Comprehensive Characterization of Heterochromatin Domains

项目摘要/摘要 异染色质是一种在所有真核生物中起作用的基因组结构，它决定细胞的特性并维持 通过沉默基因来保持基因组的稳定性。异染色质组装的要求被合并到 具有组蛋白修饰活性的抑制基因沉默蛋白复合体的染色质 表情。这一一般机制在所有真核生物中都是保守的，尽管有多种不同的 异色结构域存在，甚至在同一生物体内也是如此。关于这些因素，我们知道得很多。 与异染色质有关，但具体途径中的许多关键事件却知之甚少。一项挑战 研究异染色质的一个事实是，在体内对中央成分的操纵通常会影响多个 细胞中异染色质或其他相关途径的类型。该项目的目标将解决这一问题 问题主要有三个方面：一是利用体外重组的功能异染色质系统来更好地 了解隔离环境中异色沉默的机制。其次，使用前置 组装异染色质结构域以识别细胞内有助于异染色质的新因素 编队和维护。第三，通过建立制度来解决特定非编码的贡献 异染色质启动和维持的RNA元件。 异染色质酵母模型的初步研究将为该领域的研究做出重要贡献 染色质生物学，也将作为人体系统后续研究的模型 在过渡到独立调查员之后。该项目的主要目标是全面 确定异染色质结构域的特征，以便比较基因的中心保守特征 沉默和基因组稳定。人类异色结构域的多样性是显而易见的，但总体上 支配这些结构域组装的原理与萌芽和分裂酵母中的原理非常相似 模特们。这些基本的相似性使得将酵母菌的研究结果与人类进行比较以及 使用在更简单的酵母模型中开发的方法作为研究人类的指南 异染色质。这一主题是这项提议的基础，也是我过渡到 独立。

PROJECT SUMMARY/ABSTRACT Heterochromatin is a genomic structure that functions in all eukaryotes to determine cell identity and maintain genome stability by silencing genes. The requirements for heterochromatin assembly are incorporation into chromatin of silencing protein complexes with histone modification activity that lead to repressed gene expression. This general mechanism is conserved in all eukaryotes, though multiple varieties of heterochromatic domains exist, even within the same organism. Much is known about the factors that contribute to heterochromatin, yet many key events in specific pathways are poorly understood. One challenge in studying heterochromatin is the fact that manipulation of the central components in vivo often affects multiple types of heterochromatin or other related pathways in the cell. The aims of this project will address this problem in three ways: firstly, by using a functional in vitro reconstituted heterochromatin system to better understand the mechanism of heterochromatic silencing in an isolated environment. Secondly, using a pre- assembled heterochromatin domain to identify new factors within the cell that contribute to heterochromatin formation and maintenance. Third, by establishing a system to address the contribution of specific non-coding RNA elements to initiation and maintenance of heterochromatin. Initial studies in yeast models of heterochromatin will make important contributions to the field of chromatin biology and will also serve as a model for subsequent studies in the human system to be carried out after the transition to independent investigator. The primary goal of the project is to comprehensively characterize heterochromatin domains in order to compare conserved features that are central to gene silencing and genome stability. The diversity of human heterochromatic domains is evident, yet the general principles that govern assembly of these domains remain quite similar to those in the budding and fission yeast models. These basic similarities make it feasible to compare results of yeast studies to humans and also to use the approaches that have been developed in the simpler yeast models as a guide to study human heterochromatin. This theme is the foundation of this proposal and the direction I will take as I transition to independence.