The function of H3K23me3, a transgenerationally inherited heterochromatin mark

跨代遗传异染色质标记 H3K23me3 的功能

• 批准号: 10155982
• 负责人: LIANNA SCHWARTZ-ORBACH
• 金额: $ 4.25万
• 依托单位: RUTGERS, THE STATE UNIV OF N.J.
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-01 至 2023-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10155982
• 关键词: Address; Aging; Alleles; Animal Model; Biochemical; Biochemistry; Biology; Caenorhabditis elegans; Candidate Disease Gene; Chromatin; Chromatin Structure; Computational Biology; DNA; Development; Disease; Doctor of Philosophy; Dominant-Negative Mutation; Epigenetic Process; Future; Gene Expression Regulation; Gene Silencing; Generations; Genetic; Genome; Goals; Guide RNA; Heterochromatin; Histone Code; Histone H3; Histones; Human; Human Development; In Vitro; Inherited; Knock-out; Knowledge; Lysine; Malignant Neoplasms; Mediating; Medicine; Metabolic Diseases; Methionine; Methylation; Methyltransferase; Modeling; Modernization; Modification; Mus; Mutate; Mutation; Nuclear; Oncogenic; Organism; Pathway interactions; Phenotype; Plants; Play; Post-Translational Protein Processing; Proteins; RNA; RNA Interference; Reader; Reagent; Regulation; Research; Role; Small Interfering RNA; Small RNA; Training; Transcriptional Regulation; Work; base; chromatin modification; epigenetic regulation; epigenetic silencing; gene repression; genetic approach; histone methyltransferase; histone modification; human disease; in vivo; innovation; insight; knockout gene; mutant; non-genetic; novel; response; skills; tool; transgenerational epigenetic inheritance

PROJECT SUMMARY: H3K23 methylation is an evolutionarily conserved but understudied heterochromatic histone modification whose function is unknown. In the past year our lab used C. elegans to study H3K23 methylation and found that it plays a role in nuclear RNAi. Nuclear RNAi is an evolutionarily conserved pathway in which small interfering RNAs (siRNAs) guide chromatin modifications and transcriptional repression. It protects the host genome by epigenetically silencing transposons and other “non-self” DNA. We have made the following discoveries: (1) H3K23me3 is induced by nuclear RNAi and is inherited for four generations. (2) The histone methyltransferase SET-32, methylates H3K23 in vitro. (3) Both set-32 and the nuclear RNAi effector protein, hrde-1, are required for nuclear RNAi-induced H3K23me3 in vivo. These discoveries have raised new questions. What are the other histone methyltransferases responsible for H3K23me3? What is the function of H3K23me3? Could H3K23me3 contribute to transcriptional silencing in nuclear RNAi? In this proposal I will take genetic, biochemical, and computational approaches to address these questions in the following aims. (1) Biochemically characterize and identify the histone methyltransferase(s) responsible for this modification. (2) Create a functional knockout of H3K23me3 using a dominant negative mutation first discovered in cancer. (3) Study the function of H3K23me3 in nuclear RNAi. The proposed studies, which explore a fundamental yet unmapped territory of modern biology, will advance our understanding of the histone code, histone methyltransferases, oncogenic histones, RNA-mediated transcriptional silencing, and RNA-chromatin interaction, which are all relevant to human development and disease.

项目概要： H3K23 甲基化是一种进化上保守但尚未充分研究的异染色质组蛋白修饰 其功能未知。去年我们实验室利用秀丽隐杆线虫研究H3K23甲基化，发现 它在核 RNAi 中发挥作用。核RNAi是一种进化上保守的途径，其中小 干扰 RNA (siRNA) 引导染色质修饰和转录抑制。它可以保护主机 通过表观遗传学沉默转座子和其他“非自身”DNA 来改变基因组。我们做了以下工作 发现：（1）H3K23me3由核RNAi诱导并遗传四代。 (2)组蛋白 甲基转移酶 SET-32 在体外甲基化 H3K23。 (3) set-32 和核 RNAi 效应蛋白， hrde-1 是体内核 RNAi 诱导的 H3K23me3 所必需的。这些发现提出了新的 问题。负责 H3K23me3 的其他组蛋白甲基转移酶有哪些？的作用是什么 H3K23me3？ H3K23me3 是否有助于核 RNAi 中的转录沉默？在这个提案中我将 采用遗传、生化和计算方法来解决这些问题，以实现以下目标。 (1) 生化表征并鉴定负责这种修饰的组蛋白甲基转移酶。 (2) 使用首次在癌症中发现的显性失活突变创建 H3K23me3 的功能性敲除。 (3) 研究H3K23me3在核RNAi中的功能。拟议的研究探索了一个基本的尚未 现代生物学未绘制的领域，将增进我们对组蛋白密码、组蛋白的理解 甲基转移酶、致癌组蛋白、RNA 介导的转录沉默和 RNA 染色质 相互作用，这些都与人类发育和疾病有关。