Dynamic interaction between chaperone and its substrates

伴侣与其底物之间的动态相互作用

• 批准号: 09276101
• 负责人: YOSHIDA Masasuke
• 金额: $ 189.44万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research on Priority Areas (A)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09276101/
• 关键词: Molecular chaperone,; folding,; stress,; stress protein,; heat-shock protein,; chaperonin,; protein secretion,; purion; 熱ショックタンパク質; GroEL; 蛋白質の膜透過; タンパク質; Hsp90; タンパク質の膜透過; インクルージョンボディ

SummaryChaperonin encapsulates unfolded proteins in the cis cavity and ensures safe folding without fear of aggregation. This process requires the energy of ATP hydrolysis. Currently prevailing model of chaperonin function assumes only a single rate-limiting step in whole catalytic cycle of chaperonin, that is, ATP hydrolysis that needs 8 sec. However, Yoshida and Funatsu〓s group have proposed that there are two rate limiting steps in the cycle, one 3 sec and the other 5 sec. This is based on the single molecule observation that GroES release, ADP release, and protein folding initiated by addition of ATP only start after a 3-sec lag phase. Kuwajima showed the conformational change occurred by the ATP binding rather than ATP hydrolysis. Tokuda〓 group have found a new factor, SecG, in SecA system. Similar to SecA, during protein translocation, SecG tumbles in the membrane. Kohno identified that ER stress sensor protein, IRE1-beta, is an RNase that cleaves 28SrRNA. Gotoh succeeded in expression of human beta-microglobulin in yeast cells and pointed out that disulfide bond is important in formation of amyloid fibers. Yoshida〓s group has established a real-time observation system that allows the growth of single amyloid fiber. The result showed that fiber grew predominantly unnidirectionally.

摘要对伴侣蛋白封装在顺式腔中中展开的蛋白质，并确保安全折叠而不必担心聚集。此过程需要ATP水解的能量。目前，链蛋白功能的盛行模型仅假定链蛋白的整个催化循环中的单个速率限制步骤，即需要8秒的ATP水解。但是，吉田和Funatsu的小组提出，周期中有两个限制步骤，一个3秒，另一个5秒。这是基于单个分子观察，即仅在3-SEC滞后相后启动ATP引发的GROES释放，ADP释放和蛋白质折叠。 Kuwajima表明，ATP结合而不是ATP水解发生了会议变化。 Tokuda集团在SECA系统中找到了一个新的因素SECG。与SECA相似，在蛋白质易位期间，SECG在膜上掉落。 Kohno识别出ER应力传感器蛋白IRE1-beta是裂解28sRRNA的RNase。 GotoH成功地表达了酵母细胞中人β-微球蛋白的表达，并指出二硫键在形成淀粉样蛋白纤维中很重要。吉田小组已经建立了一个实时观察系统，该系统允许单个淀粉样纤维的生长。结果表明，纤维主要在非方向上生长。

项目成果

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Yakushi T、Masuda K、Narita S、Matsuyama S、Tokuda H：“一种新的 ABC 转运蛋白介导脂质修饰蛋白与膜的分离”Nat Cell Biol。

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Morioka,M.: "Insect chaperonin 60:symbionin" Methods in Fnzymology. 290. 181-193 (1998)

Morioka,M.：“昆虫伴侣蛋白 60：共生蛋白”酶学方法。

Taguchi,H.: "Chaperonin from thermephile Thermus thernophilus" Methods Enzymol.290. 169-180 (1998)

Taguchi,H.：“来自嗜热菌 Thermus thernophilus 的伴侣蛋白”Methods Enzymol.290。

Yamasaki, R.: "Single molecular observation of the interaction of GroEL with substrate protein"J. Mol. Biol.. 292. 965-972 (1999)

Yamasaki, R.：“GroEL 与底物蛋白相互作用的单分子观察”J.