ORGANELLE MOVEMENT IN FAST AXONAL TRANSPORT

这个项目的目标是了解膜结合细胞器是如何 在快速轴突运输过程中，神经元突起移动。两个ATPase， 动蛋白和动力蛋白，被认为是运动的马达蛋白 快速轴突内膜结合细胞器沿微管的分布 运输。人们认为，动蛋白是细胞器的马达。 顺行方向的运输(从细胞体到 突触终末)，而动力蛋白在逆行中移动细胞器 方向，从末端到细胞体。然而，许多细节 关于细胞器顺行和逆行运动的协调 仍有待解释。缺少的一个基本组成部分是理解 膜相关的动力蛋白是如何运输到突触终末的 而不干扰顺行运动。这是合理的 建议对动力蛋白的运动活性进行调控。至少两个 可以提出机制来解释这种监管：(1)a 动力蛋白的翻译后修饰可以打开和关闭它，因为 必要的；或(2)特定的调节多肽冷调节 动力蛋白的功能状态，将被确定为反映 不同功能状态的神经元胞浆动力蛋白，将 坐骨神经顺行和逆行动力蛋白的检测 神经阻滞和其他轴突运输模型系统。要确定是否 观察到的差异有助于对马达的调节 动力蛋白的活性，不同形式的功能性质 将测量动力蛋白，包括ATPase活性。功能界别 观察到的差异在磷酸化中的意义 顺行和全细胞动力蛋白多肽将被测量。这个 动力蛋白与膜结合细胞器的结合将被研究。 在体内和体外。哺乳动物脑胞浆动力蛋白抗体 将被用作动力蛋白功能的抑制性探针 挤出轴浆模型系统。

The goal of this project is to understand how membrane bounded organelles move in neuronal process during fast axonal transport. Two ATPases, kinesin and dynein, are proposed to be the motor proteins the movement of membrane bonded organelles along microtubules in fast axonal transport. It is believed that kinesin is the motor for organelle transport in the anterograde direction (from the cell body to the synaptic terminal) while dynein moves organelles in the retrograde direction, from the terminal to the cell body. However, many details about the coordination of anterograde and retrograde organelle movements remains to be explained. One basic missing component is an understanding of how membrane associated dynein is transported to the synaptic terminal without interfering with anterograde movement. It is reasonable to propose that the motor activity of dynein is regulated. At least two mechanisms can be proposed to account for such regulation:(1) a posttranslational modification of dynein could turn it on and off as necessary; or (2) specific regulatory polypeptides cold modulated the functional state of dynein, will be identified which reflect the different functional states of neuronal cytoplasmic dynein, will be tested by characterizing anterograde and retrograde dynein from sciatic nerve blocks and other axonal transport model systems. To determine if the observed differences contribute to the regulation of the motor activity of dynein, the functional properties of the different forms of dynein will be measured, including ATPase activity. The functional significance of observed differences in the phosphorylation of anterograde and whole cells dynein polypeptides will be measured. The association of dynein with membrane bounded organelles will be studied in vivo and in vitro. Antibodies to mammalian brain cytoplasmic dynein will be used as inhibitory probes of the function of dynein in the extruded axoplasm model system.