Functions of Human Rad51 and Other Recombination Factors in DNA Double-Strand Break Repair
Annual summary 1 Jun 2001-31 May 2004
TEXAS UNIV HEALTH SCIENCE CENTER AT SANANTONIO
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Gene of RAD52 epistasis group mediate homologous recombination and recombination repair of. DNA double strand breaks. Genetic and biochemical studies have suggested that the function of genes of the RAD52 group is highly conserved from yeast to humans and interestingly the efficiency of DNA double strand break repair in mammalian cells is dependent on the tumor suppressors BRCA1 and BRCA2. This underscores the importance of studying the mechanistic basis of protein factors involved in the repair pathway. Rad51 is the key protein in the process and can catalyze homologous DNA pairing and strand exchange reaction. The reaction is stimulated by RPA but interestingly RPA can also suppress the strand exchange reaction by competing with Rad51 for binding sites on the DNA. Proteins called recombination mediators can overcome the suppressive effect of RPA and few are known from prokarvotes and yeast cells. Five Rad5l like proteins, called Rad51 paralogs have been identified in vertebrate cells. In this study, we show that two of these paralogs can promote the Rad51 homologous DNA pairing and strand exchange when Rad5l must compete with RPA for DNA binding sites. This represents the first recombination mediator described for human cells.
- Anatomy and Physiology
- Medicine and Medical Research