MECHANISMS OF TRANSCIPTIONAL REGULATION BY ATF

长期目标：更好地理解真核基因的调控 表情。从动脉粥样硬化到癌症，许多疾病都是 指一个基因或一组基因的表达不足或过度表达。 因此，对基因表达的更好理解将导致更好的 了解，甚至可能治愈不同的疾病。 具体目的：研究一群人的分子机制 激活转录因子(ATF)二聚体调节转录。一 在转录研究中的最新发现是许多不同的 在体外，转录因子可以与给定的DNA调控序列结合。 由于给定的调控序列可能出现在不同的启动子中，这 发现号引发了几个问题。例如，做这些不同的 转录因子调控不同的启动子？如果是这样的话， 实现了特效性？他们在其他方面有什么不同吗 监管不同的推动者？本提案通过以下方式解决这些问题 描述研究转录因子超家族的实验： ATF/CREB和Fos/Jun“亮氨酸拉链”蛋白。这些转录 各因子通过亮氨酸拉链相互形成选择性二聚体 区域，并与相似的DNA序列结合。此外，它们还被诱导 通过许多细胞外刺激，如病毒感染、生长因子和 增加细胞内cAMP水平的多肽激素。这样做的目的是 建议使用ATF作为模型来阐明 转录调控。战略是专注于一群稳定的 ATF均二聚体和杂二聚体：ATF-1、ATF-3、ATF-4、ATF-3/c-Jun和 ATF-4/FRA-1。 具体方法：(1)“随机诱变”分析 DNA序列在ATF二聚体结合中的重要性，(2)体外实验 转录和体内转染实验，以找出 不同的ATF二聚体调节不同的基因；(3)脉冲追逐标记， 化学交联法、免疫沉淀法和二维分析 研究不同的ATF蛋白是如何被诱导转录的 被细胞外刺激激活的。

Long term objective: To better understand the regulation of eukaryotic gene expression. From atherosclerosis to cancer, many diseases are the result of under-expression or over-expression of a gene or a group of genes. Thus, a better understanding of gene expression will lead to a better understanding of, and possibly even cures to, different diseases. Specific aim: To study the molecular mechanisms by which a group of activating transcription factor (ATF) dimers regulate transcription. One recent discovery in transcription research is that many different transcription factors can bind to a given DNA regulatory sequence in vitro. Since a given regulatory sequence may occur in different promoters, this discovery raises several questions. For example, do these different transcription factors regulate different promoters? If so, how is the specificity achieved? Do they differ from one another in ways other than regulating different promoters? This proposal addresses these questions by describing experiments to study a superfamily of transcription factors: the ATF/CREB and Fos/Jun "leucine zipper" proteins. These transcription factors form selective dimers with each other via the leucine zipper regions, and bind to similar DNA sequences. In addition, they are induced by many extracellular stimuli, such as viral infection, growth factors and peptide hormones that increase cellular cAMP level. The goal of this proposal is to use ATF as a model to elucidate fundamental principles of transcriptional regulation. The strategy is to focus on a group of stable ATF homodimers and heterodimers: ATF-1, ATF-3, ATF-4, ATF-3/c-Jun and ATF-4/Fra-1. Specific methods: (1) A "random mutagenesis" analysis to study the importance of DNA sequences on ATF dimer binding, (2) In vitro transcription and in vivo transfection experiments to find out whether different ATF dimers regulate different genes; (3) Pulse-chase labeling, chemical cross-linking, immunoprecipitation and two-dimensional analysis to study how different ATF proteins are induced to become transcriptionally active by extracellular stimuli.