Enhanced Use of Backup Pathways of NHEJ in G2 in Chinese Hamster Mutant Cells with Defects in the Classical Pathway of NHEJ
Enhanced Use of Backup Pathways of NHEJ in G2 in Chinese Hamster Mutant Cells with Defects in the Classical Pathway of NHEJ
复制标题
NHEJ 经典途径缺陷的中国仓鼠突变细胞 G2 中 NHEJ 备用途径的增强使用
作者：
Wenqi Wu;Minli Wang;Tamara Mussfeldt;G. Iliakis
摘要吴，W.，王，M.，Mussfeldt，T.和Iliakis，G.在具有NHEJ经典途径缺陷的中国突变体细胞中增强G2中NHEJ备用途径的使用。Radiat. Res. 170，512-520（2008）中所述。在高等真核生物中，DNA双链断裂（DSB）通过同源重组修复（HRR）或非同源末端连接（NHEJ）来修复。除了NHEJ的DNA-PK依赖性途径（D-NHEJ）之外，细胞还采用了使用DNA连接酶III和PARP 1的备用途径（B-NHEJ）。我们以前曾报道，小鼠胚胎成纤维细胞（MEFs）缺陷的D-NHEJ显示增强修复DSB在G2不反映HRR的贡献。在这里，我们将这些研究扩展到中国仓鼠突变细胞中的DNA-PKcs，Ku 80或XRCC 4组件的D-NHEJ或在XRCC 2和XRCC 3组件的HRR的缺陷。使用细胞分选分离细胞在照射后的规定时间，我们测量DSB的修复与脉冲场凝胶电泳在未扰动的G1和G2期细胞。野生型细胞和XRCC 2和XRCC 3的突变体在G1和G2中以相似的效率修复DSB。DNA-PKcs、Ku 80和XRCC 4的突变体在G2中比在G1中显示更明显的修复。这些和先前发表的结果为G2中DSB修复的功效增加反映了B-NHEJ功能增强的观点提供了支持，这可能是啮齿动物细胞的一般特征，也适用于人类细胞。
Abstract Wu, W., Wang, M., Mussfeldt, T. and Iliakis, G. Enhanced Use of Backup Pathways of NHEJ in G2 in Chinese Hamster Mutant Cells with Defects in the Classical Pathway of NHEJ. Radiat. Res. 170, 512–520 (2008). In higher eukaryotes DNA double-strand breaks (DSBs) are repaired by homologous recombination repair (HRR) or non-homologous end joining (NHEJ). In addition to the DNA-PK dependent pathway of NHEJ (D-NHEJ), cells employ a backup pathway (B-NHEJ) using DNA ligase III and PARP1. We have reported previously that mouse embryo fibroblasts (MEFs) defective in D-NHEJ show enhanced repair of DSBs in G2 not reflecting a contribution of HRR. Here we extend these studies to Chinese hamster mutant cells with defects in the DNA-PKcs, Ku80 or XRCC4 components of D-NHEJ or in the XRCC2 and XRCC3 components of HRR. Using cell sorting to separate cells at defined times after irradiation, we measure repair of DSBs with pulsed-field gel electrophoresis in unperturbed G1- and G2-phase cells. Wild-type cells and mutants of XRCC2 and XRCC3 repair DSBs with similar efficiency in G1 and G2. Mutants of DNA-PKcs, Ku80 and XRCC4 show more pronounced repair in G2 than in G1. These and previously published results provide support for the notion that the increased efficacy of DSB repair in G2 reflects the enhanced function of B-NHEJ, which may be a general feature of rodent cells that also holds for human cells.
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DOI：
10.1016/s0921-8777(98)00063-9
发表时间：
1999-01-26
期刊：
MUTATION RESEARCH-DNA REPAIR
影响因子：
--
作者：
Bryans, M;Valenzano, MC;Stamato, TD
通讯作者：
Stamato, TD
影响因子：
11.2
作者：
S. DiBiase;Z. Zeng;Richard Chen;T. Hyslop;W. Curran;G. Iliakis
通讯作者：
S. DiBiase;Z. Zeng;Richard Chen;T. Hyslop;W. Curran;G. Iliakis
一种冷冻同步有丝分裂细胞和 G1 细胞的方法。
影响因子：
3.7
作者：
Borrelli,MJ;Mackey,MA;Dewey,WC
通讯作者：
Dewey,WC
影响因子：
16
作者：
Liu, N;Lamerdin, JE;Thompson, LH
通讯作者：
Thompson, LH
影响因子：
11.2
作者：
Wang, HC;Rosidi, B;Iliakis, G
通讯作者：
Iliakis, G