STRUCTURE AND REGULATION OF ECDYSONE-RESPONSIVE GENES

这里描述的研究计划旨在全面了解基因 由类固醇激素蜕皮激素调节。 蜕皮激素调节 昆虫的发育和诱导变态。 Eip 28/29，以及 蜕皮激素反应基因，是类固醇的模型， 调控基因 像其他这样的基因一样，它的活性可以是 激素升高或降低，取决于组织和 发育阶段 例如，Eip 28/29由蜕皮激素诱导， 血细胞（和一些细胞系），但同时它是 被表皮和脂肪体中的蜕皮激素抑制。 调节DNA 序列（蜕皮激素反应元件-EcRE-和其他顺式作用元件） 导致这些不同反应的元素）是不同的。 的 本实验的目的是了解蜕皮激素 通过识别相关的组织， 调控序列，识别和克隆相互作用的蛋白质 并测试可能的监管机制。 突变体 将在培养的细胞中测试调节区（通过瞬时 表达）和表皮（通过P元件介导的转化 苍蝇）。 与这些序列相互作用的蛋白质将被 通过它们与特定DNA序列的结合和/或通过它们的 体外转录修饰活性。 这些蛋白质应该 包括多种转录因子，包括 影响EcRE-受体结合或结合后的受体活性。 它们还应该包括转录因子， 功能协调发展的 由于蜕皮激素的信号传导与 脊椎动物类固醇的结果应该提供有用的 深入了解医学上更相关的脊椎动物的活动 荷尔蒙 类似地，在果蝇中鉴定的转录因子是 可能在其他生物的基因调控中发挥重要作用。

The research program described here aims at a full understanding of gene regulation by the steroid hormone ecdysone. Ecdysone regulates the development of insects and induces metamorphosis. Eip28/29, and ecdysone-responsive gene from Drosophila, is a model for steroid- regulated genes. Like other examples of such genes, its activity can be either elevated or depressed by the hormone, depending upon tissue and developmental stage. For example, Eip28/29 is induced by ecdysone in blood cells (and in some cell lines), but at the same time it is repressed by ecdysone in the epidermis and fat body. The regulatory DNA sequences (ecdysone response elements--EcREs--and other cis-acting elements) responsible for these diverse responses are distinct. The goal of the experiments proposed here is to understand ecdysone regulation in each class of tissue by identifying the relevant regulatory sequences, identifying and cloning the proteins that interact with them, and testing possible regulatory mechanisms. Mutant regulatory regions will be tested in cultured cells (by transient expression) and in the epidermis (by P element-mediated transformation of flies). Proteins which interact with these sequences will be identified by their binding to specific DNA sequences and/or by their activities in modifying transcription in vitro. Such proteins should include a variety of transcription factors, including factors which affect either EcRE-receptor binding or receptor activity after binding. They should also include transcription factors with more general functions. Since signal transduction by ecdysone is extremely similar to that of the vertebrate steroids, the results should provide useful insights into the activities of the more medically relevant vertebrate hormones. Similarly, transcription factors identified in Drosophila are likely to play important roles in gene regulation in other organisms.