Genetic and Molecular Mechanisms of Nuclear Receptor Signaling

该项目的广泛，长期目标是确定核受体控制胚胎后发育的遗传和分子机制。 短期目标是确定参与核受体信号通路的基因。 将使用遗传和分子方法在果蝇中鉴定参与核受体信号传导的基因。 一个主要的遗传筛选将确定候选基因座，增强表型与致敏股票，其中核受体信号已受到损害。 二次筛选将鉴定其中增强与蜕皮激素响应基因的表达水平改变相关的那些候选基因座;这些基因的表达依赖于适当的核受体信号传导。 将检测染色体缺陷贮备液的一个子集和约100份EP贮备液。 EP原种携带修饰的P元件的单个随机插入，其允许位于P元件附近的基因的异位表达。 这些遗传筛选具有鉴定与核受体物理相互作用的基因、作为核受体的直接靶点的基因以及在核受体调节途径中更下游的基因的潜力。为了补充这种遗传方法，酵母双杂交筛选将B鉴定与蜕皮激素受体A亚型（EcR-A）的氨基末端结构域物理相互作用的蛋白质。 了解核受体及其配体功能的遗传和分子机制是重要的，因为核受体信号转导协调高等真核生物中几乎所有器官和组织的发育。 因此，为了充分理解和理解发育机制，有必要了解核受体在协调发育程序中所起的作用。 所提出的活动是重要的，因为它们有可能确定参与核受体信号通路的基因之间的生物相关的相互作用。

The broad, long-term objectives of this project are to determine the genetic and molecular mechanisms by which nuclear receptors control post-embryonic development. The short-term goals are to identify genes involved in nuclear receptor signaling pathways. Genes that are involved in nuclear receptor signaling will be identified in Drosophila melanogaster using both genetic and molecular approaches. A primary genetic screen will identify candidate loci that enhance phenotypes associated with sensitized stocks in which nuclear receptor signaling has been compromised. A secondary screen will identify those candidate loci in which the enhancement correlates with altered expression levels of ecdysone-responsive genes; genes whose expression is dependent upon appropriate nuclear receptor signaling. A subset of chromosomal deficiencies stocks and approximately 100 EP stocks will be tested. EP stocks carry single random insertions of a modified P-element that allows ectopic expression of the gene residing near the P-element. These genetic screens have the potential to identify genes that physically interact with nuclear receptors, genes that are direct targets of nuclear receptors, and genes that are further downstream in nuclear receptor regulated pathways. To complement this genetic approach, a yeast two-hybrid screen will b used to identify proteins that physically interact with the amino-terminal domain of the A-isoform of the ecdysone receptor (EcR-A). Understanding the genetic and molecular mechanisms by which nuclear receptors and their ligands function is significant because nuclear receptor signaling coordinates the development of virtually all organs and tissues in higher eukaryotes. Thus, to fully appreciate and understand developmental mechanisms, it is necessary to understand the role that nuclear receptors play in orchestrating the developmental program. The proposed activities are significant because they have the potential to identify biologically relevant interactions between genes involved in nuclear receptor signaling pathways.