Dynamic behavior of clathrin in Arabidopsis thaliana unveiled by live imaging
Dynamic behavior of clathrin in Arabidopsis thaliana unveiled by live imaging
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DOI：
10.1111/j.1365-313x.2011.04782.x
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发表时间：
2012-01-01
期刊：
影响因子：
7.2
通讯作者：
Nakano, Akihiko
中科院分区：
文献类型：
--
作者：
Ito, Emi;Fujimoto, Masaru;Nakano, Akihiko
笼蛋白包裹的囊泡(CCV)是选择性转运所必需的，包括受体介导的质膜内吞作用和跨高尔基体网络(TGN)中的货物分子分类。参与CCV形成的成分包括网状蛋白重链和轻链，以及几种在植物中保守的接头蛋白。依赖于笼蛋白的内吞作用已被证明在植物的内吞作用中起着不可或缺的作用。然而，关于活的植物细胞中的网状蛋白动力学的信息很少。在本研究中，我们通过用绿色荧光蛋白(CLCGFP)标记分子筛轻链，在拟南芥中对分子筛蛋白进行了可视化。共定位的定量评估表明，CLCGFP大部分定位于TGN，少数与多囊内体和高尔基体跨池有关。活体成像进一步显示存在高动态的网状蛋白阳性的小管和囊泡，它们似乎介导了TGNs之间的相互作用。CLCGFP也针对细胞板和质膜。虽然CLCGFP与动力蛋白亚型共定位在质膜上，但这些蛋白在新形成的细胞板上表现出不同的分布。这一发现表明CLC(网状蛋白轻链)和Dynamin在细胞板形成过程中具有独立的功能。我们还发现，灯盏花素A和Wortmannin处理引起了质膜上网状蛋白涂层结构域动态和分布的明显不同变化。这可能解释了这些药物对植物内吞作用的不同影响。
Clathrin-coated vesicles (CCV) are necessary for selective transport events, including receptor-mediated endocytosis on the plasma membrane and cargo molecule sorting in the trans-Golgi network (TGN). Components involved in CCV formation include clathrin heavy and light chains and several adaptor proteins that are conserved among plants. Clathrin-dependent endocytosis has been shown to play an integral part in plant endocytosis. However, little information is known about clathrin dynamics in living plant cells. In this study, we have visualized clathrin in Arabidopsis thaliana by tagging clathrin light chain with green fluorescent protein (CLCGFP). Quantitative evaluations of colocalization demonstrate that the majority of CLCGFP is localized to the TGN, and a minor population is associated with multivesicular endosomes and the Golgi trans-cisternae. Live imaging further demonstrated the presence of highly dynamic clathrin-positive tubules and vesicles, which appeared to mediate interactions between the TGNs. CLCGFP is also targeted to cell plates and the plasma membrane. Although CLCGFP colocalizes with a dynamin isoform at the plasma membrane, these proteins exhibit distinct distributions at newly forming cell plates. This finding indicates independent functions of CLC (clathrin light chains) and dynamin during the formation of cell plates. We have also found that brefeldin A and wortmannin treatment causes distinctly different alterations in the dynamics and distribution of clathrin-coated domains at the plasma membrane. This could account for the different effects of these drugs on plant endocytosis.