Stimulation of fission yeast and mouse Hop2-Mnd1 of the Dmc1 and Rad51 recombinases.
Genetic analysis of fission yeast suggests a role for the spHop2-Mnd1 proteins in the Rad51 and Dmc1-dependent meiotic recombination pathways. In order to gain biochemical insights into this process, we purified Schizosaccharomyces pombe Hop2-Mnd1 to homogeneity. spHop2 and spMnd1 interact by co-immunoprecipitation and two-hybrid analysis. Electron microscopy reveals that S. pombe Hop2-Mnd1 binds single-strand DNA ends of 3'-tailed DNA. Interestingly, spHop2-Mnd1 promotes the renaturation of complementary single-strand DNA and catalyses strand exchange reactions with short oligonucleotides. Importantly, we show that spHop2-Mnd1 stimulates spDmc1-dependent strand exchange and strand invasion. Ca(2+) alleviate the requirement for the order of addition of the proteins on DNA. We also demonstrate that while spHop2-Mnd1 affects spDmc1 specifically, mHop2 or mHop2-Mnd1 stimulates both the hRad51 and hDmc1 recombinases in strand exchange assays. Thus, our results suggest a crucial role for S. pombe and mouse Hop2-Mnd1 in homologous pairing and strand exchange and reveal evolutionary divergence in their specificity for the Dmc1 and Rad51 recombinases.
Ploquin
Mickaël
M
Genome Stability Laboratory, Laval University Cancer Research Center, Hôtel-Dieu de Québec, 9 McMahon, Quebec city, QC, Canada G1R 2J6.
Petukhova
Galina V
GV
Morneau
Dany
D
Déry
Ugo
U
Bransi
Ali
A
Stasiak
Andrzej
A
Camerini-Otero
R Daniel
RD
Masson
Jean-Yves
JY
D000818:Animals; D018797:Cell Cycle Proteins / Q000378:metabolism; D002850:Chromatography, Gel; D004277:DNA, Single-Stranded / Q000378:metabolism / Q000648:ultrastructure; D004268:DNA-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism* / Q000648:ultrastructure; D051379:Mice; D051135:Rad51 Recombinase / Q000378:metabolism; D045522:Recombinases / Q000378:metabolism*; D011995:Recombination, Genetic; D029702:Schizosaccharomyces pombe Proteins / Q000302:isolation & purification / Q000378:metabolism* / Q000648:ultrastructure
D018797:Cell Cycle Proteins; D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; C520335:Hop2 protein, S pombe; C501202:Hop2 protein, mouse; C520336:Mnd1 protein, S pombe; C501203:Mnd1 protein, mouse; D045522:Recombinases; D029702:Schizosaccharomyces pombe Proteins; C495153:RAD51 protein, human; D051135:Rad51 Recombinase; C074556:DMC1 protein, human