Runt-dependent regulation of enhancer-promoter interactions

描述（由申请人提供）：基因转录的调节对于多细胞生物体的发育至关重要，转录调节中的畸变通常与疾病相关。转录调控涉及顺式调控DNA序列，其与DNA结合转录因子相互作用并整合信息，该信息被传递到启动子以控制RNA聚合酶合成mRNA转录物。真核生物中的顺式调节元件可以位于基因的上游、下游或甚至转录区内，并且在从果蝇延伸到人的动物系统中，经常有许多酶从转录起始位点移除。在不同发育阶段的不同细胞类型中基因的表达通过多个顺式调节元件的出现来反映，每个顺式调节元件与不同的转录因子组相互作用以整合最终导致基因转录的控制信号。虽然不同的顺式元件和转录单位之间的相互作用是这种控制基因表达的策略的核心，但至今还没有明确的理解如何调节增强子-启动子相互作用。果蝇系统中可用的工具与负责产生早期胚胎分节体模式的途径的知识框架相结合，为研究体内转录调控机制提供了有价值的模型。分割途径中的一个关键参与者是Runt，它是转录调节因子家族的创始成员，在动物发育和人类疾病中发挥着广泛的作用。这项提案中的工作源于对sloppy配对-1（slp 1）的研究，slp 1是分割途径中Runt的一个靶点，为解剖转录控制机制提供了许多优势。slp 1的初始同色异谱表达是响应于由两个不同的顺式元件介导的简单组合密码而产生的。重要的是，这两个元素一起生成的模式超出了它们独立模式的相加组合所预期的模式。占这些元素之间的功能相互作用的模型提出了一个新的角色，在调节这两个元素和slp 1启动子之间的相互作用的侏儒。拟议的工作进一步研究了这种调控现象的分子基础，并包括询问增强子-启动子相互作用的类似调控是否有助于早期胚胎中其他基因表达的实验。这些结果将为Runt和其他转录因子的调控机制提供新的见解，这些转录因子可能对理解相关蛋白质在人类发育和疾病中的作用具有广泛的意义。 公共卫生相关性：基因表达的适当调节对发育至关重要，基因调节中的畸变经常与疾病相关。该项目利用果蝇系统中可用的遗传框架和工具来研究胚胎发育过程中用于调节基因表达的基本机制。这项工作的重点是了解Runt对不同顺式调控DNA元件之间非加性相互作用的调控，Runt是一个在人类发育和疾病中具有深远作用的蛋白质家族的创始成员。

DESCRIPTION (provided by applicant): The regulation of gene transcription is critical for the development of multi-cellular organisms and aberrations in transcriptional regulation are frequently associated with disease. The regulation of transcription involves cis-regulatory DNA sequences that interact with DNA-binding transcription factors and integrate information that is communicated to the promoter to control the synthesis of mRNA transcripts by RNA polymerase. Cis-regulatory elements in eukaryotes can be located upstream, downstream, or even within the transcribed region of a gene, and in animal systems extending from fruit fly to man are frequently many kilobases removed from the transcription start site. The expression of genes in different cell types at different stages of development is reflected by the occurrence of multiple cis-regulatory elements, each of which interacts with different sets of transcription factors to integrate the control signals that eventually result in gene transcription. Although interactions between different cis-elements and the transcription unit are central to this strategy of controlling gene expression, there is as of yet no clear understanding of how enhancer-promoter interactions are regulated. The tools available in the Drosophila system in conjunction with the framework of knowledge on the pathway responsible for generating the segmented body pattern of the early embryo provide a valuable model for investigating the in vivo mechanisms of transcription regulation. A key player in the segmentation pathway is Runt, the founding member of a family of transcriptional regulators with wide-ranging roles in animal development and human disease. The work in this proposal emanates from studies on sloppy-paired-1 (slp1), a target of Runt in the segmentation pathway that offers numerous advantages for dissecting transcriptional control mechanisms. The initial metameric expression of slp1 is generated in response to a simple combinatorial code that is mediated by two distinct cis-elements. Importantly, the two elements together generate a pattern beyond what is expected from the additive combination of their independent patterns. A model accounting for the functional interplay between these elements proposes a novel role for Runt in regulating interactions between these two elements and the slp1 promoter. The proposed work further investigates the molecular basis for this regulatory phenomenon and includes experiments asking whether a similar regulation of enhancer-promoter interactions contributes to the expression of other genes in the early embryo. The results will provide new insights on the mechanisms of regulation by Runt and other transcription factors that are likely to have widespread implications for understanding the roles of related proteins in human development and disease. PUBLIC HEALTH RELEVANCE: The proper regulation of gene expression is critical for development and aberrations in gene regulation are frequently associated with disease. This project takes advantage of the genetic framework and tools available in the Drosophila system to investigate basic mechanisms used to regulate gene expression during embryonic development. The work focuses on understanding the regulation of non-additive interactions between distinct cis-regulatory DNA elements by Runt, the founding member of a protein family with profound roles in human development and disease.