Activation of p53 Facilitates the Target Search in DNA by Enhancing the Target Recognition Probability
Activation of p53 Facilitates the Target Search in DNA by Enhancing the Target Recognition Probability
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DOI：
10.1016/j.jmb.2016.06.001
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发表时间：
2016-07-17
影响因子：
5.6
通讯作者：
Kamagata, Kiyoto
中科院分区：
文献类型：
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作者：
Itoh, Yuji;Murata, Agato;Kamagata, Kiyoto
肿瘤抑制因子p53与基因组中的靶标结合并调节下游基因的表达。p53通过结合三维扩散和沿着DNA的一维滑动来搜索靶点。沿着DNA。为了研究靶点结合的调节机制，我们构建了p53的假野生型（pseudo-WT）、激活型（S392 E）和失活型（R248 Q）突变体，并使用单分子荧光成像观察它们在长DNA中的靶点结合。沿着DNA沿着滑动的伪WT显示出许多越过靶标的事件，并且具有7 +/-2%的靶标识别概率（TRP）。活化突变体的TRP增加至18 +/-2%，但失活突变体的TRP降低至0%。此外，总结合事件中通过一维滑动的靶结合分数从假WT的63 +/-9%增加到活化突变体的87 +/-2%。TRP激活后的控制，如p53所示，可能是转录因子的一般激活机制。(C)2016爱思唯尔有限公司版权所有
Tumor suppressor p53 binds to the target in a genome and regulates the expression of downstream genes. p53 searches for the target by combining three-dimensional diffusion and one-dimensional sliding along the DNA. To examine the regulation mechanism of the target binding, we constructed the pseudo-wild type (pseudo-WT), activated (S392E), and inactive (R248Q) mutants of p53 and observed their target binding in long DNA using single-molecule fluorescence imaging. The pseudo-WT sliding along the DNA showed many pass events over the target and possessed target recognition probability (TRP) of 7 +/- 2%. The TRP increased to 18 +/- 2% for the activated mutant but decreased to 0% for the inactive mutant. Furthermore, the fraction of the target binding by the one-dimensional sliding among the total binding events increased from 63 +/- 9% for the pseudo-WT to 87 +/- 2% for the activated mutant. Control of TRP upon activation, as demonstrated here for p53, might be a general activation mechanism of transcription factors. (C) 2016 Elsevier Ltd. All rights reserved.