HCV NS5A abrogates p53 protein function by interfering with p53-DNA binding.
HCV NS5A abrogates p53 protein function by interfering with p53-DNA binding.
复制标题
HCV NS5A 通过干扰 p53-DNA 结合来消除 p53 蛋白功能。
DOI：
10.3748/wjg.v10.i15.2223
复制
发表时间：
2004
影响因子：
4.3
通讯作者：
X. Su
中科院分区：
文献类型：
--
作者：
G. Gong;Yongfang Jiang;Yan He;L. Lai;Ying;X. Su
目的
目的评价HCV NS5A对p53基因转录激活的抑制作用，探讨其影响p53功能的可能机制。
方法
用p21启动子驱动的荧光素酶报告系统研究了p53对p21启动子的反式激活作用，并用电泳迁移率变动分析（EMSA）观察了p53与DNA的结合能力。用脂质体介导的p53或HCV NS5A表达载体转染肝癌细胞株，观察HCV NS5A是否能阻断p53与其特异性DNA序列的结合及p53对p21启动子的反式激活作用。Western blot检测HCV NS5A和p53蛋白表达。
结果
在内源性p53蛋白存在下，由p21启动子驱动的相对荧光素酶活性显著增加。与对照组相比，外源性p53蛋白也以剂量依赖的方式刺激p21启动子驱动的荧光素酶基因的表达。HCV NS5A蛋白随着表达质粒剂量的增加逐渐抑制p21启动子上内源性和外源性p53的反式激活。EMSA实验发现p53与其特异性DNA序列结合，当与HCV NS5A表达载体共转染时，p53与其DNA的结合亲和力逐渐降低，最后消失。在单独转染p53表达载体和共转染HCV NS5A表达载体的Huh 7细胞中，p53蛋白表达无差异。
结论
HCV NS5A通过抑制p53与其特异性DNA序列的结合而抑制p21启动子上p53的反式激活。它不影响p53蛋白的表达。
AIM
To evaluate the inhibition effect of HCV NS5A on p53 transactivation on p21 promoter and explore its possible mechanism for influencing p53 function.
METHODS
p53 function of transactivation on p21 promoter was studied with a luciferase reporter system in which the luciferase gene is driven by p21 promoter, and the p53-DNA binding ability was observed with the use of electrophoretic mobility-shift assay (EMSA). Lipofectin mediated p53 or HCV NS5A expression vectors were used to transfect hepatoma cell lines to observe whether HCV NS5A could abrogate the binding ability of p53 to its specific DNA sequence and p53 transactivation on p21 promoter. Western blot experiment was used for detection of HCV NS5A and p53 proteins expression.
RESULTS
Relative luciferase activity driven by p21 promoter increased significantly in the presence of endogenous p53 protein. Compared to the control group, exogenous p53 protein also stimulated p21 promoter driven luciferase gene expression in a dose-dependent way. HCV NS5A protein gradually inhibited both endogenous and exogenous p53 transactivation on p21 promoter with increase of the dose of HCV NS5A expression plasmid. By the experiment of EMSA, we could find p53 binding to its specific DNA sequence and, when co-transfected with increased dose of HCV NS5A expression vector, the p53 binding affinity to its DNA gradually decreased and finally disappeared. Between the Huh 7 cells transfected with p53 expression vector alone or co-transfected with HCV NS5A expression vector, there was no difference in the p53 protein expression.
CONCLUSION
HCV NS5A inhibits p53 transactivation on p21 promoter through abrogating p53 binding affinity to its specific DNA sequence. It does not affect p53 protein expression.
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影响因子：
3.7
作者：
Seng-Lai Tan;M. Katze
通讯作者：
Seng-Lai Tan;M. Katze
影响因子：
3.7
作者：
Hong Tu;Lu Gao;Stephanie T. Shi;Deborah R. Taylor;Tao Yang;A. Mircheff;Yumei Wen;A. Gorbalenya;S. Hwang;Michael M. C. Lai
通讯作者：
Hong Tu;Lu Gao;Stephanie T. Shi;Deborah R. Taylor;Tao Yang;A. Mircheff;Yumei Wen;A. Gorbalenya;S. Hwang;Michael M. C. Lai
影响因子：
3.7
作者：
Majumder, M;Ghosh, AK;Ray, RB
通讯作者：
Ray, RB
DOI：
10.1073/pnas.96.10.5533
发表时间：
1999-05-11
影响因子：
11.1
作者：
Tan, SL;Nakao, H;Katze, MG
通讯作者：
Katze, MG