IDENTIFICATION OF NUCLEAR FACTOR THAT ACTIVATED THE XRE-MEDIATED GENE TRANSCRIPTION

激活 XRE 介导的基因转录的核因子的鉴定

基本信息

批准号：
11672203
负责人：
TOHKIN Masahiro
金额：
$ 2.18万
依托单位：
NATIONAL INSTITUTE OF PUBLIC HEALTH
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11672203/
关键词：
DIOXIN GENE EXPRESSION CYP2A8 CYP2A8 マウス肝臓 One hybrid screening 核内因子 AHR XRE ダイオキシン受容体遺伝子転写活性核内転写因子

项目摘要

The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that mediates the biological responses to environmental contaminants such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Embryonic fibroblast (EF) isolated from AHR-null mice exhibited slow cell growth as compared with wild-type EF. Reintroduction of AHR into AHR-null EF increased cell growth, suggesting that AHR is involved in cell cycle control. The role of the AHR in cell cycle control was examined using the adenovirus oncoprotein E1A. EF, derived from wild-type and AHR-null mice, were transfected with two mutant E1A expression plasmids, that inactivate either p300/CBP or retinoblastoma protein (pRb). Although DNA synthesis of wild-type EF was induced by both E1A mutants, DNA synthesis in the AHR-null EF was induced only by the mutant that binds pRb but not by the mutant to p300/CBP. These data show that both pRb and p300/CBP were the target of E1A-induced DNA synthesis in wild-type EF. In AHR-null, however, only pRb was the target of E1A-induced DNA synthesis and p300/CBP cannot be inactivated by E1A in the absence of AHR. Immunoprecipitation revealed that AHR directly bound to p300 thus suggesting the intriguing possibility that AHR is involved in control of the cell cycle via interaction with p300.

芳基碳氢化合物受体（AHR）是配体激活的转录因子，可介导对环境污染物的生物学反应，例如2,3,7,8-甲基氯迪本佐-P-二恶英（TCDD）。与野生型EF相比，从AHR-NULL小鼠中分离出的胚胎成纤维细胞（EF）表现出缓慢的细胞生长。将AHR重新引入AHR-NULL EF增加了细胞的生长，这表明AHR参与了细胞周期控制。使用腺病毒癌蛋白E1A检查了AHR在细胞周期控制中的作用。 EF衍生自野生型和aHR无小鼠，用两个突变的E1a表达质粒转染，这些突变质质粒使P300/CBP或视网膜母细胞瘤蛋白（PRB）失活。尽管E1a突变体诱导了野生型EF的DNA合成，但AHR-NULL EF中的DNA合成仅由与PRB结合的突变体诱导，而不是由突变体与P300/CBP诱导的。这些数据表明，PRB和P300/CBP都是野生型EF中E1A诱导的DNA合成的靶标。然而，在AHR-NULL中，只有PRB是E1A诱导的DNA合成的靶标，而在没有AHR的情况下，E1A不能失活p300/CBP。免疫沉淀显示AHR直接与P300结合，因此表明AHR通过与P300的相互作用参与了对细胞周期的控制可能性。