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...

The literature on recreational physical activity (RPA) and ovarian cancer risk is inconclusive and most studies of RPA and ovarian cancer have been conducted in white populations. This study is the first to investigate the association between RPA and ovarian cancer in an exclusively African American (AA) population. We analyzed data from an ongoing U.S. population-based, case-control study of A...

OBJECTIVE As bradykinin (BYK) relaxes conduit (EPA) and resistance (RPA) pulmonary arteries from both perinatal and adult lungs, we investigated whether this vasodilator's relaxation-mechanisms were altered during perinatal development, differed between EPA and RPA and differed with other endothelium-dependent vasodilators, acetyicholine (ACH) and substance P (SP). METHODS Arteries from matur...

Rad51, Rad52, and RPA play central roles in homologous DNA recombination. Rad51 mediates DNA strand exchange, a key reaction in DNA recombination. Rad52 has two distinct activities: to recruit Rad51 onto single-strand (ss)DNA that is complexed with the ssDNA-binding protein, RPA, and to anneal complementary ssDNA complexed with RPA. Here, we report that Rad52 promotes annealing of the ssDNA str...

Human RPA (replication protein A), a single-stranded DNA-binding protein, is required for many cellular pathways including DNA repair, recombination and replication. However, the role of RPA in nucleotide excision repair remains elusive. In the present study, we have systematically examined the binding of RPA to a battery of well-defined ssDNA (single-stranded DNA) substrates using fluorescence...

Protein-promoted DNA strand exchange requires formation of an active presynaptic complex between the DNA-pairing protein and single-stranded DNA (ssDNA). Formation of such a contiguous filament is stimulated by a ssDNA-binding protein. Here, the effects of replication protein A (RPA) on presynaptic complex formation and DNA strand exchange activities of Rad51 protein were examined. Presynaptic ...

Replication protein A (RPA), a stable complex of three polypeptides, is the single-stranded DNA-binding protein essential for DNA replication in eukaryotic cells. Previous studies of the subcellular distribution and stability of the RPA heterotrimer during the mammalian cell cycle have produced conflicting results. Here, we present evidence that these inconsistencies can be accounted for by the...

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...

Replication protein A (RPA) plays an essential role in DNA replication by binding and unfolding non-canonical single-stranded DNA (ssDNA) structures. Of the six RPA ssDNA binding domains (labeled A-F), RPA-CDE selectively binds a G-quadruplex forming sequence (5'-TAGGGGAAGGGTTGGAGTGGGTT-3' called Gq23). In K(+), Gq23 forms a mixed parallel/antiparallel conformation, and in Na(+) Gq23 has a less...

OBJECTIVES This study was undertaken to confirm the clinical characteristics of recurrent pleomorphic adenoma (RPA), and to identify those factors that affect the development of malignant transformation (MT) from RPA. METHODS The medical records of 270 patients, who were operated upon for parotid PA, were retrospectively reviewed. The pathologic specimens of a selected series of 23 patients w...