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， 超过300种蛋白质。然而，这些和其他过渡金属也对环境构成潜在威胁。 有机体如果不加以控制，这些金属可以催化自由基的产生，破坏所有类型的组织。 生物分子过渡金属必须保持在一个生理窗口。像威尔逊氏病这样的疾病 和门克氏病证明，过多或过少的金属都可能导致肝脏病变， 肾脏、神经系统和结缔组织。显然，金属稳态是细胞内环境的一个重要方面， 功能这种控制的主要部分发生在转录水平。其中一个核心角色 金属反应元件结合蛋白（MTF-1）。MTF-1是一种序列特异性DNA结合蛋白， 感知细胞金属状态并相应激活基因的蛋白质。很多人都知道 MTF-1本身，但对帮助MTF-1有效激活的蛋白质辅因子知之甚少 转录。我们将在果蝇模型系统中使用基于RNAi的筛选，以确定 辅因子是金属刺激转录所必需的。此外，我们将描述物理和 MTF-1和这些蛋白质辅因子之间的功能相互作用，使用基于细胞的组合和在 体外测定。最后，我们将识别果蝇基因组中的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， 响应于一组不同的金属，差异调节适当的金属响应基因，以控制 金属稳态

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.