FUNCTIONAL ANALYSIS OF THE IG LOCUS CONTROL REGION

描述：体内转录调控涉及局部和 发生在特殊的“开放”染色体内的远程相互作用 域名。诱导这些病毒形成的复合DNA元件 构造被称为轨迹控制区(LCR)。转录的 LCR中的增强器在其他方面浓缩的情况下启动本地更改 高阶染色质结构，可以传播到更远的地方 存在核基质附着区的区域(MARS)。这些 LCR诱导的染色质可及性改变是功能性的 广谱分离的增强子和启动子之间的相互作用。 这些效应已经在转基因小鼠实验中得到了描述， 因此，很难在机械层面上进行研究。为此， PI最近开发了一种转基因方法，它揭示了功能 描述良好的LCR中每个子元素的贡献。这 ASA将加快识别新的DNA监管元件和 参与染色质长程重塑的反式作用因子。 免疫球蛋白MU LCR由经典的增强子元件和 在火星的侧翼。要了解这些元素如何协作来重塑大型 染色质结构域，并允许增强子和远端之间的相互作用 发起人，PI提出了以下3个具体目标：1)识别 LCR功能所需的特定MAR序列，2)识别 MAR结合蛋白因子是活性物质的功能成分 MU LCR，以及3)研究火星和 MAR结合因子控制远端增强子功能和染色质 改建。 LCRs及其控制基因表达的机制可能会 B在许多(如果不是全部)发育调节基因座上使用。这些研究 将对LCR的结构和功能产生新的见解，这应该 扩大规范和靶向基因治疗的机会。

DESCRIPTION: Transcriptional regulation in vivo involves both local and long-range interactions that occur within specialized "open" chromosomal domains. Composite DNA elements which induce the formation of these structures are termed Locus Control Regions (LCRs). Transcriptional enhancers within LCRs initiate local changes in otherwise condensed higher-order chromatin structures, which can be propagated to more distal regions in the presence of nuclear matrix attachment regions (MARs). These LCR-induced changes in chromatin accessibility are required for functional interactions between widel separated enhancers and promoters. These effects have been described in transgenic mouse experiments and are, consequently difficult to study at the mechanistic level. To this end, the PI has recently developed a transfection method which reveals the functional contribution of each of the subelements within a well described LCR. This assa will expedite the identification of novel DNA regulatory elements and trans-acting factors that participate in long-range remodeling of chromatin. The immunoglobulin mu LCR consists of a classical enhancer element and flankin MARs. To understand how these elements collaborate to remodel large chromatin domains and permit interactions between the enhancer and distal promoters, the PI proposes the following 3 specific aims: 1) To identify the specific MAR sequences necessary for LCR function, 2) To identify MAR-binding protein factors which are a functional component of the active mu LCR, and 3) To investigate the mechanism by which the MARs and MAR-binding factors govern distal enhancer function and chromatin remodeling. LCRs, and the mechanisms by which they govern gene expression, are likely to b used at many, if not all, developmentally regulated loci. These studies will yield novel insights into LCR structure and function which should expand opportunities for regulated and targeted gene therapy.