Increasing the Complexity of Microtubule-based transport: Cargo adaptors and Hitchhiking on Vesicles.

增加基于微管的运输的复杂性：货物适配器和囊泡搭便车。

• 批准号: 10713449
• 负责人: JOHN SALOGIANNIS
• 金额: $ 39万
• 依托单位: UNIVERSITY OF VERMONT & ST AGRIC COLLEGE
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-22 至 2028-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10713449
• 关键词: Adaptor Signaling Protein; Address; Affect; Binding; Biochemistry; Biological Models; Cell physiology; Defect; Development; Disease; Dynein ATPase; Eukaryotic Cell; Genetic; Goals; Growth; Kinesin; LRRK2 gene; Link; Membrane; Microscopy; Microtubules; Molecular; Molecular Motors; Motor; Movement; Mutation; Neurodegenerative Disorders; Neurodevelopmental Disorder; Organelles; Parkinson Disease; Phosphorylation Site; Phosphotransferases; Play; Positioning Attribute; Research; Role; Site; Specificity; Vesicle; age related; cell growth; macromolecule; malignant neurologic neoplasms; nervous system disorder; organelle movement; rab GTP-Binding Proteins; recruit; trafficking

PROJECT SUMMARY Proper positioning of intracellular cargos (organelles, vesicles, and macromolecules) is critical for cell growth, maturation, and survival. Eukaryotic cells use the molecular motors dynein and kinesin to transport cargos along microtubule tracks. Defects in microtubule-based transport and mutations in the motors themselves, are an underlying feature of many neurodevelopmental and neurodegenerative diseases. Since each type of cargo is tuned for specific cellular functions, their loading, movement and unloading along microtubules requires divergent transport mechanisms. How is cargo specificity on microtubules achieved? This proposal will address this with an in-depth analysis of the two major modes of microtubule-based transport. The canonical view, known as the cargo adaptor mode, is that each cargo interacts with specific adaptor proteins capable of recruiting molecular motors. The regulatory mechanisms by which cargos selectively load and unload from these cargo adaptors are not well understood. One goal of this proposal is to determine how a conserved phosphorylation site on vesicle-bound Rab GTPases affects interactions with dynein cargo adaptors and ultimately, how these interactions affect cellular function. Importantly, this Rab phosphorylation site is the predominant target of the Parkinson’s disease-linked kinase LRRK2. The other mode of transport is called organelle hitchhiking. In hitchhiking, Rab-vesicles can direct the movement of organelles on microtubules. To accomplish this, organelles attach to (or ‘hitchhike’ on) motor-driven Rab-vesicles at membrane contact sites. Organelle hitchhiking is a new, relatively unexplored paradigm of microtubule-based transport, and the underlying molecular mechanisms are not well understood. What are the molecular linkers, tethers, and regulators of organelle hitchhiking? Is this a prominent mode of microtubule-based transport? This proposal will use genetics, microscopy, and biochemistry in both fungal and mammalian model systems to address these questions. Taken together, studying the two main modes of microtubule-based transport is extremely important, given the critical roles Rabs, vesicles, and hitchhiking cargos play in development and age-related diseases.

项目概要 细胞内货物（细胞器、囊泡和大分子）的正确定位对于细胞生长至关重要， 成熟和生存。真核细胞使用分子马达动力蛋白和驱动蛋白来运输货物 微管轨道。基于微管的运输缺陷和马达本身的突变是一个 许多神经发育和神经退行性疾病的基本特征。由于每种类型的货物都是 针对特定的细胞功能进行调整，它们沿着微管的加载、移动和卸载需要 不同的运输机制。微管上的货物特异性是如何实现的？该提案将解决 这是对基于微管的运输的两种主要模式的深入分析。已知的规范观点 作为货物适配器模式，每个货物与能够招募的特定适配器蛋白相互作用 分子马达。货物选择性地装卸这些货物的监管机制 适配器还没有被很好地理解。该提案的一个目标是确定保守磷酸化如何 囊泡结合的 Rab GTPases 上的位点影响与动力蛋白货物适配器的相互作用，并最终影响这些 相互作用影响细胞功能。重要的是，这个 Rab 磷酸化位点是 帕金森病相关激酶 LRRK2。另一种交通方式称为细胞器搭便车。在 Rab 囊泡可以搭便车引导微管上细胞器的运动。为了实现这一目标，细胞器 在膜接触位点附着（或“搭便车”）电机驱动的 Rab 囊泡。细胞器搭便车是一种新的、 相对未经探索的基于微管的运输范例，其潜在的分子机制是 不太理解。细胞器搭便车的分子连接体、系链和调节因子是什么？这是一个 基于微管的运输的突出模式？该提案将使用遗传学、显微镜学和生物化学 在真菌和哺乳动物模型系统中解决这些问题。两者结合起来研究 鉴于 Rab、囊泡和细胞的关键作用，基于微管的运输的主要模式极其重要。 搭便车的货物在发育和与年龄相关的疾病中发挥着作用。