Role of novel histone modifications and variants in transcriptional regulation

新型组蛋白修饰和变异在转录调控中的作用

• 批准号: 10713891
• 负责人: Jennifer Marie Spangle
• 金额: $ 38.58万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2028-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10713891
• 关键词: Acetylation; Amino Acids; Architecture; Biochemical; Biological; Cell physiology; Chromatin; Competence; Complex; Computing Methodologies; Cues; DNA Repair; Data; Deacetylation; Disease; Gene Expression; Gene Expression Regulation; Genetic; Genetic Transcription; Genome; Histone Acetylation; Histone H3; Histones; Laboratories; Lysine; Malignant Neoplasms; Methylation; Methyltransferase; Modification; Molecular; Molecular Mechanisms of Action; N-terminal; Nucleosomes; Output; Pathogenicity; Pathologic; Pattern; Phosphorylation; Post-Translational Protein Processing; Production; Proteins; RNA; RNA Processing; RNA Splicing; Regulation; Research; Role; Series; Signal Transduction; Structure; Threonine; Transcriptional Regulation; Variant; combinatorial; epigenome; exosome; experience; histone modification; human disease; novel; programs; upstream kinase; Acetylation; Amino Acids; Architecture; Biochemical; Biological; Cell physiology; Chromatin; Competence; Complex; Computing Methodologies; Cues; DNA Repair; Data; Deacetylation; Disease; Gene Expression; Gene Expression Regulation; Genetic; Genetic Transcription; Genome; Histone Acetylation; Histone H3; Histones; Laboratories; Lysine; Malignant Neoplasms; Methylation; Methyltransferase; Modification; Molecular; Molecular Mechanisms of Action; N-terminal; Nucleosomes; Output; Pathogenicity; Pathologic; Pattern; Phosphorylation; Post-Translational Protein Processing; Production; Proteins; RNA; RNA Processing; RNA Splicing; Regulation; Research; Role; Series; Signal Transduction; Structure; Threonine; Transcriptional Regulation; Variant; combinatorial; epigenome; exosome; experience; histone modification; human disease; novel; programs; upstream kinase

PROJECT SUMMARY Posttranslational modification (PTM) of nucleosome-associated histone proteins, along with histone variant incorporation, influences transcriptional competence and their dysregulation has been identified in numerous pathological states. Histone H3 N-terminal acetylation, methylation, and phosphorylation are common PTMs; the precise combination of these PTMs can modulate chromatin architecture and genome organization, leading to changes in gene expression. Despite extensive efforts to characterize H3 PTMs and H3 variants, their mechanistic and functional interplay, and their ability to influence biological output, it remains unclear how histones and many histone PTMs integrate cues from upstream signaling cascades to regulate gene expression. The overarching objective for my laboratory is to define mechanisms that regulate histone PTM patterns and unmask how they influence transcriptional output. Over the next five years, we propose a combinatorial approach leveraging genetic, molecular, cellular, biochemical and computational methods to define novel mechanisms by which a poorly understood histone H3 PTM, H3 threonine 45 phosphorylation (pH3T45), relays cellular signals from upstream kinases to impact gene expression, and leverage this approach to delineate how novel pathogenic histone H3 variants dysregulate the epigenome to alter cellular function. Our preliminary data suggest that H3T45 phosphorylation status (1) modulates H3K4 methylation by directing specific H3K4-modifying complexes to chromatin; (2) disrupts H3K36me3 via competing histone acetylation/deacetylation; (3) regulates RNA processing through differential association with splicing factors and the RNA exosome complex. We will dissect how H3K4-methyltransferase complexes differ in structure, function, and biological output when associated with pH3T45 or unmodified H3T45. We will delineate how pH3T45 impacts the dynamics of H3K36 acetylation and H3K36 methylation in the context of DNA repair. We will then define how pH3T45 governs the production of mature RNA by examining the role of unmodified H3T45 and pH3T45 throughout RNA processing. Lastly, we have identified a series of cancer-associated H3 variants in which an amino acid is changed to a lysine, termed “H3 X to K” variants. Our preliminary data demonstrates that H3 X to K variants dysregulate proximal H3 PTMs to uniquely modulate gene expression. We will leverage our experience studying pH3T45 to mechanistically define how H3 X to K variants reprogram the epigenome to produce transcriptional and functional cellular changes. This research will address the regulation and effects of histone PTM patterns and H3 variant expression, which will inform our view of how H3 PTMs and variant expression underlies human disease.

项目摘要 核小体相关的Hisstone蛋白的翻译后修饰（PTM）以及组蛋白变体 融合，影响转录能力及其失调，已在许多中识别 病理状态。组蛋白H3 N末端乙酰化，甲基化和磷酸化是常见的PTM。这 这些PTM的精确组合可以调节染色质结构和基因组组织，从而导致 基因表达的变化。尽管为H3 PTM和H3变体做出了广泛的努力，但它们的 机械和功能相互作用及其影响生物产量的能力，尚不清楚如何 Hissones和许多Hisstone PTM都整合了来自上游信号级联的线索，以调节基因表达。 我的实验室的总体目标是定义调节组蛋白PTM模式和的机制 揭示它们如何影响转录输出。在接下来的五年中，我们提出了一种组合方法 利用遗传，分子，细胞，生化和计算方法来定义新机制 熟悉的组蛋白H3 PTM，H3苏氨酸45磷酸化（PH3T45）中继细胞信号 从上游激酶到影响基因表达，并利用这种方法来描述新颖的致病性 Hisstone H3变体使表观基因组失调以改变细胞功能。我们的初步数据表明H3T45 磷酸化状态（1）通过将特定的H3K4修饰复合物引导到 染色质； （2）通过竞争性组蛋白乙酰化/脱乙酰化破坏H3K36me3； （3）调节RNA 通过与剪接因子和RNA外泌体复合物的差异关联进行处理。我们将剖析 当与 PH3T45或未修饰的H3T45。我们将描述PH3T45如何影响H3K36乙酰化和 在DNA修复的背景下，H3K36甲基化。然后，我们将定义PH3T45如何管理 通过在RNA处理过程中检查未修饰的H3T45和PH3T45的作用，通过检查成熟的RNA。最后，我们 已经确定了一系列与癌症相关的H3变体，其中氨基酸更改为赖氨酸，称为 “ H3 X到K”变体。我们的初步数据表明，H3 X到K变体失调近端H3 PTMS 独特地调节基因表达。我们将利用学习PH3T45的经验 定义H3 X到K变体如何重新编程表观基因组以产生转录和功能性细胞 更改。这项研究将解决组蛋白PTM模式和H3变体的调节和影响 表达，这将使我们对H3 PTM和变体表达如何构成人类疾病的看法。