Cdc42 Regulates Microtubule-Dependent Golgi Positioning
Cdc42 Regulates Microtubule-Dependent Golgi Positioning
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DOI：
10.1111/j.1600-0854.2010.01082.x
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发表时间：
2010-08-01
期刊：
影响因子：
4.5
通讯作者：
Stamnes, Mark
中科院分区：
文献类型：
--
作者：
Hehnly, Heidi;Xu, Weidong;Stamnes, Mark
对依赖于细胞因子的高尔基体定位的分子机制知之甚少。在哺乳动物细胞中，高尔基体通过动力蛋白介导的沿着微管的运动而定位于细胞核中心体附近。先前的研究暗示Cdc 42在调节动力蛋白依赖的运动。在这里，我们表明，Cdc 42特异性GTPase-activating蛋白ARHGAP 21的表达减少会抑制分散的高尔基体膜在诺考达唑处理和洗脱后重新定位在中心体的能力。Cdc 42调节高尔基体定位似乎涉及ARF 1和与囊泡外壳蛋白coatomer的结合相互作用。我们测试是否Cdc 42直接影响运动，而不是形成一个贩运中间体，使用高尔基体捕获和运动测定透化细胞。破坏Cdc 42激活或coatomer/Cdc 42结合相互作用刺激高尔基体运动。coatomer/Cdc 42敏感的运动性被阻断的抑制性动力蛋白抗体的加入。总之，我们的研究结果表明，动力蛋白和微管依赖的高尔基体定位是由ARF 1，coatomer，和ARHGAP 21依赖的Cdc 42信号。
The molecular mechanisms underlying cytoskeleton-dependent Golgi positioning are poorly understood. In mammalian cells, the Golgi apparatus is localized near the juxtanuclear centrosome via dynein-mediated motility along microtubules. Previous studies implicate Cdc42 in regulating dynein-dependent motility. Here we show that reduced expression of the Cdc42-specific GTPase-activating protein, ARHGAP21, inhibits the ability of dispersed Golgi membranes to reposition at the centrosome following nocodazole treatment and washout. Cdc42 regulation of Golgi positioning appears to involve ARF1 and a binding interaction with the vesicle-coat protein coatomer. We tested whether Cdc42 directly affects motility, as opposed to the formation of a trafficking intermediate, using a Golgi capture and motility assay in permeabilized cells. Disrupting Cdc42 activation or the coatomer/Cdc42 binding interaction stimulated Golgi motility. The coatomer/Cdc42-sensitive motility was blocked by the addition of an inhibitory dynein antibody. Together, our results reveal that dynein and microtubule-dependent Golgi positioning is regulated by ARF1-, coatomer-, and ARHGAP21-dependent Cdc42 signaling.