Patterning acentrosomal microtubule arrays

摘要 微管细胞骨架支持细胞分裂、细胞形态和细胞内货物运输。而当 中心体是分裂细胞中微管成核的主要部位，许多分化的细胞 无着丝体微管阵列。突出的例子包括生殖系细胞、植物表皮、上皮和 神经元。要了解细胞分化，关键是要了解无着丝体阵列结构是如何设置的。 以实现聚合物数量、长度和动力学的特定模式，以支持特定的细胞 功能，通常贯穿有机体的整个生命。 我的实验室研究了线虫无着丝体微管的形态及其对货物运输的影响。 我们开发了成像工具和算法，使微管的分析达到前所未有的水平 活体组织，并与现场成像的货物运输兼容。我们进行了无偏见的筛选，以 发现了新的微管调节器，并正在使用遗传学、成像和生化方法来了解 他们的机制。同时，我们正在研究微管阵列模式的生物学意义 研究这些调节剂对远距离细胞内运输的影响。这份提案详细说明了 建立了我们的实验系统，设计并实现了屏幕，并初步实现了 选定的监管者的特征。然后，它概述了我们未来五年的主要目标：完成屏幕 并阐明了建立无着丝体阵列结构的机制。这些研究将确定 稳态阵列结构是如何从单一聚合物成核和动力学的控制中出现的 它是如何适应特殊细胞的功能的。 微管支持细胞迁移、极化和货物运输等基本生物过程。 因此，我们的工作将产生重大影响：它将确定新的监管机构，以安排 它将决定它们形成细胞骨架和调节细胞骨架的机制 运输。细胞骨架缺陷参与了许多疾病，这表明从长远来看，我们的 研究将有助于阐明疾病期间细胞功能障碍的机制。

Abstract The microtubule cytoskeleton supports cell-division, cellular morphology and intracellular cargo transport. While the centrosome is a major site of microtubule nucleation in dividing cells, many differentiated cells harbor acentrosomal microtubule arrays. Prominent examples include germline cells, plant epidermis, epithelia and neurons. To understand cellular differentiation, it is crucial to learn how acentrosomal array architecture is set up to achieve a specific pattern of polymer numbers, length and dynamics that would support specialized cellular functions, often throughout the life of an organism. My laboratory studies the patterning of acentrosomal microtubules and its effect on cargo transport in C. elegans. We developed imaging tools and algorithms that allow an unprecedented level of analysis of microtubule organization in vivo and are compatible with live-imaging of cargo transport. We conducted unbiased screens to uncover novel microtubule regulators and are using genetics, imaging, and biochemical methods to understand their mechanisms. In parallel, we are investigating the biological significance of microtubule array patterns by examining the effects of these regulators on long-range intracellular transport. This proposal details the establishment of our experimental system, design and implementation of the screen, and preliminary characterization of select regulators. It then outlines our main goals for the next five years: completing the screen and elucidating the mechanisms that establish acentrosomal array architecture. These studies will determine how steady-state array architecture emerges from the control of single polymer nucleation and dynamics and how it is adapted to the function of specialized cells. Microtubules support fundamental biological processes such as cell migration, polarization and cargo transport. Hence, our work will have a significant impact: It will identify novel regulators that arrange the building blocks of acentrosomal arrays and it will determine the mechanisms by which they pattern the cytoskeleton and regulate transport. The involvement of cytoskeletal defects in numerous disorders suggests that in the long-range, our studies will help to shed light on mechanisms of cellular dysfunction that occurs during disease.