Clathrin-mediated constitutive endocytosis of PIN auxin efflux carriers in Arabidopsis
Clathrin-mediated constitutive endocytosis of PIN auxin efflux carriers in Arabidopsis
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DOI：
10.1016/j.cub.2007.01.052
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发表时间：
2007-03-20
期刊：
影响因子：
9.2
通讯作者：
Friml, Jiri
中科院分区：
文献类型：
--
作者：
Dhonukshe, Pankaj;Aniento, Fernando;Friml, Jiri
内吞作用是真核细胞内化外源物质或调节细胞表面信号的重要过程[1]。不同的内吞途径在酵母和动物中都得到了很好的建立；其中最突出的是依赖于笼蛋白的内吞作用[2，3]。在植物中，内吞作用还不是很明确，迄今为止还没有证明货物内化的分子机制[4，5]，尽管最近发现受体-配体复合体在植物质膜上内化[6]。在这里，我们通过绿色到红色的光可转换荧光报告EosFP[7]演示了PIN生长素外排载体的结构性内吞作用[8]，并将它们循环到质膜上。利用一种植物笼状蛋白特异性抗体，我们显示了在拟南芥细胞膜上形成包被囊泡的不同阶段都存在笼状蛋白。笼蛋白功能的遗传干扰通常会抑制PIN的内化和内吞作用。此外，药物干扰使货物重新聚集到网状蛋白途径，阻止PINs和其他质膜蛋白的内化。我们的数据表明，依赖于笼蛋白的内吞作用在植物中是可操作的，并构成了包括PIN生长素外排载体在内的许多质膜残存蛋白内化的主要途径。
Endocytosis is an essential process by which eukaryotic cells internalize exogenous material or regulate signaling At the cell,surface [1]. Different endocytic pathways are well established in yeast and animals; prominent among them is clathrin-dependent endocytosis [2, 3]. In plants, endocytosis is poorly defined, and no molecular mechanism for cargo internalization has been demonstrated so far [4, 5], although the internalization of receptor-ligand complexes at the plant plasma membrane has recently been shown [6]. Here we demonstrate by means of a green-to-red photo-convertible fluorescent reporter, EosFP [7], the constitutive endocytosis of PIN auxin efflux carriers [8] and their recycling to the plasma membrane. Using a plant clathrin-specific antibody, we show the presence of clathrin at different stages of coated-vesicle formation at the plasma membrane in Arabidopsis. Genetic interference with clathrin function inhibits PIN internalization and endocytosis in general. Furthermore, pharmacological interference with cargo recruitment into the clathrin pathway blocks internalization of PINs and other plasma-membrane proteins. Our data demonstrate that clathrin-dependent endocytosis is operational in plants and constitutes the predominant pathway for the internalization of numerous plasma-membrane-resid nt proteins including PIN auxin efflux carriers.