IC138 Defines a Subdomain at the Base of the I1 Dynein That Regulates Microtubule Sliding and Flagellar Motility
IC138 Defines a Subdomain at the Base of the I1 Dynein That Regulates Microtubule Sliding and Flagellar Motility
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DOI：
10.1091/mbc.e09-04-0277
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发表时间：
2009-07-01
影响因子：
3.3
通讯作者：
Porter, Mary E.
中科院分区：
文献类型：
--
作者：
Bower, Raqual;VanderWaal, Kristyn;Porter, Mary E.
为了了解调节鞭毛动力蛋白的组装和活性的机制，我们专注于I1内臂动力蛋白（动力蛋白f）和无效等位基因bop 5 -2，在编码IC 138磷蛋白亚基的基因中存在缺陷。I1动力蛋白在bop 5 -2轴丝中组装，但缺乏至少四个亚基：IC 138，IC 97，LC 7 b和鞭毛相关蛋白（FAP）120-定义新的I1亚复合物。电子显微镜和图像平均显示在I1动力蛋白的基础上，在径向辐条1和外部动力蛋白武器之间的缺陷。微管滑动速度也降低。用野生型IC 138转化恢复IC 138亚复合物的组装并挽救微管滑动。这些观察结果表明，IC 138亚复合体是协调I1运动活动所必需的。为了进一步验证这一假设，我们分析了微管滑动径向辐条和双突变株。结果表明，IC 138亚复合物在调节I1活性的径向辐条/磷酸化途径中发挥着重要作用。
To understand the mechanisms that regulate the assembly and activity of flagellar dyneins, we focused on the I1 inner arm dynein (dynein f) and a null allele, bop5-2, defective in the gene encoding the IC138 phosphoprotein subunit. I1 dynein assembles in bop5-2 axonemes but lacks at least four subunits: IC138, IC97, LC7b, and flagellar-associated protein (FAP) 120-defining a new I1 subcomplex. Electron microscopy and image averaging revealed a defect at the base of the I1 dynein, in between radial spoke 1 and the outer dynein arms. Microtubule sliding velocities also are reduced. Transformation with wild-type IC138 restores assembly of the IC138 subcomplex and rescues microtubule sliding. These observations suggest that the IC138 subcomplex is required to coordinate I1 motor activity. To further test this hypothesis, we analyzed microtubule sliding in radial spoke and double mutant strains. The results reveal an essential role for the IC138 subcomplex in the regulation of I1 activity by the radial spoke/phosphorylation pathway.