Wang Qian, Pan Junmin, Snell William J
Department of Cell Biology, University of Texas Southwestern Medical School, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
Cell. 2006 May 5;125(3):549-62. doi: 10.1016/j.cell.2006.02.044.
Primary cilia are widely used for signal transduction during development and in homeostasis and are assembled and maintained by intraflagellar transport (IFT). Here, we have dissected the role of IFT in signaling within the flagella (structural and functional counterparts of cilia) of the biflagellated green alga Chlamydomonas. Using a conditional IFT mutant enables us to deplete the IFT machinery from intact, existing flagella. We identify a cGMP-dependent protein kinase (CrPKG) within flagella as the substrate of a protein tyrosine kinase activated by flagellar adhesion during fertilization. We demonstrate that flagellar adhesion stimulates association of CrPKG with a new flagellar compartment. Moreover, formation of the compartment requires IFT, and IFT particles themselves are part of the compartment. Our results lead to a model in which the IFT machinery is required not only for assembling cilia and flagella but also for organizing a signaling pathway within the organelles during cilium-generated signaling.
初级纤毛在发育和体内平衡过程中广泛用于信号转导，并通过鞭毛内运输（IFT）进行组装和维持。在这里，我们剖析了IFT在双鞭毛绿藻衣藻鞭毛（纤毛的结构和功能对应物）内信号传导中的作用。使用条件性IFT突变体使我们能够从完整的现有鞭毛中耗尽IFT机制。我们确定鞭毛内的一种cGMP依赖性蛋白激酶（CrPKG）是受精过程中由鞭毛粘附激活的蛋白酪氨酸激酶的底物。我们证明鞭毛粘附刺激CrPKG与一个新的鞭毛区室结合。此外，区室的形成需要IFT，并且IFT颗粒本身是区室的一部分。我们的结果得出一个模型，其中IFT机制不仅是组装纤毛和鞭毛所必需的，而且在纤毛产生信号期间用于在细胞器内组织信号通路。
