Mechanism of the Transcriptional Response to Transition Metals

必需的二价过渡金属，如锌、铜和铁，起着重要的结构和催化作用。 在300多种蛋白质中扮演重要角色。然而，这些和其他过渡金属也对 有机体。如果不加以控制，这些金属可以催化自由基的产生，从而破坏所有类型的 生物分子。过渡金属必须保存在一个生理窗口中。像威尔逊病这样的疾病 门克氏病表明，金属过多或过少都会导致肝脏病变， 肾脏、神经系统和结缔组织。显然，金属动态平衡是细胞的一个重要方面 功能。这种控制的主要部分发生在转录水平上。这件事的核心人物之一 调节是金属反应元件结合蛋白(MTF-1)。MTF-1是一种序列特异性DNA结合 感知细胞的金属状态并相应地激活基因的蛋白质。一笔不错的交易是众所周知的 MTF-1本身，但对帮助MTF-1有效激活的蛋白质辅助因子知之甚少 抄写。我们将在果蝇模型系统中使用基于RNAi的筛选来确定什么蛋白质 辅因子是金属刺激转录所必需的。此外，我们还将描述物理和 MTF-1与这些蛋白辅助因子的功能相互作用 体外试验。最后，我们将确定整个果蝇基因组中的MTF-1结合位点，以定义MTF-1 对金属刺激有反应的调节子。我们研究的长期目标是了解一个细胞是如何 对一组不同的金属的反应，差异地调节适当的金属反应基因来控制 金属动态平衡。

Essential divalent transition metals such as zinc, copper, and iron play important structural and catalytic roles in over 300 proteins. However, these and other transition metals also pose a potential threat to an organism. Left unchecked these metals can catalyze the generation of free radicals that damage all types of biological molecules. Transition metals must be kept in a physiological window. Diseases like Wilson's disease and Menke's disease demonstrate that either too much or too little metal can lead to pathologies of the liver, kidney, nervous system and connective tissues. Clearly metal homeostasis is an important aspect of cellular function. A major part of this control occurs at the level of transcription. One of the central players in this regulation is the metal response element binding protein (MTF-1). MTF-1 is a sequence specific DNA binding protein that perceives the metal status of a cell and activates genes accordingly. A good deal is known about MTF-1 itself, but very little is known about the protein co-factors that help MTF-1 efficiently activate transcription. We will use an RNAi based screen, in the Drosophila model system, to determine what protein co-factors are required for metal stimulated transcription. In addition we will characterize the physical and functional interactions between MTF-1 and these protein co-factors using a combination of cell based and in vitro assays. Finally we will identify the MTF-1 binding sites across the Drosophila genome to define the MTF-1 regulon that responds to metal stimuli. The long-term objective of our studies is to understand how a cell, in response to a diverse set of metals, differentially regulates the appropriate metal responsive genes to control metal homeostasis.