In polarized MDCK cells basolateral vesicles arise from clathrin-gamma-adaptin-coated domains on endosomal tubules.
In polarized MDCK cells basolateral vesicles arise from clathrin-gamma-adaptin-coated domains on endosomal tubules.
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DOI：
10.1083/jcb.141.3.611
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发表时间：
1998-05-04
期刊：
影响因子：
--
通讯作者：
Hopkins CR
中科院分区：
文献类型：
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作者：
Futter CE;Gibson A;Allchin EH;Maxwell S;Ruddock LJ;Odorizzi G;Domingo D;Trowbridge IS;Hopkins CR
在极化的MDCK细胞中表达的人转铁蛋白受体(Tr)和聚合免疫球蛋白受体(PIgR)保持稳定的、不对称的分布，即使它们持续地进入和穿过这些细胞。维持这些不对称分布所需的细胞内机制尚未确定。在这里，我们展示了tR和pIgR从两个表面内化到一个共同的相互连接的内体隔室，该内体隔间包括带有包裹着网状蛋白晶格的花蕾的小管。这些花蕾产生囊泡，将TR带到基底侧缘。这些晶格含有γ适配素，并通过布雷菲尔丁A(BFA)处理进行分散。由于BFA处理取消了TRR在极化的MDCK细胞中的载体运输，我们认为内体小管的网状蛋白涂层结构域包含极化分选机制，这是导致它们优先基侧分布的原因。
Human transferrin receptors (TR) and receptors for polymeric immunoglobulins (pIgR) expressed in polarized MDCK cells maintain steady-state, asymmetric distributions on the separate basolateral and apical surfaces even though they are trafficking continuously into and across these cells. The intracellular mechanisms required to maintain these asymmetric distributions have not been located. Here we show that TR and pIgR internalize from both surfaces to a common interconnected endosome compartment that includes tubules with buds coated with clathrin lattices. These buds generate vesicles that carry TR to the basolateral border. The lattices contain γ-adaptin and are dispersed by treatment with brefeldin A (BFA). Since BFA treatment abrogates the vectorial trafficking of TR in polarized MDCK cells, we propose that the clathrin-coated domains of the endosome tubules contain the polarized sorting mechanism responsible for their preferential basolateral distribution.