ORDER OF EVENTS IN THE YEAST SECRETORY PATHWAY
ORDER OF EVENTS IN THE YEAST SECRETORY PATHWAY
复制标题
DOI：
10.1016/0092-8674(81)90064-7
复制
发表时间：
1981-01-01
期刊：
影响因子：
64.5
通讯作者：
SCHEKMAN, R
中科院分区：
文献类型：
--
作者：
NOVICK, P;FERRO, S;SCHEKMAN, R
借助于影响分泌器的突变体，确定了酵母糖蛋白输出中翻译后事件的顺序。温度敏感型分泌突变体（sec）。当在非允许生长温度（37 ℃）下培养时，C），积累输出糖蛋白的细胞内前体形式，如转化酶，并扩增或扩增3种不同分泌细胞器中的1种或多种。表征的单倍体双秒突变株，关于积累的转化酶的结构和夸张的细胞器的形态，允许评估的顺序，其中需要的基因产物，转化酶成熟步骤的顺序和分泌细胞器的途径。从一个细胞器到下一个细胞器的转换需要能量和sec基因产物。其中一个突变体（sec 7）根据培养基中葡萄糖的浓度积累不同的细胞器。在正常的生长介质（2%葡萄糖），一个热不可逆的结构，伯克利体，占主导地位;在低葡萄糖（0.1%），高尔基体结构积累热可逆。结果与以下模型一致。分泌蛋白进入内质网，在那里发生糖基化的初始步骤。需要九个或更多的sec基因产物和能量将物质转移到高尔基体样结构，在那里发生进一步的糖基化。需要两个或更多的功能和能量来将几乎完全糖基化的蛋白质包装成囊泡，然后将囊泡运输到芽中，在那里它们与质膜融合，这一过程需要至少10个额外的基因产物和能量。
The sequence of posttranslational events in the export of yeast glycoproteins was determined with the aid of mutants that affect the secretory apparatus. Temperature-sensitive secretory mutants (sec) of S. cerevisiae, when incubated at a nonpermissive growth temperature (37.degree. C), accumulate intracellular precursor forms of exported glycoproteins, such as invertase, and expand or amplify 1 or more of 3 different secretory organelles. Characterization of haploid double-sec-mutant strains, with regard to the structure of the accumulated invertase and the morphology of the exaggerated organelles, allowed assessment of the order in which the gene products are required, the sequence of invertase maturation steps and a pathway of secretory organelles. The transitions from one organelle to the next require energy and sec gene products. One of the mutants (sec7) accumulates a different organelle depending on the concentration of glucose in the medium. In normal growth medium (2% glucose), a thermally irreversible structure, the Berkeley body, predominates; in low glucose (0.1%), Golgi structures accumulate thermoreversibly. The results are consistent with the following model. Secretory proteins enter the endoplasmic reticulum, where the initial steps of glycosylation occur. Nine or more sec gene products and energy are required to transfer material to a Golgi-like structure, where further glycosylation occurs. Two or more functions and energy are required to package nearly fully glycosylated proteins into vesicles that are then transported into the bud, where they fuse with the plasma membrane in a process that requires at least 10 additional gene products and energy.