Regulation of flagellar dynein by calcium and a role for an axonemal calmodulin and calmodulin-dependent kinase.
Regulation of flagellar dynein by calcium and a role for an axonemal calmodulin and calmodulin-dependent kinase.
复制标题
钙对鞭毛动力蛋白的调节以及轴丝钙调蛋白和钙调蛋白依赖性激酶的作用。
DOI：
10.1091/mbc.e02-04-0185
复制
发表时间：
2002
影响因子：
3.3
通讯作者：
Smith,ElizabethF
中科院分区：
文献类型：
--
作者：
Smith,ElizabethF
纤毛和鞭毛的运动由鞭毛内钙的变化来调节。然而，钙控制运动的分子机制尚不清楚。我们测试了钙通过控制动力蛋白驱动的微管滑动来调节运动的假设，以及中央对和径向辐条参与了这一调节。我们从衣原体突变株中分离出轴丝，并在含有1 mM三磷酸腺苷和不同浓度钙的缓冲液中测量微管滑动速度。在使用PCA>；8的缓冲液中，缺少中枢器的轴丝(pf18和pf15)的微管滑动速度比野生型轴丝的微管滑动速度要慢。相反，在pCa4，pf18和pf15轴丝的动力蛋白活性恢复到野生型水平。钙诱导的pf18轴丝的动力蛋白活性增加可被钙调素和钙调蛋白依赖的激酶II拮抗剂抑制。缺少c1中央小管的轴丝(Pf16)或缺乏径向辐条成分的轴丝(pf14和pf17)不表现出钙诱导的pCa4缓冲液中动力蛋白活性的增加。我们的结论是，钙对鞭毛运动的调节涉及到对动力蛋白驱动的微管滑动的调节，钙调蛋白和钙调蛋白依赖的激酶II可能介导了钙信号，中枢器和放射状辐条是钙信号通路的关键组成部分。
Ciliary and flagellar motility is regulated by changes in intraflagellar calcium. However, the molecular mechanism by which calcium controls motility is unknown. We tested the hypothesis that calcium regulates motility by controlling dynein-driven microtubule sliding and that the central pair and radial spokes are involved in this regulation. We isolated axonemes fromChlamydomonasmutants and measured microtubule sliding velocity in buffers containing 1 mM ATP and various concentrations of calcium. In buffers with pCa > 8, microtubule sliding velocity in axonemes lacking the central apparatus (pf18andpf15) was reduced compared with that of wild-type axonemes. In contrast, at pCa4, dynein activity inpf18andpf15axonemes was restored to wild-type level. The calcium-induced increase in dynein activity inpf18axonemes was inhibited by antagonists of calmodulin and calmodulin-dependent kinase II. Axonemes lacking the C1 central tubule (pf16) or lacking radial spoke components (pf14andpf17) do not exhibit calcium-induced increase in dynein activity in pCa4 buffer. We conclude that calcium regulation of flagellar motility involves regulation of dynein-driven microtubule sliding, that calmodulin and calmodulin-dependent kinase II may mediate the calcium signal, and that the central apparatus and radial spokes are key components of the calcium signaling pathway.