Analysis on the mechanism of ER membrane proliferation upon ER protein overproduction in yeast

酵母内质网蛋白过量产生内质网膜增殖机制分析

• 批准号: 10460034
• 负责人: OHTA Akinori
• 金额: $ 8.45万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-10460034/
• 关键词: endoplasmic reticulum; Saccharomyces cerevisiae; Candida maltosa; cytochrome P450A1k; ER proliferation; phospholipid; IRE1; ER membrane; cytochrome P45Alk

Endoplasmic reticulum (ER) is the center of secretory protein and lipid syntheses in eukaryotic cells. Although it has been attracted many researchers who are interested in those biosynthetic pathways, its proliferation and biogenesis are not yet well understood. We overproduced an ER membrane protein cytochrome P450Alk1 of Candida maltosa in Saccharomyces cerevisiae and analyzed the mechanism of the resultant ER proliferation, especially in the aspects of ER chaperone induction and membrane lipid metabolism. The results are; 1) There is no enhanced synthesis of membrane phospholipids during ER proliferation. 2) The requirement of Ire1p for ER proliferation is dependent on the genetic backgrounds of employed yeast strains. 3) Degradation of ER misfolded proteins does not necessarily occur by the proteasome system. 4) We established a system where yeast growth is dependent on the externally-supplied phospholipids. This enables us to analyze membrane lipid metabolism during ER protein-induced ER proliferation.

内质网（ER）是真核细胞中分泌蛋白和脂质合成的中心。尽管它吸引了许多对这些生物合成途径感兴趣的研究人员，但其增殖和生物发生尚未得到充分了解。我们过量生产了酿酒酵母中念珠菌念珠菌的ER膜蛋白细胞色素P450alk1，并分析了所得ER增生的机制，尤其是在ER伴侣伴侣诱导和膜脂质代谢方面。结果是； 1）在ER增殖过程中，膜磷脂的合成没有增强。 2）IRE1P对ER增殖的需求取决于使用的酵母菌菌株的遗传背景。 3）ER错误折叠蛋白的降解不一定是蛋白酶体系统发生的。 4）我们建立了一个系统，其中酵母生长取决于外部磷脂。这使我们能够在ER蛋白诱导的ER增殖过程中分析膜脂质代谢。

项目成果

Umebayasi,K.,Hirata,A.,et al.: "Unfolded protein response-induced BiP/Kar2p production protects cell growth against accumulation of misfolded protein aggregates in the yeast endoplasmic reticulum"European Journal of Cell Biology. 78. 726-738 (1999)

Umebayasi,K.,Hirata,A.,et al.：“未折叠蛋白质反应诱导的 BiP/Kar2p 产生可保护细胞生长，防止酵母内质网中错误折叠蛋白质聚集体的积累”《欧洲细胞生物学杂志》。

Nakamura,H.,Miura,K.,et al.: "Phosphatidylserine synthesis required for the maximal tryptophan transport activity in Saccharomyces cerevisiae"Bioscience,Biotechnology,and Biochemistry. 64. 167-172 (2000)

Nakamura, H., Miura, K., et al.：“酿酒酵母中最大色氨酸转运活性所需的磷脂酰丝氨酸合成”生物科学、生物技术和生物化学。

Zimmer,T.,Ogura,A.,et al.: "Misfolded membrane-bound cytochrome P450 activates KAR2 induction through two distinct mechanisms"Journal of Biochemistry. 126. 1080-1089 (1999)

Zimmer,T.,Ogura,A.,et al.：“错误折叠的膜结合细胞色素 P450 通过两种不同的机制激活 KAR2 诱导”《生物化学杂志》。

Umebayasi,K.,Hirata,A., et al.: "Unfolded protein response-induced BiP/Kar2p production protects cell growth against accumu protein aggregates in the yeast endoplasmic reticulum."European Journal of Cell Biology. 78. 726-738 (1999)

Umebayasi,K.、Hirata,A. 等人：“未折叠的蛋白质反应诱导的 BiP/Kar2p 产生可保护细胞生长免受酵母内质网中accummu 蛋白质聚集的影响。”《欧洲细胞生物学杂志》。

Takewaka,T.,Zimmer,T., et al.: "Null mutation in IRE1 gene inhibits Overproduction of microsome P450Alk1 (CYP52A3) and endoplasmic reticulum in Saccharomyces cerevisiae"Journal of Biochemistry. 125. 507-514 (1999)

Takewaka,T.,Zimmer,T.等人：“IRE1 基因的无效突变抑制酿酒酵母中微粒体 P450Alk1 (CYP52A3) 和内质网的过量生产”《生物化学杂志》。