Resection of DNA double-strand break (DSB) ends is generally considered a critical determinant in pathways of DSB repair and genome stability. Unlike for enzymatically induced site-specific DSBs, little is known about processing of random "dirty-ended" DSBs created by DNA damaging agents such as ionizing radiation. Here we present a novel system for monitoring early events in the repair of rand...

BACKGROUND In response to DNA double-strand breaks (DSBs), eukaryotic cells rapidly phosphorylate histone H2A isoform H2AX at a C-terminal serine (to form gamma-H2AX) and accumulate repair proteins at or near DSBs. To date, these events have been defined primarily at the resolution of light microscopes, and the relationship between gamma-H2AX formation and repair protein recruitment remains to ...

Signaling of chromosomal DNA breaks is of primary importance for initiation of repair and, thus, for global genomic stability. Although the Mre11-Rad50-Nbs1 (MRN) complex is the first sensor of double-strand breaks, its role in double-strand break (DSB) signaling is not fully understood. We report the absence of γ-ray-induced, ATM/ATR-dependent histone H2AX phosphorylation in Arabidopsis thalia...

The single-stranded DNA (ssDNA)-binding protein replication protein A (RPA) is essential for both DNA replication and recombination. Chromatin immunoprecipitation techniques were used to visualize the kinetics and extent of RPA binding following induction of a double-strand break (DSB) and during its repair by homologous recombination in yeast. RPA assembles at the HO endonuclease-cut MAT locus...

Several modes of eukaryotic of DNA double strand break repair (DSBR) depend on synapsis of complementary DNA. The Rad51 ATPase, the S. cerevisiae homolog of E. coli RecA, plays a key role in this process by catalyzing homology searching and strand exchange between an invading DNA strand and a repair template (e.g. sister chromatid or homologous chromosome). Synthesis dependent strand annealing ...

Introduction The aim of this study was toinvestigate the sterilization potential of atmospheric pressure plasma jet (APPJ) and interactions of this technology with double-stranded DNA using the polymerase chain reaction (PCR) and single-strand conformation polymorphism (SSCP) techniques. Materials and Methods The plasma jet was produced through a high voltage sinusoidal power supplyusing a mixt...

The analysis of double-strand break (DSB) repair is complicated by the existence of several pathways utilizing a large number of genes. Moreover, many of these genes have been shown to have multiple roles in DSB repair. To address this complexity we used a repair reporter construct designed to measure multiple repair outcomes simultaneously. This approach provides estimates of the relative usag...

Broken DNA can be repaired by homologous recombination mechanisms, which initially align both ends of a DNA double-strand break (DSB) with a homologous repair template. Particularly in the context of a crowded eukaryotic nucleus, it remains mysterious how the two ends of a broken DNA molecule coordinate their actions to identify an appropriate template and initiate repair. In this issue, Brown ...

Direct cellular DNA damage may lead to genome destabilization in unexposed, bystander, cells sharing the same milieu with directly damaged cells by means of the bystander effect. One proposed mechanism involves double strand break (DSB) formation in S phase cells at sites of single strand lesions in the DNA of replication complexes, which has a more open structure compared with neighboring DNA....

Homologous recombination (HR) repairs DNA double-strand breaks and maintains genome stability. HR between linked, direct repeats can occur by gene conversion without an associated crossover that maintains the gross repeat structure. Alternatively, direct repeat HR can occur by gene conversion with a crossover, or by single-strand annealing (SSA), both of which delete one repeat and the sequence...