GLUCOCORTICOID ACTION IN SYNCHRONIZED CELLS

这个项目的目标是阐明细胞机制 控制糖皮质激素受体基因的表达和功能，并 蛋白。具体地说，我们将重点研究分子 糖皮质激素同源下调机制的研究 糖皮质激素或拮抗剂对受体(GR)的作用及其相关过程 受体回收。尽管类固醇和其他药物的调节下调 受体对配体的反应是一个常见的生物过程，它是 被认为是细胞适应机制的一个组成部分，有 这一假设几乎没有直接的证据。在此应用程序中，我们寻求 用于测试糖皮质激素下调的假设的资金 糖皮质激素受体是血管紧张素转换酶过程中的关键成分 减弱体内的类固醇反应。为了检验这一假设，我们建议 描述糖皮质激素和拮抗剂的遗传学研究(RU486) 控制糖皮质激素受体基因的表达和 受体蛋白的代谢。对这些机制的了解将 允许我们在基因上设计出“抗下调调节” 糖皮质激素受体基因和蛋白及其功能的研究 活着。为实现这些目标，提出了以下具体目标： 1)对小说《基因内向下》进行定义和功能评价 HGR基因内的调控元件。2)以确定贡献 糖皮质激素受体基因启动子和3‘端非翻译区 相应的下调。3)评价糖皮质激素的疗效 关于GR mRNA的稳定性和翻译为功能性受体。4)至 设计一个下调缺陷的HGR基因并确定其作用 MRNA下调在激素反应减弱中的作用。5)至 通过结合受体诱变和免疫组织化学分析 配体对核摄取、保留和再循环的影响 糖皮质激素受体。6)定义所需的分子信号 糖皮质激素受体的核退出。7)描述如何 糖皮质激素受体被降解，工程抗降解GR 并研究它们的功能。总而言之，这些研究应该 显著增强我们对GR基因表达和蛋白质的了解 代谢和确定下调在激素依赖中的作用 信号转导。

The goal of this project is to elucidate the cellular mechanisms that control the expression and function of the glucocorticoid receptor gene and protein. Specifically, we will focus our studies on the molecular mechanisms involved in homologous down regulation of glucocorticoid receptors (GR) by glucocorticoid or antagonists, and the related process of receptor recycling. Although down regulation of steroid and other receptors in response to ligands is a common biological process which is thought to be a component of the cellular adaptive mechanisms, there is little direct proof of this supposition. In this application, we seek funds to test the hypothesis that the down regulation of glucocorticoid receptors by glucocorticoids is a critical component in the process of attenuating steroid responses in vivo. To test this hypothesis, we propose genetic studies to delineate how glucocorticoids and antagonists (RU486) control the expression of the glucocorticoid receptor gene and the metabolism of the receptor protein. Knowledge of these mechanisms will permit us to genetically engineer "down regulation resistant" glucocorticoid receptor genes and proteins and evaluate their function in vivo. The following specific aims are proposed to accomplish these goals: 1) To define and functionally evaluate the novel "intragenic down regulatory elements" within the hGR cDNA. 2) To determine the contribution of the glucocorticoid receptor gene promoter and 3' untranslated region in homologous down regulation. 3) To evaluate the effect of glucocorticoids on GR mRNA stability and translation into a functional receptor. 4) To engineer a down regulation deficient hGR gene and determine the role of hGR mRNA down regulation in the attenuation of hormone response. 5) To analyze, by combining receptor mutagenesis and immunohistochemistry, the influence of ligand on a nuclear uptake, retention and recycling of glucocorticoid receptors. 6) To define the molecular signals necessary for nuclear exit of glucocorticoid receptors. 7) To delineate how glucocorticoid receptors are degraded, engineer degradation resistant GR proteins and study their function. Together, these studies should significantly enhance our knowledge of GR gene expression and protein metabolism and determine the role of down regulation in hormone-dependent signal transduction.