Structural and Cellular Choreography for Decommissioning and Recycling of PP2A Holoenzymes

PP2A 全酶退役和回收的结构和细胞编排

• 批准号: 10210932
• 负责人: Yongna Xing
• 金额: $ 31.85万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-04-01 至 2025-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10210932
• 关键词: Active Sites; Address; Affinity; Alzheimer' s Disease; Back; Binding; Binding Sites; Biochemical; Biogenesis; Biological; Biophysics; Catalytic Domain; Cell Cycle; Cell Death; Cell physiology; Cells; Complex; Cryoelectron Microscopy; DNA Damage; Data; Disease; Disease susceptibility; Dissociation; Electrons; Enzymes; Family; Heart Diseases; Holoenzymes; Human; Ions; Knowledge; Malignant Neoplasms; Mammalian Cell; Mediating; Metals; Methylation; Microscopic; Molecular; Molecular Chaperones; Molecular Conformation; Mutation; Names; Pathway interactions; Phosphoric Monoester Hydrolases; Phosphorylation; Physiological Processes; Process; Protein Analysis; Protein Deregulation; Protein phosphatase; Proteins; Publishing; Recycling; Regulation; Research; Resolution; Role; Series; Signal Pathway; Signal Transduction; Structure; Viral Pathogenesis; base; cancer type; chelation; demethylation; human disease; insight; interdisciplinary approach; metalloenzyme; nanomolar; nervous system disorder; novel; particle; pathogen; protein folding; response; scaffold

PROJECT SUMMARY Protein phosphatase 2A (PP2A) is a ubiquitous and the most prominant Ser/Thr phosphatase that regulates the phosphorylation status of a large number of cellular proteins involved in diverse biological pathways. Derulagulation of PP2A is associated with many human cancers, Alzheimer's Disease and susceptibility to pathogens. The PP2A core enzyme is a heterodimer of highly conserved scaffold and catalytic subunits, which forms the heterotrimeric holoenzyme by binding a variable and highly diverse regulatory subunit that determines substrate selectivity. Built on recent advance on structural choreography of tight control of PP2A holoenzyme biogenesis, in particular, the conformational switches of PP2Ac required for its latency and activation, we further made a striking observation on recycling of PP2Ac from holoenzymes. We also observed a novel function of PME-1 (PP2A-specific methylesterase 1) in demethylation of and interaction with PP2A holoenzymes; PME-1 was previously thought to specifically act on the core enzyme. The research proposed here will extend our preliminary electron microscopic analyses of PP2A complexes, and use structural, biochemical, biophysical and cell biological approaches to elucidate mechanisms that control novel function and mechanism of PME-1 in holoenzyme regulation (Specific Aim 1), recycling of PP2Ac from PP2A holoenzymes (Specific Aim 2), and novel insights into PP2A holoenzyme biogenesis and recycling and the multi-faceted roles of PME-1 in cellular signaling. These studies will establish a novel regulation loop of PP2A holoenzyme biogenesis and recycling for precise and dynamic control of PP2A holoenzymes in diverse cellular and physiological processes, and provides a novel framework for understanding the mechanisms that regulate PP2A functions in normal and transformed human cells.

项目概要 蛋白磷酸酶 2A (PP2A) 是一种普遍存在且最重要的 Ser/Thr 磷酸酶，可调节 参与不同生物途径的大量细胞蛋白的磷酸化状态。 PP2A 的去规则化与许多人类癌症、阿尔茨海默病和易感性相关 病原体。 PP2A核心酶是高度保守的支架和催化亚基的异二聚体， 通过结合可变且高度多样化的调节亚基形成异三聚体全酶，该亚基决定 底物选择性。基于严格控制 PP2A 全酶的结构编排的最新进展 生物发生，特别是其潜伏和激活所需的 PP2Ac 构象转换，我们进一步 对从全酶中回收 PP2Ac 做出了惊人的观察。我们还观察到一个新功能 PME-1（PP2A 特异性甲基酯酶 1）在 PP2A 全酶的去甲基化及其相互作用中； PME-1 以前被认为专门作用于核心酶。这里提出的研究将扩展我们的 PP2A 复合物的初步电子显微镜分析，并使用结构、生物化学、生物物理和 细胞生物学方法阐明控制 PME-1 新功能的机制和机制 全酶调控（具体目标 1）、从 PP2A 全酶中回收 PP2Ac（具体目标 2）以及新颖的 深入了解 PP2A 全酶生物发生和回收以及 PME-1 在细胞中的多方面作用 发信号。这些研究将建立一个新的 PP2A 全酶生物发生和循环的调节回路 PP2A全酶在多种细胞和生理过程中的精确和动态控制，并提供 一个新的框架，用于理解正常和转化中调节 PP2A 功能的机制 人体细胞。