Rad52 protein plays a central role in double strand break repair and homologous recombination in Saccharomyces cerevisiae. We have identified a new mechanism by which Rad52 protein stimulates Rad51 protein-promoted DNA strand exchange. This function of Rad52 protein is revealed when subsaturating amounts (relative to the single-stranded DNA concentration) of replication protein-A (RPA) are used...

One of the first responses observed in S phase mammalian cells that have suffered DNA damage is the inhibition of initiation of DNA replicons. In cells exposed to ionizing radiation, a single-strand break appears to be the stimulus for this effect, whereby the initiation of many adjacent replicons (a replicon cluster) is blocked by a single-strand break in any one of them. In cells exposed to u...

DNA damage, malfunctions in DNA repair, and genomic instability are processes that intersect at the crossroads of carcinogenesis. Underscoring the importance of DNA repair in breast and ovarian tumorigenesis is the familial inherited cancer predisposition gene BRCA2. The role of BRCA2 in DNA double-strand break repair was first revealed based on its interaction with RAD51, a central player in h...

The integrity of genomic DNA is crucial for its function. And yet, DNA in living cells is inherently unstable. It is subject to mechanical stress and to many types of chemical modification that may lead to breaks in one or both strands of the double helix. Within the cell, reactive oxygen species generated by normal respiratory metabolism can cause double-strand breaks, as can stalled DNA repli...

We show that RecN protein is recruited to a defined DNA double strand break (DSB) in Bacillus subtilis cells at an early time point during repair. Because RecO and RecF are successively recruited to DSBs, it is now clear that dynamic DSB repair centers (RCs) exist in prokaryotes. RecA protein was also recruited to RCs and formed highly dynamic filamentous structures, which we term threads, acro...

ownloade C regulates a myriad of genes controlling cell proliferation, metabolism, differentiation, and apoptosis. lso controls the expression of DNA double-strand break (DSB) repair genes and therefore may be a ial target for anticancer therapy to sensitize cancer cells to DNA damage or prevent genetic instability. report, we studied whether MYC binds to DSB repair gene promoters and modulates...

Homologous recombination (HR) is a universally conserved DNA double-strand break repair pathway. Single-molecule fluorescence imaging approaches have revealed new mechanistic insights into nearly all aspects of HR. These methods are especially suited for studying protein complexes because multicolor fluorescent imaging can parse out subassemblies and transient intermediates that associate with ...

The process of information exchange between two homologous DNA duplexes is known as homologous recombination (HR) or double-strand break repair (DSBR), depending on the context. HR is the fundamental process underlying the genome shuffling that expands genetic diversity (for example during meiosis in eukaryotes). DSBR is an essential repair pathway in all three domains of life, and plays a majo...