Key mediators of the enhancer blocker function of Drosophila CTCF

功能真核基因单元包括其所有调控元件彼此隔离，以允许调控元件作用于适当的基因。我们和其他人已经分析了DNA结合因子CTCF，这是已知的唯一一种在脊椎动物中介导增强子元件定向阻断活性的蛋白质。尽管几个实验室做出了许多努力，但介导增强子阻断的机制尚未确定。相比之下，在果蝇中，其他因素已经被描述，介导染色质绝缘和增强子阻断。在这个应用程序中，我们第一次有可能将未发表的果蝇CTCF同源物的性质与脊椎动物CTCF的功能进行比较。我们将利用这两种系统的优势来识别CTCF结构域和参与增强子阻断的核小体修饰，以揭示增强子阻断的分子机制。

Functional eukaryotic gene units including all of their regulatory elements are insulated from each other to allow the action of regulatory elements on the appropriate gene. We and others have analyzed the DNA binding factor CTCF, which is the only protein known to mediate a directional blocking activity of enhancer elements in vertebrates. Despite many efforts from several laboratories, a mechanism mediating enhancer blocking has not been determined. In contrast, in Drosophila other factors have been descr ibed, mediating chromatin insulation and enhancer blocking. In this application, for the first time, we have the possibility to compare the properties of the unpublished Drosophila orthologue of CTCF with the function of vertebrate CTCF. We will use the advantages of both systems to identify CTCF domains and nucleosomal modifications involved in enhancer blocking in order to unravel the molecular mechanism of enhancer blocking.