Regulation and Function of Histone H3K36 Methylation in Mammalian Chromatin

哺乳动物染色质组蛋白 H3K36 甲基化的调控和功能

• 批准号: 10459623
• 负责人: Chao Lu
• 金额: $ 40.5万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10459623
• 关键词: ASH1L gene; Affect; Biochemistry; Biology; Chemicals; Chromatin; Clustered Regularly Interspaced Short Palindromic Repeats; Communities; Complex; DNA Methylation; DNA Modification Methylases; DNA Modification Process; Disease; Enzymes; Family member; Genetic Screening; Genome; Genomics; Germ-Line Mutation; Goals; Head and Neck Cancer; Histone H3; Histones; Human; Human Development; Intercistronic Region; Intergenic DNA; Introns; Kinetics; Lead; Lysine; Malignant Neoplasms; Mediating; Methylation; Methyltransferase; Molecular; Molecular Genetics; Mutation; Neoplastic Cell Transformation; Neurodevelopmental Disorder; Pathogenesis; Recurrence; Regulation; Repetitive Sequence; Research; Resources; System; Therapeutic; Work; Yeasts; antagonist; base; bone; chromatin modification; developmental disease; epigenetic regulation; epigenome editing; epigenomics; genome editing; histone methylation; human disease; innovation; insight; interest; knowledge base; novel; programs; recruit; tool; transcription factor

PROJECT SUMMARY Chemical modifications of DNA and histones represent carriers of regulatory information that cooperate with transcription factors to control genome accessibility. Methylation at histone H3 lysine 36 (H3K36) is an evolutionarily conserved chromatin modification. In yeast, a single methyltransferase Set2 catalyzes all methylation states on H3K36. In contrast, H3K36 methylation states are subject to more complex regulation in mammalian chromatin. Whereas SETD2 is the sole enzyme catalyzing tri-methyl H3K36 (H3K36me3), several additional enzymes including NSD family members and ASH1L have evolved as the methyltransferases specific for di-methyl H3K36 (H3K36me2). Accordingly, the genomic distribution of H3K36me2 is distinct from that of H3K36me3, implying a possible functional divergence that remains incompletely understood. Germline mutations in NSD and ASH1L lead to various neurodevelopmental disorders, whereas somatic alterations of these enzymes are frequently found in human cancers. Recent work by us and others have identified and elucidated recurrent mutations directly affecting histone H3K36 that induced global depletion of H3K36me2 in human bone and head and neck cancers. Therefore, precise regulation of NSD/ASH1L-mediated H3K36me2 is critical for human development and represents a key barrier to neoplastic transformation. Despite its importance, there is limited understanding of the regulatory mechanisms governing H3K36me2 establishment and its function in genome regulation. Therefore, the five-year goal of my research program is to systematically examine the chromatin biology of H3K36me2 and its associated modifiers. The conceptual innovation is built on our recent findings of an interplay between H3K36me2 and intergenic DNA methylation through the recruitment of de novo DNA methyltransferase DNMT3A. In addition, we have developed tractable experimental systems and novel CRISPR/Cas-based genome- and epigenome-editing platforms that allow us to dissect the regulation of H3K36me2 in a multiplexed manner. We will determine the respective contribution of NSD and ASH1L to establishing H3K36me2 at introns and intergenic regions. A combination of chromatin biochemistry and functional genetic screening approaches will be employed to understand the regulatory input that guides the formation of H3K36me2. We will perform structural-functional analysis to better understand the molecular basis of DNMT3A recruitment by H3K36me2, and kinetic studies to delineate its relationship with the well-known antagonism between H3K36me2 and H3K27 methylation. Lastly, we will employ integrative epigenomics and epigenome-editing tools to determine the impact of H3K36me2 on the accessibility of cis-regulatory and repetitive elements. Together, these studies will provide a knowledge base upon which mechanistic insights into pathogenesis and targets amenable for therapy can be uncovered for human diseases driven by H3K36me2 dysregulation. Furthermore, the technical tools and resources could be readily applied to the study of additional chromatin modifications and of broad interest to the chromatin research community.

项目摘要 DNA和组蛋白的化学修饰代表了调控信息的载体， 转录因子来控制基因组的可及性。在组蛋白H3赖氨酸36（H3 K36）的甲基化是一个很好的选择。 进化上保守的染色质修饰。在酵母中，单一甲基转移酶Set 2催化所有 H3 K36上的甲基化状态。相比之下，H3 K36甲基化状态受到更复杂的调控， 哺乳动物的染色质尽管SETD 2是催化三甲基H3 K36（H3 K36 me 3）的唯一酶，但几种酶都是由三甲基H3 K36（H3 K36 me 3）催化的。 另外的酶包括NSD家族成员和ASH 1 L已经进化为甲基转移酶特异性的 对于二甲基H3 K36（H3 K36 me 2）。因此，H3 K36 me 2的基因组分布不同于H3 K36 me 2的基因组分布。 H3 K36 me 3，这意味着可能存在功能分歧，但目前仍不完全清楚。 NSD和ASH 1 L的种系突变导致各种神经发育障碍，而体细胞突变导致神经发育障碍。 在人类癌症中经常发现这些酶的改变。我们和其他人最近的工作 鉴定并阐明了直接影响组蛋白H3 K36的复发性突变， H3 K36 me 2在人类骨和头颈癌中的作用因此，精确调节NSD/ASH 1 L介导的 H3 K36 me 2对人类发育至关重要，是肿瘤转化的关键障碍。 尽管其重要性，但对管理机制的了解有限， H3 K36 me 2的构建及其在基因组调控中的作用因此，我研究的五年目标 该项目旨在系统地研究H3 K36 me 2及其相关修饰物的染色质生物学。的 概念创新是建立在我们最近发现的H3 K36 me 2和基因间DNA之间的相互作用 通过从头DNA甲基转移酶DNMT 3A的募集来进行甲基化。此外，我们还开发了 易于处理的实验系统和基于CRISPR/Cas的新型基因组和表观基因组编辑平台， 允许我们以多重方式剖析H3 K36 me 2的调控。我们将确定各自的 NSD和ASH 1 L对在内含子和基因间区域建立H3 K36 me 2的贡献。的组合 染色质生物化学和功能遗传筛选方法将被用来了解 调控输入，指导H3 K36 me 2的形成。我们将进行结构功能分析，以更好地 了解H3 K36 me 2募集DNMT 3A的分子基础，并进行动力学研究，以描述其 与众所周知的H3 K36 me 2和H3 K27甲基化之间的拮抗作用有关。最后，我们将采用 综合表观基因组学和表观基因组编辑工具，以确定H3 K36 me 2对可及性的影响 顺式调控和重复元件的组合。总之，这些研究将提供一个知识基础， 可以揭示人类疾病的发病机理和治疗靶点 由H3 K36 me 2失调驱动。此外，技术工具和资源可随时用于 对染色质修饰的研究，对染色质研究界具有广泛的意义。