Differential regulation of AQP2 trafficking in endosomes by microtubules and actin filaments
Differential regulation of AQP2 trafficking in endosomes by microtubules and actin filaments
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DOI：
10.1007/s00418-005-0010-3
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发表时间：
2005-07-01
影响因子：
2.3
通讯作者：
Takata, K
中科院分区：
文献类型：
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作者：
Tajika, Y;Matsuzaki, T;Takata, K
加压素诱导的肾脏集合管细胞水通道蛋白2（AQP2）的运输对调节尿液浓度至关重要。为了更好地理解AQP2的亚细胞运输机制，我们检测了表达AQP2的MDCK细胞作为模型。我们首先进行了双重免疫标记的AQP2与内体标记蛋白，并显示AQP2是存储在Rab11阳性subapical室。在转运到质膜后，AQP2被内吞到EEA1阳性的早期内体，然后转移回原来的Rab11阳性隔室。当Rab11被RNA干扰耗尽时，AQP2在根尖下储存室的保留受损。我们接下来研究了细胞骨架在AQP2运输和定位中的作用。用微管破坏剂如诺考达唑或秋水仙胺处理，改变了AQP2储存室的分布。用细胞松弛素D或latrunculin B破坏肌动蛋白丝可诱导AQP2在EEA1阳性早期内体中积累。总之，我们的数据表明，Rab11和微管保持适当的分布的亚顶端AQP2的存储室，和肌动蛋白丝调节运输的AQP2从早期内体的存储室。
Vasopressin-induced trafficking of aquaporin-2 (AQP2) water channels in kidney collecting duct cells is critical to regulate the urine concentration. To better understand the mechanism of subcellular trafficking of AQP2, we examined MDCK cells expressing AQP2 as a model. We first performed double-immunolabeling of AQP2 with endosomal marker proteins, and showed that AQP2 is stored at a Rab11-positive subapical compartment. After the translocation to the plasma membrane, AQP2 was endocytosed to EEA1-positive early endosomes, and then transferred back to the original Rab11-positive compartment. When Rab11 was depleted by RNA interference, retention of AQP2 at the subapical storage compartment was impaired. We next examined the role of cytoskeleton in the AQP2 trafficking and localization. By the treatment with microtubule-disrupting agent such as nocodazole or colcemid, the distribution of AQP2 storage compartment was altered. The disruption of actin filaments with cytochalasin D or latrunculin B induced the accumulation of AQP2 in EEA1-positive early endosomes. Altogether, our data suggest that Rab11 and microtubules maintain the proper distribution of the subapical AQP2 storage compartment, and actin filaments regulate the trafficking of AQP2 from early endosomes to the storage compartment.