IDENTIFICATION OF A GENE REQUIRED FOR MEMBRANE-PROTEIN RETENTION IN THE EARLY SECRETORY PATHWAY
IDENTIFICATION OF A GENE REQUIRED FOR MEMBRANE-PROTEIN RETENTION IN THE EARLY SECRETORY PATHWAY
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DOI：
10.1073/pnas.90.17.8179
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发表时间：
1993-09-01
影响因子：
11.1
通讯作者：
NAKANO, A
中科院分区：
文献类型：
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作者：
NISHIKAWA, S;NAKANO, A
酵母 SEC12 基因产物 (Sec12p) 是蛋白质从内质网 (ER) 转运至高尔基体所需的整合膜蛋白。尽管这种蛋白质几乎完全定位于 ER，但 Sec12p 的很大一部分被高尔基体早期室中的酶修饰，表明 Sec12p 在 ER 和早期高尔基体之间循环。我们采用遗传学方法来研究 Sec12p 的保留机制。对早期分泌室中 Sec12-Mfalpha1 融合蛋白保留有缺陷的突变体进行分析，发现了一个基因 RER1。 RER1 的隐性突变导致真正的 Sec12p 以及两种不同的 Sec12 融合蛋白错误定位到晚期高尔基体，甚至细胞表面。然而，rer1 突变体在保留 ER 驻留的可溶性蛋白 BiP 方面没有缺陷，这表明可溶性蛋白和膜蛋白通过不同的机制保留在 ER 中。
The yeast SEC12 gene product (Sec12p) is an integral membrane protein required for the protein transport from the endoplasmic reticulum (ER) to the Golgi apparatus. Although this protein is almost exclusively localized in the ER, a significant fraction of Sec12p is modified by an enzyme that resides in the early compartment of the Golgi apparatus, suggesting that Sec12p is cycling between the ER and the early Golgi. We have taken a genetic approach to investigate the retention mechanism of Sec12p. Analysis of mutants that are defective in the retention of the Sec12-Mfalpha1 fusion protein in the early secretory compartments has identified a gene, RER1. A recessive mutation in RER1 causes mislocalization of the authentic Sec12p as well as two different Sec12 fusion proteins to the late Golgi apparatus and even to the cell surface. However, the rer1 mutant is not defective in the retention of an ER-resident soluble protein, BiP, suggesting that soluble and membrane proteins are retained in the ER by distinct mechanisms.