Role of Rad51-Mediated Interactions in Recombination
Annual summary rept. 1 Aug 2003-31 Jul 2004
YALE UNIV NEW HAVEN CT
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The repair of DNA double-stranded breaks by homologous recombination is mediated by genes of RAD52 epistasis group. Rad5l protein, a key member of the RAD52 group, forms a helical filament on single-stranded DNA that is derived from double-stranded breaks. The Rad5l-DNA filament searches for a DNA homologue, either the sister chromatid or homologous chromosome, and catalyzes the formation of a DNA joint with the homologue. Rad5l interacts with other RAD52 group proteins including Rad52, Rad54, and XRCC3. In addition, the breast tumor suppressor BRCA2 associates with Rad5l. Consistent with this, cell lines mutated for BRCA2 are sensitive to agents that cause DNA double-stranded breaks and have recombination deficiencies. Using a yeast two-hybrid based genetic screen, I will isolate Rad5l mutants that are defective in interaction with BRCA2 and Rad54. These Rad5l mutants will be characterized biochemically and genetically to establish the significance of the noted protein-protein interactions in recombination and repair. The results from my proposed studies will be important for understanding the mechanistic underpinnings of the human recombination machinery and will make an important contribution toward further delineating the role of recombinational DNA repair in breast tumor suppression.
- Medicine and Medical Research