Vid28 Protein Is Required for the Association of Vacuole Import and Degradation (Vid) Vesicles with Actin Patches and the Retention of Vid Vesicle Proteins in the Intracellular Fraction
Vid28 Protein Is Required for the Association of Vacuole Import and Degradation (Vid) Vesicles with Actin Patches and the Retention of Vid Vesicle Proteins in the Intracellular Fraction
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DOI：
10.1074/jbc.m112.419895
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发表时间：
2013-04-26
影响因子：
4.8
通讯作者：
Chiang, Hui-Ling
中科院分区：
文献类型：
--
作者：
Giardina, Bennett J.;Dunton, Danielle;Chiang, Hui-Ling
当酿酒酵母缺乏葡萄糖时，会诱导糖异生酶。然而，当将葡萄糖添加到长期饥饿的细胞中时，这些酶会通过液泡导入和降解 (Vid) 途径在液泡中降解。 Vid 途径与非经典分泌和内化途径相关。在长期饥饿的细胞中，大量关键的糖异生酶果糖-1,6-双磷酸酶 (FBPase) 存在于细胞外部分（周质）中。然而，当葡萄糖被添加到葡萄糖饥饿的细胞中时，细胞外FBP酶的水平迅速下降。超微结构研究表明，添加葡萄糖后，FBPase 存在于 Vid/核内体中，这表明 FBPase 响应葡萄糖再喂食而内化。在相同条件下，大多数 Vid 囊泡蛋白位于细胞内部分。在酵母中，肌动蛋白聚合参与胞吞作用。视频囊泡最初与肌动蛋白斑块结合，随后解离。在这里，我们表明 VID28 在 Vid 囊泡与肌动蛋白斑块的关联以及 Vid 囊泡蛋白在细胞内部分中的保留中发挥着关键作用。 Vid28p 分布到 Vid 囊泡并与其他 Vid 囊泡蛋白相互作用。 Vid28p 包含 FBPase 降解所需的犰狳 (ARM) 结构域。当VID28被删除或ARM结构域发生突变时，Vid囊泡无法与肌动蛋白斑块共定位，并且Vid囊泡蛋白出现在细胞外部分中。我们认为 ARM 结构域是 Vid 囊泡与肌动蛋白斑块的关联以及 Vid 囊泡蛋白在细胞内部分中的保留所必需的。
Gluconeogenic enzymes are induced when Saccharomyces cerevisiae are starved of glucose. However, when glucose is added to prolonged starved cells, these enzymes are degraded in the vacuole via the vacuole import and degradation (Vid) pathway. The Vid pathway is linked to the nonclassical secretory and internalizing pathways. In prolonged starved cells, substantial amounts of the key gluconeogenic enzyme fructose-1,6-bisphosphatase (FBPase) are in the extracellular fraction (periplasm). However, when glucose is added to glucose-starved cells, levels of extracellular FBPase decrease rapidly. Ultrastructural studies indicate that FBPase is in Vid/endosomes following glucose addition, suggesting that FBPase is internalized in response to glucose refeeding. Under the same conditions, the majority of Vid vesicle proteins are in the intracellular fraction. In yeast, actin polymerization is involved in endocytosis. Vid vesicles associate with actin patches initially, and they dissociate later. Here, we show that VID28 plays a critical role in the association of Vid vesicles with actin patches and the retention of Vid vesicle proteins in the intracellular fraction. Vid28p was distributed to Vid vesicles and interacted with other Vid vesicle proteins. Vid28p contains an Armadillo (ARM) domain required for FBPase degradation. When VID28 was deleted or when the ARM domain was mutated, Vid vesicles failed to co-localize with actin patches, and Vid vesicle proteins appeared in the extracellular fraction. We suggest that the ARM domain is required for the association of Vid vesicles with actin patches and the retention of Vid vesicle proteins in the intracellular fraction.