Understanding the Role of Histone Demethylases and Heterochromatin in Cell Cycle

了解组蛋白去甲基酶和异染色质在细胞周期中的作用

基本信息

批准号：
8415931
负责人：
Johnathan R. Whetstine
金额：
$ 31.9万
依托单位：
MASSACHUSETTS GENERAL HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-02-01 至 2016-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8415931
关键词：
Accounting Address Affect Applications Grants Binding Binding Proteins Biochemical Biological Assay Biological Process Bromodeoxyuridine Cell Cycle Cell Cycle Progression Cell Nucleus Cells ChIP-seq Chromatin Chromatin Structure Clinical Complex Coupling Cullin Proteins DNA DNA Replication Timing DNA biosynthesis Data Defect Development Diagnostic Disease Ensure Environment Enzymes Euchromatin Event Family member Fiber G1 Phase Genetic Transcription Genome Genome Stability Genomic Instability Genomics Goals Grant Heterochromatin Histones Human Human Cell Line Link Lysine Maintenance Malignant Neoplasms Mass Spectrum Analysis Mediating Methylation Molecular Outcome Phenotype Play Post-Translational Protein Processing Proteins Proteomics Regulation Role S Phase Site Structure Therapeutic Therapeutic Intervention Time Ubiquitin Ubiquitination abstracting age related base cancer risk cancer therapy chromosome replication in vivo insight novel novel therapeutics origin recognition complex overexpression public health relevance tool tumor tumorigenesis ubiquitin ligase

项目摘要

DESCRIPTION (provided by applicant): Abstract. Genomic instability is a major contributing factor to the development and onset of age-related diseases such as cancer. Aberrant regulation of the spatial-temporal timing of DNA replication is a critical factor involved in genomic instability and increased cancer risk. Chromatin structure plays a fundamental role in coordinating the timing of DNA replication during G1 and S phases of cell cycle. Chromatin is a highly ordered structure that contains DNA, histones, and other chromosomal proteins. Posttranslational modifications of histones influence the outcomes of numerous biological processes including transcription, replication, and chromosome maintenance. Histone 3 lysine 9 tri-methylation (H3K9me3) is considered a hallmark of heterochromatin, a repressive structure found at repetitive and telomeric regions in the genome. Alterations in H3K9me3 and heterochromatin levels result in aberrant replication timing and the onset of genomic instability and cancer. Understanding how the dynamics of methylation and heterochromatin formation and maintenance are regulated throughout cell cycle is critical for uncovering both basic principals governing replication timing, but most importantly, identifying regulatory factors that could contribute to replication timing defects and genomic instability observed in cancer. We have recently identified the JMJD2A H3K9/36 tri-demethylase as a regulator of chromatin accessibility, heterochromatin (HP13), DNA replication timing and S phase progression. We also demonstrated that JMJD2A levels and localization are regulated over cell cycle by ubiquitination, which directly impacts the role of JMJD2A in S phase progression. These data are exciting since regulating ubiquitination has emerged as a therapeutic strategy in cancer treatment. We hypothesize that HP13 and the ubiquitination of JMJD2A regulate the targeting of specific genomic regions so that orderly cell cycle progression occurs. This grant proposal will determine the impact ubiquitination has on JMJD2A cell cycle function (Aim 1) and determine how JMJD2A alters chromatin structure so that DNA replication timing is properly spatially and temporally regulated (Aim 2). In aim 1, we will use proteomic and biochemical approaches to determine the sites/regions that are modified within JMJD2A, the enzymes involved in adding and removing the ubiquitin, and their impact on JMD2A- dependent S phase progression. In aim 2, we will use genomics to determine the regions regulated by both JMJD2A and heterochromatin throughout cell cycle as well as determine the impact JMJD2A has on replication timing (i.e., initiation and/or elongation). These studies will significantly impact our basic understanding of S phase progression and clinical understanding of JMJD2A overexpressing tumors.

描述（由申请人提供）：抽象的。基因组不稳定性是导致与年龄相关疾病（如癌症）发育和发作的主要因素。对DNA复制的空间时机的异常调节是基因组不稳定性和癌症风险增加的关键因素。染色质结构在协调G1和细胞周期中S相的DNA复制时间方面起着基本作用。染色质是一种高度有序的结构，其中包含DNA，组蛋白和其他染色体蛋白。组蛋白的翻译后修饰会影响许多生物学过程的结果，包括转录，复制和染色体维持。组蛋白3赖氨酸9三甲基化（H3K9me3）被认为是异染色质的标志，这是一种在基因组重复和端粒区域发现的抑制性结构。 H3K9me3和异染色质水平的改变会导致复制时机异常以及基因组不稳定性和癌症的发作。了解在整个细胞周期中如何调节甲基化和异染色质形成和维持的动力学对于揭示两个控制复制时间的基本原理至关重要，但最重要的是，确定可能有助于复制时间缺陷和基因组不稳定性的调节因素。我们最近确定了JMJD2A H3K9/36三甲基酶是染色质访问性，异染色质（HP13），DNA复制时机和S相进展的调节剂。我们还证明了JMJD2A水平和定位通过泛素化在细胞周期中受到调节，这直接影响JMJD2A在S相进展中的作用。这些数据令人兴奋，因为调节泛素化已成为癌症治疗中的一种治疗策略。我们假设HP13和JMJD2A的泛素化调节了特定基因组区域的靶向，以便有序的细胞周期进程发生。该赠款提案将确定泛素化对JMJD2A细胞周期函数的影响（AIM 1），并确定JMJD2A如何改变染色质结构，从而在空间和时间上适当地调节DNA复制时间（AIM 2）。在AIM 1中，我们将使用蛋白质组学和生化方法来确定在JMJD2A中修改的位点/区域，添加和去除泛素及其对JMD2A-依赖性S相进展的影响。在AIM 2中，我们将使用基因组学来确定在整个细胞周期中由JMJD2A和异染色质调节的区域，并确定JMJD2A对复制时间的影响（即启动和/或延长）。这些研究将显着影响我们对S相进展的基本理解和对JMJD2A过表达肿瘤的临床理解。