Cell Surface Recognition and Cell Interactions

描述（由申请人提供）：发育中的关键信号通路取决于初级纤毛产生的动态细胞区室。在脊椎动物中，只有当质膜定位的Shh效应Smo在初级纤毛中积累时，Shh通路才被激活，Smo在初级纤毛中调节纤毛定位的转录因子和组织发育。在单细胞双鞭毛绿色衣原体中，粘附受体SAG 1存在于质膜上，并通过功能屏障限制其进入纤毛。然而，在细胞-细胞相互作用期间纤毛产生信号后，SAG 1移动到纤毛的基部，克服屏障，并移动到睫状膜上。生物学中一个关键的未回答的问题是细胞如何在信号通路的激活过程中建立和调节纤毛的蛋白质组成。与动物细胞不同，我们可以从衣原体中分离出纤毛，我们可以分离出纤毛运输机制，IFT。在这里，我们将利用这个简单的系统来研究细胞和分子机制的基础上的能力，细胞调节纤毛定位的膜蛋白在纤毛产生的信号。

DESCRIPTION (provided by applicant): Key signaling pathways in development depend on the dynamic cellular compartment created by the primary cilium. In vertebrates, the Shh pathway is activated only when the plasma membrane-localized Shh effector Smo accumulates in the primary cilium, where Smo regulates cilium-localized transcription factors and tissue development. In the unicellular biflagellated green alga Chlamydomonas, the adhesion receptor SAG1 is present on the plasma membrane and restricted from entering the cilium by a functional barrier. Upon cilium-generated signaling during cell-cell interactions, however, SAG1 moves to the bases of the cilia, overcomes the barrier, and moves onto the ciliary membrane. A crucial unanswered question in biology is how cells establish and regulate the protein composition of cilia during activation of signaling pathways. Unlike in animal cells, we can isolate cilia from Chlamydomonas and we can inactivate the ciliary transport machinery, IFT. Here, we will exploit the multiple advantages of this simple system to study the cellular and molecular mechanisms that underlie the ability of cells to regulate the ciliary localization of a membrane protein during cilium-generated signaling.