Function of active chromatin domains in erythropoiesis

活性染色质结构域在红细胞生成中的功能

• 批准号: 8034237
• 负责人: MICHAEL D BULGER
• 金额: $ 30.32万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-01-15 至 2011-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8034237
• 关键词: Acetylation; Address; Adult; Antigens; Binding; Cell Differentiation process; Cell Line; Cells; Chromatin; Chromatin Structure; Chromosomes, Human, Pair 11; Clinical; DNA; DNA Sequence; Disease; Distal; Distal Enhancer Elements; ES Cell Line; Embryo; Enhancers; Environment; Erythrocytes; Erythroid; Erythroid Cells; Erythropoiesis; Exhibits; Gene Activation; Gene Expression; Gene Expression Regulation; Genes; Globin; Glycophorin A; Histones; Human; Human Chromosomes; In Vitro; Malignant Neoplasms; Mediating; Methodology; Methods; Mus; Nature; Nuclear; Pattern; Play; Processed Genes; Public Health; Regulatory Element; Relaxation; Research; Role; Site; Surveys; System; Testing; Tissue-Specific Gene Expression; Tissues; Trans-Activators; cell type; design; embryonic stem cell; gene repression; gene therapy; histone modification; homologous recombination; interest; novel; progenitor; promoter; therapeutic gene; transcription factor; transgene expression

DESCRIPTION (provided by applicant): Terminal differentiation of erythroid cells is associated with generalized heterochromatinization and gene repression, reflected in decreased nuclear size and visibly more compact chromatin structure as red cells mature prior to enucleation. In the midst of this repressive environment, however, high-level expression of a select group of genes - especially the ?- and ?-globins - must be established and maintained. The mechanisms by which this is accomplished represent a basic question with implications both for studies of tissue-specific gene regulation and for clinical gene therapies, in which transgene expression must similarly be maintained in differentiating cells. Abundant evidence has been presented to establish the role of covalent histone modifications, such as acetylation, in the process of gene activation. For the most part, histone hyperacetylation is confined to promoter-proximal regions, where it presumably contributes to chromatin decondensation, relaxation of histone-DNA interactions, and stabilization of transcription factor interactions. At certain genes, however, histone hyperacetylation extends across much broader regions. In erythroid cells, the ?- and ?-globin loci exhibit such "domains" of hyperacetylation, and we have characterized several additional erythroid-specific gene loci that have them as well. Our results, along with studies of other gene loci, suggest that such domains are a crucial feature of their activation, and that they reflect the activity of distal enhancer elements required for high-level expression. As yet, however, the mechanisms by which such domains are formed, and the precise role they play in gene expression during terminal differentiation, are unknown. We propose to characterize cis-acting DNA sequences required for domain formation at the p-globin and other loci in erythroid cells, and eventually to identify the trans-acting factors that bind to these sequences and mediate domain formation. In this way, we will establish systems that can be used to elucidate the formation and function of hyperacetylated domains. Public Health Statement: This research, while highly basic in nature, is designed to elucidate mechanisms that underlie gene expression during terminal cellular differentiation. As such, it has relevance to disorders in which tissue-specific gene expression is disrupted - which include a number of cancers - as well as gene therapy approaches involving stable transgene expression in specific cell types.

描述（由申请人提供）：红细胞细胞的末端分化与普遍的异染色性和基因抑制有关，反映在核大小的降低中，明显更紧凑的染色质结构是在唤醒之前成熟的红细胞。然而，在这种抑制性环境中，必须建立和维护一组基因（尤其是？ - globins）的高级表达。实现这一目标的机制代表了一个基本问题，对组织特异性基因调节和临床基因疗法的研究既有意义，在该基因疗法中，必须类似地将转基因表达保持在分化细胞中。已经提供了大量证据，以确定基因激活过程中共价组蛋白修饰（例如乙酰化）的作用。在大多数情况下，组蛋白高乙酰化局限于启动子 - 二乙基区域，大概有助于染色质降解，组蛋白-DNA相互作用的松弛以及转录因子相互作用的稳定化。然而，在某些基因上，组蛋白高乙酰化在更广泛的区域延伸。在红细胞细胞中，？ - 和？ - 格珠蛋白基因座表现出高乙酰化的这种“结构域”，我们表征了几个其他具有它们的红系特异性基因基因座。我们的结果以及对其他基因基因座的研究表明，这种结构域是它们激活的关键特征，并且反映了高级表达所需的远端增强子元素的活性。然而，迄今为止，形成此类域的机制以及它们在终末分化过程中基因表达中起的确切作用尚不清楚。我们建议表征在红色细胞中域和其他基因座的域形成所需的顺式作用DNA序列，并最终确定与这些序列结合并介导域形成的反式作用因子。这样，我们将建立可用于阐明高乙酰化结构域的形成和功能的系统。公共卫生声明：这项研究虽然本质上是高基本的，但旨在阐明终末细胞分化过程中基因表达的机制。因此，它与组织特异性基因表达受到破坏的疾病有关 - 包括许多癌症 - 以及涉及特定细胞类型中稳定转基因表达的基因治疗方法。