Mechanistic framework for cell-intrinsic re-establishment of PIN2 polarity after cell division
Mechanistic framework for cell-intrinsic re-establishment of PIN2 polarity after cell division
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DOI：
10.1038/s41477-018-0318-3
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发表时间：
2018-12-01
期刊：
影响因子：
18
通讯作者：
Friml, Jiri
中科院分区：
文献类型：
--
作者：
Glanc, Matous;Fendrych, Matyas;Friml, Jiri
细胞极性，表现为蛋白质在不同极性质膜域的定位，是多细胞生命的关键先决条件。在植物中，PIN生长素转运体是重要的极性标记，对多种发育过程至关重要。植物的细胞极性机制不同于其他真核生物，在很大程度上仍然难以捉摸。特别是，细胞极性是如何在细胞分裂后传播和维持的，仍然是未知的。植物的细胞分裂是由细胞板组织的，细胞板是一个短暂的离心生长的膜室，最终形成交叉壁(1)。极性膜蛋白的运输通常被重定向到细胞板，因此它们在至少一个子细胞中具有相反的极性（2-5）。在这里，我们提供了细胞动力学后细胞极性重建的机制见解，这体现在PIN2的顶端、极性定位上。我们发现，顶端结构域是以细胞固有的方式定义的，PIN2在该结构域的重新定位需要从头开始的蛋白质分泌和内吞作用，而不是基底到顶端的胞吞作用。此外，我们发现了一种pinoid相关的激酶WAG1，它在体外磷酸化PIN2(6)，并且在分裂细胞中特异性上调转录，作为细胞动力学后PIN2极性重建的关键调节因子。
Cell polarity, manifested by the localization of proteins to distinct polar plasma membrane domains, is a key prerequisite of multicellular life. In plants, PIN auxin transporters are prominent polarity markers crucial for a plethora of developmental processes. Cell polarity mechanisms in plants are distinct from other eukaryotes and still largely elusive. In particular, how the cell polarities are propagated and maintained following cell division remains unknown. Plant cytokinesis is orchestrated by the cell plate-a transient centrifugally growing endomembrane compartment ultimately forming the cross wall(1). Trafficking of polar membrane proteins is typically redirected to the cell plate, and these will consequently have opposite polarity in at least one of the daughter cells(2-5). Here, we provide mechanistic insights into post-cytokinetic re-establishment of cell polarity as manifested by the apical, polar localization of PIN2. We show that the apical domain is defined in a cell-intrinsic manner and that re-establishment of PIN2 localization to this domain requires de novo protein secretion and endocytosis, but not basal-to-apical transcytosis. Furthermore, we identify a PINOID-related kinase WAG1, which phosphorylates PIN2 in vitro(6) and is transcriptionally upregulated specifically in dividing cells, as a crucial regulator of post-cytokinetic PIN2 polarity re-establishment.