A view of acidic intracellular compartments.
A view of acidic intracellular compartments.
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酸性细胞内室的视图。
DOI：
10.1083/jcb.106.3.539
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发表时间：
1988-03
影响因子：
7.8
通讯作者：
Orci, L
中科院分区：
文献类型：
--
作者：
Anderson, R G;Orci, L
在过去的十年中，已经积累了大量的证据，表明细胞内吞和胞吐空泡器的内部都维持在低pH值下（30，47，60）。内吞囊泡（4，17，29，57，59）、溶酶体（37，43）、高尔基体（3，38，39）、某些分泌囊泡（14，22，23，38，48）和植物液泡膜（7）的内部是酸性的。高H §浓度的维持取决于周围膜的性质和由ATP依赖性H §泵介导的质子的矢量运动（1，30，47）。(a)使用纯化的分泌囊泡（24，36）、酵母液泡（49）和溶酶体（42，53），低分子量溶质的流入和流出已显示取决于跨膜H §梯度和由这些囊泡的膜中的ATP依赖性H §泵产生的电梯度。(b)几个实验室已经分离出H §泵送缺陷的突变细胞系（28，31，45）;这些细胞对某些通过酸性内体进入细胞的毒素具有抗性，并且在受体介导的内吞作用期间无法从转铁蛋白中获得铁。(c)中和低pH区室或消散H §梯度的试剂抑制多种内吞和外吞活性，包括受体介导的内吞作用期间的受体再循环（9）、外吞作用期间内容物和膜蛋白的分选（19，33，58）和内吞作用（9）以及通过高尔基体的大分子的翻译后加工（39）。为了更好地理解酸性区室的功能，研究人员使用重要的pH指示剂研究了活细胞中的H §梯度。当被细胞吸收时，这些指示剂选择性地积聚在低pH区室中或检测它们所驻留的区室的pH。如下所述，免疫细胞化学、流式细胞术和视频增强显微镜的最新进展为感兴趣的研究者提供了新的机会，可以使用这些指示剂来”捕获”活细胞中存在的H §梯度，并检测在该环境中发生的化学反应。
ONSIDERABLE evidence has accumulated over the past ten years that the interior of both the endocytic and exocytic vacuolar apparatus in cells is maintained at a low pH (30, 47, 60). The interior of endocytic vesicles (4, 17, 29, 57, 59), lysosomes (37, 43), portions of the trans-Golgi apparatus (3, 38, 39), certain secretory vesicles (14, 22, 23, 38, 48), and plant tonoplasts (7) is acidic. The maintenance of the high H § concentration depends upon the properties of the surrounding membrane and the vectorial movement of protons mediated by an ATP dependent H § pump (1, 30, 47).A variety of different techniques have been used to study the function of low pH compartments.(a) Using purified secretory vesicles (24, 36), yeast vacuoles (49), and lysosomes (42, 53), the influx and effiux of low molecular weight solutes has been shown to depend on both a transmembrane H § gradient and an electrical gradient generated by an ATP-dependent H § pump in the membrane of these vesicles.(b) Several laboratories have isolated mutant cell lines that are defective in H § pumping (28, 31, 45); these cells are resistant to certain toxins that gain entry to cells by acidic endosomes and they are unable to obtain iron from transferrin during receptor-mediated endocytosis.(c) Reagents that either neutralize low pH compartments or dissipate H § gradients inhibit a variety of endocytic and exocytic activities including receptor recycling during receptor-mediated endocytosis (9), the sorting of both content and membrane proteins during exocytosis (19, 33, 58) and endocytosis (9), and the posttranslational processing of macromolecules that pass through the Golgi apparatus (39). To better understand the function of acidic compartments, investigators have studied H § gradients in the living cell using vital pH indicators. When taken up by cells, these indicators either selectively accumulate in low pH compartments or detect the pH of the compartment in which they reside. As outlined below, recent advances in immunocytochemistry, flow cytometry, and videoenhanced microscopy offer the interested investigator new opportunities for using these indicators to" capture" the H § gradient as it exists in the living cell and detect the chemical reactions that occur in that environment.