权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Repression via Facultative Heterochomatin

通过兼性异染色质抑制

基本信息

批准号：
8964481
负责人：
DANNY REINBERG
金额：
$ 36.23万
依托单位：
NEW YORK UNIVERSITY SCHOOL OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2002
资助国家：
美国
起止时间：
2002-01-01 至 2020-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8964481
关键词：
Affect Applied Genetics Binding Binding Sites Biochemical Biology CCCTC-binding factor Cardiac Myocytes Catalysis Catalytic Domain Cell Differentiation process Cell division Cells ChIP-seq Chemicals Chromatin Chromatin Loop Chromatin Structure Clustered Regularly Interspaced Short Palindromic Repeats Complex DNA Deposition Development Disease Dominant-Negative Mutation EZH2 gene Environment Epigenetic Process Exhibits Foundations Funding Gene Cluster Gene Expression Gene Expression Profile Gene Expression Regulation Genes Genetic Genetic Screening Genetic Transcription Genome Genomic Instability Genomic approach Genomics Goals HDAC2 gene Heterochromatin Histone H2A Histone H3 Histones Homeobox Genes In Vitro Insulator Elements Investigation Lysine Maintenance Malignant Neoplasms Mammalian Cell Mediating Methylation Modification Molecular Molecular Profiling Monoubiquitination Motor Neurons Mus Mutation Neurons Organism Outcome Output PRC1 Protein Phosphorylation Physiological Polycomb Positron-Emission Tomography Post-Translational Protein Processing Process Proteins RNA RNA Binding Recruitment Activity Regulation Regulatory Pathway Repression Role Specificity Staging Structure Subgroup Technology Tissues Transcription Coactivator Untranslated RNA base cell type gene repression genetic information genetic selection genome-wide in vivo insight mouse model mutant neuron development novel prevent programs public health relevance

项目摘要

DESCRIPTION (provided by applicant): The intricate programs of mammalian cell differentiation ultimately target chromatin, formulating chromatin environments accessible to or deflective of the transcriptional machinery and thus conducive to distinct gene expression profiles. How these chromatin structures are first established to set the transcription program and how these established structures are then re-instated on newly replicated DNA during cell division is the crux of epigenetics. Based on preliminary findings obtained during the previous funding period, we will comprehensively explore two major modulators of epigenetic information that we have investigated extensively: PRC1 and PRC2, and a third potential epigenetic modulator, CTCF. We will continue our investigation of the molecular basis of their specificity in targeting discrete regions of the genome, the dynamics controlling their activity, and how their activities convey appropriate transcription outputs. Two mammalian complexes that comprise Polycomb Group proteins, PRC1 and PRC2 are recognized epigenetic conveyers of transcriptional repression. PRC1 transmits repression through catalysis of monoubiquitination of histone H2A at lysine 119 and chromatin compaction. Through our extensive biochemical analyses, we demonstrated that PRC1 embodies discrete yet heterogenous complexes. In aim 1, we expand on our preliminary results showing that the distinguishing proteins for some of the PRC1 subgroups either convert PRC1 into a transcriptional activator, as in the case of the neuronal-specific protein, AUTS2, or exhibit cell-type specificity and a possible novel repressive mechanism as in the case of FBRSL1 in cardiomyocytes, or modulate PRC1 recruitment to chromatin as in the case of motor neuron enriched YAF1. The underlying mechanistic basis and the outcome to specific gene expression will be studied using biochemical and genomic approaches, respectively and with mouse models in the case of AUTS2 and FBRSL1. In aim 2, we continue our extensive analyses of PRC2 that catalyses methylation of histone H3 at lysine 27, a modification of repressive chromatin. We explore parameters regulating PRC2 activity including post-translational modifications of its catalytic subunit Ezh2, and the negative effects of naturally occurring, dominant negative histone mutants using biochemical analyses and CRISPR technology. With the foundation of our studies of interactions of long noncoding RNA with both Ezh2 and the PRC2 associated protein Jarid2, we expand into the role of these interactions in mediating specificity in PRC2 recruitment to chromatin. In aim 3, we pursue our preliminary results of RNA-mediated CTCF multimerization and its possible role in CTCF- mediated regulation of chromatin boundaries within the HOX gene cluster using ChIP-seq, sequence capture Hi-C and ChIA-PET technologies.

描述（由申请人提供）：哺乳动物细胞分化的复杂程序最终靶向染色质，形成可接近或偏离转录机制的染色质环境，从而有助于不同的基因表达谱。这些染色质结构如何首先建立以设置转录程序，以及这些已建立的结构如何在细胞分裂期间重新建立在新复制的DNA上，这是表观遗传学的关键。基于上一个资助期获得的初步研究结果，我们将全面探索我们广泛研究的表观遗传信息的两个主要调节剂：PRC 1和PRC 2，以及第三个潜在的表观遗传调节剂CTCF。我们将继续研究它们在靶向基因组离散区域的特异性的分子基础，控制它们活性的动力学，以及它们的活性如何传递适当的转录输出。两个哺乳动物复合物，包括Polycomb组蛋白，PRC 1和PRC 2是公认的转录抑制的表观遗传学标记。PRC 1通过催化组蛋白H2 A在赖氨酸119处的单泛素化和染色质致密化来传递阻遏。通过我们广泛的生化分析，我们证明了PRC 1体现离散而异质的复合物。在目标1中，我们扩展了我们的初步结果，表明PRC 1亚组的一些区别蛋白质要么将PRC 1转化为转录激活因子，如神经元特异性蛋白AUTS 2的情况，要么表现出细胞类型特异性和可能的新抑制机制，如心肌细胞中FBRSL 1的情况，或调节PRC 1向染色质的募集，如在运动神经元富集的YAF 1的情况下。潜在的机制基础和特定基因表达的结果将分别使用生物化学和基因组方法以及AUTS 2和FBRSL 1的小鼠模型进行研究。在目标2中，我们继续对PRC 2进行广泛的分析，PRC 2催化组蛋白H3在赖氨酸27处的甲基化，这是一种抑制性染色质的修饰。我们探索调节PRC 2活性的参数，包括其催化亚基Ezh 2的翻译后修饰，以及使用生化分析和CRISPR技术的天然存在的显性负性组蛋白突变体的负面影响。在我们研究长非编码RNA与Ezh 2和PRC 2相关蛋白Jarid 2相互作用的基础上，我们扩展到这些相互作用在介导PRC 2招募染色质的特异性中的作用。在目标3中，我们使用ChIP-seq、序列捕获Hi-C和ChIA-PET技术，追求RNA介导的CTCF多聚化及其在CTCF介导的HOX基因簇内染色质边界调节中的可能作用的初步结果。