Interplay Between Nuclear Organization and Function

核组织与功能之间的相互作用

• 批准号: 10582338
• 负责人: Gary H KARPEN
• 金额: $ 24.87万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-12-01 至 2025-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10582338
• 关键词: 3-Dimensional; Address; Aging; Animals; Architecture; Binding; Biochemical; Biological; Biology; Biophysical Process; Biophysics; Cells; Chromatin; Chromosome Pairing; Complex; Congenital Abnormality; DNA Repair; Dementia; Diagnosis; Foundations; Gene Expression; Gene Silencing; Genetic Transcription; Genome; Genome Stability; Genomic Instability; Goals; Health; Heterochromatin; Histone H3; Image; Knowledge; Liquid substance; Lysine; Malignant Neoplasms; Membrane; Methylation; Nuclear; Oils; Phase; Play; Property; Proteins; Publishing; System; Testing; Water; bioimaging; biophysical properties; biophysical techniques; chemical property; experience; heterochromatin-specific nonhistone chromosomal protein HP-1; human disease; in vivo; innovation; interdisciplinary approach; novel; novel strategies; recruit; repaired

PROJECT SUMMARY/ABSTRACT Goals: Peri-Centromeric Heterochromatin (PCH) is required for genome stability/DNA repair, chromosome pairing, nuclear architecture, and transposon and gene silencing. Previous studies suggested that histone H3 lysine 9 methylation (H3K9me2/3), Heterochromatin Protein 1 (HP1) binding, HP1-interacting protein recruitment and chromatin compaction are sufficient to explain PCH formation and function. In 2017, my lab and the Narlikar lab published complementary studies suggesting that 3D PCH domains form via liquid-liquid phase separation (LLPS), generating membrane-less condensates with an immobile HP1a core surrounded by a liquid. We proposed that novel properties associated with highly networked, phase separated systems (e.g. liquidity) are critical to understand how PCH, and other chromatin domains, form and regulate essential nuclear functions. However, we lack a mechanistic understanding of the organization, dynamics and biophysical/material properties of PCH components and condensates in a cellular and organismal context. In addition, we need to determine if and how biophysical properties regulate genome functions such as repair, replication and transcription, a current major challenge for the whole field of condensate biology. Approach: This MIRA will interrogate how LLPS and biophysical properties impact the in vivo organization and function of heterochromatin and other associated nuclear bodies. We will capitalize on our preliminary results and knowledge of PCH biology, combined with advanced imaging, biochemical, and experimental and theoretical biophysical approaches, to elucidate 1) the molecular interactions responsible for PCH domain formation; 2) the architectural, biophysical and chemical properties of the domain; and 3) whether or not phase separation and liquidity regulate PCH functions and interplay with other nuclear bodies. Innovation: Although LLPS and biological condensates have become a popular topic for study and discussion in recent years, we know little about in vivo mechanisms and relevance to function in the complex but important cellular and organismal contexts. This is an emerging field, with unique challenges, and an interdisciplinary approach is required to address these key questions. Thus in this MIRA proposal we will combine our decades of experience in PCH biology with the expertise of collaborators in experimental and theoretical biophysics, and advanced bioimaging. Testing our hypothesis will elucidate important information about the organization and function of heterochromatin in cells and animals, potentially providing a paradigm- shifting foundation for understanding how chromatin domains in general form and function. Health Relatedness: Defective PCH causes genome instability and altered gene expression, contributing to cancer, birth defects, and aging. Understanding how biophysical properties that underlie PCH formation and function are altered in human diseases will likely result in novel approaches to diagnosis and treatment.

项目概要/摘要 目标：着丝粒周围异染色质 (PCH) 是基因组稳定性/DNA 修复、染色体所必需的 配对、核结构、转座子和基因沉默。先前的研究表明组蛋白 H3 赖氨酸 9 甲基化 (H3K9me2/3)、异染色质蛋白 1 (HP1) 结合、HP1 相互作用蛋白 募集和染色质压缩足以解释 PCH 的形成和功能。 2017年，我的实验室 Narlikar 实验室发表了补充研究，表明 3D PCH 结构域是通过液-液形成的 相分离 (LLPS)，产生无膜冷凝物，其周围有固定的 HP1a 核心 一种液体。我们提出与高度网络化、相分离的系统（例如， 流动性）对于理解 PCH 和其他染色质结构域如何形成和调节重要的核 功能。然而，我们缺乏对组织、动态和机制的机械理解。 PCH 成分和缩合物在细胞和有机体环境中的生物物理/材料特性。在 此外，我们需要确定生物物理特性是否以及如何调节基因组功能，例如修复、 复制和转录是整个凝聚生物学领域当前的主要挑战。 方法：该 MIRA 将探究 LLPS 和生物物理特性如何影响体内组织 以及异染色质和其他相关核体的功能。我们将利用我们的初步 PCH 生物学的结果和知识，结合先进的成像、生化和实验和 理论生物物理方法，阐明 1) 负责 PCH 结构域的分子相互作用 形成； 2) 领域的结构、生物物理和化学特性； 3）是否相 分离和流动性调节 PCH 的功能以及与其他核机构的相互作用。 创新：虽然LLPS和生物凝聚物已成为研究和应用的热门话题 近年来的讨论，我们对体内机制及其与复合物功能的相关性知之甚少 但重要的细胞和有机体背景。这是一个新兴领域，具有独特的挑战，并且 需要跨学科方法来解决这些关键问题。因此，在这个 MIRA 提案中，我们将 将我们数十年的 PCH 生物学经验与实验和合作者的专业知识相结合 理论生物物理学和先进的生物成像。检验我们的假设将阐明重要信息 关于细胞和动物中异染色质的组织和功能，可能提供一个范例- 改变理解染色质结构域的一般形式和功能的基础。 健康相关性：PCH 缺陷会导致基因组不稳定和基因表达改变，从而导致 癌症、出生缺陷和衰老。了解 PCH 形成的生物物理特性和 人类疾病中功能的改变可能会带来新的诊断和治疗方法。