Structure and Function of Protein Disorder in Membrane Trafficking and Organization

膜运输和组织中蛋白质紊乱的结构和功能

• 批准号: 10609819
• 负责人: David Eliezer
• 金额: $ 42.38万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-05-01 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10609819
• 关键词: AGFG1 gene; Area; Awareness; Binding; Binding Proteins; Biological Assay; Biological Models; Biological Process; Cell Survival; Cell physiology; Cellular Membrane; Disease; Exocytosis; Goals; In Situ; In Vitro; Inosine Diphosphate; Link; Mediating; Membrane; Membrane Fusion; Modeling; Nature; Neurons; Organelles; Pathway interactions; Physical condensation; Physiological; Physiological Processes; Prevalence; Property; Protein Region; Proteins; Reaction; Recycling; Regulation; Research; Role; Specificity; Structure; Synapsins; System; Vesicle; cell type; in vivo; protein function; recruit; synuclein; trafficking

Project Summary/Abstract Intrinsically disordered proteins and protein regions (IDPs and IDRs) lack stable tertiary structure but retain biological function. Understanding the structure/function relationships of such disordered protein regions presents a significant challenge because of their highly variable and dynamic nature. The past few years have resulted in an increased awareness and recognition of the prevalence and roles of IDPs and IDRs in membrane trafficking and organization. The primary goal of the proposed research is to advance our understanding of how the dynamic and highly variable structure of IDPs mediates their functions in membrane trafficking and organization. A key aspect of IDP function in membrane trafficking and organization involves direct IDP-membrane interactions, which can occur in conjunction with disorder-to-order transitions, or in the absence of protein ordering. Formation of membrane-binding amphipathic helices (AHs) is the most common example of the former, but the mechanisms underlying and regulating the formation, stability, specificity and function of such membrane-associated AHs remain poorly understood. Factors that govern membrane binding by IDRs that remain disordered in the bound state are even less well understood. A major area of proposed research centers on delineating mechanisms for these types of IDP-membrane interactions using the protein complexin as a model via a combination of in vitro characterization of structure and dynamics and in vivo functional assays. Another emerging aspect of IDP function is their ability to mediate the formation of condensates or membraneless organelles. Recently, it has been demonstrated that IDR-containing membrane- binding proteins can form cytosolic condensates that sequester and organize intracellular reservoirs of membrane vesicles. The mechanisms that regulate the ability of condensates to interact with and organize membranous vesicles or compartments have barely been explored and represent second major focus of this proposal. The primary model system for these efforts will be the clustering of membrane vesicles mediated by the protein synapsin, and the regulation of this clustering by IDPs and IDRs such as synucleins and rab proteins. Efforts will also include investigating the role of condensate formation in the organization of tubulo- vesicular organelles such as the endocytic recycling compartment (ERC). These systems will be characterized using structure/function analyses combining in vitro characterization of condensate formation and vesicle recruitment/release with in situ and in vivo functional studies. Achieving the overarching goals of this proposal will serve to advance our understanding of different mechanisms that underlie the roles of IDPs and IDRs in the regulation of membrane trafficking and organization. By focusing on specific models with physiological significance, namely factors governing vesicle exocytosis and the formation of clustered vesicular structures in neurons and other cell types, the results will make a significant impact on specific fields as well as broaden our general understanding of how protein disorder contributes to the organization of cellular membranes.

项目总结/摘要 内含子无序蛋白和蛋白质区域（IDP和IDR）缺乏稳定的三级结构，但保留了其特有的结构。 生物功能。理解这种无序蛋白质区域的结构/功能关系 由于其高度可变和动态的性质，这是一个重大挑战。过去几年 导致人们进一步认识和认识到国内流离失所者和国内流离失所者在 膜运输和组织。拟议研究的主要目标是推进我们的 了解IDP的动态和高度可变的结构如何介导其在膜中的功能 贩运和组织。膜运输和组织中IDP功能的一个关键方面涉及 直接的IDP-膜相互作用，这可以与无序到有序的转变结合发生，或者在 没有蛋白质排序。膜结合两亲性螺旋（AH）的形成是最常见的 前者的例子，但潜在的机制和调节的形成，稳定性，特异性和 这种膜相关AH的功能仍然知之甚少。控制膜结合的因素 在束缚态下保持无序的IDR甚至更不容易理解。拟议的一个主要领域 研究中心是利用蛋白质描绘这些类型的IDP-膜相互作用的机制 复合蛋白作为模型，通过体外结构和动力学表征以及体内 功能测定IDP功能的另一个新出现的方面是它们能够介导 浓缩物或无膜细胞器。最近，已经证明含IDR的膜- 结合蛋白可以形成胞质凝聚物，其隔离和组织细胞内的 膜囊泡调节冷凝物与有机物相互作用和组织能力的机制 膜囊泡或隔室几乎没有被探索过，代表了本领域的第二个主要焦点。 提议这些努力的主要模型系统将是由蛋白质介导的膜囊泡的聚集。 突触蛋白，以及由IDP和IDR（如突触核蛋白和rab）对这种聚集的调节， proteins.努力还将包括调查凝析油形成在组织中的作用， 囊泡细胞器，如内吞再循环室（ERC）。这些系统将被描述为 使用结构/功能分析，结合体外表征冷凝物形成和囊泡 通过原位和体内功能研究进行募集/释放。实现本提案的总体目标 这将有助于我们进一步了解国内流离失所者和国内流离失所者在以下方面的作用所依据的不同机制： 膜运输和组织的调节。通过关注具有生理学特征的特定模型， 的意义，即控制囊泡胞吐作用和聚集的囊泡结构的形成的因素， 神经元和其他细胞类型，结果将对特定领域产生重大影响，并拓宽我们的研究领域。 对蛋白质紊乱如何促进细胞膜组织的一般理解。