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”染色体内的长程相互作用 域。 诱导这些物质形成的复合DNA元件 结构被称为轨迹控制区域（LCR）。 转录的 LCR 内的增强子启动其他浓缩的局部变化 高阶染色质结构，可以传播到更远端 存在核基质附着区域（MAR）的区域。 这些 LCR 诱导的染色质可及性变化是功能性所必需的 广泛分离的增强子和启动子之间的相互作用。 这些效应已在转基因小鼠实验中得到描述，并且是： 因此很难在机械层面上进行研究。 为此， PI 最近开发了一种转染方法，揭示了功能 详细描述的 LCR 中每个子元素的贡献。 这个 assa 将加快新型 DNA 调控元件的鉴定 参与染色质远距离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 侧翼 MAR。 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 针对发起人，PI 提出了以下 3 个具体目标： 1) 确定 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 MAR 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）发育调控基因座。 这些研究 将对 LCR 结构和功能产生新的见解，这应该 扩大受监管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.