Epigenetic gene regulation in Arabidopsis

拟南芥表观遗传基因调控

• 批准号: 10092195
• 负责人: STEVEN E JACOBSEN
• 金额: $ 31.2万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-02-01 至 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10092195
• 关键词: Arabidopsis; Binding; Biological Models; Biology; Cancer Etiology; Cells; Chemicals; Cytosine; DNA; DNA Damage; DNA Methylation; DNA Modification Methylases; DNA-Directed RNA Polymerase; Defect; Epigenetic Process; Five-Year Plans; Gene Expression; Gene Expression Regulation; Gene Silencing; Genes; Genetic; Genome; Genome Stability; Genomics; Heterochromatin; Histones; Laboratories; Laboratory Finding; Lead; Maintenance; Mass Spectrum Analysis; Methods; Methylation; Modification; Mouse-ear Cress; Nature; Pathway interactions; Pattern; Play; Post-Translational Protein Processing; Proteins; Proteomics; RNA; Repression; Research; Tissues; Untranslated RNA; derepression; gene function; histone modification; methylation pattern; mutant; prevent; protein complex; response; structural biology

Project Summary/Abstract Our laboratory focuses on the biology and mechanisms of gene silencing by DNA methylation and histone modifications, primarily using Arabidopsis thaliana as a model system. Recent efforts have focused on the mechanisms by which DNA methylation is properly patterned in the genome. The main findings are that four distinct DNA methylation pathways, driven by four different DNA methyltransferases act in self- reinforcing mechanisms to maintain cytosine methylation in three different sequence contexts, CG, CHG and CHH (where H = A, T, or C). The establishment of DNA methylation is controlled by the RNA-directed DNA methylation pathway, and studying this pathway has been a major recent focus of the lab. Most recently, the laboratory has used genetics, genomics, proteomics, and structural biology approaches to characterize the mechanisms by which two RNA polymerases, Pol IV and Pol V, act to produce non- coding RNAs that act to target RNA-directed DNA methylation to specific loci. The newest findings from the laboratory are also taking us into new directions aimed at understanding factors that act downstream of DNA methylation, to both control gene expression and to maintain genome stability. In the next five years, we plan to utilize all available approaches to understand the proteins that recognize methylated DNA and certain modified histones, and to decipher their functions in gene expression and in the maintenance of genome stability. These approaches will include mass spectrometry to directly identify proteins and protein complexes able to bind to methylated DNA and methylated histones. The laboratory will also use Arabidopsis mutant screens to identify factors that act downstream of DNA methylation and various histone marks. A post translational modification of histones called H3K27 monomethylation is critical for repression of heterochromatin. In the absence of this mark, cells undergo both inappropriate gene expression and a massive DNA damage response resulting in amplification of heterochromatic DNA. A key part of the five-year plan will be to understand the mechanisms at play, and to understand the precise nature of the relationship between gene derepression and DNA damage.

项目摘要/摘要 我们的实验室主要研究DNA甲基化和组蛋白导致的基因沉默的生物学和机制。 改进，主要使用拟南芥作为模型系统。最近的努力集中在 DNA甲基化在基因组中形成适当模式的机制。主要发现是 四种不同的DNA甲基化途径，由四种不同的DNA甲基转移酶驱动，在自身 在三种不同的序列环境中维持胞嘧啶甲基化的增强机制 和CHH(其中H=A、T或C)。DNA甲基化的建立是由RNA控制的 DNA甲基化途径，对这一途径的研究一直是实验室最近的一个主要焦点。多数 最近，该实验室使用遗传学、基因组学、蛋白质组学和结构生物学的方法 描述两种RNA聚合酶Pol IV和Pol V产生非 编码RNA的作用是将RNA定向的DNA甲基化作用于特定的基因座。最新的发现来自于 实验室还将把我们带入新的方向，旨在了解下游的作用因素。 DNA甲基化，既控制基因表达，又保持基因组稳定。在接下来的五年里 几年来，我们计划利用所有可用的方法来了解识别甲基化的蛋白质 DNA和某些修饰的组蛋白，并破译它们在基因表达和基因表达中的功能 保持基因组的稳定性。这些方法将包括质谱仪，以直接识别 能够与甲基化DNA和甲基化组蛋白结合的蛋白质和蛋白质复合体。实验室 还将使用拟南芥突变筛选来识别作用于DNA甲基化下游的因子和 各种各样的组蛋白印记。组蛋白的翻译后修饰称为H3K27单甲基化 对异染色质的抑制至关重要。在没有这种标记的情况下，细胞经历了两种不适当的 基因表达和大量的DNA损伤反应导致异染色质DNA的扩增。 五年计划的一个关键部分将是了解发挥作用的机制，并了解 基因去阻遏和DNA损伤之间关系的精确本质。