Enhanced strand break induction of DNA by resonant metal-innershell photoabsorption

2001 ◽  
Vol 79 (2) ◽  
pp. 196-200 ◽  
Author(s):  
C Le Sech ◽  
K Takakura ◽  
C Saint-Marc ◽  
H Frohlich ◽  
M Charlier ◽  
...  
Keyword(s):  
Platinum Complex ◽  
Strand Break ◽  
Double Strand Breaks ◽  
Platinum Atom ◽  
Dna Breaks ◽  
Platinum Concentration ◽  
Strand Breaks ◽  
Auger Effect

We determined The number of single and double strand breaks (ssb and dsb) in a DNA-chloroterpyridine platinum complex induced by resonant photoabsorption in the LIII innershell of a platinum atom. The number of ssb and dsb were measured in supercoiled plasmids (AG30) versus the chloroterpyridine platinum concentration, i.e., the ratio of intercalated molecules to the number of phosphate sites in DNA. A significant increase in the number of ssb and dsb was observed when the DNA contained intercalated molecules. This technique is an efficient way to induce ssb and dsb triggered by the atomic Auger effect.Key words: DNA breaks, Auger effect, resonant photoabsorption, intercalated molecules.

scholarly journals Double-strand DNA breaks recruit the centromeric histone CENP-A

2009 ◽  
Vol 106 (37) ◽  
pp. 15762-15767 ◽  
Author(s):  
Samantha G. Zeitlin ◽  
Norman M. Baker ◽  
Brian R. Chapados ◽  
Evi Soutoglou ◽  
Jean Y. J. Wang ◽  
...  
Keyword(s):  
Dna Cleavage ◽  
Strand Break ◽  
Double Strand Breaks ◽  
Dna Breaks ◽  
End Joining ◽  
Strand Breaks ◽  
Double Strand Dna Breaks ◽  
Histone H3 Variant ◽  
Radiation Induced ◽  
Non Homologous End Joining

The histone H3 variant CENP-A is required for epigenetic specification of centromere identity through a loading mechanism independent of DNA sequence. Using multiphoton absorption and DNA cleavage at unique sites by I-SceI endonuclease, we demonstrate that CENP-A is rapidly recruited to double-strand breaks in DNA, along with three components (CENP-N, CENP-T, and CENP-U) associated with CENP-A at centromeres. The centromere-targeting domain of CENP-A is both necessary and sufficient for recruitment to double-strand breaks. CENP-A accumulation at DNA breaks is enhanced by active non-homologous end-joining but does not require DNA-PKcs or Ligase IV, and is independent of H2AX. Thus, induction of a double-strand break is sufficient to recruit CENP-A in human and mouse cells. Finally, since cell survival after radiation-induced DNA damage correlates with CENP-A expression level, we propose that CENP-A may have a function in DNA repair.

scholarly journals YGR042W/MTE1 Functions in Double-Strand Break Repair with MPH1

2015 ◽  
Author(s):  
Askar Yimit ◽  
TaeHyung Kim ◽  
Ranjith Anand ◽  
Sarah Meister ◽  
Jiongwen Ou ◽  
...  
Keyword(s):  
Dna Damage ◽  
Strand Break ◽  
Double Strand Break ◽  
Dna Helicase ◽  
Double Strand Breaks ◽  
Double Strand Break Repair ◽  
Dependent Manner ◽  
Dna Breaks ◽  
Strand Breaks ◽  
Break Repair

Double-strand DNA breaks occur upon exposure of cells to agents such as ionizing radiation and ultraviolet light or indirectly through replication fork collapse at DNA damage sites. If left unrepaired double-strand breaks can cause genome instability and cell death. In response to DNA damage, proteins involved in double-strand break repair by homologous recombination re-localize into discrete nuclear foci. We identified 29 proteins that co-localize with the recombination repair protein Rad52 in response to DNA damage. Of particular interest, Ygr042w/Mte1, a protein of unknown function, showed robust colocalization with Rad52. Mte1 foci fail to form when the DNA helicase Mph1 is absent. Mte1 and Mph1 form a complex, and are recruited to double-strand breaks in vivo in a mutually dependent manner. Mte1 is important for resolution of Rad52 foci during double-strand break repair, and for suppressing break-induced replication. Together our data indicate that Mte1 functions with Mph1 in double-strand break repair.

scholarly journals Physiological Roles of DNA Double-Strand Breaks

2017 ◽  
Vol 2017 ◽  
pp. 1-20 ◽  
Author(s):  
Farhaan A. Khan ◽  
Syed O. Ali
Keyword(s):  
Double Helix ◽  
Strand Break ◽  
Double Strand Breaks ◽  
Genomic Integrity ◽  
Dna Double Strand Breaks ◽  
Dna Breaks ◽  
Strand Breaks ◽  
Spatiotemporal Regulation ◽  
Dna Double Strand Break

Genomic integrity is constantly threatened by sources of DNA damage, internal and external alike. Among the most cytotoxic lesions is the DNA double-strand break (DSB) which arises from the cleavage of both strands of the double helix. Cells boast a considerable set of defences to both prevent and repair these breaks and drugs which derail these processes represent an important category of anticancer therapeutics. And yet, bizarrely, cells deploy this very machinery for the intentional and calculated disruption of genomic integrity, harnessing potentially destructive DSBs in delicate genetic transactions. Under tight spatiotemporal regulation, DSBs serve as a tool for genetic modification, widely used across cellular biology to generate diverse functionalities, ranging from the fundamental upkeep of DNA replication, transcription, and the chromatin landscape to the diversification of immunity and the germline. Growing evidence points to a role of aberrant DSB physiology in human disease and an understanding of these processes may both inform the design of new therapeutic strategies and reduce off-target effects of existing drugs. Here, we review the wide-ranging roles of physiological DSBs and the emerging network of their multilateral regulation to consider how the cell is able to harness DNA breaks as a critical biochemical tool.

Transcription and Double-Strand Breaks Induce Similar Mitotic Recombination Events inSaccharomyces cerevisiae

Genetics ◽  
2002 ◽  
Vol 162 (2) ◽  
pp. 603-614 ◽  
Author(s):  
Sergio González-Barrera ◽  
María García-Rubio ◽  
Andrés Aguilera
Keyword(s):  
Comparative Analysis ◽  
Dna Sequence ◽  
Recombination Event ◽  
Strand Break ◽  
Double Strand Breaks ◽  
The Other ◽  
Dna Breaks ◽  
Strand Breaks ◽  
Spontaneous Recombination ◽  
Gene Conversions

AbstractWe have made a comparative analysis of double-strand-break (DSB)-induced recombination and spontaneous recombination under low- and high-transcription conditions in yeast. We constructed two different recombination substrates, one for the analysis of intermolecular gene conversions and the other for intramolecular gene conversions and inversions. Such substrates were based on the same leu2-HOr allele fused to the tet promoter and containing a 21-bp HO site. Gene conversions and inversions were differently affected by rad1, rad51, rad52, and rad59 single and double mutations, consistent with the actual view that such events occur by different recombination mechanisms. However, the effect of each mutation on each type of recombination event was the same, whether associated with transcription or induced by the HO-mediated DSB. Both the highly transcribed DNA and the HO-cut sequence acted as recipients of the gene conversion events. These results are consistent with the hypothesis that transcription promotes initiation of recombination along the DNA sequence being transcribed. The similarity between transcription-associated and DSB-induced recombination suggests that transcription promotes DNA breaks.

scholarly journals Focused Genetic Recombination of Bacteriophage T4 Initiated by Double-Strand Breaks

Genetics ◽  
2002 ◽  
Vol 162 (2) ◽  
pp. 543-556
Author(s):  
Victor Shcherbakov ◽  
Igor Granovsky ◽  
Lidiya Plugina ◽  
Tamara Shcherbakova ◽  
Svetlana Sizova ◽  
...  
Keyword(s):  
Genetic Recombination ◽  
Bacteriophage T4 ◽  
Proximal Part ◽  
Coupling Model ◽  
Strand Break ◽  
Double Strand Breaks ◽  
Strand Breaks ◽  
The Right ◽  
Frequency Distance

Abstract A model system for studying double-strand-break (DSB)-induced genetic recombination in vivo based on the ets1 segCΔ strain of bacteriophage T4 was developed. The ets1, a 66-bp DNA fragment of phage T2L containing the cleavage site for the T4 SegC site-specific endonuclease, was inserted into the proximal part of the T4 rIIB gene. Under segC+ conditions, the ets1 behaves as a recombination hotspot. Crosses of the ets1 against rII markers located to the left and to the right of ets1 gave similar results, thus demonstrating the equal and symmetrical initiation of recombination by either part of the broken chromosome. Frequency/distance relationships were studied in a series of two- and three-factor crosses with other rIIB and rIIA mutants (all segC+) separated from ets1 by 12-2100 bp. The observed relationships were readily interpretable in terms of the modified splice/patch coupling model. The advantages of this localized or focused recombination over that distributed along the chromosome, as a model for studying the recombination-replication pathway in T4 in vivo, are discussed.

scholarly journals End-resection at DNA double-strand breaks in the three domains of life

2013 ◽  
Vol 41 (1) ◽  
pp. 314-320 ◽  
Author(s):  
John K. Blackwood ◽  
Neil J. Rzechorzek ◽  
Sian M. Bray ◽  
Joseph D. Maman ◽  
Luca Pellegrini ◽  
...  
Keyword(s):  
Dna Repair ◽  
Homologous Recombination ◽  
Strand Break ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Strand Breaks ◽  
Homologous Chromosomes ◽  
Domains Of Life ◽  
Strand Invasion ◽  
End Resection

During DNA repair by HR (homologous recombination), the ends of a DNA DSB (double-strand break) must be resected to generate single-stranded tails, which are required for strand invasion and exchange with homologous chromosomes. This 5′–3′ end-resection of the DNA duplex is an essential process, conserved across all three domains of life: the bacteria, eukaryota and archaea. In the present review, we examine the numerous and redundant helicase and nuclease systems that function as the enzymatic analogues for this crucial process in the three major phylogenetic divisions.

Homologous recombination and the repair of double-strand breaks during cotransformation of Dictyostelium discoideum

1988 ◽  
Vol 8 (7) ◽  
pp. 2779-2786
Author(s):  
K S Katz ◽  
D I Ratner
Keyword(s):  
Homologous Recombination ◽  
Dictyostelium Discoideum ◽  
Strand Break ◽  
Double Strand Breaks ◽  
Restriction Endonucleases ◽  
Linear Molecule ◽  
Strand Breaks ◽  
Transformation Vector ◽  
Closed Circle ◽  
Primary Vector

We examined the ability of unlinked nonreplicating plasmid molecules to undergo homologous recombination during cotransformation of Dictyostelium amoebae. The transformation vector B10S confers resistance to the antibiotic G418 and was always presented to amoebae as a closed circle. Cotransforming DNA, containing a slime mold cDNA and sequences homologous to the primary vector, was presented either as a closed circle or as a linear molecule after digestion with restriction endonucleases which cut within one of three distinct regions of the plasmid. Remarkably, homologous recombination occurred in every clone examined. Moreover, the products of recombination were identical in all instances, irrespective of the presence or position of linearized ends. The ends of the linear templates were not recombinogenic. Repair of the introduced double-strand break occurred frequently during recombination. The repair could occur intermolecularly or, more likely, intramolecularly, i.e., by recircularization. Many of the recombination events were of a nonreciprocal nature. Despite the startlingly frequent level of homologous recombination, the use of cotransforming DNA which contains no homology to the selected vector established that such recombination was not required for cotransformation.

scholarly journals i-BLESS is an ultra-sensitive method for detection of DNA double-strand breaks

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Anna Biernacka ◽  
Yingjie Zhu ◽  
Magdalena Skrzypczak ◽  
Romain Forey ◽  
Benjamin Pardo ◽  
...  
Keyword(s):  
Cell Fate ◽  
Genome Stability ◽  
Strand Break ◽  
Double Strand Breaks ◽  
Universal Method ◽  
Dna Double Strand Breaks ◽  
Strand Breaks ◽  
Agarose Beads ◽  
Genome Wide ◽  
Dna Double Strand Break

AbstractMaintenance of genome stability is a key issue for cell fate that could be compromised by chromosome deletions and translocations caused by DNA double-strand breaks (DSBs). Thus development of precise and sensitive tools for DSBs labeling is of great importance for understanding mechanisms of DSB formation, their sensing and repair. Until now there has been no high resolution and specific DSB detection technique that would be applicable to any cells regardless of their size. Here, we present i-BLESS, a universal method for direct genome-wide DNA double-strand break labeling in cells immobilized in agarose beads. i-BLESS has three key advantages: it is the only unbiased method applicable to yeast, achieves a sensitivity of one break at a given position in 100,000 cells, and eliminates background noise while still allowing for fixation of samples. The method allows detection of ultra-rare breaks such as those forming spontaneously at G-quadruplexes.

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 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.

Sign in / Sign up

Export Citation Format

Share Document