XRCC2 protein shares weak amino acid sequence similarity with Rad51, which is a central player in homologous recombinational repair (HRR). Rad51 proteins assemble at the sites of HRR and form visible nuclear foci in response to DNA damage. Xrcc2 hamster mutant irs1 cells are incapable of forming Rad51 foci after ionizing irradiation or DNA cross-linking agent mitomycin C treatment, though the R...

Meiotic recombination requires the meiosis-specific RecA homolog Dmc1 as well as the mitotic RecA homolog Rad51. Here, we show that the two meiosis-specific proteins Mei5 and Sae3 are necessary for the assembly of Dmc1, but not for Rad51, on chromosomes including the association of Dmc1 with a recombination hot spot. Mei5, Sae3, and Dmc1 form a ternary and evolutionary conserved complex that re...

Progressive multifocal leukoencephalopathy (PML) is a fatal demyelinating disorder of the CNS caused by infection of glial cells with the polyomavirus, JCV. Here we report that genomic stability and DNA repair are significantly dysregulated by JCV infection of human astrocytes. Metaphase spreads exhibited increased ploidy correlating with duration of infection. Increased micronuclei formation a...

(-)-Guaiol, generally known as an antibacterial compound, has been found in many medicinal plants. Its roles in tumor suppression are still under investigation. In the study, we mainly focused on exploring its applications in dealing with non-small cell lung cancer (NSCLC) and the underlying mechanisms. Here, we show that (-)-Guaiol significantly inhibits cell growth of NSCLC cells both in vitr...

Transcription from the HIV-1 promoter is controlled by a series of ubiquitous and inducible cellular proteins with the ability to enter the nucleus and interact with the promoter. A DNA sequence spanning nucleotides -120 to -80, which supports the association of the inducible NF-κB transcription factor, has received much attention. Here we demonstrate that the interplay between Rad51, a key reg...

Rad54 protein is a Snf2-like ATPase with a specialized function in the recombinational repair of DNA damage. Rad54 is thought to stimulate the search of homology via formation of a specific complex with the presynaptic Rad51 filament on single-stranded DNA. Herein, we address the interaction of Rad54 with Rad51 filaments on double-stranded (ds) DNA, an intermediate in DNA strand exchange with u...

Many interacting proteins regulate and/or assist the activities of RAD51, a recombinase which plays a critical role in both DNA repair and meiotic recombination. Yeast two-hybrid screening of a human testis cDNA library revealed a new protein, RAD51AP2 (RAD51 Associated Protein 2), that interacts strongly with RAD51. A full-length cDNA clone predicts a novel vertebrate-specific protein of 1159 ...

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 ...

Artesunate, a semi-synthetic derivative of arteminisin originally developed for the treatment of malaria, has recently been shown to possess antitumor properties. One of the cytotoxic effects of artesunate on cancer cells is mediated by induction of oxidative stress and DNA double-strand breaks (DSBs). We report here that in addition to inducing oxidative stress and DSBs, artesunate can also do...

Streptomyces RecA proteins are characterized by a conserved, positively charged extension of unknown function appended at their C-termini. To investigate the function of this element, we introduced the Streptomyces rimosus recA gene and its mutant form encoding the protein with a C-terminal deletion into S. rimosus. Both transcript and protein levels were dramatically increased in the strain ex...