Interaction between heat shock transcription factor and transcription initiation complex.

热休克转录因子和转录起始复合物之间的相互作用。

基本信息

批准号：
13680760
负责人：
SAKURAI Hiroshi
金额：
$ 2.24万
依托单位：
Kanazawa University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13680760/
关键词：
stress response heat shock factor phosphorylation yeast 基本転写因子転写開始抑圧変異酵母

项目摘要

The transcription activation signals of transcription activators are transmitted to the transcription initiation complex via intermediary factors such as Mediator and TAF(TBP-associated factor). The initiation complex consists of RNA polymerase II and the general transcription factors TBP,TFIIB,TFIIE,TFIIF,and TFIIH. By using the methods of yeast molecular genetics, it has been disclosed that activity of the TFIIH kinase(encoded by the KIN28 gene), which phosphorylates the carboxy-terminal domain(CTD) of RNA polymerase II, is dispensable for activation of several stress responsive genes such as heat shock genes. In this study, I have shown that the Kin28-independent activation of the heat-inducible genes is mediated by the heat shock transaction factor Hsfl. In addition, the general transcription factor IIE, which regulates the kinase activity of Kin28, was dispensable for copper-induced transcription of the CUP1 gene encoding copper metallothionein. Transcription of CUP1 is regulated by Hsfl and Aoe 1(copper-inducible activator). I further analyzed the Kin28-and TFIIE-independent transcription mechanisms and revealed the following. 1)The TFIIE-independent activation of CUP1 is mediated by oertain components of the Mediator complex. 2)The recruitment of TAFs, another well-known intermediary factor, is involved in the Kin28-independent transcription by Hsfl. 3) The C-terminal half of Hsfl has activities to recruit TAFs to a promoter and to undergo transcription independently of Kin28. 4)The C-terminal region of Hsfl contains a novel domain that regulates heat-inducible phosphorylation of Hsfl. These results illustrated that an alternate pathway of transcription reaction, in which a specific domain of activator plays a critical role in abrogation of requirement for subset of general transcription factors that are prerequisites in the main pathway of the transcription reaction.

转录激活剂的转录激活信号通过中介因子（例如介体和TAF（TBP相关因子））传输到转录起始复合物。起始复合物由RNA聚合酶II和一般转录因子TBP，TFIIB，TFIIE，TFIIF和TFIIH组成。通过使用酵母分子遗传学的方法，已经披露了TFIIH激酶的活性（由KIN28基因编码），该活性可磷酸化RNA聚合酶II的羧基末端结构域（CTD）II，可用于激活几种应激响应式响应式响应式响应性响应性响应性响应性响应性响应效果。诸如热休克基因之类的基因。在这项研究中，我已经表明，热诱导基因的KIN28无关激活是由热休克交易因子HSFL介导的。此外，调节KIN28激酶活性的一般转录因子IIE是可用于铜诱导的编码铜金属硫蛋白的CUP1基因的转录。 CUP1的转录由HSFL和AOE 1（铜诱导剂）调节。我进一步分析了KIN28和与TFIIE无关的转录机制，并揭示了以下内容。 1）CUP1的非tfiie非依赖性激活是由介体复合物的确定成分介导的。 2）HSFL的KIN28独立转录涉及TAFS（另一个众所周知的中间因素）的募集。 3）HSFL的C末端一半具有将TAF招募到启动子并独立于KIN28进行转录的活动。 4）HSFL的C末端区域包含一个新的结构域，该结构域调节HSFL的热诱导磷酸化。这些结果表明，转录反应的替代途径，其中，激活因子的特定结构域在废除对通用转录因子子集的需求中起关键作用，这在转录反应的主要途径中是先决条件。