Characterization of a Filopodial Myosin

项目总结/摘要 丝状伪足在多种细胞过程中发挥重要作用，包括免疫反应、神经元功能、 发病机制和伤口愈合。细胞使用丝状伪足来观察它们的环境， 在运动细胞中。丝状伪足是由平行的肌动蛋白束组成的细杆状细胞突起， 分化的生物体，如社会性变形虫、网骨藻和后生动物。背后的核心机制 丝状伪足的形成在整个后生动物和变形虫中是保守的，然而丝状伪足的形成机制 启动仍然未知。 MyTH 4-FERM（MF）肌球蛋白，即变形虫肌球蛋白7（DdMyo 7）和后生动物肌球蛋白10（Myo 10），是 对丝状伪足的起始至关重要。它们靶向于细胞膜，形成起始病灶，随后被 在伸长过程中富含丝状伪足尖端。丝状伪足的发生正在简单模式生物中进行研究 网骨藻，因为它具有最小的蛋白质冗余，允许有效的遗传操作， 生物化学量的材料容易获得。这项工作的最终目标是了解 MF肌球蛋白在丝状伪足起始过程中的作用。为了实现这一点，我将1）定义电机属性， DdMyo 7使用标准运动性测定和2）使用无偏接近性测定鉴定DdMyo 7相互作用配偶体 连接酶筛选。拟议实验产生的数据将提供所需的关键信息， 理解丝状伪足肌球蛋白如何驱动起始。

Project Summary/Abstract Filopodia play important roles in a variety of cellular processes including immune response, neuronal pathogenesis, and wound healing. Cells use filopodia to survey their environment and are typically upregulated in motile cells. Filopodia are thin, rod-like cellular protrusions composed of parallel bundles of actin and found in divergent organisms such as the social amoeba Dictyostelium and metazoans. The core mechanisms behind filopodia formation are conserved throughout metazoans and amoebozoans, yet the mechanism of filopodia initiation is still unknown. MyTH4-FERM (MF) myosins, the amoeboid Myosin 7 (DdMyo7) and metazoan Myosin 10 (Myo10), are essential for filopodia initiation. They are targeted to the membrane, form initiation foci, and are subsequently enriched in filopodia tips during elongation. Filopodia initiation is being studied in the simple model organism Dictyostelium because it has minimal protein redundancy, allows for efficient genetic manipulation, and biochemical quantities of material are easily obtained. The ultimate goal of the proposed work is to understand the role of MF myosins during filopodia initiation. To accomplish this, I will 1) define the motor properties of DdMyo7 using standard motility assays and 2) identify DdMyo7 interacting partners using an unbiased proximity ligase screen. The data generated by the proposed experiments will provide critical information needed to understand how a filopodia myosin drives initiation.