Accurate Molecular Decision Making during Protein Biogenesis

蛋白质生物合成过程中准确的分子决策

• 批准号: 10372995
• 负责人: Shu-ou Shan
• 金额: $ 97.03万
• 依托单位: CALIFORNIA INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-04-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10372995
• 关键词: ATP phosphohydrolase; Bacteria; Biochemical; Biogenesis; Biophysical Process; Biophysics; Cells; Client; Crowding; Decision Making; Disease; Ensure; Environment; Enzymes; Eukaryotic Cell; Excision; Generations; Goals; Grant; Individual; Investigation; Knowledge; Maintenance; Mediating; Membrane; Membrane Proteins; Methionine; Modeling; Molecular; Molecular Chaperones; N-terminal; Pathology; Pathway interactions; Physiology; Plant Roots; Process; Proteins; Proteome; Reagent; Regulation; Research; Resolution; Ribosomes; Signal Recognition Particle; System; Tail; Time; Translations; Triage; design; experimental study; in vivo; insight; prevent; programs; proteostasis; spatiotemporal; targeted delivery; tool

Project Summary: Accurate Molecular Decision Making during Protein Biogenesis Accurate protein biogenesis is essential for the generation and maintenance of a functional proteome. Our long term goal is to understand the molecular mechanisms by which diverse protein biogenesis pathways in the cell accurately select nascent protein substrates and ensure their correct folding, localization, and maturation. Two major components define our research program in this grant cycle. First, we will use a combination of biochemical, biophysical, and in vivo experiments to decipher the mechanisms by which nascent proteins emerging from the ribosome are selected and processed by ribosome-associated protein biogenesis factors (RPBs) in the crowded space of the ribosome tunnel exit. These studies will include a new co-translational membrane protein targeting pathway mediated by SecA, enzymes mediating N-terminal methionine excision on nascent proteins in bacteria, and co-translational protein targeting mediated by SRP in the mammalian system. In addition to studying the biochemical and biophysical mechanisms of the individual protein biogenesis pathways, we will also elucidate how each of these factors coordinates with other RPBs in space and time during ongoing translation, and how this coordination reshapes the efficiency and fidelity of the individual pathways. Second, we will decipher the mechanisms by which aggregation-prone membrane proteins are effectively protected and facilely guided to the target membrane during their post-translational targeting. These studies will use two membrane protein biogenesis pathways as models: (i) an ATP-independent chaperone cpSRP43, which allows us to decipher, at biophysical resolution, the molecular mechanisms by which a small chaperone effectively protects multi-pass membrane protein clients and achieves spatiotemporal regulation of its client interactions in the absence of ATPase cycles or cochaperones; (ii) the guided-entry of tail-anchored proteins (GET) pathway, which provides an excellent system to decipher how a multi-component Hsp70- cochaperone cascade protects, funnels, and triages nascent membrane proteins during their targeted delivery. Investigation of the GET pathway will also allow us to gain insights into the design and organizational principles of analogous chaperone networks in the cell. The proposed experiments will not only generate high resolution understandings of the individual protein biogenesis pathways, but also establish valuable tools, reagents to explore the action of other protein biogenesis machineries. Most importantly, this research will generate important conceptual frameworks to understand how nascent proteins are accurately selected into their appropriate biogenesis pathways in the crowded cytosolic environment.

项目摘要：蛋白质生物发生过程中的准确分子决策 准确的蛋白质生物发生对于生成和维持功能至关重要 蛋白质组。我们的长期目标是了解各种各样的分子机制 细胞中的蛋白质生物发生途径准确选择新生的蛋白质底物，并确保 它们正确的折叠，定位和成熟。两个主要组成部分定义了我们的研究 在此赠款周期中的程序。 首先，我们将使用生化，生物物理和体内实验的组合来解密 选择了从核糖体中出现新生蛋白的机制，并 通过核糖体相关的蛋白质生物发生因子（RPB）在拥挤的空间中处理 核糖体隧道出口。这些研究将包括一种新的共同翻译膜蛋白 靶向由SECA介导的途径，介导N末端蛋氨酸切除的酶 细菌中的新生蛋白，以及靶向由SRP介导的靶蛋白 哺乳动物系统。除了研究的生化和生物物理机制 单个蛋白质生物发生途径，我们还将阐明这些因素如何 在正在进行的翻译过程中与其他RPB在时空和时间上进行协调，以及如何 协调重塑了各个途径的效率和忠诚度。 其次，我们将破译易于聚集的膜蛋白的机制 在翻译后有效地保护并将其分别引导到靶膜 定位。这些研究将使用两种膜蛋白生物发生途径作为模型：（i） 非依赖ATP的伴侣CPSRP43，这使我们能够以生物物理分辨率解密， 小伴侣有效保护多通的分子机制 膜蛋白客户并实现其客户相互作用的时空调节 没有ATPase循环或联合酮； （ii）尾锚蛋白的指导入境（GET） 途径，它提供了一个很好的系统，可以破译多组分HSP70- 掌控级联反应在其期间保护，funnels和Triages新生的膜蛋白 目标交付。对GET道路的调查也将使我们能够深入了解 细胞中类似伴侣网络的设计和组织原理。 提出的实验不仅会产生高分辨率的理解 单个蛋白质生物发生途径，但也建立了有价值的工具，试剂以探索 其他蛋白质生物发生机制的作用。最重要的是，这项研究将产生 重要的概念框架，以了解如何准确选择新生蛋白 在拥挤的胞质环境中进入适当的生物发生途径。