Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan.
PLoS One. 2013;8(1):e54075. doi: 10.1371/journal.pone.0054075. Epub 2013 Jan 10.
Epstein-Barr virus (EBV) expresses an immediate-early protein, Rta, to activate the transcription of EBV lytic genes. This protein usually binds to Rta-response elements or interacts with Sp1 or Zta via a mediator protein, MCAF1, to activate transcription. Rta is also known to interact with TBP and TFIIB to activate transcription. This study finds that Rta interacts with TAF4, a component of TFIID complex, in vitro and in vivo, and on the TATA sequence in the BcLF1 promoter. Rta also interacts with TAF4 and Sp1 on Sp1-binding sequences on TATA-less promoters, including those of BNLF1, BALF5, and the human androgen receptor. These interactions are important to the transcriptional activation of these genes by Rta since introducing TAF4 shRNA substantially reduces the ability of Rta to activate these promoters. This investigation reveals how Rta interacts with TFIID to stimulate transcription.
EBV 表达一种早期蛋白 Rta，以激活 EBV 裂解基因的转录。该蛋白通常通过中介蛋白 MCAF1 与 Rta 反应元件结合或与 Sp1 或 Zta 相互作用，以激活转录。Rta 还已知与 TBP 和 TFIIB 相互作用以激活转录。本研究发现，Rta 在体外和体内与 TFIID 复合物的组成部分 TAF4 相互作用，并与 BcLF1 启动子上的 TATA 序列相互作用。Rta 还与 TATA 缺失启动子上的 Sp1 结合序列上的 TAF4 和 Sp1 相互作用，包括 BNLF1、BALF5 和人雄激素受体。这些相互作用对于 Rta 对这些基因的转录激活很重要，因为引入 TAF4 shRNA 会大大降低 Rta 激活这些启动子的能力。该研究揭示了 Rta 如何与 TFIID 相互作用以刺激转录。
