The early endosome: a busy sorting station for proteins at the crossroads.
The early endosome: a busy sorting station for proteins at the crossroads.
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早期的内体：在十字路口的蛋白质繁忙分类站。
DOI：
10.14670/hh-25.99
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发表时间：
2010-01
影响因子：
2
通讯作者：
Caplan S
中科院分区：
文献类型：
--
作者：
Jovic M;Sharma M;Rahajeng J;Caplan S
内吞作用标志着内化受体进入内吞转运途径的复杂网络。内吞囊泡迅速靶向一个独特的膜结合的内吞细胞器称为早期内体。尽管存在许多内化途径，早期内体（EE）作为内吞途径的焦点。在该隔室开始的分选事件决定了内化的蛋白质和脂质的后续命运，使它们再循环至质膜、在溶酶体中降解或递送至trans-Golgi网络。通过在早期内体内形成不同的微结构域，通过分选机器的协调募集和组装，将内吞货物分选到后面的隔室。内吞调节蛋白之间的相互作用的一个精心设计的网络，确保货物的同步分选微结构域，随后在早期内体膜的形态变化。因此，被靶向用于再循环回到质膜或用于逆行运输到trans-Golgi网络的货物定位于新形成的管状膜。与高比例的膜表面内腔体积，这些小管有效地集中回收货物，确保有效的运输出EE。相反，受体分类降解集群在平面网格蛋白晶格参与内陷的限制膜，与新形成的腔内囊泡。在这篇综述中，我们将讨论早期内体的特点，它们在调节内吞转运中的作用，以及它们在各种疾病中的异常功能。
Endocytosis marks the entry of internalized receptors into the complex network of endocytic trafficking pathways. Endocytic vesicles are rapidly targeted to a distinct membrane-bound endocytic organelle referred to as the early endosome. Despite the existence of numerous internalization routes, early endosomes (EE) serve as a focal point of the endocytic pathway. Sorting events initiated at this compartment determine the subsequent fate of internalized proteins and lipids, destining them either for recycling to the plasma membrane, degradation in lysosomes or delivery to the trans-Golgi network. Sorting of endocytic cargo to the latter compartments is accomplished through the formation of distinct microdomains within early endosomes, through the coordinate recruitment and assembly of the sorting machinery. An elaborate network of interactions between endocytic regulatory proteins ensures synchronized sorting of cargo to microdomains followed by morphological changes at the early endosomal membranes. Consequently, the cargo targeted either for recycling back to the plasma membrane, or for retrograde transport to the trans-Golgi network, localizes to newly-formed tubular membranes. With a high ratio of membrane surface to lumenal volume, these tubules effectively concentrate the recycling cargo, ensuring efficient transport out of the EE. Conversely, receptors sorted for degradation cluster at the flat clathrin lattices involved in invaginations of the limiting membrane, associating with newly formed intralumenal vesicles. In this review we will discuss the characteristics of early endosomes, their role in the regulation of endocytic transport, and their aberrant function in a variety of diseases.