FUNCTIONAL ANALYSIS OF THE IG LOCUS CONTROL REGION

描述：体内转录调控涉及局部和 发生在专门的“开放”染色体内的长距离相互作用 域. 复合DNA元件，诱导形成这些 这些结构被称为基因座控制区（LCR）。 转录 LCR中的增强子启动了原本浓缩的 更高级的染色质结构，可以传播到更远的 在核基质附着区（MAR）的存在下的区域。 这些 LCR诱导的染色质可及性的变化是功能性免疫应答所必需的。 广泛分离的增强子和启动子之间的相互作用。 这些作用已经在转基因小鼠实验中描述， 因此很难在机械水平上进行研究。 为此中央 PI最近开发了一种转染方法，该方法揭示了功能性 在一个描述良好的LCR中每个子元素的贡献。 这 assa将加快新的DNA调控元件的鉴定， 反式作用因子参与染色质的长距离重塑。 免疫球蛋白μ LCR由经典的增强子元件组成， 侧翼MARs。 要了解这些元素如何协作来改造大型 染色质结构域，并允许增强子和远端 促进者，PI提出以下3个具体目标：1）识别 LCR功能所必需的特定MAR序列，2）为了鉴定 MAR结合蛋白因子是活性物质的功能成分 3）探讨MARs和 MAR结合因子控制远端增强子功能和染色质 重塑 LCR及其控制基因表达的机制可能会 B用于许多（如果不是全部）发育调节位点。 这些研究 将对LCR结构和功能产生新的见解， 扩大受调控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.