Caenorhabditis elegans screen reveals role of PAR-5 in RAB-11-recycling endosome positioning and apicobasal cell polarity
Caenorhabditis elegans screen reveals role of PAR-5 in RAB-11-recycling endosome positioning and apicobasal cell polarity
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DOI：
10.1038/ncb2508
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发表时间：
2012-07-01
影响因子：
21.3
通讯作者：
Zerial, Marino
中科院分区：
文献类型：
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作者：
Winter, Julia Franziska;Hoepfner, Sebastian;Zerial, Marino
顶端浓缩的Rab11阳性循环内含体(Rab11-RES)对于建立和维持上皮极性非常重要。然而，关于在体内控制Rab11-RES在上皮细胞中运输的分子还知之甚少。在这里，我们报告了一个全基因组的，基于图像的RNA干扰屏幕，用于调节Rab11-RE顶膜蛋白(PEPT-1)在线虫肠道中的定位和运输。在356个屏幕点击中，有14-3-3和分割缺陷蛋白PAR-5，我们发现它是Rab11-RE定位和基底根尖极性维持所特需的。PAR-5的缺失导致Rab11-RES异常聚集到含有F-肌动蛋白和其他顶端结构域成分的基底外侧皮质的异位部位。这种表型需要F-肌动蛋白动力学和极性的关键调节因子，如Rho GTP酶(Rho-1和rac1同源CED-10)和顶端PAR蛋白。我们的数据表明，PAR-5作为调节中心，为F-肌动蛋白的基底部不对称和正确的Rab11-RE定位所需的极性维持网络发挥作用。
Apically enriched Rab11-positive recycling endosomes (Rab11-REs) are important for establishing and maintaining epithelial polarity. Yet, little is known about the molecules controlling trafficking of Rab11-REs in an epithelium in vivo. Here, we report a genome-wide, image-based RNA interference screen for regulators of Rab11-RE positioning and transport of an apical membrane protein (PEPT-1) in C. elegans intestine. Among the 356 screen hits was the 14-3-3 and partitioning defective protein PAR-5, which we found to be specifically required for Rab11-RE positioning and apicobasal polarity maintenance. Depletion of PAR-5 induced abnormal clustering of Rab11-REs to ectopic sites at the basolateral cortex containing F-actin and other apical domain components. This phenotype required key regulators of F-actin dynamics and polarity, such as Rho GTPases (RHO-1 and the Rac1 orthologue CED-10) and apical PAR proteins. Our data suggest that PAR-5 acts as a regulatory hub for a polarity-maintaining network required for apicobasal asymmetry of F-actin and proper Rab11-RE positioning.