Nuclear Pore Complexes As Scaffolds For Genome Architecture And Epigenetic Maintenance

核孔复合物作为基因组结构和表观遗传维护的支架

• 批准号: 9365129
• 负责人: Maya Capelson
• 金额: $ 33.81万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9365129
• 关键词: Affect; Architecture; Area; Binding; Binding Sites; Biology; Cell Culture Techniques; Cell Nucleus; Cells; Chromatin; Complex; Cytoplasm; DNA; Data; Deposition; Development; Developmental Gene; Developmental Process; Drosophila genome; Drosophila genus; Ecdysone; Elements; Enhancers; Epigenetic Process; Event; Future; Gene Cluster; Gene Expression; Gene Expression Regulation; Gene Targeting; Genes; Genetic Transcription; Genome; Genome Components; Genome engineering; Genomics; Goals; Heart Diseases; Hematologic Neoplasms; Homeobox Genes; Hormones; Human Pathology; Imaging Techniques; Investigation; Knowledge; Link; Macromolecular Complexes; Maintenance; Mediating; Memory; Methods; Molecular; Nuclear Envelope; Nuclear Pore; Nuclear Pore Complex; Nuclear Pore Complex Proteins; Pathology processes; Phenotype; Play; Proteins; Proteomics; Role; Tissues; Transcriptional Activation; Transcriptional Regulation; base; chromatin immunoprecipitation; chromosome conformation capture; driving force; experimental study; fly; gene repression; genome-wide; nucleocytoplasmic transport; promoter; response; scaffold

Abstract: The Nuclear Pore Complex (NPC) is a nuclear envelope-embedded multi-component complex, which mediates transport of molecules between the nucleus and the cytoplasm. In addition to their classical function in transport, NPC components (Nups) have been implicated in transcriptional regulation via binding to the genome. Yet what regulatory steps of transcription are controlled by Nups and how chromatin-binding roles of Nups contribute to metazoan development is currently unclear. We identified the binding of multiple Nups to hundreds of promoters and enhancers in the Drosophila genome, and discovered a previously unreported role of the NPC in the formation of enhancer-promoter loops. Specifically, we identified Nup98 to be required for the formation of an enhancer-promoter loop at a gene activated by a developmental hormone ecdysone. Functionally, we found that the loss of Nup98-mediated enhancer-promoter loop affected the primed response to subsequent activation or transcriptional memory. Interestingly, ecdysone-regulated genes stably associated with nuclear pores before and after activation, suggesting that metazoan NPCs can be utilized as an organizing scaffold for genes awaiting future activation events. Together, these findings implicate Nups as a new class of architectural proteins for enhancers and suggest that stabilization of enhancer-promoter loops by nuclear pore binding constitutes a mechanism of epigenetic maintenance. We project that this function of the nuclear pore will be highly relevant to gene regulation during metazoan development. To be able to investigate the genome- organizing role of Nups in developmental gene regulation, we first plan to identify molecular determinants of Nup-mediated enhancer-promoter looping. Thus, in Aim 1, we will define which Nups and which other architectural proteins participate in the establishment of ecdysone- induced genomic loops. Additionally, we plan to identify DNA elements that are sufficient to tether to the NPC or that are necessary for loop stabilization. In Aim 2, we propose to define the relationship between formation of Nup-mediated enhancer-promoter loops and transcriptional activation and memory, by identifying chromatin changes that occur as a specific consequence of looping. Furthermore, we will examine the effect of Nups on maintenance of genomic loops in fly tissues during development and identify a comprehensive set of genomic contacts that are regulated by Nups. Together, these experiments are expected to expand our knowledge of the driving forces and principles of genome architecture, gene expression and nuclear pore biology.

抽象的： 核孔复合物（NPC）是核包膜包裹的多组分络合物， 它介导细胞核和细胞质之间的分子转运。此外 它们在运输中的经典功能，NPC组件（NUP）已与 通过与基因组结合的转录调节。然而，哪些调节步骤的转录步骤 由NUPS控制以及NUP的染色质结合作用如何促进后生动物 开发目前尚不清楚。我们确定了多个NUP与数百种的结合 果蝇基因组中的启动子和增强剂，并发现了先前未报告的 NPC在增强子启动器循环形成中的作用。具体来说，我们确定了NUP98 需要在A激活的基因上形成增强子启动器循环所必需的 发育激素ecdysone。在功能上，我们发现NUP98介导的损失 增强器促进圈循环影响了对随后激活或 转录记忆。有趣的是，ecdysone调节的基因与核稳定相关 激活前后的毛孔，表明可以将后生NPC用作 组织脚手架的基因，等待未来的激活事件。在一起，这些发现 将NUPs视为增强剂的新类建筑蛋白质，并建议 通过核孔结合对增强子启动器环的稳定构成了一种机制 表观遗传维护。我们预测核孔的这一功能将非常相关 在后生动物发育过程中调节基因调节。能够研究基因组 NUPS在发育基因调控中的作用，我们首先计划鉴定分子 NUP介导的增强器促销循环的决定因素。因此，在AIM 1中，我们将定义哪个 NUPS和其他建筑蛋白参与ecdysone-的建立 诱导的基因组环。此外，我们计划识别足够的DNA元素 将循环稳定所必需的NPC系系在一起。在AIM 2中，我们建议定义 NUP介导的增强器启动器循环的形成与转录之间的关系 激活和记忆，通过识别作为特定结果发生的染色质变化 循环。此外，我们将研究NUPS对基因组循环维持的影响 在开发过程中飞行组织，并确定一组全面的基因组接触 由NUPS监管。共同期望这些实验会扩大我们对 基因组结构，基因表达和核孔生物学的驱动力和原理。