Morphology and dynamics of clathrin/GGA1-coated carriers budding from the trans-Golgi network
Morphology and dynamics of clathrin/GGA1-coated carriers budding from the trans-Golgi network
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DOI：
10.1091/mbc.02-07-0109
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发表时间：
2003-04-01
影响因子：
3.3
通讯作者：
Bonifacino, JS
中科院分区：
文献类型：
--
作者：
Puertollano, R;van der Wel, NN;Bonifacino, JS
分选跨膜蛋白及其配体的内吞和分泌途径的各个隔室介导的选择性纳入网格蛋白包被的中间体。先前的形态学和生物化学研究表明，这些网格蛋白包被的中间体由直径为60-100 nm的球形囊泡组成。在此，我们报告使用荧光成像的活细胞，以证明存在一种不同类型的运输中间含有相关的网格蛋白外套。网格蛋白和衔接GGA 1和衔接蛋白-1，标记有不同的光谱变体的绿色荧光蛋白，显示共定位到trans-Golgi网络和一个人口的囊泡和小管出芽从it. These中间体是高度pleiomorphic和移动到外周细胞质的距离高达10 μ m，平均速度为-1 μ m/s。标记的网格蛋白和GGA 1周期上和关闭膜的半衰期为10-20秒，独立于囊泡出芽。我们的观察表明，存在一种新型的反式高尔基体网络衍生的载体含有相关的网格蛋白，GGA 1和衔接蛋白-1，大于传统的网格蛋白包被的囊泡，并经历长距离易位在细胞质中失去外套之前。
Sorting of transmembrane proteins and their ligands at various compartments of the endocytic and secretory pathways is mediated by selective incorporation into clathrin-coated intermediates. Previous morphological and biochemical studies have shown that these clathrin-coated intermediates consist of spherical vesicles with a diameter of 60-100 nm. Herein, we report the use of fluorescent imaging of live cells to demonstrate the existence of a different type of transport intermediate containing associated clathrin coats. Clathrin and the adaptors GGA1 and adaptor protein-1, labeled with different spectral variants of the green fluorescent protein, are shown to colocalize to the trans-Golgi network and to a population of vesicles and tubules budding from it. These intermediates are highly pleiomorphic and move toward the peripheral cytoplasm for distanced of up to 10 mum with average speeds of -1 mum/s. The labeled clathrin and GGA1 cycle on and off membranes with half-times of 10-20 s, independently of vesicle budding. Our observations indicate the existence of a novel type of trans-Golgi network-derived carriers containing associated clathrin, GGA1 and adaptor protein-1 that are larger than conventional clathrin-coated vesicles, and that undergo long-range translocation in the cytoplasm before losing their coats.