Mechanism of centrosome regulation from the Golgi

描述（由申请人提供）：本项目的目的是了解哺乳动物细胞中从邻近高尔基体调节中心体的控制机制。虽然高尔基体和中心体的接近是哺乳动物细胞所特有的，并且在酵母、植物或苍蝇细胞中没有观察到，但其功能意义一直是难以捉摸的。我们实验室的工作已经确定了一个中心体调节途径，其中高尔基体蛋白GM 130导致称为Tuba的鸟嘌呤核苷酸交换因子激活高尔基体上的Cdc 42。本项目旨在确定这些事件在高尔基体控制中心体的组织和功能，以及它们是否依赖于高尔基体中心体的接近。 目的1将确定GM 130是否通过增加Tuba对Cdc 42的结合亲和力或通过将Cdc 42募集到高尔基体来激活高尔基体处的Cdc 42。这一目标还将检查是否GM 130是主要的调节器Cdc 42在高尔基体的检测是否GM 130控制额外的细胞过程中，在高尔基体是已知的由Cdc 42，如高尔基体ER运输和本地肌动蛋白组装在高尔基体。一个潜在的高尔基体相关的Cdc 42负调节也将进行研究。 目的2将研究GM 130-Cdc 42通路如何对中心体发挥作用。Cdc 42效应子Par 6？，将进行研究，以确定它是否是该调节途径的下游组分，以及它是否通过动力蛋白动力蛋白通过与动力肌动蛋白亚基p150 Glued的相互作用转运到中心体。PCM-1，一种招募额外蛋白质到中心体的蛋白质，将被研究以确定它是否在Par 6下游起作用？通过GM 130-Cdc 42途径介导中心体组织的控制。 目的3通过检测Cdc 42是否可以从高尔基体被动员到中心体，从而调节中心体的组织，来研究高尔基体-中心体邻近的功能意义。高尔基体的中心粒周围位置将被破坏，作为另一种测试高尔基体中心体邻近是否是由GM 130-Cdc 42途径调节中心体组织所必需的手段。

DESCRIPTION (provided by applicant): The objective of this project is to understand a control mechanism that regulates the centrosome from the adjacent Golgi apparatus in mammalian cells. While the proximity of the Golgi and centrosome is unique to mammalian cells, and not observed in yeast, plant or fly cells, its functional significance has been elusive. Work in our laboratory has identified a centrosome regulatory pathway in which a Golgi protein, GM130, causes a guanine nucleotide exchange factor called Tuba to activate Cdc42 at the Golgi. This project seeks to determine how these events at the Golgi control centrosome organization and function and whether they depend on Golgi-centrosome proximity. Aim 1 will determine whether GM130 activates Cdc42 at the Golgi by increasing the binding affinity of Tuba for Cdc42 or by recruiting Cdc42 to the Golgi. This aim will also examine if GM130 is the major regulator of Cdc42 at the Golgi by assaying whether GM130 controls additional cellular processes at the Golgi that are known to be regulated by Cdc42, such as Golgi to ER transport and local actin assembly at the Golgi. A potential negative regulator of Golgi-associated Cdc42 will also be studied. Aim 2 will examine how the GM130-Cdc42 pathway exerts its effect on the centrosome. A Cdc42 effector, Par6?, will be studied to determine if it is a downstream component of this regulatory pathway and if it is transported to the centrosome by the motor protein, dynein, through interactions with the dynactin subunit, p150Glued. PCM-1, a protein that recruits additional proteins to the centrosome, will be studied to determine if it acts downstream of Par6? to mediate the control of centrosome organization by the GM130-Cdc42 pathway. Aim 3 will study the functional significance of Golgi-centrosome proximity by examining if Cdc42 can be mobilized from the Golgi to the centrosome so that it can regulate centrosome organization. The pericentriolar location of the Golgi will be disrupted as another means of testing whether Golgi centrosome proximity is necessary for regulation of centrosome organization by the GM130-Cdc42 pathway.