P53 promotes the fidelity of DNA end-joining activity by, in part, enhancing the expression of heterogeneous nuclear ribonucleoprotein G
P53 promotes the fidelity of DNA end-joining activity by, in part, enhancing the expression of heterogeneous nuclear ribonucleoprotein G
复制标题
DOI：
10.1016/j.dnarep.2007.01.013
复制
发表时间：
2007-06-01
期刊：
影响因子：
3.8
通讯作者：
Park, No-Hee
中科院分区：
文献类型：
--
作者：
Shin, Ki-Hyuk;Kim, Reuben H.;Park, No-Hee
许多研究表明野生型p53通过DNA末端连接（EJ）过程参与DNA双链断裂（DSB）的修复。为了研究这种可能性，我们比较了含有野生型p53的RKO细胞和不含p53的RKO细胞（p53敲低的RKO细胞）中DNA EJ的能力和保真度。与对照RKO细胞相比，p53敲低细胞显示出较低的DNA EJ保真度。DNA末端保护试验揭示了包括异质核核糖核蛋白G（hnRNP G）的蛋白复合物与含有wt p53的RKO细胞中的DNA末端的关联，但不与具有p53敲低的RKO细胞中的DNA末端的关联。内源性hnRNP G的消耗显著降低了表达wt p53的RKO细胞中EJ的保真度。此外，hnRNP G的异位表达显着增强了DNA EJ的保真度和DNA末端的保护在缺乏hnRNP G蛋白或含有突变hnRNP G的人癌细胞中。最后，使用重组hnRNP G蛋白，我们证明了hnRNP G蛋白能够结合并保护DNA末端免受核酸酶的降解。我们的研究结果表明，野生型p53调节DNA DSB修复，部分，诱导hnRNP G，和hnRNP G的能力，结合和保护DNA末端可能有助于其能力，以促进DNA EJ的保真度。(c)2007 Elsevier B.V保留所有权利。
Many studies have suggested the involvement of wild-type (wt) p53 in the repair of DNA double-strand breaks (DSBs) via DNA end-joining (EJ) process. To investigate this possibility, we compared the capacity and fidelity of DNA EJ in RKO cells containing wt p53 and RKO cells containing no p53 (RKO cells with p53 knockdown). The p53 knockdown cells showed lower fidelity of DNA EJ compared to the control RKO cells. The DNA end-protection assay revealed the association of a protein complex including heterogeneous nuclear ribonucleoprotein G (hnRNP G) with the DNA ends in RKO cells containing wt p53, but not with the DNA ends in RKO cells with p53 knockdown. Depletion of endogenous hnRNP G notably diminished the fidelity of EJ in RKO cells expressing wt p53. Moreover, an ectopic expression of hnRNP G significantly enhanced the fidelity of DNA EJ and the protection of DNA ends in human cancer cells lacking hnRNP G protein or containing mutant hnRNP G. Finally, using recombinant hnRNP G proteins, we demonstrated the hnRNP G protein is able to bind to and protect DNA ends from degradation of nucleases. Our results suggest that wt p53 modulates DNA DSB repair by, in part, inducing hnRNP G, and the ability of hnRNP G to bind and protect DNA ends may contribute its ability to promote the fidelity of DNA EJ. (c) 2007 Elsevier B.V All rights reserved.