A novel class of clathrin-coated vesicles budding from endosomes.
A novel class of clathrin-coated vesicles budding from endosomes.
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一类新型的网状蛋白涂层囊泡从内体萌芽。
DOI：
10.1083/jcb.132.1.21
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发表时间：
1996-01
期刊：
影响因子：
--
通讯作者：
Geuze HJ
中科院分区：
文献类型：
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作者：
Stoorvogel W;Oorschot V;Geuze HJ
网格蛋白包被的囊泡将选择性的整体膜蛋白从质膜运输到核内体，从TGN运输到核内体。蛋白质从核内体到质膜的再循环是通过未知的囊泡进行的。为了研究这一途径，我们使用了一种新的技术，允许在未切片的细胞中对含转铁蛋白受体的内体进行免疫电镜检查。内体被鉴定为独立的不连续的管泡实体。每个核内体都有装饰，主要在小管上，有许多被网格蛋白包裹的芽。通过三个标准从质膜来源的网格蛋白包被囊泡中区分出与核内体相关的网格蛋白包被芽：大小（分别为60 nm和100 nm），与核内体的连续性，以及缺乏α -适应蛋白标记。它们也与tgn衍生的网格蛋白包被囊泡区分开来，因为它们位于细胞的外围，大小和缺乏γ适应蛋白的标记。在brefeldin A存在的情况下，形成了一个大的连续的内体网络。brefeldin a的存在抑制了转铁蛋白受体的循环以及核内体中网格蛋白包被凹坑的形成，再加上转铁蛋白受体在核内体相关芽中的定位，这表明一类新型的网格蛋白包被囊泡是核内体的出口途径。然而，内核体衍生的网格蛋白包被囊泡的靶细胞器仍有待鉴定。
Clathrin-coated vesicles transport selective integral membrane proteins from the plasma membrane to endosomes and from the TGN to endosomes. Recycling of proteins from endosomes to the plasma membrane occurs via unidentified vesicles. To study this pathway, we used a novel technique that allows for the immunoelectron microscopic examination of transferrin receptor-containing endosomes in nonsectioned cells. Endosomes were identified as separate discontinuous tubular-vesicular entities. Each endosome was decorated, mainly on the tubules, with many clathrin-coated buds. Endosome-associated clathrin-coated buds were discerned from plasma membrane-derived clathrin-coated vesicles by three criteria: size (60 nm and 100 nm, respectively), continuity with endosomes, and the lack of labeling for alpha-adaptin. They were also distinguished from TGN-derived clathrin-coated vesicles by their location at the periphery of the cell, size, and the lack of labeling for gamma-adaptin. In the presence of brefeldin A, a large continuous endosomal network was formed. Transferrin receptor recycling as well as the formation of clathrin-coated pits at endosomes was inhibited in the presence of brefeldin A. Together with the localization of transferrin receptors at endosome-associated buds, this indicates that a novel class of clathrin-coated vesicles serves an exit pathway from endosomes. The target organelles for endosome-derived clathrin-coated vesicles remain, however, to be identified.