OSTEOBLAST CHROMATIN STRUCTURE AND NUCLEAR DOMAINS

这个项目的目标是了解染色质的组织和 核区划有助于并支持对 成骨细胞相关基因表达。转录因子和蛋白质- DNA相互作用显然在细胞和组织中发挥着重要作用- 特定的基因调控。然而，这种基因调控的相互作用 发生在被包装为染色质并进一步组织的DNA中 在原子核内。我们有兴趣了解染色质是如何 包装影响基因的表达能力和序列 元素和结合因子介导骨组织特异性染色质 结构/组织。我们还将讨论核能的作用 成骨细胞表达基因的定位和空间组织 骨性和非骨性细胞。我们假设， 染色质结构和核组织伴随和调节 基因表达的变化。我们的具体目标是：(1)确定 调节骨组织染色质结构的调节参数- 成骨细胞中的特异基因。序列特异性基因调控 元素、核小体定位和组蛋白乙酰化 对染色质结构和表达的影响 在稳定的细胞系中进行评估。(2)生化和生化分析 改变细胞染色质结构的分子机制 骨钙素基因启动子。我们将使用以下方法来解决这些机制 一种用于监测染色质变化的体外无细胞系统 由组织特异性转录相互作用产生的结构 因子、激素受体和SWI/SNF与DNA的复合体 核小体背景。(三)审视城市空间关系 成骨细胞表达核内区划的基因 成骨细胞，与非骨细胞相比。我们将分析 骨骼和肌肉染色质相对于SC-35结构域的分布 在诱导细胞从肌源性向成骨性转换中 发展规划。这些研究将有助于理解 监管支持核架构的一个关键组件 成骨细胞分化过程中的转录。

The goal of this project is to understand how chromatin organization and nuclear compartmentalization contribute to and support regulation of osteoblast-related gene expression. Transcription factors and protein- DNA interactions clearly play an important role in cell and tissue- specific gene regulation. However, such gene-regulatory interactions occur within DNA that is packaged as chromatin and further organized within the nucleus. We are interested in understanding how chromatin packaging affects the ability of a gene to be expressed and how sequence elements and binding factors mediate bone tissue-specific chromatin structure/organization. We will also address the role of nuclear location and spatial organization of osteoblast-expressed genes in osseous and non-osseous cells. We hypothesize that alterations in chromatin structure and nuclear organization accompany and mediate changes in gene expression. Our specific aims are: (1) To determine regulatory parameters that mediate chromatin structure of a bone tissue- specific gene in osteoblastic cells. Sequence-specific gene regulatory elements, nucleosome positioning, and histone acetylation will be manipulated and effects on chromatin structure and expression will be evaluated in stable cell lines. (2) To analyze biochemical and molecular mechanisms that alter the chromatin structure of the osteocalcin gene promoter. We will address these mechanisms by using an in vitro, cell-free system to monitor alterations in chromatin structure that result from interactions of tissue-specific transcription factors, hormone receptors, and the SWI/SNF complex with DNA in a nucleosomal context. (3) To examine the spatial relationship of osteoblast expressed genes to intra-nuclear compartmentalization in osteogenic cells, contrasted with non-osseous cells. We will analyze the distribution of bone and muscle chromatin, relative to Sc-35 domains in cells induced to switch from a myogenic to an osteogenic developmental program. These studies will contribute to understanding regulation of a key component of nuclear architecture that supports transcription during osteoblast differentiation.