XRCC1-DNA polymerase β interaction is required for efficient base excision repair
XRCC1-DNA polymerase β interaction is required for efficient base excision repair
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DOI：
10.1093/nar/gkh567
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发表时间：
2004-04-01
影响因子：
14.9
通讯作者：
Dianov, GL
中科院分区：
文献类型：
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作者：
Dianova, II;Sleeth, KM;Dianov, GL
X射线修复交叉互补蛋白-1(XRCC1)缺陷细胞对DNA损伤剂敏感，并延迟DNA碱基损伤的处理。为了支持其在碱基切除修复中的作用，人们发现XRCC1与DNA连接酶IIIpha形成紧密的复合体，并与DNA聚合酶β(Polβ)和其他碱基切除修复(BER)蛋白相互作用。我们分离了野生型XRCC1-DNA连接酶IIIpha异二聚体和突变的不与Polβ相互作用的XRCC1-DNA连接酶IIIpha复合体，并用人纯化的蛋白重组BER进行了活性测试。我们发现，在重组的BER反应中，XRCC1蛋白中的一个点突变破坏了与Polβ的功能相互作用，影响了突变的XRCC1-DNA连接酶IIIpha异源二聚体的连接效率。我们还比较了野生型CHO-9细胞、XRCC1缺陷EM-C11细胞和空质粒载体以及携带野生型和突变型XRCC1基因的EM-C11细胞对过氧化氢的敏感性，发现编码XRCC1蛋白的质粒不与Polβ相互作用，降低了XRCC1缺陷细胞对过氧化氢敏感性的拯救能力。这些数据表明，XRCC1-POL Beta相互作用在协调BER过程的效率方面发挥了重要作用。
X-ray repair cross-complementing protein-1 (XRCC1)-deficient cells are sensitive to DNA damaging agents and have delayed processing of DNA base lesions. In support of its role in base excision repair, it was found that XRCC1 forms a tight complex with DNA ligase IIIalpha and also interacts with DNA polymerase beta (Pol beta) and other base excision repair (BER) proteins. We have isolated wild-type XRCC1-DNA ligase IIIalpha heterodimer and mutated XRCC1-DNA ligase IIIalpha complex that does not interact with Pol beta and tested their activities in BER reconstituted with human purified proteins. We find that a point mutation in the XRCC1 protein which disrupts functional interaction with Pol beta, affected the ligation efficiency of the mutant XRCC1-DNA ligase IIIalpha heterodimer in reconstituted BER reactions. We also compared sensitivity to hydrogen peroxide between wild-type CHO-9 cells, XRCC1-deficient EM-C11 cells and EM-C11 cells transfected with empty plasmid vector or with plasmid vector carrying wild-type or mutant XRCC1 gene and find that the plasmid encoding XRCC1 protein, that does not interact with Pol beta has reduced ability to rescue the hydrogen peroxide sensitivity of XRCC1- deficient cells. These data suggest an important role for the XRCC1-Pol beta interaction for coordinating the efficiency of the BER process.