Mechanisms of regulation of LRH-1, Nanog and SF-1 by DAX-1

核受体调节许多对健康和生命至关重要的内分泌过程。其中最神秘的是那些受体，它们至关重要，但调节荷尔蒙未知， 如DAX-1、LRH-1和SF-1。这些都是这项提案的目标。医学障碍教会了我们这些受体在内分泌系统中的相互作用，但没有告诉我们它们的机制。DAX-1基因编码一种不寻常的核受体，缺乏DNA相互作用结构域。然而，它控制着许多组织中许多靶基因的活性。DAX-1基因突变影响胚胎干细胞进程、肾上腺和脑下垂体、下丘脑以及卵巢或睾丸的发育，导致严重的内分泌疾病。受体LRH-1和SF-1在发育过程中起关键作用，它们的结构性激活被DAX-1抑制。这三种核受体和转录因子之所以被称为孤儿，是因为它们的控制荷尔蒙(如果存在的话)还没有确定。这些相关核受体的调控机制的最基本细节尚不清楚。这项提案的目标是了解DAX-1对LRH-1和SF-1的调节机制的原理和原子水平的细节。由于它停止转录激活，DAX-1可能被归类为激素未知的辅助抑制因子。由于DAX-1的调节依赖于这些蛋白质的结合，我们将在原子分辨率下分析DAX-1与LRH-1和SF-1的结合作用。DAX-1蛋白从未在功能活性状态下制备用于生化或结构研究，将被分离并与LRH-1和SF-1结晶，以便分析组件的三维结构。在结构模型的指导下，将在细胞中进行功能研究，以揭示这些受体的作用机制。这些信息将是了解众多人类内分泌综合征的分子病理学的基础，并为治疗干预提供建议。我们正在研究的核受体与许多疾病过程有关，包括癌症、不孕不育、遗传代谢疾病和精神健康缺陷。了解其作用机制 这些受体，以及疾病中的问题，将有助于为这些疾病设计新的药物治疗方法。

Nuclear receptors program many endocrine processes essential for health and life. Among the most enigmatic are those receptors, which are critically important but have unknown regulating hormones, such as DAX-1, LRH-1 and SF-1. These are the targets of this proposal. Medical disorders teach us about the interplay of these receptors in the endocrine system without telling us their mechanisms. The DAX-1 gene codes an unusual nuclear receptor lacking a DNA interaction domain. Yet it controls the activity of many target genes in many tissues. Mutations in DAX-1 affect embryonic stem cell progression, development of the adrenal and pituitary glands, the hypothalamus and the ovaries or testes leading to severe endocrine disorders. The receptors LRH-1 and SF-1 are critical in developmental processes, and their constitutive activation is muted by DAX-1. These three nuclear receptors and transcription factors are called orphans because their controlling hormones, if they exist, have not been identified. The most basic details of the mechanisms of regulation of these related nuclear receptors are not known. The goal of this proposal is to understand the principles and atomic level details of the mechanisms of regulation of LRH-1 and SF-1 by DAX-1. Since it halts transcriptional activation, DAX-1 may be classed as a co-repressor with unknown hormone. Because regulation by DAX-1 depends on the associations of these proteins we will analyze, at atomic resolution, the binding interactions of DAX-1 with LRH-1 and SF-1. DAX-1 protein, which has never been prepared in a functionally active state for either biochemical or structural studies, will be isolated and crystallized with LRH-1 and SF-1 so that three-dimensional structures of the assemblies may be analyzed. Functional studies guided by the structural models will carried out in cells to reveal the mechanisms of action of these receptors. This information will be the foundation for understanding the molecular pathology of numerous human endocrine syndromes and suggest pathways for therapeutic intervention. The nuclear receptors we are studying are associated with many disease processes, including cancer, infertility, genetic metabolic diseases, and mental health defects. Learning the mechanisms of action of these receptors, and what goes wrong in the diseases, will help suggest pathways for design of new drug treatments for these conditions.