Genetic dissection of vertebrate 53BP1: A major role in non-homologous end joining of DNA double strand breaks
Genetic dissection of vertebrate 53BP1: A major role in non-homologous end joining of DNA double strand breaks
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DOI：
10.1016/j.dnarep.2006.03.008
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发表时间：
2006-06-10
期刊：
影响因子：
3.8
通讯作者：
Taniguchi, Yoshihito
中科院分区：
文献类型：
--
作者：
Nakamura, Kyoko;Sakai, Wataru;Taniguchi, Yoshihito
53BP1（p53 结合蛋白）是一种包含 BRCT 结构域的蛋白，可快速募集至 DNA 双链断裂 (DSB)。为了研究 53BP1 在 DNA 损伤反应中的作用，我们从鸡 DT40 细胞系中产生了 53BP1(-/-) 细胞。与哺乳动物细胞一样，53BP1 的突变增加了细胞对电离辐射的敏感性。尽管53BP1的缺失导致哺乳动物细胞中检查点缺陷，但DT40 53BP1(-/-)细胞具有正常的S内期和G2/M检查点。 G1 特异性放射敏感性和对拓扑异构酶 II 的较高敏感性表明 DT40 53BP1(-/-) 细胞中存在缺陷的非同源末端连接 (NHEJ) 缺陷。遗传分析证实了这一建议，因为我们已经证明 53BP1 与 NHEJ 基因、Ku70 和 Artemis 之间存在上位关系，但与 Rad54 之间没有上位关系，Rad54 是通过同源重组修复 DSB 所必需的基因。我们得出的结论是，53BP1 在支持遭受 DNA DSB 的 DT40 细胞存活方面的主要作用是促进 NHEJ 的修复。 (c) 2006 Elsevier B.V. 保留所有权利。
53BP1 (p53 binding protein) is a BRCT domain-containing protein that is rapidly recruited to DNA double strand breaks (DSBs). To investigate the role of 53BP1 in the DNA damage response, we generated 53BP1(-/-) cells from the chicken DT40 cell line. As in mammalian cells, mutation of 53BP1 increased cellular sensitivity to ionizing radiation. Although depletion of 53BP1 resulted in checkpoint defects in mammalian cells, DT40 53BP1(-/-) cells had normal intra S phase and G2/M checkpoints. G1 specific radiosensitivity and a higher sensitivity to topoisomerase II suggested defective non-homologous end joining (NHEJ) defects in DT40 53BP1(-/-) cells. Genetic analyses confirm this suggestion as we have demonstrated an epistatic relationship between 53BP1 and the NHEJ genes, Ku70 and Artemis, but not with Rad54, a gene essential for repair of DSBs by homologous recombination. We conclude that the major role of 53BP1 in supporting survival of DT40 cells that have suffered DNA DSBs is in facilitating repair by NHEJ. (c) 2006 Elsevier B.V. All rights reserved.