CtIP-BRCA1 modulates the choice of DNA double-strand-break repair pathway throughout the cell cycle

Maximina H. Yun, Kevin Hiom (Lead / Corresponding author)

    Research output: Contribution to journalArticle

    306 Citations (Scopus)

    Abstract

    The repair of DNA double-strand breaks (DSBs) is tightly regulated during the cell cycle. In G1 phase, the absence of a sister chromatid means that repair of DSBs occurs through non-homologous end-joining or microhomology-mediated end-joining (MMEJ)(1). These pathways often involve loss of DNA sequences at the break site and are therefore error-prone. In late S and G2 phases, even though DNA end-joining pathways remain functional(2), there is an increase in repair of DSBs by homologous recombination, which is mostly error-free(3,4). Consequently, the relative contribution of these different pathways to DSB repair in the cell cycle has a large influence on the maintenance of genetic integrity. It has remained unknown how DSBs are directed for repair by different, potentially competing, repair pathways. Here we identify a role for CtIP (also known as RBBP8) in this process in the avian B-cell line DT40. We establish that CtIP is required not only for repair of DSBs by homologous recombination in S/G2 phase but also for MMEJ in G1. The function of CtIP in homologous recombination, but not MMEJ, is dependent on the phosphorylation of serine residue 327 and recruitment of BRCA1. Cells expressing CtIP protein that cannot be phosphorylated at serine 327 are specifically defective in homologous recombination and have a decreased level of single-stranded DNA after DNA damage, whereas MMEJ remains unaffected. Our data support a model in which phosphorylation of serine 327 of CtIP as cells enter S phase and the recruitment of BRCA1 functions as a molecular switch to shift the balance of DSB repair from error-prone DNA end-joining to error-free homologous recombination.

    Original languageEnglish
    Pages (from-to)460-U184
    Number of pages5
    JournalNature
    Volume459
    Issue number7245
    DOIs
    Publication statusPublished - 21 May 2009

    Keywords

    • HOMOLOGOUS RECOMBINATION
    • END RESECTION
    • MAMMALIAN-CELLS
    • DAMAGE
    • BRCA1
    • CTIP
    • DOMAINS
    • PROTEIN
    • GENE
    • LINE

    Cite this

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    title = "CtIP-BRCA1 modulates the choice of DNA double-strand-break repair pathway throughout the cell cycle",
    abstract = "The repair of DNA double-strand breaks (DSBs) is tightly regulated during the cell cycle. In G1 phase, the absence of a sister chromatid means that repair of DSBs occurs through non-homologous end-joining or microhomology-mediated end-joining (MMEJ)(1). These pathways often involve loss of DNA sequences at the break site and are therefore error-prone. In late S and G2 phases, even though DNA end-joining pathways remain functional(2), there is an increase in repair of DSBs by homologous recombination, which is mostly error-free(3,4). Consequently, the relative contribution of these different pathways to DSB repair in the cell cycle has a large influence on the maintenance of genetic integrity. It has remained unknown how DSBs are directed for repair by different, potentially competing, repair pathways. Here we identify a role for CtIP (also known as RBBP8) in this process in the avian B-cell line DT40. We establish that CtIP is required not only for repair of DSBs by homologous recombination in S/G2 phase but also for MMEJ in G1. The function of CtIP in homologous recombination, but not MMEJ, is dependent on the phosphorylation of serine residue 327 and recruitment of BRCA1. Cells expressing CtIP protein that cannot be phosphorylated at serine 327 are specifically defective in homologous recombination and have a decreased level of single-stranded DNA after DNA damage, whereas MMEJ remains unaffected. Our data support a model in which phosphorylation of serine 327 of CtIP as cells enter S phase and the recruitment of BRCA1 functions as a molecular switch to shift the balance of DSB repair from error-prone DNA end-joining to error-free homologous recombination.",
    keywords = "HOMOLOGOUS RECOMBINATION, END RESECTION, MAMMALIAN-CELLS, DAMAGE, BRCA1, CTIP, DOMAINS, PROTEIN, GENE, LINE",
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    CtIP-BRCA1 modulates the choice of DNA double-strand-break repair pathway throughout the cell cycle. / Yun, Maximina H.; Hiom, Kevin (Lead / Corresponding author).

    In: Nature, Vol. 459, No. 7245, 21.05.2009, p. 460-U184.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - CtIP-BRCA1 modulates the choice of DNA double-strand-break repair pathway throughout the cell cycle

    AU - Yun, Maximina H.

    AU - Hiom, Kevin

    PY - 2009/5/21

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    N2 - The repair of DNA double-strand breaks (DSBs) is tightly regulated during the cell cycle. In G1 phase, the absence of a sister chromatid means that repair of DSBs occurs through non-homologous end-joining or microhomology-mediated end-joining (MMEJ)(1). These pathways often involve loss of DNA sequences at the break site and are therefore error-prone. In late S and G2 phases, even though DNA end-joining pathways remain functional(2), there is an increase in repair of DSBs by homologous recombination, which is mostly error-free(3,4). Consequently, the relative contribution of these different pathways to DSB repair in the cell cycle has a large influence on the maintenance of genetic integrity. It has remained unknown how DSBs are directed for repair by different, potentially competing, repair pathways. Here we identify a role for CtIP (also known as RBBP8) in this process in the avian B-cell line DT40. We establish that CtIP is required not only for repair of DSBs by homologous recombination in S/G2 phase but also for MMEJ in G1. The function of CtIP in homologous recombination, but not MMEJ, is dependent on the phosphorylation of serine residue 327 and recruitment of BRCA1. Cells expressing CtIP protein that cannot be phosphorylated at serine 327 are specifically defective in homologous recombination and have a decreased level of single-stranded DNA after DNA damage, whereas MMEJ remains unaffected. Our data support a model in which phosphorylation of serine 327 of CtIP as cells enter S phase and the recruitment of BRCA1 functions as a molecular switch to shift the balance of DSB repair from error-prone DNA end-joining to error-free homologous recombination.

    AB - The repair of DNA double-strand breaks (DSBs) is tightly regulated during the cell cycle. In G1 phase, the absence of a sister chromatid means that repair of DSBs occurs through non-homologous end-joining or microhomology-mediated end-joining (MMEJ)(1). These pathways often involve loss of DNA sequences at the break site and are therefore error-prone. In late S and G2 phases, even though DNA end-joining pathways remain functional(2), there is an increase in repair of DSBs by homologous recombination, which is mostly error-free(3,4). Consequently, the relative contribution of these different pathways to DSB repair in the cell cycle has a large influence on the maintenance of genetic integrity. It has remained unknown how DSBs are directed for repair by different, potentially competing, repair pathways. Here we identify a role for CtIP (also known as RBBP8) in this process in the avian B-cell line DT40. We establish that CtIP is required not only for repair of DSBs by homologous recombination in S/G2 phase but also for MMEJ in G1. The function of CtIP in homologous recombination, but not MMEJ, is dependent on the phosphorylation of serine residue 327 and recruitment of BRCA1. Cells expressing CtIP protein that cannot be phosphorylated at serine 327 are specifically defective in homologous recombination and have a decreased level of single-stranded DNA after DNA damage, whereas MMEJ remains unaffected. Our data support a model in which phosphorylation of serine 327 of CtIP as cells enter S phase and the recruitment of BRCA1 functions as a molecular switch to shift the balance of DSB repair from error-prone DNA end-joining to error-free homologous recombination.

    KW - HOMOLOGOUS RECOMBINATION

    KW - END RESECTION

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    KW - DAMAGE

    KW - BRCA1

    KW - CTIP

    KW - DOMAINS

    KW - PROTEIN

    KW - GENE

    KW - LINE

    UR - http://www.scopus.com/inward/record.url?scp=67349246802&partnerID=8YFLogxK

    U2 - 10.1038/nature07955

    DO - 10.1038/nature07955

    M3 - Article

    C2 - 19357644

    VL - 459

    SP - 460-U184

    JO - Nature

    JF - Nature

    SN - 0028-0836

    IS - 7245

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