OSTEOBLAST CHROMATIN STRUCTURE AND NUCLEAR DOMAINS

这个项目的目标是了解如何染色质组织和 核划分有助于并支持对核武器的管制， 成骨细胞相关基因表达。转录因子和蛋白质- DNA相互作用在细胞和组织中显然起着重要作用- 特异性基因调控然而，这种基因调控相互作用 发生在DNA中，包装成染色质并进一步组织 在细胞核内。 我们感兴趣的是了解染色质 包装会影响基因表达的能力， 元件和结合因子介导骨组织特异性染色质 结构/组织。 我们还将讨论核武器的作用， 成骨细胞表达基因的位置和空间组织， 骨细胞和非骨细胞。 我们假设， 染色质结构和核组织伴随并介导 基因表达的变化。具体目标是：（1）确定 调节骨组织染色质结构的调节参数- 成骨细胞中的特异性基因。 序列特异性基因调控 元素，核小体定位和组蛋白乙酰化将是 操纵和对染色质结构和表达的影响将是 在稳定的细胞系中评价。 (2)分析生化和 分子机制，改变染色质结构的细胞， 骨钙素基因启动子 我们将通过使用 一种体外无细胞系统，用于监测染色质的变化 由组织特异性转录相互作用产生结构 因子、激素受体和SWI/SNF与DNA的复合物， 核小体环境 (3)检查的空间关系 成骨细胞表达基因的核内区室化， 成骨细胞，与非骨细胞相比。 我们将分析 骨和肌肉染色质的分布，相对于Sc-35结构域 在诱导细胞从肌源性转变为成骨性的细胞中， 发展计划。 这些研究将有助于理解 核结构的一个关键组成部分的监管， 在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.