Mechanisms for the Termination of Myosin V-Mediated Transport

肌球蛋白 V 介导的转运终止机制

• 批准号: 9327467
• 负责人: Sara Wong
• 金额: $ 3.58万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-02-28 至 2020-02-27
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9327467
• 关键词: Actins; Adaptor Signaling Protein; Affect; Animals; BRCT Domain; Binding; Biology; CDC2 Protein Kinase; Cell Cycle; Cell Polarity; Cell physiology; Cells; Complex; Cyclin-Dependent Kinases; Cytomegalovirus Infections; Cytoskeleton; Data; Defect; Destinations; Disease; Event; Goals; Griscelli Syndrome; Impairment; Inherited; Knowledge; Laboratories; Lead; Location; Lysosomes; Malignant Neoplasms; Mediating; Modeling; Molecular; Molecular Conformation; Molecular Motors; Motor; Mutate; Mutation; Myosin ATPase; Myosin Type V; Neurologic; Organelles; Pathway interactions; Phosphorylation; Physiology; Pigments; Recruitment Activity; Regulation; Role; Signal Transduction; Skin; Skin Pigmentation; Tertiary Protein Structure; Testing; Time; Travel; Ubiquitin-Conjugating Enzymes; Vacuole; Yeasts; base; cell type; cellular microvillus; in vivo; insight; mutant; nervous system disorder; novel; p21 activated kinase; peroxisome; polarized cell; spatiotemporal; ubiquitin-protein ligase

Project Summary/Abstract: The organization of organelles within cells is a critical factor in normal cellular function as well as animal physiology. Many pathways contribute to the localization of organelles; one example is molecular motors that transport cargoes to a designated location to establish cellular polarity. This proposal focuses on myosin V motors. Defects in myosin V motors cause mislocalization of cargoes, which underlies several diseases including skin pigment disorders, gut diseases, and neurological disorders. The regulation of myosin V based cargo transport occurs in part via the regulation of cargo-specific adaptor proteins. This proposal focuses on the yeast vacuole/lysosome, which is inherited in coordination with the cell cycle. Early in the cell cycle, the myosin V motor, Myo2, attaches to the vacuole via the vacuole specific adaptor, Vac17. This attachment is regulated in part by the cyclin dependent kinase Cdk1. Notably, detachment from Myo2 is also highly controlled, indicating that complex mechanisms signal that the cargo has arrived at the correct location. Release of Myo2 from the vacuole requires an E3 ubiquitin ligase, Dma1, which is recruited to the PEST sequence on Vac17. Moreover, Dma1 is also essential for the release of peroxisomes, suggesting a conserved role for Dma1 in terminating Myo2 mediated cargo transport. Our preliminary studies suggest that an additional step is required to facilitate Dma1 dependent ubiquitylation of Vac17. We found that Cla4 directly phosphorylates Vac17-S222, and that this phosphorylation event is important for release of the vacuole from the bud tip, ubiquitylation of Vac17, and ultimately Vac17 turnover. Additionally, inhibiting Cla4-dependent phosphorylation of Va17 results in the accumulation of Vac17 at the bud tip, suggesting that Cla4 acts as a spatiotemporal regulator and initiates the termination of vacuole transport. My central hypothesis is that there are mechanisms that signal that myosin V has arrived at its destination, which in turn regulates the release of its cargoes. In this proposal, I aim to determine the downstream consequences of Cla4-dependent phosphorylation of Vac17. These studies will elucidate mechanisms that regulate motor-based cargo delivery and provide greater insight into diseases caused by impaired myosin V mediated cargo transport.

项目摘要/摘要： 细胞内细胞器的组织是正常细胞功能和动物的关键因素 生理。许多途径有助于细胞器的定位。一个例子是分子电机 将货物运输到指定位置以建立细胞极性。该建议重点介绍肌球蛋白V 电动机。肌球蛋白V电动机的缺陷导致货物的错误定位，这是几种疾病的基础 包括皮肤色素疾病，肠道疾病和神经系统疾病。基于肌球蛋白V的调节 货物运输部分通过调节货物特异性适配器蛋白的调节而发生。该提议重点 酵母液泡/溶酶体，与细胞周期协调。在细胞周期的早期， 肌球蛋白V电动机MyO2通过液泡特定的适配器VAC17连接到液泡上。这个附件是 部分由细胞周期蛋白依赖性激酶CDK1调节。值得注意的是，与Myo2的分离也很高 受控，表明复杂的机制表明货物已经到达正确的位置。 从液泡中释放Myo2需要E3泛素连接酶DMA1，该连接酶被招募到害虫 VAC17的序列。此外，DMA1对于释放过氧化物酶体也是必不可少的，这表明 DMA1在终止Myo2介导的货物运输方面的保守作用。我们的初步研究表明 需要一个额外的步骤来促进VAC17的DMA1依赖性泛素化。我们发现Cla4直接 磷酸化VAC17-S222，并且这种磷酸化事件对于从中释放液泡很重要 VAC17的芽尖，泛素化和最终的VAC17营业额。另外，抑制CLA4依赖性 VA17的磷酸化导致VAC17在芽尖端的积累，表明CLA4充当 时空调节器并启动液泡运输的终止。我的中心假设是 是肌球蛋白V到达目的地的机制，这反过来又调节了释放 它的货物。在此提案中，我旨在确定CLA4依赖性的下游后果 VAC17的磷酸化。这些研究将阐明调节基于电机货物的机制 并提供对肌球蛋白V介导的货物运输受损引起的疾病的更深入的洞察力。