Compensatory functions and interdependency of the DNABinding domain of BRCA2 with the BRCA1-PALB2-BRCA2 complex

Muthana Al Abo, Donniphat Dejsuphong, Kouji Hirota, Yasukazu Yonetani, Mitsuyoshi Yamazoe, Hitoshi Kurumizaka, Shunichi Takeda

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    9 Citations (Scopus)

    Abstract

    BRCA1, BRCA2, and PALB2 are key players in cellular tolerance to chemotherapeutic agents, including camptothecin, cisplatin, and PARP inhibitor. The N-terminal segment of BRCA2 interacts with PALB2, thus contributing to the formation of the BRCA1-PALB2-BRCA2 complex. To understand the role played by BRCA2 in this complex, we deleted its N-terminal segment and generated BRCA2DN mutant cells. Although previous studies have suggested that BRCA1-PALB2 plays a role in the recruitment of BRCA2 to DNA-damage sites, BRCA2DN mutant cells displayed a considerably milder phenotype than did BRCA2-/- null-deficient cells. We hypothesized that the DNA-binding domain (DBD) of BRCA2 might compensate for a defect in BRCA2DN that prevented stable interaction with PALB2. To test this hypothesis, we disrupted the DBD of BRCA2 in wild-type and BRCA2DN cells. Remarkably, although the resulting BRCA2DDBD cells displayed a moderate phenotype, the BRCA2DN+DDBD cells displayed a very severe phenotype, as did the BRCA2-/- cells, suggesting that the N-terminal segment and the DBD play a substantially overlapping role in the functionality of BRCA2. We also showed that the formation of both the BRCA1-PALB2-BRCA2 complex and the DBD is required for efficient recruitment of BRCA2 to DNA-damage sites. Our study revealed the essential role played by both the BRCA1-PALB2-BRCA2 complex and the DBD in the functionality of BRCA2, as each can compensate for the other in the recruitment of BRCA2 to DNA-damage sites. This knowledge adds to our ability to accurately predict the efficacy of antimalignant therapies for patients carrying mutations in the BRCA2 gene.

    Original languageEnglish
    Pages (from-to)797-807
    Number of pages11
    JournalCancer Research
    Volume74
    Issue number3
    DOIs
    Publication statusPublished - 2014 Feb 1

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    ASJC Scopus subject areas

    • Cancer Research
    • Oncology

    Cite this

    Al Abo, M., Dejsuphong, D., Hirota, K., Yonetani, Y., Yamazoe, M., Kurumizaka, H., & Takeda, S. (2014). Compensatory functions and interdependency of the DNABinding domain of BRCA2 with the BRCA1-PALB2-BRCA2 complex. Cancer Research, 74(3), 797-807. https://doi.org/10.1158/0008-5472.CAN-13-1443