Cellular and Molecular Requirements for Polar PIN Targeting and Transcytosis in Plants
Cellular and Molecular Requirements for Polar PIN Targeting and Transcytosis in Plants
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DOI：
10.1093/mp/ssn062
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发表时间：
2008-11-01
期刊：
影响因子：
27.5
通讯作者：
Friml, Jiri
中科院分区：
文献类型：
--
作者：
Kleine-Vehn, Jurgen;Langowski, Lukasz;Friml, Jiri
PIN生长素流出载体的极性亚细胞定位决定了细胞间生长素流动的方向，从而定义了生长素信号传导的空间方面。PIN蛋白质的动态转胞吞样重新定位响应于外部和内部信号而发生，将这些信号整合到生长素分布的变化中。在这里，我们研究了极性PIN传递和胞吞作用的细胞和分子机制。ARF-GEF依赖的极性靶向和转胞吞作用的机制是非常保守的，并且在不同的拟南芥生态型中几乎没有变化，这与它们在调节植物发育中的根本重要性一致。在细胞水平上，我们完善了以前的研究结果的肌动蛋白细胞骨架的作用，顶端和基底PIN的目标，并确定了一个以前未知的作用微管，特别是在基础上的目标。PIN蛋白递送到细胞的不同侧面是由ARF依赖性运输介导的，其具有先前未知的复杂水平的不同ARF-GEF囊泡运输调节剂。我们的数据表明，通过这些不同的途径，PIN蛋白的替代招聘可以解释极性靶向的细胞类型和货物特异性方面，以及响应于不同信号的极性变化。由此产生的动态PIN定位到细胞的不同侧面定义了植物组织内生长素通量的三维模式。
The polar, sub-cellular localization of PIN auxin efflux carriers determines the direction of intercellular auxin flow, thus defining the spatial aspect of auxin signalling. Dynamic, transcytosis-like relocalizations of PIN proteins occur in response to external and internal signals, integrating these signals into changes in auxin distribution. Here, we examine the cellular and molecular mechanisms of polar PIN delivery and transcytosis. The mechanisms of the ARF-GEF-dependent polar targeting and transcytosis are well conserved and show little variations among diverse Arabidopsis ecotypes consistent with their fundamental importance in regulating plant development. At the cellular level, we refine previous findings on the role of the actin cytoskeleton in apical and basal PIN targeting, and identify a previously unknown role for microtubules, specifically in basal targeting. PIN protein delivery to different sides of the cell is mediated by ARF-dependent trafficking with a previously unknown complex level of distinct ARF-GEF vesicle trafficking regulators. Our data suggest that alternative recruitment of PIN proteins by these distinct pathways can account for cell type- and cargo-specific aspects of polar targeting, as well as for polarity changes in response to different signals. The resulting dynamic PIN positioning to different sides of cells defines a three-dimensional pattern of auxin fluxes within plant tissues.