Efficient repair of chromosomal double-strand breaks (DSBs) by homologous recombination relies on the formation of a Rad51 recombinase filament that forms on single-stranded DNA (ssDNA) created at DSB ends. This filament facilitates the search for a homologous donor sequence and promotes strand invasion. Recently caffeine treatment has been shown to prevent gene targeting in mammalian cells by ...

The Rad51 nucleoprotein filament mediates DNA strand exchange, a key step of homologous recombination. This activity is stimulated by replication protein A (RPA), but only when RPA is introduced after Rad51 nucleoprotein filament formation. In contrast, RPA inhibits Rad51 nucleoprotein complex formation by prior binding to single-stranded DNA (ssDNA), but Rad52 protein alleviates this inhibitio...

Repair of double-strand breaks by gene conversions between homologous sequences located on different Saccharomyces cerevisiae chromosomes or plasmids requires RAD51. When repair occurs between inverted repeats of the same plasmid, both RAD51-dependent and RAD51-independent repairs are found. Completion of RAD51-independent plasmid repair events requires RAD52, RAD50, RAD59, TID1 (RDH54), and SR...

Patients with glioblastoma die from local relapse despite surgery and high-dose radiotherapy. Resistance to radiotherapy is thought to be due to efficient DNA double-strand break (DSB) repair in stem-like cells able to survive DNA damage and repopulate the tumor. We used clinical samples and patient-derived glioblastoma stem cells (GSCs) to confirm that the DSB repair protein RAD51 is highly ex...

The highly conserved Saccharomyces cerevisiae Rad51 protein plays a central role in both mitotic and meiotic homologous DNA recombination. Seven members of the Rad51 family have been identified in vertebrate cells, including Rad51, Dmc1, and five Rad51-related proteins referred to as Rad51 paralogs, which share 20 to 30% sequence identity with Rad51. In chicken B lymphocyte DT40 cells, we gener...

Mutations in BRCA1 and BRCA2 account for the majority of familial breast cancers. Cells with mutated BRCA1 or BRCA2 are hypersensitive to ionizing radiation (IR) and exhibit defective DNA repair. Both BRCA1 and BRCA2 have been reported to bind Rad51, a protein essential for homologous recombination and the recombinational repair of DNA double-strand breaks. In normal cells, a redistribution of ...

Both Rad51 and Rad52 are required for homologous genetic recombination in Saccharomyces cerevisiae. Rad51 promotes heteroduplex joint formation, a general step in homologous recombination. Rad52 facilitates the binding of Rad51 to replication protein A (RPA)-coated single-stranded DNA. The requirement of RPA can be avoided in vitro, if the single-stranded DNA is short. Using short single-strand...

An open question in meiosis is whether the Rad51 recombination protein functions solely in meiotic recombination or whether it is also involved in the chromosome homology search. To address this question, we have performed three-dimensional high-resolution immunofluorescence microscopy to visualize native Rad51 structures in maize male meiocytes. Maize has two closely related RAD51 genes that a...

Rad51 is a conserved protein essential for recombinational repair of double-stranded DNA breaks (DSBs) in somatic cells and during meiosis in germ cells. Yeast Rad51 mutants are viable but show meiosis defects. In the mouse, RAD51 deletions cause early embryonic death, suggesting that in higher eukaryotes Rad51 is required for viability. Here we report the identification of SpnA as the Drosophi...

Previous studies showed that the K342E substitution in the Saccharomyces cerevisiae Rad51 protein increases the interaction with Rad54 protein in the two-hybrid system, leads to increased sensitivity to the alkylating agent MMS and hyper-recombination in an oligonucleotide-mediated gene targeting assay. K342 localizes in loop 2, a region of Rad51 whose function is not well understood. Here, we ...