Vesicle Associated Myosin-V Motor Complex

我们的神经系统包含超过10亿个神经细胞。神经细胞是专门用于将电信号从一个细胞传递到另一个细胞，并从神经细胞传递到效应细胞，如肌肉细胞。神经细胞能够以学习和记忆的形式存储信息。为了完成这些任务，神经细胞的末梢，即细胞间的通讯地点，会随着电活动而改变。肌动蛋白丝介导神经末梢的结构变化。肌动蛋白丝也作为货物向神经末梢运动的轨道。了解肌动蛋白丝重塑神经末梢和支持膜质货物向末梢运动的机制是理解学习和记忆过程所必需的。本项目旨在研究运动蛋白肌球蛋白- v如何将货物运送到神经末梢。鱿鱼是一种海洋无脊椎动物，它的神经系统将被用于这些研究。之所以选择乌贼巨大的神经纤维进行研究，是因为它足够大，可以在不损害其活性的情况下解剖观察。主要目标是确定货物运输受到管制的机制。本方案分为3个项目。第一个项目旨在了解肌凝蛋白- v如何与它的货物结合。第二个项目是确定电机与货物的绑定是否会使其从非活动状态变为活动状态。第三个项目是纯化肌球蛋白- v及其结合伙伴，并确定将马达与其货物连接起来的蛋白质。将进行生物化学和细胞生物学实验的结合。FRET是一种荧光显微镜，可以检测一种蛋白质与另一种蛋白质的直接结合，它将被用来确定与之结合的调节蛋白是否影响肌球蛋白- v的活性。化学交联和抗体沉淀实验将用于识别肌球蛋白- v的蛋白质伙伴，将其连接到其货物。这些研究将促进我们对学习和记忆机制的理解。

Our nervous system contains over a billion nerve cells. Nerve cells are specialized to transit electrical signals from cell to cell and from nerve cell to an effector cell such as a muscle cell. Nerve cells are able to store information in the form of learning and memory. To accomplish these tasks, the terminals of nerve cells, the sites of communication between cells, change in response to electrical activity. Actin filaments mediate the structural changes of the nerve terminal. Actin filaments also serve as tracks for the movement of cargo to the nerve terminal. An understanding of the mechanism by which actin filaments remodel nerve terminals and support the movement of membranous cargo to terminals are required to understand the processes of learning and memory. This project is designed to study how cargo is transported to the nerve terminal by the motor protein myosin-V. The nervous system of the squid, a marine invertebrate, will be used for these studies. The giant nerve fiber of squid is chosen for these studies because it is large enough to be dissected for observation without damaging its activity. The principal goal is to determine the mechanism by which transport of cargo is regulated. The proposal is divided into 3 projects. The first project is designed to understand how myosin-V binds to its cargo. The second project is to determine if binding of the motor to its cargo changes it from an inactive to an active state. The third project is to purify myosin-V in association with its binding partners and to identify the proteins that link the motor to its cargo. A combination of biochemical and cell biological experiments will be performed. FRET, a form of fluorescence microscopy that detects the direct binding of one protein to another will be used to determine whether regulatory proteins that bind to it affect the activity of myosin-V. Chemical cross-linking and antibody precipitation experiments will be used to identify protein partners of myosin-V that link it to its cargo. These studies will advance our understanding of the mechanisms of learning and memory.