MECHANISMS OF TRANSCIPTIONAL REGULATION BY ATF

长期目标：更好地了解真核基因的调控 表情 从动脉粥样硬化到癌症， 一个基因或一组基因的表达不足或过度。 因此，更好地理解基因表达将导致更好的 了解甚至治愈不同的疾病。 具体目标：研究一组 激活转录因子（ATF）二聚体调节转录。 一 转录研究的最新发现是， 转录因子可以在体外与给定的DNA调节序列结合。 由于给定的调控序列可以存在于不同的启动子中，因此， 发现引发了几个问题。 例如，这些不同的 转录因子调控不同的启动子？如果是， 具体实现？他们之间的差异，难道不是因为 监管不同的发起人本提案通过以下方式解决这些问题： 描述了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 因子通过亮氨酸拉链相互形成选择性二聚体 区域，并结合到相似的DNA序列。 此外，它们还被诱导 许多细胞外刺激，如病毒感染，生长因子和 增加细胞cAMP水平的肽激素。 这个目标 建议使用ATF作为模型来阐明 转录调控 战略是集中一批稳定的 ATF同二聚体和异二聚体：ATF-1、ATF-3、ATF-4、ATF-3/c-Jun和 ATF-4/Fra-1 具体方法：（1）采用“随机诱变”分析法研究 DNA序列对ATF二聚体结合的重要性，（2）体外 转录和体内转染实验，以找出是否 不同的ATF二聚体调节不同的基因;（3）脉冲追踪标记， 化学交联、免疫沉淀和二维分析 研究不同的ATF蛋白如何被诱导转录， 由细胞外刺激激活。

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.