Characterization of DUX4-induced histone H3 variants

DUX4 诱导的组蛋白 H3 变体的表征

• 批准号: 9397378
• 负责人: Rebecca May Resnick
• 金额: $ 3.95万
• 依托单位: FRED HUTCHINSON CANCER RESEARCH CENTER
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-16 至 2018-12-15
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9397378
• 关键词: ATAC-seq; Address; Affect; Amino Acids; Animals; Apoptosis; Binding; Biological Assay; Biological Markers; Cancer cell line; Cell Cycle; Cells; ChIP-seq; Chromatin; Chromatin Structure; DNA; DNA Binding; Data Set; Development; Disease; Facioscapulohumeral Muscular Dystrophy; Family; Gene Activation; Gene Expression; Gene Targeting; Genes; Genetic; Genetic Transcription; Genome; Germ Cells; Goals; Heterochromatin; Histone H3; Histones; Homeobox; Human; Human Development; In Vitro; Kinetics; Knowledge; Lead; Malignant Neoplasms; Mediating; Memory; Modification; Molecular Conformation; Muscle; Muscle Fibers; Myoblasts; Nucleosomes; Pathology; Physiologic pulse; Play; Population; Primates; Process; Progressive Disease; Property; Repression; Retroelements; Role; Site; Testing; Testis; Testis Brain; Time; Tissues; Toxic effect; Transcriptional Regulation; Variant; Work; bisulfite sequencing; blastocyst; epigenetic memory; genome-wide; genome-wide analysis; in vivo; induced pluripotent stem cell; knock-down; neoplastic cell; new therapeutic target; novel; novel therapeutics; permissiveness; prevent; programs; targeted treatment; therapeutic biomarker; transcription factor; transcriptome; transcriptome sequencing

PROJECT SUMMARY Histones play a major role in the regulation of transcription across the animal kingdom, and different variants play important roles in a variety of specific tissues and processes. Two recently-described histones, H3.X and H3.Y, are primate-specific and are expressed in human testis and brain, as well as some tumors and cancer cell lines. My preliminary studies have identified these genes as targets of DUX4, a double-homeobox transcription factor that is normally expressed in the germ cells of the testis. When mis-expressed in muscle, DUX4 causes facioscapulohumeral muscular dystrophy (FSHD), a progressive disease for which there are no treatments, and may drive some cancers. Expression of DUX4 drastically alters transcription and leads to de- repression of many genes and sequences throughout the genome that are normally repressed in heterochromatin. H3.X/Y have been validated as histones and shown to facilitate a more open chromatin conformation than H3.3 in vitro, but their in vivo effects in FSHD are as yet unknown. Aim 1 will identify genes that go from off to on and inaccessible chromatin to an open chromatin state with expression of DUX4. It will then determine whether H3.X/Y are preferentially incorporated at these loci as well as examining their effects on expression. This will determine the genome-wide incorporation of H3.X/Y in FSHD and effects on expression of DUX4 targets. Aim 2 will determine the role of H3.X/Y in epigenetic memory of the DUX4 transcriptome. It will extend preliminary studies suggesting that H3.X/Y increase the perdurance of DUX4 target expression as well as examine the effects over time of H3.X/Y on chromatin structure and features of heterochromatin. Additionally, this aim will examine the relationship between cumulative DUX4 toxicity, H3.X/Y, and cell cycle, as mature muscle is postmitotic. Epigenetic memory mediated through histone variants could explain why FSHD pathology is typically restricted to muscle and suggest a mechanism to target for therapy. Additionally, the datasets will be independently useful to determine chromatin changes induced by DUX4 that can be applied to the study of FSHD. This proposal will test the hypotheses that H3.X/Y are incorporated into and facilitate expression of genes transcriptionally activated by DUX4 that are normally repressed by heterochromatin, and provide an epigenetic memory of the DUX4 transcriptional program.

项目摘要 组蛋白在动物界的转录调控中起着重要作用， 在多种特定组织和过程中发挥重要作用。两个最近描述的组蛋白，H3.X和 H3.Y是灵长类动物特异性的，在人类睾丸和脑以及一些肿瘤和癌症中表达 细胞系我的初步研究已经确定这些基因是DUX 4的靶基因，DUX 4是一种双同源异型框 通常在睾丸生殖细胞中表达的转录因子。当在肌肉中错误表达时， DUX 4导致面肩肱型肌营养不良症（FSHD），这是一种进行性疾病， 治疗，并可能导致某些癌症。DUX 4的表达显著改变了转录，并导致了 在整个基因组中，许多基因和序列的阻遏通常在 异染色质H3.X/Y已被证实为组蛋白，并显示出促进更开放的染色质 在体外，它们的构象比H3.3更好，但它们在FSHD中的体内作用尚不清楚。目标1将确定基因 从关闭到打开，从不可接近的染色质到开放的染色质状态，并表达DUX 4。它将 然后确定H3.X/Y是否优先掺入这些基因座以及检查它们的作用 在表情上。这将确定FSHD中H3.X/Y的全基因组掺入以及对FSHD的影响。 DUX 4靶点的表达。目的2将确定H3.X/Y在DUX 4的表观遗传记忆中的作用 转录组它将扩展初步研究表明H3.X/Y增加DUX 4的持久性 靶向表达，并检查H3.X/Y随时间对染色质结构和特征的影响。 异染色质此外，该目的将检查累积DUX 4毒性、H3.X/Y、 和细胞周期，因为成熟肌肉是有丝分裂后的。通过组蛋白变体介导的表观遗传记忆可以 解释为什么FSHD病理学通常仅限于肌肉，并提出一种靶向治疗的机制。 此外，数据集将独立地用于确定由DUX 4诱导的染色质变化， 可应用于FSHD的研究。本提案将检验H3.X/Y被纳入的假设 进入并促进由DUX 4转录激活的基因的表达，这些基因通常被抑制 通过异染色质，并提供DUX 4转录程序的表观遗传记忆。