Function of a membrane-localized nuclear receptor

膜定位核受体的功能

• 批准号: 7409077
• 负责人: Joel H. Rothman
• 金额: $ 27.47万
• 依托单位: UNIVERSITY OF CALIFORNIA SANTA BARBARA
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-04-05 至 2011-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7409077
• 关键词: Affect; Attenuated; Binding; Caenorhabditis elegans; Cell Nucleus; Cell membrane; Cell surface; Cells; Condition; Crowding; Cytoplasm; Defect; Deletion Mutation; Development; Dissection; Elements; Genes; Genetic; Goals; Hormonal; Hormones; Human; Human Pathology; Kinetics; Larva; Learning; Ligands; Localized; Mammalian Cell; Mediating; Membrane; Molecular; Nuclear; Nuclear Hormone Receptors; Nuclear Receptors; Organism; Pathway interactions; Phenotype; Pheromone; Physiology; Process; Protein Overexpression; Proteins; RNA Interference; Rate; Receptor Signaling; Regulation; Regulatory Pathway; Relative (related person); Research; Role; Signal Pathway; Signal Transduction; Staging; Steroids; Structure; System; Temperature; Testing; Transcript; activating transcription factor; base; functional genomics; gene function; non-genomic; novel; receptor; receptor function; response; transcription factor; transmission process

The long-term goals are to understand how a nuclear hormone receptor (NHR)is directed to the plasma membrane in response to a signal and how it might function in a non-nuclear signal transduction system. While the classical view of steroid signaling holds that these hormones bind intracellular receptors that act as ligand-activated transcription factors, extensive evidence indicates that steroids can also act by a non- genomic mechanism at the cell surface. We have identified a C. elegans NHR, DPR-1, that may act through such a membrane-based signaling system, providing the first genetic system for dissecting a membrane- based NHR signaling system. In the presence of a small lipophilic molecule (dauer pheromone or "daumone") DPR-1 moves from the cytoplasm to the plasma membrane. Daumone triggers an alternative, developmental^ arrested state, the dauer larva. A deletion mutation of the dpr-1 gene attenuates responsiveness to dauer pheromone and accelerates exit from the dauer state, and overexpression of DPR- 1 triggers inappropriate dauer development and inhibits exit from the dauer state. The dauer regulatory pathway is required for relocalization of DPR-1 to the membrane. The proposed studies will test the hypothesis that DPR-1 regulates dauer formation through a plasma membrane signal transduction system. Aim 1 will investigate parameters that influence relocalization of DPR-1 in response to dauer pheromone, analyze the essential function of dpr-1, test for redundant partners of DPR-1, and assess the relationship between DPR-1 and the dauer pathway. Aim 2 will identify structural elements and components required for DPR-1 signaling and membrane association, test its signaling function when targeted to the membrane and nucleus, examine the basis for a membrane-tenacious form of DPR-1in dauer larvae, and investigate physical interactions between DPR-1 and other proteins. Aim 3 will examine whether DPR-1responds to dauer pheromone in heterologous cells and whether DPR-1 relatives and the dauer-regulating NHR, DAF- 12, associate with the membrane under dauer-favoring conditions. Aim 4 will initiate RNAi screens to identify components responsible for relocalization of DPR-1and genes with which it collaborates. The elucidation of novel pathways through which NHRs function may advance our understanding of many developmental defects and the hormonal influences on normal human physiology and a variety of human pathologies.

长期目标是了解核激素受体 (NHR) 如何定向到血浆 膜响应信号以及它如何在非核信号转导系统中发挥作用。 虽然类固醇信号传导的经典观点认为这些激素与细胞内受体结合，这些受体充当 配体激活的转录因子，大量证据表明类固醇也可以通过非- 细胞表面的基因组机制。我们已经鉴定出一种秀丽隐杆线虫 NHR，DPR-1，它可能通过 这种基于膜的信号系统，提供了第一个用于解剖膜的遗传系统 基于NHR信号系统。在存在亲脂性小分子（dauer 信息素或 “daumone”）DPR-1 从细胞质移动到质膜。 Daumone 触发了另一种选择， 发育^停滞状态，dauer 幼虫。 dpr-1 基因的缺失突变减弱 对 dauer 信息素的反应性并加速从 dauer 状态的退出，以及 DPR- 的过度表达 1 触发不适当的 dauer 发育并抑制从 dauer 状态退出。多尔监管 DPR-1 重新定位到膜上需要途径。拟议的研究将测试 假设 DPR-1 通过质膜信号转导系统调节 dauer 形成。 目标 1 将研究影响 DPR-1 响应 dauer 信息素重新定位的参数， 分析 dpr-1 的基本功能，测试 DPR-1 的冗余伙伴，并评估其关系 DPR-1 和 dauer 通路之间。目标 2 将确定所需的结构元素和组件 DPR-1 信号传导和膜关联，测试其靶向膜时的信号传导功能， 细胞核，检查 dauer 幼虫中 DPR-1 膜坚韧形式的基础，并研究 DPR-1 和其他蛋白质之间的物理相互作用。目标 3 将检查 DPR-1 是否响应 异源细胞中的 dauer 信息素以及 DPR-1 亲属是否与 dauer 调节 NHR、DAF- 12、在有利的条件下与膜结合。目标 4 将启动 RNAi 筛选 确定负责 DPR-1 重新定位的组件以及与其协作的基因。这 阐明 NHR 发挥作用的新途径可能会增进我们对许多方面的理解 发育缺陷和荷尔蒙对正常人体生理和各种人类的影响 病理学。