ABT1‐associated protein (ABTAP), a novel nuclear protein conserved from yeast to mammals, represses transcriptional activation by ABT1
ABT1‐associated protein (ABTAP), a novel nuclear protein conserved from yeast to mammals, represses transcriptional activation by ABT1
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DOI：
10.1002/jcb.20114
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发表时间：
2004-11
影响因子：
4
通讯作者：
T. Oda;A. Fukuda;H. Hagiwara;Y. Masuho;M. Muramatsu;K. Hisatake;T. Yamashita
中科院分区：
文献类型：
--
作者：
T. Oda;A. Fukuda;H. Hagiwara;Y. Masuho;M. Muramatsu;K. Hisatake;T. Yamashita
各种 TATA 结合蛋白 (TBP) 相关蛋白通过 RNA 聚合酶 (Pol) II 指导的基础转录控制来参与基因表达的调节。我们最近发现了一种新的核蛋白，即基础转录激活剂 1 (ABT1)，它结合 TBP 和 DNA，并增强 Pol II 指导的基础转录。为了更好地了解 ABT1 的调控机制，我们使用酵母双杂交筛选来寻找 ABT1 结合蛋白，并分离出编码一种称为 ABT1 相关蛋白 (ABTAP) 的新型蛋白的 cDNA 克隆。 ABTAP 与 ABT1 形成复合物，并抑制 ABT1 诱导的哺乳动物细胞中 Pol II 定向转录的激活。此外，ABTAP 直接与 ABT1 结合，破坏 ABT1 和 TBP 之间的相互作用，并在体外抑制 ABT1 诱导的 Pol II 指导的基础转录激活。这两种蛋白共定位于核仁和核质中，并且在 ABTAP 表达较高时同时重新定位到离散的核体中。总而言之，这些结果表明 ABTAP 结合 ABT1 并对 ABT1 进行负调节。 ABT1/ABTAP 复合体在进化上是保守的，可能构成一种新的基础转录调控系统。 © 2004 Wiley-Liss, Inc.
Various TATA‐binding protein (TBP)‐associated proteins are involved in the regulation of gene expression through control of basal transcription directed by RNA polymerase (Pol) II. We recently identified a novel nuclear protein, activator of basal transcription 1 (ABT1), which binds TBP and DNA, and enhances Pol II‐directed basal transcription. To better understand regulatory mechanisms for ABT1, we searched for ABT1‐binding proteins using a yeast two‐hybrid screening and isolated a cDNA clone encoding a novel protein termed ABT1‐associated protein (ABTAP). ABTAP formed a complex with ABT1 and suppressed the ABT1‐induced activation of Pol II‐directed transcription in mammalian cells. Furthermore, ABTAP directly bound to ABT1, disrupted the interaction between ABT1 and TBP, and suppressed the ABT1‐induced activation of Pol II‐directed basal transcription in vitro. These two proteins colocalized in the nucleolus and nucleoplasm and were concomitantly relocalized into discrete nuclear bodies at higher expression of ABTAP. Taken together, these results suggest that ABTAP binds and negatively regulates ABT1. The ABT1/ABTAP complex is evolutionarily conserved and may constitute a novel regulatory system for basal transcription. © 2004 Wiley‐Liss, Inc.