REGULATED EXPRESSION OF CATECHOLAMINE BIOSYNTHESIS GENES

儿茶酚胺生物合成基因的调控表达

• 批准号: 6018701
• 负责人: Elaine J. Lewis
• 金额: $ 16.26万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-07-01 至 2000-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6018701
• 关键词: biosynthesis; catecholamines; cyclic AMP; dopamine beta monooxygenase; enzyme induction /repression; gene mutation; genetic regulatory element; laboratory mouse; transcription factor

DESCRIPTION: The development and maintenance of a neurotransmitter system is one of the essential events in the generation of neural function and specificity. The events that influence the neurotransmitter phenotype of a specified cell are initiated during development and continue postnatally. Environmental stimuli and positional information stimulate intracellular signals that lead to neurotransmitter production. In nearly all situations studied the critical decisive regulatory event is the activation or repression of genes encoding the enzymes producing the neurotransmitter. This proposal aims to understand the genetic and biochemical regulatory elements of the DBH and TH genes that are critical for appropriate expression. In the previous granting period the applicants identified a homeodomain transcription factor termed, Arix which binds to the DBH gene and is expressed selectively in noradrenergic cells. Arix will regulate DBH gene transcription but it is dependent upon simultaneous activation of the cAMP second messenger pathway. Arix will also stimulate transcription of the DBH gene, independent of second messenger stimulation. In addition to the characterization of the positive genomic regulatory elements, they characterized a negative regulatory element of the DBH gene which functions to repress expression in the inappropriate cells. In this proposed granting period the goal is to define the molecular and biochemical mechanisms underlying these genetic regulatory events, and to begin testing the importance of these regulatory element in vivo. To achieve this goal the proteins that contribute to transcriptional regulation of TH and DBH will be identified and characterized. The mechanism by which these factors modify specific gene expression will be evaluated in cultured cells and in defined biochemical systems. In addition, the importance of one defined regulatory element of the DBH gene will be evaluated in vivo though construction of transgeneic animals. These experiments could be significant towards understanding the process by which a neuroendocrine cell carries out its specialized function. There are 4 specific aims: 1. Define the biochemical and molecular interactions between the newly identified homeodomain factor, Arix, and the cAMP system which leads to synergistic stimulation of DBH gene expression.; 2. Understand the basis of the difference between TH and DBH genes in requirements for Arix mediated transcriptional activation; 3. Identify and characterize the protein that interacts with the DBH silencer.; 4. Evaluate the importance of the CRE/Arix regulatory element in vivo by introduction of DNA containing mutation of this element into mice.

描述：神经递质系统的发展和维持 是神经功能产生的重要事件之一， 的特异性影响神经递质表型的事件 在开发期间启动指定的单元格，并继续 出生后 环境刺激和位置信息刺激 导致神经递质产生的细胞内信号。在 几乎所有研究的情况下，关键的决定性监管事件是 激活或抑制编码产生这些酶的基因， 神经传递素这项建议旨在了解遗传和 DBH和TH基因的生化调控元件， 关键在于恰当的表达。在上一个授予期间， 本申请人鉴定了一种称为Arix的同源结构域转录因子 它与DBH基因结合，并选择性地在 去甲肾上腺素能细胞Arix将调节DBH基因的转录，但它是 依赖于cAMP第二信使的同时激活 通路 Arix还将刺激DBH基因的转录， 独立于第二信使刺激。除了有 正基因组调控元件的表征，它们 其特征在于DBH基因的负调控元件， 在不适当的细胞中抑制表达。 在这一拟议的授权期内，目标是确定分子和 这些遗传调控事件背后的生化机制， 开始在体内测试这些调节元件的重要性。到 实现这一目标的蛋白质，有助于转录 TH和DBH的调节将被识别和表征。的 这些因子改变特定基因表达的机制将 在培养的细胞和确定的生化系统中进行评估。在 此外，一个定义的调控因素的DBH的重要性 将通过构建转基因小鼠， 动物这些实验对于理解 神经内分泌细胞进行其特化的 功能 具体目标有四个：1。定义生物化学和分子 新发现的同源结构域因子Arix和 导致DBH基因协同刺激的cAMP系统 表达。2. 了解TH和TH之间差异的基础 Arix介导的转录激活所需的DBH基因; 3.鉴定和表征与DBH相互作用的蛋白质 消音器。4.评估CRE/Arix监管要素的重要性 通过将含有该元件突变的DNA引入体内， 小鼠