Varicella-zoster virus IE62 protein utilizes the human mediator complex in promoter activation.
Varicella-zoster virus IE62 protein utilizes the human mediator complex in promoter activation.
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水痘带状疱疹病毒 IE62 蛋白利用人类介质复合物激活启动子。
DOI：
10.1128/jvi.01693-08
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发表时间：
2008
影响因子：
5.4
通讯作者：
Ruyechan,WilliamT
中科院分区：
文献类型：
--
作者：
Yang,Min;Hay,John;Ruyechan,WilliamT
水痘-带状疱疹病毒(VZV)主要反式激活因子IE62参与了所有VZV基因的表达，也可以激活细胞启动子、异源病毒启动子和只含有TATA元件的人工启动子。IE62反式激活机制的一个关键成分是由IE62的N端86个氨基酸组成的酸性激活结构域。然而，这种N末端酸性激活的细胞靶标尚不清楚。在这里的工作中，我们表明IE62激活域通过Med25(ARC92)亚单位靶向人类介体复合体，这种相互作用似乎是IE62激活域反式激活的基础。相反，中介复合体的Med23亚单位(Sur2/TRAP150β/DRIP130/CRSP130)对于IE62介导的激活并不是必需的。此外，IE62激活域似乎选择性地与缺乏CDK8的一种形式的介体复合体相互作用。染色质免疫沉淀实验表明，IE62刺激介体向IE62反应模型启动子的募集。最后，VZV感染细胞的免疫荧光显微镜显示，介体复合体在核内移位到病毒复制间隔。这些研究表明，Mediator是VZV基因高效表达的重要组成部分。
The varicella-zoster virus (VZV) major transactivator, IE62, is involved in the expression of all kinetic classes of VZV genes and can also activate cellular promoters, promoters from heterologous viruses, and artificial promoters containing only TATA elements. A key component of the mechanism of IE62 transactivation is an acidic activation domain comprising the N-terminal 86 amino acids of IE62. However, the cellular target of this N-terminal acidic activation is unknown. In the work presented here, we show that the IE62 activation domain targets the human Mediator complex via the Med25 (ARC92) subunit and that this interaction appears to be fundamental for transactivation by the IE62 activation domain. In contrast, the Med23 subunit (Sur2/TRAP150β/DRIP130/CRSP130) of the Mediator complex is not essential for IE62-mediated activation. Further, the IE62 activation domain appears to selectively interact with a form of the Mediator complex lacking CDK8. Chromatin immunoprecipitation experiments showed that IE62 stimulates recruitment of Mediator to an IE62-responsive model promoter. Finally, immunofluorescence microscopy of VZV-infected cells demonstrated intranuclear translocation of the Mediator complex to viral replication compartments. These studies suggest that Mediator is an essential component for efficient VZV gene expression.