Defining the Role of Poly ADP-ribose in Biomolecular Condensation in ALS and FTLD

项目摘要 聚ADP-核糖（PAR）是一种RNA样蛋白质修饰，其失调与年龄有关。 依赖性神经退行性疾病，包括ALS、帕金森病和阿尔茨海默病。 PAR是一种无膜核糖核蛋白（RNP），是应激颗粒的核心成分 这些颗粒可导致异常蛋白质聚集，从而导致神经病理学。与RNA不同，PAR 可以形成直链和支链结构。引人注目的是，PAR聚合酶的抑制剂， 是一类FDA批准的抗癌药物，在细胞模型中显示可减轻神经毒性 的神经变性，反映了潜在的作用PAR的神经毒性。约翰的两个实验室 霍普金斯大学的Sua Myong（生物物理系）和Anthony K. L.梁 （生物化学和分子生物学系）汇集了正交专业知识， 分子成像、化学和蛋白质组学方法来研究PAR的分子基础， 导致神经退行性变的蛋白质凝聚和聚集机制 疾病，这可能为开发治疗方法铺平新的道路。我们最近发现了一种PAR FUS液-液相的修饰方法（Leung et al，Mol Cell，2019）和机理 ALS/FTLD相关病例的分离（Myong et al，Mol Cell，2019）使我们处于理想的位置 用于解决PAR在生物分子缩合中的作用， 神经退行性疾病在初步研究中，我们发现（i）PAR是非常 在浓缩FUS（融合于肉瘤中）中有效，FUS是一种定位于应激颗粒中的RNA结合蛋白 并牵连ALS/FTLD和（ii）PAR靶向蛋白质组是丰富的应激颗粒 件.基于这些令人兴奋的结果，我们建议揭示PAR在驾驶中的作用。 通过使用单分子、生物化学、介观尺度、生物物理 和蜂窝平台。

PROJECT SUMMARY Poly ADP-ribose (PAR) is an RNA-like protein modification whose dysregulation is linked to age- dependent neurodegenerative diseases including ALS, Parkinson’s and Alzheimer’s disease. PAR is a core component of stress granules, a type of membraneless ribonucleoprotein (RNP) granules that can seed aberrant protein aggregation leading to neuropathology. Unlike RNA, PAR can form into both linear and branched structures. Strikingly, inhibitors of PAR polymerase, which is a class of FDA-approved anticancer drugs, were shown to mitigate neurotoxicity in cell models of neurodegeneration, reflecting a potential role of PAR in neurotoxicity. Two laboratories at Johns Hopkins University led by Sua Myong (Biophysics department) and Anthony K. L. Leung (Department of Biochemistry and Molecular Biology ) bring together orthogonal expertise in molecular imaging, chemical and proteomic methods to investigate the molecular basis of PAR- driven protein condensation and aggregation mechanism responsible for neurodegenerative diseases, which may pave new ways of developing therapy. Our recent discovery of a PAR modifying method (Leung et al, Mol Cell, 2019) and mechanism of FUS liquid-liquid phase separation in ALS/FTLD-linked cases (Myong et al, Mol Cell, 2019) places us in an ideal position for tackling the poorly understood role of PAR in biomolecular condensation implicated in neurodegenerative diseases. In Preliminary Studies, we discovered that (i) PAR is extremely potent in condensing FUS (fused in sarcoma), an RNA binding protein localized in stress granules and implicated in ALS/FTLD and (ii) PAR targeted proteome is enriched in stress granule components. Building on these exciting results, we propose to uncover the role of PAR in driving biomolecular condensation by employing single molecule, biochemical, meso-scale, biophysical and cellular platforms.