1 (MRN) complex promote DNA end resection and thus HR. DNA resection is influenced by the cell cycle, the chromatin environment, and the complexity of the DNA end break. Herein, we summarize the key factors involved in repair pathway selection for DSBs and discuss recent related publications.

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