Plasticity of BRCA2 function in homologous recombination: genetic interactions of the PALB2 and DNA binding domains.
Plasticity of BRCA2 function in homologous recombination: genetic interactions of the PALB2 and DNA binding domains.
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DOI：
10.1371/journal.pgen.1002409
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发表时间：
2011-12
期刊：
影响因子：
4.5
通讯作者：
Jasin M
中科院分区：
文献类型：
--
作者：
Siaud N;Barbera MA;Egashira A;Lam I;Christ N;Schlacher K;Xia B;Jasin M
The breast cancer suppressor BRCA2 is essential for the maintenance of genomic integrity in mammalian cells through its role in DNA repair by homologous recombination (HR). Human BRCA2 is 3,418 amino acids and is comprised of multiple domains that interact with the RAD51 recombinase and other proteins as well as with DNA. To gain insight into the cellular function of BRCA2 in HR, we created fusions consisting of various BRCA2 domains and also introduced mutations into these domains to disrupt specific protein and DNA interactions. We find that a BRCA2 fusion peptide deleted for the DNA binding domain and active in HR is completely dependent on interaction with the PALB2 tumor suppressor for activity. Conversely, a BRCA2 fusion peptide deleted for the PALB2 binding domain is dependent on an intact DNA binding domain, providing a role for this conserved domain in vivo; mutagenesis suggests that both single-stranded and double-stranded DNA binding activities in the DNA binding domain are required for its activity. Given that PALB2 itself binds DNA, these results suggest alternative mechanisms to deliver RAD51 to DNA. In addition, the BRCA2 C terminus contains both RAD51-dependent and -independent activities which are essential to HR in some contexts. Finally, binding the small peptide DSS1 is essential for activity when its binding domain is present, but not when it is absent. Our results reveal functional redundancy within the BRCA2 protein and emphasize the plasticity of this large protein built for optimal HR function in mammalian cells. The occurrence of disease-causing mutations throughout BRCA2 suggests sub-optimal HR from a variety of domain modulations. The breast tumor suppressor BRCA2 has a major role in DNA repair by homologous recombination (HR). BRCA2 is a large protein with multiple domains that interact with several proteins as well as with DNA, complicating our understanding of how the protein functions in cells. To investigate the mechanism by which BRCA2 functions in HR in cells, we created fusions consisting of various BRCA2 domains and also introduced mutations into these domains to disrupt specific protein and DNA interactions. We find that DNA binding by BRCA2 is critical when a BRCA2 peptide is deficient in binding another breast cancer suppressor, PALB2, but not when the peptide can bind PALB2, suggesting alternative mechanisms of activity. Binding the small peptide DSS1 is also essential for HR only in some contexts, as are activities in the BRCA2 C terminus. Our results reveal redundancy of BRCA2 domains and emphasize plasticity within this large protein built for optimal HR function in mammalian cells. The occurrence of disease-causing mutations throughout BRCA2 suggests sub-optimal HR from a variety of domain modulations.
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影响因子：
30.8
作者：
Connor, F;Bertwistle, D;Ashworth, A
通讯作者：
Ashworth, A
DOI：
10.1016/j.cub.2009.05.057
发表时间：
2009-07-14
期刊：
Current biology : CB
影响因子：
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作者：
Ayoub N;Rajendra E;Su X;Jeyasekharan AD;Mahen R;Venkitaraman AR
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10.1016/j.mrfmmm.2010.08.007
发表时间：
2010-12-10
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作者：
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