Structural and functional studies of chromatin modifiers

染色质修饰剂的结构和功能研究

基本信息

批准号：
10322987
负责人：
Mario Halic
金额：
$ 37.7万
依托单位：
ST. JUDE CHILDREN'S RESEARCH HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-01-01 至 2023-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10322987
关键词：
Active Sites Acute leukemia Address Aging Binding Binding Proteins Biochemical Biochemistry Cell Proliferation Cell physiology Cells Centromere Chromatin Chromatin Remodeling Factor Chromatin Structure Chromosome Segregation Chromosomes Clear cell renal cell carcinoma Complex Congenital Abnormality Cryoelectron Microscopy DNA Repair DNA-Binding Proteins Data Deposition Development Disease Enzymes Epigenetic Process Gene Expression Genes Genetic Genetic Transcription Genome Genome Stability Genomic Instability Genomics Glioblastoma Goals Heterochromatin Histone H3 Histone-Lysine N-Methyltransferase Histones Human In Vitro Infertility Kinetochores Knowledge Lead Lysine Malignant Neoplasms Malignant neoplasm of brain Malignant neoplasm of lung Malignant neoplasm of ovary Malignant neoplasm of urinary bladder Messenger RNA Methylation Microtubules Mutate Mutation Nucleosomes Outcome Peptides Pharmaceutical Preparations Physical condensation Positioning Attribute Proteins RNA Splicing Reader Regulation Research Specificity Structural Protein Structure Ubiquitin Ubiquitination Variant Work biophysical analysis cancer cell cancer genome centromere autoantigen 80K centromere protein A centromere protein C chromatin modification chromatin protein chromatin remodeling experimental study histone methylation histone modification in vitro activity in vivo malignant breast neoplasm overexpression prevent protein complex recruit small molecule therapeutic target tumorigenesis

项目摘要

Summary Regulation of genome expression is essential for cells to maintain their identity and loss of cell identity leads to tumorigenesis. Cancer Genome Project has revealed that chromatin modifiers and remodelers are highly mutated in human cancers, however, despite the importance of these factors, we know little about their mechanisms of activity. To address this knowledge gap, we will combine cryo-EM, biochemistry and genetics to determine how enzymes and structural proteins modify nucleosome and chromatin structure. Among the key players in the control of genome expression are histone modifications that, through specific reader domains, recruit various protein complexes to chromatin. Histone lysine methylation is a stable chromatin mark that is deposited by histone lysine methyltransferases (KMTs) and methylation of different lysine residues has different outcomes on gene expression; H3K36 methylation is deposited over actively transcribed genes, whereas H3K9 methylation is a hallmark of silent heterochromatin. Perturbations in KMT levels lead to aberrant genome expression and formation of cancers cells, however, we do not understand how KMTs bind and modify nucleosome. H3K9 methylation and heterochromatin are required for deposition of centromere specific histone H3 variant CENP-A to chromatin, an epigenetic mark of centromeres. The centromere is the specialized chromatin region on which kinetochores assemble to segregate chromosomes. Despite the importance, structure of centromeric chromatin assembled on CENP-A nucleosome is still largely unknown. Guided by the strong preliminary data, we propose to pursue three Specific Aims to understand how KMTs bind and modify nucleosomes and to characterize centromeric chromatin. We will combine cryo-EM with biochemistry and genetics to determine mechanisms of H3K36 (Aim 1) and H3K9 (Aim 2) methylation. Moreover, we will use cryo-EM to visualize centromeric chromatin assembled on CENP-A nucleosome (Aim 3). Together, our proposed studies will have broad impact in chromatin field by showing how chromatin proteins bind the nucleosome and how this interaction provides specificity for their activity. Our long-term goals are to understand the regulation of genome expression by chromatin and discover why mutations in chromatin proteins lead to the formation of cancer cells.

概括基因组表达的调节对于维持细胞的身份和细胞身份丧失至关重要导致肿瘤发生。癌症基因组项目表明，染色质修饰剂和然而，尽管这些因素很重要，但重塑剂在人类癌症中被高度突变。我们对它们的活动机制知之甚少。为了解决这个知识差距，我们将结合冷冻EM，生物化学和遗传学，以确定酶和结构蛋白如何修饰核小体和染色质结构。在控制基因组表达的主要参与者中，组蛋白修饰，通过特定的读取器结构域，将各种蛋白质复合物募集到染色质。组蛋白赖氨酸甲基化是由组蛋白赖氨酸甲基转移酶（KMTS）沉积的稳定染色质标记和不同赖氨酸残基的甲基化在基因表达上具有不同的预后。 H3K36 甲基化沉积在积极转录的基因上，而H3K9甲基化是无声异染色质。 KMT水平的扰动导致异常基因组表达和形成但是，在癌细胞中，我们不了解KMT如何结合和修饰核小体。 H3K9 甲基化和异染色质是丝粒特异性组蛋白H3所必需的变体CENP-A至染色质，染色质，一种表观遗传标记。中心是专业动力学组合以分离染色体的染色质区域。尽管有重要性，在CENP-A核小体上组装的丝粒染色质的结构仍然很大未知。在强大的初步数据的指导下，我们提议追求三个具体目标了解KMT如何结合和修饰核小体并表征着丝粒染色质。我们将结合冷冻EM与生物化学和遗传学结合，以确定H3K36的机制（AIM 1）和H3K9（AIM 2）甲基化。此外，我们将使用冷冻EM可视化丝粒染色质组装在CENP-A核小体上（AIM 3）。一起，我们提出的研究将通过显示染色质如何在染色质领域产生广泛的影响蛋白质结合核小体以及这种相互作用如何为其活性提供特异性。我们的长期目标是了解染色质对基因组表达的调节，并发现为什么染色质蛋白的突变导致癌细胞的形成。