UPTAKE AND INTRACELLULAR PROCESSING OF EPIDERMAL-GROWTH-FACTOR RECEPTOR COMPLEXES
UPTAKE AND INTRACELLULAR PROCESSING OF EPIDERMAL-GROWTH-FACTOR RECEPTOR COMPLEXES
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DOI：
10.1042/bst0120165
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发表时间：
1984-01-01
影响因子：
3.9
通讯作者：
HOPKINS, CR
中科院分区：
文献类型：
--
作者：
BEARDMORE, J;HOPKINS, CR
细胞表面受体通过内吞作用的内化已经在多种不同的系统中描述（Steinman等人，1983年）。已经详细描述了可能涉及被占据和未被占据的受体两者的摄取过程;在大多数情况下，它涉及受体在网格蛋白包被的凹坑（代表总细胞表面的约2%的质膜的局部凹陷）中的聚集（Goldstein等人，1979年）。质膜在被膜小凹处的内陷将受体转移到细胞内膜边界，对于与吸收配体以进行降解有关的受体，这是最终导致溶酶体的途径中的第一步。然而，最近已经变得明显的是，在质膜和溶酶体之间存在细胞内区室系统，在该系统内，内化的受体和它们结合的配体可以被差异加工（Steinman等人，1983; Helenius等人，1983年）。这些区室的存在（其一起构成内体系统）对于携带信号的配体是特别感兴趣的，因为已知这些区室中的一些最佳特征（例如胰岛素、EGF*）经由包被的凹坑内化（Kaplan，1981; Krupp & Lane，1981; Carpentier等人，1982年）。然而，到目前为止，内体加工在配体信号转导和调节细胞表面上可用受体群体中的作用仍有待评估。
The internalization of cell-surface receptors by endocytosis has been described in a wide variety of different systems (Steinman er al., 1983). The uptake process, which may involve both occupied and unoccupied receptors, has been described in detail; in most instances it involves the clustering of the receptors in clathrin-coated pits, localized depressions of the plasma membrane which represent about 2% of the total cell surface (Goldstein et al., 1979). Invagination of the plasma membrane at the coated pit transfers the receptor to an intracellular membrane boundary, and for receptors concerned with the uptake of ligands for degradation this is the first step in the pathway which leads eventually to the lysosome. Recently, however, it has become apparent that between the plasma membrane and the lysosome there is a system of intracellular compartments within which the internalized receptors and their bound ligand can be differentially processed (Steinman et a/., 1983; Helenius et al., 1983). The existence of these compartments, which together comprise the endosome system, is of special interest for signal-bearing ligands, since some of the best characterized of these (eg insulin, EGF*) are known to be internalized via coated pits (Kaplan, 1981; Krupp & Lane, 1981; Carpentier et a/., 1982). As yet, however, the role of endosomal processing in the transduction of ligand signals and in the regulation of the available receptor population on the cell surface remains to be evaluated.