Pan Junmin, Wang Qian, Snell William J
Department of Cell Biology, University of Texas Southwestern Medical School, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
Dev Cell. 2004 Mar;6(3):445-51. doi: 10.1016/s1534-5807(04)00064-4.
Cilia and flagella play key roles in development and sensory transduction, and several human disorders, including polycystic kidney disease, are associated with the failure to assemble cilia. Here, we show that the aurora protein kinase CALK in the biflagellated alga Chlamydomonas has a central role in two pathways for eliminating flagella. Cells rendered deficient in CALK were defective in regulated flagellar excision and regulated flagellar disassembly. Exposure of cells to altered ionic conditions, the absence of a centriole/basal body for nucleating flagellar assembly, cessation of delivery of flagellar components to their tip assembly site, and formation of zygotes all led to activation of the regulated disassembly pathway as indicated by phosphorylation of CALK and the absence of flagella. We propose that cells have a sensory pathway that detects conditions that are inappropriate for possession of a flagellum, and that CALK is a key effector of flagellar disassembly in that pathway.
纤毛和鞭毛在发育和感觉转导中发挥关键作用，包括多囊肾病在内的几种人类疾病都与纤毛组装失败有关。在此，我们表明双鞭毛藻类衣藻中的极光蛋白激酶CALK在两条消除鞭毛的途径中起核心作用。CALK功能缺失的细胞在受调控的鞭毛切除和受调控的鞭毛解聚方面存在缺陷。将细胞暴露于改变的离子条件下、缺乏用于启动鞭毛组装的中心粒/基体、停止向鞭毛顶端组装位点输送鞭毛成分以及合子形成，所有这些都导致受调控的解聚途径被激活，这表现为CALK的磷酸化和鞭毛的缺失。我们提出细胞具有一种感觉途径，可检测到不适合拥有鞭毛的条件，并且CALK是该途径中鞭毛解聚的关键效应器。
