MULTIHORMONAL REGULATION OF GENE EXPRESSION

大多数真核基因受到多因子调控， 由发育、激素、组织触发的信号通路， 具体的和/或环境线索。这些通路通常激活复杂的 转录级联导致蛋白质数量的改变 由靶基因编码的基因在初始信号后数小时甚至数天内被激活。 我们 长期目标是了解这些复杂的监管事件是如何 协调以引发适当水平的基因表达。整体 该建议的目的是研究转录级联， 是由类固醇激素与其同源受体结合引起的。 特别是，我们的目标是研究雌激素和糖皮质激素 诱导“次级”或迟发反应基因。卵清蛋白基因是 由雌激素、糖皮质激素、雄激素间接诱导， 孕酮因此，该基因是一个很好的模型系统， 研究类固醇结合的分子事件 受体的早期反应基因与随后的激活晚 反应基因该补助金的具体目标是：一。确定如何 雌激素和皮质酮诱导卵清蛋白基因的表达;和 二.定义消极调节因素在积极和消极调节因素中的作用 卵清蛋白基因的负调控。为了实现第一个目标， 计划是克隆两种类固醇反应性、环己酰亚胺敏感性蛋白质 通过酵母单杂交系统。 体内足迹技术 将为研究几个重要问题提供基础。 这些包括确定雌激素和皮质酮如何协同作用， 诱导卵清蛋白基因的转录，并确定是否 单链DNA结合蛋白参与转录 调控将采用诱变和转染实验， 继续对NRE进行功能分析。由于类固醇激素一直是 与某些癌症的病因有关，更好。理解 类固醇引起的分子事件只能改善治疗， 预防这些恶性肿瘤。此外，这些知识可以提供 深入了解如何开发更好的避孕药具， 生殖和代谢紊乱的治疗。

Most eucaryotic genes are subject to multifactorial regulation by signaling pathways that are triggered by developmental, hormonal, tissue- specific, and/or environmental cues. These pathways often activate complex transcriptional cascades that give rise to altered amounts of protein encoded by target genes hours and even days after the initial signal. Our long term goal is to understand how these complex regulatory events are coordinated to elicit appropriate levels of gene expression. The overall aim of this proposal is to investigate the transcriptional cascades that are evoked by the binding of steroid hormones to their cognate receptors. In particular, our goal is to investigate how estrogen and glucocorticoid induce "secondary" or late response genes. The ovalbumin gene is indirectly induced by estrogen, glucocorticoid, androgen, and progesterone. Thus, this gene is an excellent model system for investigating the molecular events linking the binding of steroid receptors to early response genes with the subsequent activation of late response genes. The Specific Aims of this grant are to: I. Ascertain how estrogen and corticosterone induce expression of the ovalbumin gene; and II. Define the role of the negative regulatory element in the positive and negative regulation of the ovalbumin gene. To address the first aim, the plan is to clone two steroid-responsive, cycloheximide-sensitive proteins by using the yeast one-hybrid system. In vivo footprinting techniques will provide the basis for investigating several important questions. These include determining how estrogen and corticosterone synergize to induce transcription of the ovalbumin gene and ascertaining whether single-stranded DNA binding proteins are involved in transcriptional regulation. Mutagenesis and transfection experiments will be employed to continue the functional analysis of the NRE. As steroid hormones have been implicated in the etiology of some cancers, a better. understanding of the molecular events provoked by steroids can only improve the treatment and prevention of these malignancies. Furthermore, such knowledge may provide insights into the development of better contraceptives and aid in the treatment of reproductive and metabolic disorders.