Molecular motors in cell biology

运动蛋白、动力蛋白和肌球蛋白是分子马达超家族的成员，它们是驱动多种形式的关键细胞内运输的机器。这三个运动家族与动态的(和高度调控的)细胞骨架细丝协调它们的活动，以控制细胞生长，确定细胞形状，运送和极化细胞内的货物，运输内体膜，并参与信号级联。许多关键的细胞过程涉及一种类型的细胞骨架中货物细胞器的调节切换 细丝到另一个，但多个电机之间必要的协调和竞争还不清楚。这个综合计划项目将研究生长和功能细胞中分子马达的相互作用、结构、调节和生物物理机制。细胞内运动的细胞骨架轨迹，肌动蛋白和微管，基于肌动蛋白的马达，肌球蛋白I，肌球蛋白V，和基于微管的马达，细胞质动力蛋白和运动蛋白，将使用最先进的电池进行深入研究 开启激动人心的研究机会的方法。单分子荧光偏振、纳米分辨荧光团定位、红外光学陷阱、快速生化反应动力学、遗传操作以及与同一地区的超分辨光学显微镜相关的新形式的电子显微镜将被应用于合作研究，以了解单个分子马达的机制及其相互作用。这些方法产生了高度的时间和空间 分辨率，使我们能够剖析分子复杂性增加的分析中的机制，对细胞内环境的各个方面进行建模。为了便于研究以及与更广泛的细胞内运动机制相关的特定生物系统是神经元的内吞作用和囊泡运输，以及胰岛素刺激的葡萄糖转运体囊泡与脂肪细胞表膜的融合。在这项计划的所有部分和核心之间有密切的协同作用和实际联系。我们预计，拟议的工作将使我们朝着了解细胞正常和病理功能中的运动性的目标迈进一大步。

Members of the superfamilies of molecular motors, kinesins, dyneins and myosins, are the machines that drive many forms of crucial intracellular transport. The three motor families coordinate their actions with dynamic (and highly regulated) cytoskeletal filaments to control cell growth, define cell shape, deliver and polarize intracellular cargoes, traffic endosomal membranes, and participate in signaling cascades. Many critical cellular processes involve the regulated switching of cargo organelles from one type of cytoskeletal filament to another, but the requisite coordination and competition among multiple motors are not understood. This integrated program project will study the interactions, structure, regulation, and biophysical mechanisms of the molecular motors in growing and functioning cells. The cytoskeletal tracks for intracellular motility, actin and microtubules, the actin-based motors, myosin I, myosin V, and the microtubule-based motors, cytoplasmic dynein and kinesin, will be studied intensively using a battery of state-of-the-art approaches that open exciting research opportunities. Single-molecule fluorescence polarization, nanometer-resolved fluorophore localization, infrared optical traps, rapid biochemical reaction kinetics, genetic manipulations, and novel forms of electron microscopy, correlated with hyper-resolution light microscopy in the same regions, will be applied in collaborative studies to understand the mechanisms of individual molecular motors and their mutual interactions. These approaches yield high temporal and spatial resolution that enables us to dissect mechanisms in assays of increasing molecular complexity that model aspects of the intracellular environment. Particular biological systems, selected for facility of study as well as relevance to broader mechanisms of intracellular motility are endocytosis and vesicle trafficking in neurons and insulin-stimulated fusion of glucose transporter vesicles with the surface membrane in adipocytes. There are close synergies and practical links between all of the sections and cores in this program. We anticipate that the proposed work will take us significantly further toward our goal of understanding motility in the normal and pathological function of cells.