TY - JOUR
T1 - BRCA2 regulates DMC1-mediated recombination through the BRC repeats
AU - Martinez, Juan S.
AU - Von Nicolai, Catharina
AU - Kim, Taeho
AU - Ehlén, Åsa
AU - Mazin, Alexander V.
AU - Kowalczykowski, Stephen C.
AU - Carreira, Aura
N1 - Funding Information:
ACKNOWLEDGMENTS. This work was supported by the ATIP-AVENIR CNRS/INSERM Young Investigator grant, EC-CIG grant, and by Fondation pour la Recherche Médicale (FRM) Grant AJE201101 (to A.C.). J.S.M. was supported by a postdoctoral Fellowship from Fondation de France. C.N. was supported by a PhD Fellowship from Institut Curie and an FRM Fellowship for the 4th year of PhD; Å.E. was supported by Swedish Society for Medical Research. This work was also supported by NIH Grants CA100839 and P30dCA056036 and a Basser Innovation Award to A.V.M., and by NIH Grant GM62653 and DOD Grant W81XWH-13-1-0322 (to S.C.K.).
PY - 2016/3/29
Y1 - 2016/3/29
N2 - In somatic cells, BRCA2 is needed for RAD51-mediated homologous recombination. The meiosis-specific DNA strand exchange protein, DMC1, promotes the formation of DNA strand invasion products (joint molecules) between homologous molecules in a fashion similar to RAD51. BRCA2 interacts directly with both human RAD51 and DMC1; in the case of RAD51, this interaction results in stimulation of RAD51-promoted DNA strand exchange. However, for DMC1, little is known regarding the basis and functional consequences of its interaction with BRCA2. Here we report that human DMC1 interacts directly with each of the BRC repeats of BRCA2, albeit most tightly with repeats 1-3 and 6-8. However, BRC1-3 bind with higher affinity to RAD51 than to DMC1, whereas BRC6-8 bind with higher affinity to DMC1, providing potential spatial organization to nascent filament formation. With the exception of BRC4, each BRC repeat stimulates joint molecule formation by DMC1. The basis for this stimulation is an enhancement of DMC1-ssDNA complex formation by the stimulatory BRC repeats. Lastly, we demonstrate that full-length BRCA2 protein stimulates DMC1-mediated DNA strand exchange between RPA-ssDNA complexes and duplex DNA, thus identifying BRCA2 as a mediator of DMC1 recombination function. Collectively, our results suggest unique and specialized functions for the BRC motifs of BRCA2 in promoting homologous recombination in meiotic and mitotic cells.
AB - In somatic cells, BRCA2 is needed for RAD51-mediated homologous recombination. The meiosis-specific DNA strand exchange protein, DMC1, promotes the formation of DNA strand invasion products (joint molecules) between homologous molecules in a fashion similar to RAD51. BRCA2 interacts directly with both human RAD51 and DMC1; in the case of RAD51, this interaction results in stimulation of RAD51-promoted DNA strand exchange. However, for DMC1, little is known regarding the basis and functional consequences of its interaction with BRCA2. Here we report that human DMC1 interacts directly with each of the BRC repeats of BRCA2, albeit most tightly with repeats 1-3 and 6-8. However, BRC1-3 bind with higher affinity to RAD51 than to DMC1, whereas BRC6-8 bind with higher affinity to DMC1, providing potential spatial organization to nascent filament formation. With the exception of BRC4, each BRC repeat stimulates joint molecule formation by DMC1. The basis for this stimulation is an enhancement of DMC1-ssDNA complex formation by the stimulatory BRC repeats. Lastly, we demonstrate that full-length BRCA2 protein stimulates DMC1-mediated DNA strand exchange between RPA-ssDNA complexes and duplex DNA, thus identifying BRCA2 as a mediator of DMC1 recombination function. Collectively, our results suggest unique and specialized functions for the BRC motifs of BRCA2 in promoting homologous recombination in meiotic and mitotic cells.
KW - BRCA2
KW - DMC1
KW - Mediator
KW - Meiosis
KW - RAD51
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U2 - 10.1073/pnas.1601691113
DO - 10.1073/pnas.1601691113
M3 - Article
C2 - 26976601
AN - SCOPUS:84962195712
SN - 0027-8424
VL - 113
SP - 3515
EP - 3520
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 13
ER -