Feng Qi, Düring Louis, de Mayolo Adriana Antúnez, Lettier Gaëlle, Lisby Michael, Erdeniz Naz, Mortensen Uffe H, Rothstein Rodney
Department of Genetics & Development, Columbia University Medical Center, 701 West 168th Street, New York, NY 10032-2704, USA.
DNA Repair (Amst). 2007 Jan 4;6(1):27-37. doi: 10.1016/j.dnarep.2006.08.007. Epub 2006 Sep 20.
Homologous recombination is an important pathway for the repair of DNA double-strand breaks (DSBs). In the yeast Saccharomyces cerevisiae, Rad52 is a central recombination protein, whereas its paralogue, Rad59, plays a more subtle role in homologous recombination. Both proteins can mediate annealing of complementary single-stranded DNA in vitro, but only Rad52 interacts with replication protein A and the Rad51 recombinase. We have studied the functional overlap between Rad52 and Rad59 in living cells using chimeras of the two proteins and site-directed mutagenesis. We find that Rad52 and Rad59 have both overlapping as well as separate functions in DSB repair. Importantly, the N-terminus of Rad52 possesses functions not supplied by Rad59, which may account for its central role in homologous recombination.
同源重组是DNA双链断裂(DSB)修复的重要途径。在酿酒酵母中,Rad52是一种核心重组蛋白,而其旁系同源物Rad59在同源重组中发挥着更为微妙的作用。两种蛋白在体外均能介导互补单链DNA的退火,但只有Rad52与复制蛋白A和Rad51重组酶相互作用。我们利用这两种蛋白的嵌合体和定点诱变技术,研究了活细胞中Rad52和Rad59之间的功能重叠。我们发现,Rad52和Rad59在DSB修复中既有重叠功能,也有各自独立的功能。重要的是,Rad52的N端具有Rad59所不具备的功能,这可能解释了其在同源重组中的核心作用。