Histone demethylases and regulation of chromatin and transcription in eukaryotes

真核生物中组蛋白去甲基化酶以及染色质和转录的调节

基本信息

批准号：
8460446
负责人：
Yang Shi
金额：
$ 28.19万
依托单位：
BOSTON CHILDREN'S HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2006
资助国家：
美国
起止时间：
2006-07-13 至 2016-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8460446
关键词：
Acetylation Address Affect Biochemical Biological Biological Assay Cell Cycle Arrest Cell Death Cells Chromatin Complex Coupled DNA Damage DNA Double Strand Break DNA Repair DNA biosynthesis Defect Development Double Strand Break Repair Enzymes Epigenetic Process Eukaryota Event Funding Genetic Transcription Genome Stability Health Histone H2A Histones In Vitro Investigation Lead Light Malignant Neoplasms Mass Spectrum Analysis Mediating Methylation Methyltransferase Modeling Modification Molecular Mono-S N-terminal Nuclear Nucleosomes Oncogenic Pathway interactions Phenocopy Phosphorylation Play Process Proteins RNA Interference Recruitment Activity Regulation Role Signal Transduction Site Tail Testing Transcriptional Regulation Work base chromatin immunoprecipitation cofactor demethylation gene repair histone modification improved insight novel protein protein interaction recombinational repair repaired research study response

项目摘要

DESCRIPTION (provided by applicant): The N-terminal tails of histone proteins are heavily decorated by a plethora of covalent modifications including methylation, acetylation, phosphorylation, sumoylation and ubiquitylation. These modifications work together to generate appropriate chromatin templates for a host of important nuclear events, including transcription, DNA replication, recombination and repair. A defect in the DNA damage signaling and repair machinery can lead to the development of cancer, and therefore understanding the mechanisms that control this pathway has important health implications. In recent years, although significant progress has been made in our understanding of histone modifications in transcriptional regulation, much less is known about how these modifications impact the DNA damage response (DDR) and the precise molecular mechanisms by which histone- modifying enzymes regulate the DDR pathway. In the past funding period, we discovered that the histone demethylase LSD1, which thus far is thought to function only as a transcriptional regulator, also plays an evolutionarily conserved role in the DDR. Loss of LSD1 does not affect the expression of repair genes; furthermore, chromatin immunoprecipitation places LSD1 at DNA damage sites, suggesting a direct involvement of LSD1 in this process. Importantly, loss of LSD1 results in impaired histone H2A/H2A.X ubiquitylation, with subsequent loss of 53BP1 recruitment, a molecule important for DNA damage repair. In this application, we propose to test our hypothesis that a novel crosstalk exists between histone H3K4 demethylation and H2A/H2A.X ubiquitylation important for the DDR by identifying molecular mechanisms by which LSD1 regulates histone H2A/H2A.X ubiquitylation. Given that LSD1 mediates demethylation of mono- and di-methylated histone H3K4, we will also investigate whether H3K4 methylation dynamics is generally important for the DDR by determining whether demethylases for the tri-methylated H3K4 as well as a host of H3K4 methyltransferases also play a role in the DDR. Lastly we will begin to address the question of whether there is a specific constellation of histone modifications at DNA damage sites that induce a distinct chromatin domain for DNA repair, by delineating the histone modification landscape and the responsible enzymes at DNA damage sites. We anticipate that new paradigms to emerge from the proposed studies, significantly impacting our understanding of epigenetic regulation in the DDR.

描述（由申请人提供）：组蛋白的 N 末端尾部经过大量共价修饰，包括甲基化、乙酰化、磷酸化、苏酰化和泛素化。这些修饰共同作用，为一系列重要的核事件（包括转录、DNA 复制、重组和修复）生成适当的染色质模板。 DNA 损伤信号传导和修复机制的缺陷可能导致癌症的发生，因此了解控制该途径的机制具有重要的健康意义。近年来，尽管我们对转录调控中组蛋白修饰的理解取得了重大进展，但对于这些修饰如何影响 DNA 损伤反应 (DDR) 以及组蛋白修饰酶调节 DDR 的精确分子机制知之甚少。途径。在过去的资助期间，我们发现组蛋白去甲基化酶LSD1（迄今为止被认为仅作为转录调节因子）也在DDR中发挥着进化上保守的作用。 LSD1的缺失并不影响修复基因的表达；此外，染色质免疫沉淀将 LSD1 置于 DNA 损伤位点，表明 LSD1 直接参与了这一过程。重要的是，LSD1 的缺失会导致组蛋白 H2A/H2A.X 泛素化受损，随后 53BP1 募集（一种对 DNA 损伤修复很重要的分子）的缺失。在本申请中，我们建议通过确定 LSD1 调节组蛋白 H2A/H2A.X 泛素化的分子机制来检验我们的假设，即组蛋白 H3K4 去甲基化和 H2A/H2A.X 泛素化之间存在一种新的串扰，这对 DDR 很重要。鉴于 LSD1 介导单甲基化和二甲基化组蛋白 H3K4 的去甲基化，我们还将通过确定三甲基化 H3K4 的去甲基化酶以及许多 H3K4 甲基转移酶是否也发挥重要作用，研究 H3K4 甲基化动态对于 DDR 是否普遍重要。在DDR中的作用。最后，我们将通过描述 DNA 损伤位点的组蛋白修饰景观和负责的酶来开始解决 DNA 损伤位点是否存在一组特定的组蛋白修饰，从而诱导用于 DNA 修复的独特染色质结构域的问题。我们预计拟议研究中会出现新的范式，从而显着影响我们对 DDR 表观遗传调控的理解。