CYTOSKELETAL AND SIGNALING MECHANISMS REGULATING CILIARY TRAFFIC

项目摘要/摘要 细胞生物学中的一个基本问题是如何实现有针对性的细胞内蛋白质运输，以及 受监管的。问这个问题的一个很好的框架是研究到特定细胞器或细胞内的运输 车厢。蛋白质进出真核鞭毛是研究极化的理想模型 鉴于鞭毛蛋白质的合成和运输可以在实验上按需诱导运输，货物 通过蛋白质组学鉴定了蛋白质，最终的货物目的地被定位到一个非常小的 顶端细胞表面的区域。这种转运途径以前被认为只需要微管 以及通过信号通路对微管电机的调节。通过对鞭毛的定量分析 在典型的鞭毛模型系统中，我们发现肌动蛋白和 以肌动蛋白为基础的肌球蛋白马达在调节肌球蛋白的定位和区划中起着重要作用。 鞭毛蛋白。我们还确定了多种信号通路，包括磷酸酶MKP-2，它们是 是正常的鞭毛组装所必需的。我们工作的主要目标是：1)使用化学和遗传筛选 识别整合以控制鞭毛蛋白运输和鞭毛分子马达的新途径 进入；以及2)使用细胞和分子分析工具箱来剖析它们发挥作用的机制 控制力。我们希望发现一种全新的途径来研究所有被保护的分泌途径。 以及已知基因在协调细胞运输中的新功能。

Project Summary/Abstract A fundamental question in cell biology is how targeted intracellular protein trafficking is achieved and regulated. An excellent framework to ask this question is to study transport to a specific organelle or intracellular compartment. Trafficking of proteins to and into the eukaryotic flagellum is an ideal model to study polarized transport given that flagellar protein synthesis and trafficking can be induced experimentally on-demand, cargo proteins have been identified through proteomics and the ultimate cargo destination is localized to a very small region at the apical cell surface. This trafficking pathway was previously thought to only require microtubules and the regulation of microtubule motors through signaling pathways. Through quantitative analysis of flagellar motor dynamics in the canonical flagellar model system Chlamydomonas reinhardtii, we discovered that actin and an actin-based myosin motor play an important role in regulating the localization and compartmentalization of flagellar proteins. We also identified a variety of signaling pathways including a phosphatase, MKP-2, that are required for proper flagellar assembly. The broad goals of our work are to: 1) use chemical and genetic screening to identify novel pathways that integrate to control flagellar protein trafficking and molecular motors flagellar entry; and 2) use a toolbox of cellular and molecular assays to dissect the mechanisms by which they exert this control. We expect to uncover entirely new avenues for the study of secretory pathways conserved in all eukaryotes as well as novel functions for known genes in coordinated cellular trafficking.