Prelysosomal acidic vacuoles in Dictyostelium discoideum.
Prelysosomal acidic vacuoles in Dictyostelium discoideum.
复制标题
迪斯特尔迪斯特尔的质体酸性液泡。
DOI：
10.1083/jcb.108.3.865
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发表时间：
1989-03
影响因子：
7.8
通讯作者：
Steck, T L
中科院分区：
文献类型：
--
作者：
Padh, H;Lavasa, M;Steck, T L
我们已经检查了阿米巴盘基骨柱在内吞作用中离散的，溶酶体前体，酸性接收室的证据。我们在细胞质中观察到大量直径达2微米的圆形液泡，这些液泡通过7-氯-4-硝基苯-2-氧-1,3-二唑（ndd - cl）抑制的过程浓缩吖啶橙。因此它们被认为是酸性的。观察到液泡在30分钟内几乎定量地与初代吞噬体融合，从而赋予它们积累吖啶橙的能力。吞噬货物进入溶酶体的时间较晚。在没有吞噬作用的情况下，几乎所有的酸性液泡都迅速积累了荧光标记物，这些荧光标记物要么与细胞表面共价偶联，要么作为可溶性葡聚糖偶联物供给。因此，这些液泡也位于胞饮作用途径上。25 μ m NBD-Cl抑制的亚细胞atp酶活性在蔗糖平衡密度梯度上与能浓缩吖啶橙的液泡共同分布。与只含有少量这种atp酶的溶酶体酸水解酶相比，其峰更宽，更有浮力。在浮力峰中迁移的还有内化的质膜标记物；例如，3H-半乳糖已共价偶联到完整细胞的表面，并允许进入脂质体。我们得出结论,在d . discoideum广泛prelysosomal空泡的隔间提供质子泵酸化时间和胞饮作用。
We have examined the ameba Dictyostelium discoideum for evidence of a discrete, prelysosomal, acidic receiving compartment in endocytosis. We observed in the cytoplasm abundant round vacuoles with diameters up to 2 microns that concentrated acridine orange by a process inhibited by 7- chloro-4-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl). They were therefore taken to be acidic. The vacuoles were observed to fuse nearly quantitatively with primary phagosomes over 30 min and thereby to confer upon them the ability to accumulate acridine orange. The entry into lysosomes of phagocytic cargo occurred later. In the absence of phagocytosis, almost all of the acidic vacuoles rapidly accumulated fluorescent markers that had either been covalently coupled to the cell surface or fed as the soluble dextran conjugate. Therefore, these vacuoles also lie on the pathway of pinocytosis. A prominent subcellular ATPase activity inhibited by 25 microM NBD-Cl co- distributed on sucrose equilibrium density gradients with vacuoles capable of concentrating acridine orange in vitro. The peak was broad and more buoyant than that bearing lysosomal acid hydrolases, which contained only a minor amount of this ATPase. Also migrating in the buoyant peak were internalized plasma membrane markers; e.g., 3H- galactose had been covalently coupled to the surface of intact cells and allowed to enter pinosomes. We conclude that in D. discoideum an extensive prelysosomal vacuolar compartment provides the proton pumps that acidify both phagosomes and pinosomes.