Gemcitabine (2',2'-difluorodeoxycytidine), a deoxycytidine analog, and erlotinib, an epidermal growth factor receptor-tyrosine kinase inhibitor, are used clinically to treat patients with non-small-cell lung cancer (NSCLC). However, the molecular mechanisms for the drug resistance of gemcitabine in NSCLC cells are poorly understood. In this study, we used constructs containing human Rad51 cDNA ...

The Rad51 protein, a eukaryotic homologue of Escherichia coli RecA, plays a central role in both mitotic and meiotic homologous DNA recombination (HR) in Saccharomyces cerevisiae and is essential for the proliferation of vertebrate cells. Five vertebrate genes, RAD51B, -C, and -D and XRCC2 and -3, are implicated in HR on the basis of their sequence similarity to Rad51 (Rad51 paralogs). We gener...

It has been shown that the key homologous recombination protein Rad51 accumulates in DNA damage-induced nuclear foci that are attached to the nuclear matrix. In the present communication we attempted to find whether Rad51 contains a functional domain responsible for nuclear matrix binding. By alignments of the sequences encoding nuclear matrix targeting signals of human nuclear matrix binding p...

Radiation therapy and chemotherapy are commonly used treatments for head and neck cancer. RAD51 is a highly conserved DNA repair protein that serves a central function in the homologous recombination pathway. High levels of RAD51 protein expression have been reported in number of human cancer cell lines, and studies suggest that RAD51 overexpression can increase cellular resistance to radiation...

After UV irradiation, DNA polymerases specialized in translesion DNA synthesis (TLS) aid DNA replication. However, it is unclear whether other mechanisms also facilitate the elongation of UV-damaged DNA. We wondered if Rad51 recombinase (Rad51), a factor that escorts replication forks, aids replication across UV lesions. We found that depletion of Rad51 impairs S-phase progression and increases...

Human RAD51 is a key protein in the repair of DNA by homologous recombination. Its assembly onto DNA, which induces changes in DNA structure, results in the formation of a nucleoprotein filament that forms the basis of strand exchange. Here, we determine the structural and mechanical properties of RAD51-dsDNA filaments. Our measurements use two recently developed magnetic tweezers assays, freel...

The RAD54 family DNA translocases have several biochemical activities. One activity, demonstrated previously for the budding yeast translocases, is ATPase-dependent disruption of RAD51-dsDNA binding. This activity is thought to promote dissociation of RAD51 from heteroduplex DNA following strand exchange during homologous recombination. In addition, previous experiments in budding yeast have sh...

The Rad51 protein is essential for DNA repair by homologous recombination. After DNA damage, Rad51 localizes to nuclear foci that represent sites of DNA repair in vivo. In vitro, Rad51 self-assembles on single- or double-stranded DNA to form a nucleoprotein filament. Recently, the merging of innovative single-molecule techniques with ensemble methods has provided unique insights into the dynami...

BACKGROUND Tumour suppressor genes such as TP53, BRCA1 and RAD51 are involved in DNA repair and their malfunctions result in genomic instability and cancer. Wild type (WT) TP53 binds to BRCA1and RAD51 in vivo and in vitro. However, mutated TP53 in tumours can interfere with WT TP53 function. We studied how mutation of TP53 in MDA-MB-468 cell line could affect its binding capacity and interfere ...

Human RAD51 protein catalyzes DNA pairing and strand exchange reactions that are central to homologous recombination and homology-directed DNA repair. Successful recombination/repair requires the formation of a presynaptic filament of RAD51 on ssDNA. Mutations in BRCA2 and other proteins that control RAD51 activity are associated with human cancer. Here we describe a set of mutations associated...