A role for clathrin in the sorting of vacuolar proteins in the Golgi complex of yeast.
A role for clathrin in the sorting of vacuolar proteins in the Golgi complex of yeast.
复制标题
网格蛋白在酵母高尔基复合体液泡蛋白分类中的作用。
DOI：
10.1002/j.1460-2075.1992.tb05348.x
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Payne,GS
中科院分区：
文献类型：
--
作者：
Seeger,M;Payne,GS
我们使用携带网格蛋白重链（chc1-ts）温度敏感等位基因的酵母菌株研究了网格蛋白在液泡蛋白分选中的作用。在非允许温度（37 ℃）下孵育5分钟后，chc1-ts菌株在内腔液泡蛋白的分选中显示出严重缺陷。在37 ℃下，液泡膜蛋白、碱性磷酸酶的分选和细胞壁蛋白向表面的运输没有受到影响。在37 ℃孵育的chc1-ts细胞中，错误分选的内腔液泡蛋白羧肽酶Y（CPY）的分泌被sec1突变阻断，该突变阻止分泌囊泡与质膜融合。出乎意料的是，在37 ℃下长时间孵育的chc1-ts细胞恢复了分选CPY的能力。携带CHC1基因（chc1 delta）缺失的细胞即使在温度变化下也能将CPY分选到液泡中。CPY在chc1 δ细胞中的单极性递送不被sec1阻断，这表明转运不通过分泌和内吞发生。这些结果提供了在体内的证据，网格蛋白在高尔基复合体中的液泡蛋白从分泌途径的分选中发挥作用。然而，随着时间的推移，缺乏功能性网格蛋白重链的酵母细胞能够以允许恢复高尔基复合体中的液泡蛋白分选的方式进行适应。这些结论澄清了以前的研究chc1 δ细胞提出的可能性，网格蛋白是不参与液泡蛋白分选。
We have investigated the role of clathrin in vacuolar protein sorting using yeast strains harboring a temperature‐sensitive allele of clathrin heavy chain (chc1‐ts). After a 5 min incubation at the non‐permissive temperature (37 degrees C), the chc1‐ts strains displayed a severe defect in the sorting of lumenal vacuolar proteins. Sorting of a vacuolar membrane protein, alkaline phosphatase, and transport to the surface of a cell wall protein, was not affected at 37 degrees C. In chc1‐ts cells incubated at 37 degrees C, secretion of the missorted lumenal vacuolar protein carboxypeptidase Y (CPY) was blocked by the sec1 mutation which prevents fusion of secretory vesicles to the plasma membrane. Unexpectedly, chc1‐ts cells incubated for extended periods at 37 degrees C regained the ability to sort CPY. Cells carrying deletions of the CHC1 gene (chc1 delta) also sorted CPY to the vacuole even when subjected to temperature shifts. Vacuolar delivery of CPY in chc1 delta cells was not blocked by sec1 suggesting that transport does not occur by secretion and endocytosis. These results provide in vivo evidence that clathrin plays a role in the Golgi complex in sorting of vacuolar proteins from the secretory pathway. With time, however, yeast cells lacking functional clathrin heavy chains are able to adapt in a way that allows restoration of vacuolar protein sorting in the Golgi complex. These conclusions clarify previous studies of chc1 delta cells which raised the possibility that clathrin is not involved in vacuolar protein sorting.