Transcriptional activation domain of p300/CBP-associated factor(P/CAF)

p300/CBP相关因子(P/CAF)转录激活域

• 批准号: 09672226
• 负责人: NISHIKAWA Jun-ichi
• 金额: $ 1.73万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09672226/
• 关键词: transcriptional regulation; histone acetyltransferase; chromatin

In eukaryores, transcription of mRNA-encoding classII genes involves the ordered recruitment of general factors and the RNA polymerase II holoenzyme into the basal transcription pre-initiation complex on promoter.The transcription is efficiently enhanced by transcriptional activators which bind to specific DNA sequences outside of the core promoter.Sequence-specific activators work in conjunction with other factors which do not bind DNA directly.These factors are termed co-activators and are recruited to promoters via their interaction with the DNA-bound transcription factors.P/CAF was originally identified as a p300/CBP-binding protein by virtue of its sequence similarity to a yeast histone acetyltransferase (HAT), namely yGCN5.In addition, P/CAF interacts with other co-activators such as ACIR and SRC-1 which are also HAT.In this study, I focused on the function of P/CAF in the transcriptional regulation and investigated the transcriptional activation domain of P/CAF.In order to examine the activation function of P/CAF, I expressed various regions of P/CAF as GALA DNA binding domain in yeast.P/CAF indeed worked as a transcriptional activator protein in yeast and the region of amino acids 366-654 was necessary for activation function.As this region is identical to the HAT domain, the activation function of P/CAF might be related to the acetylation of histones.On the other hand, the interaction of P/CAF with CBP was independent on the activation domain. The complex formation of co-activators in vitro was also examined using surface plasmon resonance anaysis.

在真核生物中，编码 mRNA 的 II 类基因的转录涉及将通用因子和 RNA 聚合酶 II 全酶有序招募到启动子上的基础转录前起始复合物中。转录激活剂可与核心启动子外部的特定 DNA 序列结合，从而有效增强转录。序列特异性激活剂与不直接结合 DNA 的其他因子协同工作。这些因子 被称为共激活因子，并通过与 DNA 结合的转录因子相互作用而被招募至启动子。P/CAF 最初因其与酵母组蛋白乙酰转移酶 (HAT)（即 yGCN5）的序列相似性而被鉴定为 p300/CBP 结合蛋白。此外，P/CAF 与其他共激活因子（如 ACIR 和 SRC-1）相互作用，这些共激活因子也是 HAT。 在本研究中，我重点研究了P/CAF在转录调控中的功能，并研究了P/CAF的转录激活结构域。为了检验P/CAF的激活功能，我将P/CAF的各个区域表达为酵母中的GALA DNA结合结构域。P/CAF确实在酵母中作为转录激活蛋白，并且氨基酸366-654的区域是激活功能所必需的。由于该区域 与HAT结构域相同，P/CAF的激活功能可能与组蛋白的乙酰化有关。另一方面，P/CAF与CBP的相互作用不依赖于激活结构域。还使用表面等离子体共振分析检查了体外共激活剂的复合物形成。