Molecular motors in cell biology

分子马达超家族的成员，驱动蛋白，动力蛋白和肌球蛋白，是驱动许多形式的关键细胞内运输的机器。这三个运动家族与动态的（和高度调节的）细胞骨架丝协调它们的行动，以控制细胞生长，限定细胞形状，递送和运输细胞内货物，运输内体膜，并参与信号级联。许多关键的细胞过程涉及货物细胞器从一种类型的细胞骨架的调节转换， 灯丝到另一个，但多个电机之间的必要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，肌动蛋白为基础的马达，肌球蛋白I，肌球蛋白V，和微管为基础的马达，细胞质动力蛋白和驱动蛋白，将使用一组最先进的研究 这些方法打开了令人兴奋的研究机会。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，遗传操作和新形式的电子显微镜，与超分辨率光学显微镜在同一地区相关，将应用于合作研究，以了解单个分子马达及其相互作用的机制。这些方法在时间和空间上产生了很高的 分辨率，使我们能够剖析机制，在日益增加的分子复杂性，模型方面的细胞内环境的测定。为便于研究以及与更广泛的细胞内运动机制相关而选择的特定生物系统是神经元中的内吞作用和囊泡运输以及脂肪细胞中葡萄糖转运体囊泡与表面膜的胰岛素刺激融合。有密切的协同作用和实际联系之间的所有部分和核心在这个程序。我们预计，拟议的工作将使我们进一步朝着我们的目标，了解运动在正常和病理功能的细胞。

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.