scholarly journals Hot spots of DNA double-strand breaks in human rDNA units are produced in vivo

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Nickolai A. Tchurikov ◽  
Dmitry V. Yudkin ◽  
Maria A. Gorbacheva ◽  
Anastasia I. Kulemzina ◽  
Irina V. Grischenko ◽  
...  
Keyword(s):  
Hot Spots ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Strand Breaks

Involvement of Ku80 in microhomology-mediated end joining for DNA double-strand breaks in vivo

DNA Repair ◽  
2007 ◽  
Vol 6 (5) ◽  
pp. 639-648 ◽  
Author(s):  
Yukitaka Katsura ◽  
Shigeru Sasaki ◽  
Masanori Sato ◽  
Kiyoshi Yamaoka ◽  
Kazumi Suzukawa ◽  
...  
Keyword(s):  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
End Joining ◽  
Strand Breaks

scholarly journals Autophosphorylation of DNA-PKCS regulates its dynamics at DNA double-strand breaks

2007 ◽  
Vol 177 (2) ◽  
pp. 219-229 ◽  
Author(s):  
Naoya Uematsu ◽  
Eric Weterings ◽  
Ken-ichi Yano ◽  
Keiko Morotomi-Yano ◽  
Burkhard Jakob ◽  
...  
Keyword(s):  
Kinase Activity ◽  
Laser System ◽  
Double Strand Breaks ◽  
Dependent Manner ◽  
Dna Double Strand Breaks ◽  
End Joining ◽  
Dsb Repair ◽  
Strand Breaks ◽  
Dna Ends

The DNA-dependent protein kinase catalytic subunit (DNA-PKCS) plays an important role during the repair of DNA double-strand breaks (DSBs). It is recruited to DNA ends in the early stages of the nonhomologous end-joining (NHEJ) process, which mediates DSB repair. To study DNA-PKCS recruitment in vivo, we used a laser system to introduce DSBs in a specified region of the cell nucleus. We show that DNA-PKCS accumulates at DSB sites in a Ku80-dependent manner, and that neither the kinase activity nor the phosphorylation status of DNA-PKCS influences its initial accumulation. However, impairment of both of these functions results in deficient DSB repair and the maintained presence of DNA-PKCS at unrepaired DSBs. The use of photobleaching techniques allowed us to determine that the kinase activity and phosphorylation status of DNA-PKCS influence the stability of its binding to DNA ends. We suggest a model in which DNA-PKCS phosphorylation/autophosphorylation facilitates NHEJ by destabilizing the interaction of DNA-PKCS with the DNA ends.

scholarly journals Genetic Separation of Sae2 Nuclease Activity from Mre11 Nuclease Functions in Budding Yeast

2017 ◽  
Vol 37 (24) ◽  
Author(s):  
Sucheta Arora ◽  
Rajashree A. Deshpande ◽  
Martin Budd ◽  
Judy Campbell ◽  
America Revere ◽  
...  
Keyword(s):  
Nuclease Activity ◽  
Double Strand Breaks ◽  
Endonuclease Activity ◽  
Dna Double Strand Breaks ◽  
Dna Breaks ◽  
Content Type ◽  
Strand Breaks ◽  
Dna Ends

ABSTRACT Sae2 promotes the repair of DNA double-strand breaks in Saccharomyces cerevisiae. The role of Sae2 is linked to the Mre11/Rad50/Xrs2 (MRX) complex, which is important for the processing of DNA ends into single-stranded substrates for homologous recombination. Sae2 has intrinsic endonuclease activity, but the role of this activity has not been assessed independently from its functions in promoting Mre11 nuclease activity. Here we identify and characterize separation-of-function mutants that lack intrinsic nuclease activity or the ability to promote Mre11 endonucleolytic activity. We find that the ability of Sae2 to promote MRX nuclease functions is important for DNA damage survival, particularly in the absence of Dna2 nuclease activity. In contrast, Sae2 nuclease activity is essential for DNA repair when the Mre11 nuclease is compromised. Resection of DNA breaks is impaired when either Sae2 activity is blocked, suggesting roles for both Mre11 and Sae2 nuclease activities in promoting the processing of DNA ends in vivo. Finally, both activities of Sae2 are important for sporulation, indicating that the processing of meiotic breaks requires both Mre11 and Sae2 nuclease activities.

scholarly journals βarrestin-1 regulates DNA repair by acting as an E3-ubiquitin ligase adaptor for 53BP1

2019 ◽  
Vol 27 (4) ◽  
pp. 1200-1213 ◽  
Author(s):  
Ainhoa Nieto ◽  
Makoto R. Hara ◽  
Victor Quereda ◽  
Wayne Grant ◽  
Vanessa Saunders ◽  
...  
Keyword(s):  
Dna Damage ◽  
Ionizing Radiation ◽  
Ubiquitin Ligase ◽  
E3 Ubiquitin Ligase ◽  
Strand Break ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Molecular Scaffold ◽  
Strand Breaks

Abstract Cellular DNA is constantly under threat from internal and external insults, consequently multiple pathways have evolved to maintain chromosomal fidelity. Our previous studies revealed that chronic stress, mediated by continuous stimulation of the β2-adrenergic-βarrestin-1 signaling axis suppresses activity of the tumor suppressor p53 and impairs genomic integrity. In this pathway, βarrestin-1 (βarr1) acts as a molecular scaffold to promote the binding and degradation of p53 by the E3-ubiquitin ligase, MDM2. We sought to determine whether βarr1 plays additional roles in the repair of DNA damage. Here we demonstrate that in mice βarr1 interacts with p53-binding protein 1 (53BP1) with major consequences for the repair of DNA double-strand breaks. 53BP1 is a principle component of the DNA damage response, and when recruited to the site of double-strand breaks in DNA, 53BP1 plays an important role coordinating repair of these toxic lesions. Here, we report that βarr1 directs 53BP1 degradation by acting as a scaffold for the E3-ubiquitin ligase Rad18. Consequently, knockdown of βarr1 stabilizes 53BP1 augmenting the number of 53BP1 DNA damage repair foci following exposure to ionizing radiation. Accordingly, βarr1 loss leads to a marked increase in irradiation resistance both in cells and in vivo. Thus, βarr1 is an important regulator of double strand break repair, and disruption of the βarr1/53BP1 interaction offers an attractive strategy to protect cells against high levels of exposure to ionizing radiation.

scholarly journals Methyl methanesulfonate (MMS) produces heat-labile DNA damage but no detectable in vivo DNA double-strand breaks

2012 ◽  
Vol 40 (12) ◽  
pp. 5794-5794
Author(s):  
C. Lundin ◽  
M. North ◽  
K. Erixon ◽  
K. Walters ◽  
D. Jenssen ◽  
...  
Keyword(s):  
Dna Damage ◽  
Double Strand Breaks ◽  
Methyl Methanesulfonate ◽  
Dna Double Strand Breaks ◽  
Strand Breaks ◽  
Heat Labile

scholarly journals Quantitative, Noninvasive Imaging of Radiation-Induced DNA Double-Strand Breaks In Vivo

2011 ◽  
Vol 71 (12) ◽  
pp. 4130-4137 ◽  
Author(s):  
Wenrong Li ◽  
Fang Li ◽  
Qian Huang ◽  
Jingping Shen ◽  
Frank Wolf ◽  
...  
Keyword(s):  
Noninvasive Imaging ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Strand Breaks ◽  
Radiation Induced

Disruption of the Arabidopsis AtKu80 gene demonstrates an essential role for AtKu80 protein in efficient repair of DNA double-strand breaks in vivo

2002 ◽  
Vol 31 (4) ◽  
pp. 517-528 ◽  
Author(s):  
Christopher E. West ◽  
Wanda M. Waterworth ◽  
Geraint W. Story ◽  
Paul A. Sunderland ◽  
Qing Jiang ◽  
...  
Keyword(s):  
Essential Role ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Strand Breaks

scholarly journals Endogenous Hot Spots ofDe NovoTelomere Addition in the Yeast Genome Contain Proximal Enhancers That Bind Cdc13

2016 ◽  
Vol 36 (12) ◽  
pp. 1750-1763 ◽  
Author(s):  
Udochukwu C. Obodo ◽  
Esther A. Epum ◽  
Margaret H. Platts ◽  
Jacob Seloff ◽  
Nicole A. Dahlson ◽  
...  
Keyword(s):  
Hot Spots ◽  
High Frequency ◽  
Genome Stability ◽  
De Novo ◽  
Dna Binding Protein ◽  
Double Strand Breaks ◽  
Yeast Genome ◽  
Dna Double Strand Breaks ◽  
Strand Breaks ◽  
Mutagenic Process

DNA double-strand breaks (DSBs) pose a threat to genome stability and are repaired through multiple mechanisms. Rarely, telomerase, the enzyme that maintains telomeres, acts upon a DSB in a mutagenic process termed telomere healing. The probability of telomere addition is increased at specific genomic sequences termed sites of repair-associated telomere addition (SiRTAs). By monitoring repair of an induced DSB, we show that SiRTAs on chromosomes V and IX share a bipartite structure in which a core sequence (Core) is directly targeted by telomerase, while a proximal sequence (Stim) enhances the probability ofde novotelomere formation. The Stim and Core sequences are sufficient to confer a high frequency of telomere addition to an ectopic site. Cdc13, a single-stranded DNA binding protein that recruits telomerase to endogenous telomeres, is known to stimulatede novotelomere addition when artificially recruited to an induced DSB. Here we show that the ability of the Stim sequence to enhancede novotelomere addition correlates with its ability to bind Cdc13, indicating that natural sites at which telomere addition occurs at high frequency require binding by Cdc13 to a sequence 20 to 100 bp internal from the site at which telomerase acts to initiatede novotelomere addition.

scholarly journals DNA-dependent macromolecular condensation drives self-assembly of the meiotic DNA break machinery

2020 ◽  
Author(s):  
Corentin Claeys Bouuaert ◽  
Stephen Pu ◽  
Juncheng Wang ◽  
Dinshaw J. Patel ◽  
Scott Keeney
Keyword(s):  
Self Assembly ◽  
Chromosome Structure ◽  
Coiled Coil ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Strand Breaks ◽  
Dna Breakage ◽  
And Control

Formation of meiotic DNA double-strand breaks (DSBs) by Spo11 is tightly regulated and tied to chromosome structure, but the higher-order assemblies that execute and control DNA breakage are poorly understood. We address this question through molecular characterization of Saccharomyces cerevisiae RMM proteins (Rec114, Mei4 and Mer2)—essential, conserved components of the DSB machinery. Each subcomplex of Rec114–Mei4 (2:1 heterotrimer) or Mer2 (homotetrameric coiled coil) is monodisperse in solution, but they independently condense with DNA into dynamic, reversible nucleoprotein clusters that share properties with phase-separated systems. Multivalent interactions drive condensation, which correlates with DSB formation in vivo. Condensates fuse into mixed Rec114–Mei4–Mer2 clusters that further recruit Spo11 complexes. Our data show how the DSB machinery self-assembles on chromosome axes to create centers of DSB activity. We propose that multilayered control of Spo11 arises from recruitment of regulatory components and modulation of biophysical properties of the condensates.

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