Study of the G1-phase specific novel repair pathway for X-ray-induced DNA damage

X射线诱导的DNA损伤G1期特异性新型修复途径的研究

• 批准号: 18510050
• 负责人: IWABUCHI Kuniyoshi
• 金额: $ 2.61万
• 依托单位: Kanazawa Medical University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2006
• 资助国家: 日本
• 起止时间: 2006 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18510050/
• 关键词: Molecular biology; nuculeus; DNA double-strand break; Ionizing radiation; repair; Nonhomologous end joining; 53BP1; DNA損傷

Ionizing radiation (IR) induces a variety of DNA lesions. The most significant lesion is a DNA double-strand break (DSB), which is repaired by homologous recombination or nonhomologous end joining (NHEJ) pathway. Since we previously demonstrated that IR-responsive protein 53BP1 specifically enhances activity of DNA ligase IV, a DNA ligase required for NHEJ, we investigated responses of 53BP1-deficient chicken DT40 cells to IR. 53BP1-deficient cells showed increased sensitivity to X-rays during G1 phase. Although intra-S and G2/M checkpoints were intact, a frequency of isochromatid-type chromosomal aberrations was elevated after irradiation in 53BP1-deficient cells. Furthermore, disappearance of X-ray-induced γ-H2AX foci, a marker of DNA DSBs, was prolonged in 53BP1-deficient cells. Thus, the elevated X-ray sensitivity in G1 phase cells was attributable to repair defect for IR-induced DNA-damage. Epistasis analysis revealed that 53BP1 plays a role in a pathway distinct from the Ku-dependent and Artemis-dependent NHEJ pathways, but requires DNA ligase IV. Strikingly, disruption of the 53BP1 gene together with inhibition of phosphatidylinositol 3-kinase family by wortmannin completely abolished colony formation by cells irradiated during G1 phase. These results demonstrate that the 53BP1-dependent repair pathway is important for survival of cells irradiated with IR during the G1 phase of the cell cycle.

电离辐射（IR）诱导多种DNA病变。最重要的病变是DNA双链断裂（DSB），该病变通过同源重组或非系统性末端连接（NHEJ）途径来修复。由于我们先前证明了IR响应蛋白53BP1特异性增强了DNA连接酶IV的活性，DNA连接酶IV是NHEJ所需的DNA连接酶，因此我们研究了53BP1缺陷鸡DT40细胞对IR的反应。在G1期间，53BP1缺陷细胞对X射线的敏感性增加。尽管S-S和G2/M检查点是完整的，但在53BP1缺陷细胞中辐照后，异染色型染色体畸变的频率升高。此外，在53BP1缺陷细胞中延长了X射线诱导的γ-H2AX灶（DNA DSB的标记）的消失。这就是G1相细胞上位分析中X射线灵敏度的升高表明，53BP1在与KU依赖性和依赖Artemis依赖性的NHEJ途径不同的途径中起作用，但需要DNA连接酶IV。令人惊讶的是，磨牙中抑制53BP1基因的破坏以及抑制磷脂酰肌醇3-激酶家族的抑制作用，完全消除了G1期间受照射的细胞的菌落形成。这些结果表明，53BP1依赖性修复途径对于在细胞周期的G1阶段辐照IR辐照的细胞的存活很重要。

项目成果

BRCT domain protein PTIP disruptants of chicken DT40 cells are viable, butdefective in proliferation and highly sensitive to ionizing radiation.

鸡DT40细胞的BRCT结构域蛋白PTIP破坏体是可行的，但增殖有缺陷并且对电离辐射高度敏感。

• 发表时间: 2007
• 作者: Nakamura;K.;Sakamoto;S.;Iijima;K.;Mochizuki;D.;Teshigawara;K. Kobavashi;J.;Matsuura;S.;Tauchi;H.;Komatsu;K;Kobayashi J;Kobayashi J;Matsumoto M;Matsumoto M;Matsumoto M;Iwabuchi K;Iwabuchi K;Iwabuchi K;岩淵 邦芳;Iwabuchi K;岩淵 邦芳;Iwabuchi K;Iwabuchi K;Iwabuchi K;Morohoshi F;Utsumi H;Morohoshi F;Utsumi H;Morohoshi F
• 通讯作者: Morohoshi F

53BP1-dependent repair pathway for X-ray induced DNA damage.

X 射线诱导的 DNA 损伤的 53BP1 依赖性修复途径。

• 发表时间: 2007
• 作者: Nakamura;K.;Sakamoto;S.;Iijima;K.;Mochizuki;D.;Teshigawara;K. Kobavashi;J.;Matsuura;S.;Tauchi;H.;Komatsu;K;Kobayashi J;Kobayashi J;Matsumoto M;Matsumoto M;Matsumoto M;Iwabuchi K;Iwabuchi K;Iwabuchi K;岩淵 邦芳;Iwabuchi K;岩淵 邦芳;Iwabuchi K
• 通讯作者: Iwabuchi K

Suppression of DNA-damage dependent total premature separation by 53BP1

53BP1 抑制 DNA 损伤依赖性完全过早分离

• 发表时间: 2006
• 作者: Nakamura;K.;Sakamoto;S.;Iijima;K.;Mochizuki;D.;Teshigawara;K. Kobavashi;J.;Matsuura;S.;Tauchi;H.;Komatsu;K;Kobayashi J;Kobayashi J;Matsumoto M;Matsumoto M;Matsumoto M;Iwabuchi K;Iwabuchi K;Iwabuchi K;岩淵 邦芳;Iwabuchi K;岩淵 邦芳;Iwabuchi K;Iwabuchi K;Iwabuchi K;Morohoshi F;Utsumi H;Morohoshi F;Utsumi H;Morohoshi F;Iwabuchi K;Iwabuchi K;岩淵 邦芳;Iwabuchi K
• 通讯作者: Iwabuchi K

Use of a cell sorter for fractionation of G1 phase DT40 cells

使用细胞分选仪分离 G1 期 DT40 细胞

• 发表时间: 2007
• 作者: Nakamura;K.;Sakamoto;S.;Iijima;K.;Mochizuki;D.;Teshigawara;K. Kobavashi;J.;Matsuura;S.;Tauchi;H.;Komatsu;K;Kobayashi J;Kobayashi J;Matsumoto M;Matsumoto M;Matsumoto M;Iwabuchi K;Iwabuchi K;Iwabuchi K;岩淵 邦芳;Iwabuchi K;岩淵 邦芳;Iwabuchi K;Iwabuchi K
• 通讯作者: Iwabuchi K

Current topics in DNA double-strand break repair

• DOI: 10.1269/jrr.07130
• 发表时间: 2008-03-01
• 期刊: JOURNAL OF RADIATION RESEARCH
• 影响因子: 2
• 作者: Kobayashi, Junya;Iwabuchi, Kuniyoshi;Tauchi, Hiroshi
• 通讯作者: Tauchi, Hiroshi