An outer arm Dynein conformational switch is required for metachronal synchrony of motile cilia in planaria.
An outer arm Dynein conformational switch is required for metachronal synchrony of motile cilia in planaria.
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DOI：
10.1091/mbc.e10-04-0373
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发表时间：
2010-11-01
影响因子：
3.3
通讯作者：
King SM
中科院分区：
文献类型：
--
作者：
Rompolas P;Patel-King RS;King SM
在这里，我们使用地中海涡虫的活动腹侧纤毛来检查外臂动力蛋白在产生和维持超同步中的作用。我们证明了单个动力蛋白轻链在机械感觉上起着必要的作用，以牵引和维持运动性纤毛的超时同步。在后生动物中，运动纤毛介导粘液和其他液体在特化上皮表面的流动。睫状体周围液体的有效清除依赖于睫状体搏动的精确协调，以产生超向波。单个动力马达的作用和这一过程所需的机械反馈机制还没有得到很好的理解。在这里，我们使用地中海施米德涡虫的纤毛上皮来解剖外臂动力马达在运动性纤毛的异时同步中的作用。我们证明，完全缺乏外部动力蛋白臂的动物表现出搏动频率的显著下降，并且纤毛无法协调它们的振荡并形成异向波。此外，缺乏关键的机械敏感调节成分（LC1）产生了类似的表型，即使外臂仍然在轴突中组装。异时性的缺乏并不仅仅是由于纤毛搏动频率的降低，因为通过改变介质粘度来降低该参数并不影响纤毛的配位性。此外，我们没有观察到受损纤毛的跳动周期有显著的时间变化。我们提出，这种构象开关在外臂动力蛋白中提供了一个机械反馈系统，这是携带超同步所必需的。
Here we use the motile ventral cilia of the planarian S. mediterranea to examine the role of outer arm dynein in the generation and maintenance of metachronal synchrony. We demonstrate that a single dynein light chain plays a mechanosensory role necessary to entrain and maintain the metachronal synchrony of motile cilia. Motile cilia mediate the flow of mucus and other fluids across the surface of specialized epithelia in metazoans. Efficient clearance of peri-ciliary fluids depends on the precise coordination of ciliary beating to produce metachronal waves. The role of individual dynein motors and the mechanical feedback mechanisms required for this process are not well understood. Here we used the ciliated epithelium of the planarian Schmidtea mediterranea to dissect the role of outer arm dynein motors in the metachronal synchrony of motile cilia. We demonstrate that animals that completely lack outer dynein arms display a significant decline in beat frequency and an inability of cilia to coordinate their oscillations and form metachronal waves. Furthermore, lack of a key mechanosensitive regulatory component (LC1) yields a similar phenotype even though outer arms still assemble in the axoneme. The lack of metachrony was not due simply to a decrease in ciliary beat frequency, as reducing this parameter by altering medium viscosity did not affect ciliary coordination. In addition, we did not observe a significant temporal variability in the beat cycle of impaired cilia. We propose that this conformational switch provides a mechanical feedback system within outer arm dynein that is necessary to entrain metachronal synchrony.