Role of Enhancers Regulating Renin Gene Expression

肾素-血管紧张素系统(RAS)是血压和电解质平衡的主要调节因子。 在动物和人类身上。肾素是RAS级联反应的限速酶，其合成是 在转录、转录后和分泌水平上都受到高度调控。尽管多年来 在调查中，我们对肾素基因表达的调控机制的理解仍然 非常不完整。因此，这项提议的目的是检验总体假设，即 发现肾素基因上游的增强子及其同源转录因子(和 特定的配体)、共激活物和共抑制物在控制细胞-和 表达的组织特异性和对生理提示的转录反应。为了测试 在这一假设的基础上，我们提出了以下三个主要的具体目标：1)测试 假设与肾素增强子结合的单个转录因子是 肾素启动子/增强子活性和内源性肾素表达的重要调节因子 基线，在肾素表达受到刺激或抑制的情况下，2)测试 假设有两种转录增强子，肾脏增强子(KE)和绒毛膜增强子 (Ce)在人类肾素5‘侧翼区是控制组织和细胞的基本元件- 特定的表达和对生理暗示的反应，以及3)检验假设 转录因子EAR2(负调节因子)和RARA(正调节因子)是主要的调节因子 肾素在整个动物中表达的决定因素。随着新的创新的发展 细胞和整个动物中单个基因和蛋白质的询问技术，我们 现在准备首次做出重要发现，将转录事件与 特定的生理反应和途径。

The renin-angiotensin system (RAS) is a major regulator of blood pressure and electrolyte balance in animals and humans. Renin is the rate limiting enzyme of the RAS cascade and its synthesis is highly regulated at both the transcriptional, post-transcriptional and secretory level. Despite years of investigation, our understanding of the mechanisms regulating renin gene expression remained very incomplete. The purpose of this proposal therefore is to test the overall hypothesis that the enhancers found upstream of the renin gene along with their cognate transcription factors (and specific ligands), co-activators, and co-repressors play a major role in controlling the cell- and tissue-specificity of expression and the transcriptional responses to physiological cues. To test and expand upon this hypothesis we have developed the following three main specific aims: 1) test the hypothesis that individual transcription factors identified to bind to the renin enhancer are important modulators of renin promoter/enhancer activity and endogenous renin expression at baseline, and under conditions where renin expression is either stimulated or repressed, 2) test the hypothesis that two enhancers of transcription, the kidney enhancer (KE) and chorionic enhancer (CE) in the human renin 5' flanking region are essential elements controlling tissue- and cell- specific expression and the responses to physiological cues, and 3) test the hypothesis that the transcription factors Ear2 (a negative regulator) and RARa (a positive regulator) are major determinants of renin expression in whole animals. With the development of new innovative technologies for interrogation of individual genes and proteins in both cells and whole animals, we are now poised for the first time to make important discoveries linking transcriptional events to specific physiological responses andpathways.