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: 7785719
• 负责人: MICHAEL D BULGER
• 金额: $ 0.15万
• 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/7785719
• 关键词: Acetylation; Address; Adult; Antigens; Binding; Cell Differentiation process; Cell Line; Cells; Chromatin; Chromatin Structure; Chromosomes, Human, Pair 11; Clinical; 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（由申请方提供）：红系细胞的终末分化与全身异染色质化和基因抑制相关，反映在核尺寸减小和明显更紧凑的染色质结构，因为红细胞在去核前成熟。然而，在这种压抑的环境中，一组选定的基因的高水平表达--尤其是？然后呢？球蛋白-必须建立和维持。实现这一点的机制代表了一个基本问题，其对组织特异性基因调控的研究和临床基因治疗都有影响，其中转基因表达必须类似地在分化细胞中维持。大量的证据表明，组蛋白的共价修饰，如乙酰化，在基因激活过程中的作用。在大多数情况下，组蛋白超乙酰化仅限于启动子近端区域，在那里它可能有助于染色质解凝聚，组蛋白-DNA相互作用的松弛和转录因子相互作用的稳定。然而，在某些基因中，组蛋白超乙酰化延伸到更广泛的区域。在红系细胞中，然后呢？珠蛋白基因座表现出这种超乙酰化的“结构域”，我们已经鉴定了几个另外的红细胞特异性基因座也具有这种结构域。我们的研究结果，沿着其他基因位点的研究，表明这些结构域是其激活的一个重要特征，它们反映了高水平表达所需的远端增强子元件的活性。然而，到目前为止，这些结构域形成的机制，以及它们在终末分化过程中在基因表达中所起的确切作用，都是未知的。我们建议的特点，顺式作用的DNA序列所需的结构域形成的p-珠蛋白和红细胞中的其他位点，并最终确定的反式作用因子结合到这些序列和介导的结构域形成。通过这种方式，我们将建立可用于阐明超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，虽然在性质上是高度基本的，旨在阐明在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被破坏的疾病（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相关。