Biochemical characterization of human Ecdysoneless reveals a role in transcriptional regulation.
Biochemical characterization of human Ecdysoneless reveals a role in transcriptional regulation.
复制标题
DOI：
10.1515/bc.2010.004
复制
发表时间：
2010-01
影响因子：
3.7
通讯作者：
Band V
中科院分区：
文献类型：
--
作者：
Kim JH;Gurumurthy CB;Band H;Band V
无脱模蛋白（Ecd）是一种进化保守蛋白，其功能对果蝇胚胎发育和酵母细胞生长至关重要。然而，它的功能直到最近才为人所知。对酵母的研究表明，Ecd在转录中有潜在的作用；然而，Ecd缺乏DNA结合域。利用gal4 -荧光素酶报告基因分析和GAL4-DNA结合域（DBD）与Ecd或其突变体的融合，我们提出了证据，证明人类Ecd在其c端区域具有反激活活性。重要的是，使用点突变体的进一步分析表明，Asp-484或Leu-489的单个氨基酸变化基本上完全消除了Ecd的转激活活性。我们进一步证明Ecd与p300（一种组蛋白乙酰转移酶）相互作用，Ecd与p300的共表达增强了Ecd介导的交易激活活性。Ecd定位于细胞核和细胞质，并在细胞核和细胞质之间穿梭；然而，它显示出强大的核出口。基于之前的酵母研究和本文提供的证据，我们认为Ecd是一种转录调控因子。该研究指出了人类Ecd的重要功能，为探索Ecd的转录伙伴提供了基础。
Ecdysoneless (Ecd) is an evolutionarily conserved protein whose function is essential for embryonic development in Drosophila and cell growth in yeast. However, its function has remained unknown until recently. Studies in yeast suggested a potential role of Ecd in transcription; however Ecd lacks a DNA binding domain. Using a GAL4-luciferase reporter assay and a GAL4-DNA binding domain (DBD) fusion with Ecd or its mutants, we present evidence that human Ecd has a transactivation activity in its C-terminal region. Importantly, further analyses using point mutants showed that a single amino acid change at either Asp-484 or Leu-489 essentially completely abolishes the transactivation activity of Ecd. We further demonstrate that Ecd interacts with p300, a histone acetyltransferase and the co-expression of Ecd with p300 enhances the Ecd-mediated transactivation activity. Ecd localizes to both nucleus and cytoplasm and shuttles between the nucleus and cytoplasm; however it exhibits strong nuclear export. Based on previous yeast studies and evidence provided here, we suggest that Ecd functions as a transcriptional regulator. This study points out to an important function of human Ecd and provides a basis to explore the transcriptional partners of Ecd.