Mechanism of myosin motor-dependent filopodia formation

肌球蛋白运动依赖性丝状伪足形成机制

• 批准号: 10220456
• 负责人: MARGARET A TITUS
• 金额: $ 38.51万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-15 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10220456
• 关键词: 3-Dimensional; Actins; Amoeba genus; Biological Assay; Biological Models; Cells; Cellular Structures; Complex; Dictyostelium; Dictyostelium discoideum; Environment; Epithelial; Event; Filopodia; Fluorescence Resonance Energy Transfer; Generations; Head; Human; In Vitro; Invaded; Knowledge; Lead; Length; Mammalian Cell; Mediating; Membrane; Microfilaments; Modeling; Molecular; Monomeric GTP-Binding Proteins; Motor; Motor Activity; Myosin ATPase; Nature; Neurons; Nonmuscle Myosin Type IIA; Organism; Polymerase; Process; Property; Proteins; Regulation; Role; Signal Transduction; Structure; Tail; Test Result; Tissues; Work; axon guidance; base; cancer cell; cell type; cohort; crosslink; experimental study; high resolution imaging; imaging approach; in silico; in vitro Assay; in vivo; insight; mathematical model; migration; polymerization; recruit; social; therapeutic development; tumor; vasodilator-stimulated phosphoprotein

Project Summary Migrating cells use filopodia to interact with and efficiently move through their complex 3D environments. Filopodia are slender actin-filled projections composed of a core of cross-linked, parallel actin bundles. They are highly dynamic, vary in length and found in a wide variety of cell types such as neurons that use them for gradient sensing and efficient directional migration or cancer cells that employ them for moving out from tumors into neighboring tissue. The first steps of filopodia formation are poorly understood. Three conserved proteins are required for their formation - a MyTH4-FERM myosin) and two regulators ofactin polymerization, VASP and Formin. How the action of these three proteins is coordinated to initiate filopodia formation is unknown. The objective of this proposal is to define the molecular mechanism of filopodia initiation with an emphasis on the role of a MF myosin and its functional relationship to the actin polymerase VASP in this process. Recent work revealed that activation and specific targeting of the MF myosin to the cortex requires the actin polymerization activity of the regulator VASP. The versatile model system Dictyostelium will be used to define the mechanism of this collaborative interaction. It will also be used to investigate how the myosin motor and actin regulator work together to organize the fast-growing ends of actin filaments at the membrane to initiate polymerization. A combination of in vivo, in vitro and in silico approaches will be employed to a) gain new insight into the regulation and mechanism of filopodia initiation and filopodial function in vivo; b) characterize the MF myosin motor and its interaction with the actin network in vitro; and c) build a predictive mathematical model of filopodia initiation. The knowledge generated by this project will reveal how cells use a myosin-based motor to build specific actin-based structures such as filopodia. Understanding how initiation occurs will also reveal how cells control filopodia formation to undergo directed migration or invade into surrounding tissues.

项目摘要 迁移细胞使用丝状伪足与复杂的3D环境进行交互并有效地移动。 丝状伪足是由交联的平行肌动蛋白束组成的细长的肌动蛋白填充的突起。他们 是高度动态的，长度不同，并发现在各种各样的细胞类型，如神经元，使用它们 梯度传感和有效的定向迁移或癌细胞， 肿瘤扩散到邻近组织 丝状伪足形成的第一步知之甚少。三个保守的蛋白质是必需的， 形成-MyTH 4-FERM肌球蛋白）和两种肌动蛋白聚合调节剂VASP和形成蛋白。如何 这三种蛋白质的协同作用引发丝状伪足的形成尚不清楚。的目的 建议是定义丝状伪足起始的分子机制，重点是MF的作用 肌球蛋白及其在此过程中与肌动蛋白聚合酶VASP的功能关系。最近的研究表明， MF肌球蛋白的激活和特异性靶向皮质需要肌球蛋白的肌动蛋白聚合活性。 调节器VASP。多功能模型系统Dictyosteoblast将被用来定义这一机制， 协作互动。它也将用于研究肌球蛋白马达和肌动蛋白调节器如何工作 一起组织细胞膜上快速生长的肌动蛋白丝末端，引发聚合。一 将采用体内、体外和计算机模拟方法的组合，以a）获得对 体内丝状伪足起始和丝状伪足功能的调节和机制; B）表征MF肌球蛋白 运动及其与体外肌动蛋白网络的相互作用;以及c）建立运动的预测数学模型。 丝状伪足起始 该项目产生的知识将揭示细胞如何使用基于肌球蛋白的马达来构建特定的细胞。 肌动蛋白为基础的结构，如丝状伪足。了解启动如何发生也将揭示细胞如何控制 丝状伪足形成经历定向迁移或侵入周围组织。