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.

摘要伴侣蛋白将未折叠的蛋白质封装在顺式腔中，并确保安全折叠，而无需担心聚集。目前流行的伴侣蛋白功能模型假设伴侣蛋白的整个催化循环中只有一个限速步骤。 ATP 水解需要 8 秒。然而，Yoshida 和 Funatsu 的小组提出，循环中有两个限速步骤，一个是 3 秒。另一个 5 秒是基于单分子观察，即通过添加 ATP 引发的 GroES 释放、ADP 释放和蛋白质折叠仅在 3 秒滞后期后才开始，而不是通过 ATP 结合发生构象变化。与 ATP 水解相比，Tokuda 团队在 SecA 系统中发现了一个新因子 SecG，与 SecA 类似，在蛋白质易位过程中，SecG 在膜中翻滚。 Gotoh 成功地在酵母细胞中表达了 ER 应激传感器蛋白 IRE1-beta，它是一种裂解 28SrRNA 的 RNase，并指出二硫键对于淀粉样纤维的形成非常重要。允许单个淀粉样纤维生长的时间观察系统结果表明纤维主要是单向生长的。

项目成果

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。

Kumata,K.: "Alpha→beta transition of beta-lactoglobulin as evidenced by heteronuclear" J.Mol.Biol.283. 731-739 (1998)

Kumata, K.：“异核所证明的 β-乳球蛋白的 α→β 转变”J.Mol.Biol.283 (1998)。

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.

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。

Yakushi T, Masuda K, Narita S, Matsuyama S, Tokuda H: "A new ABC transporter mediating the detachment of lipid-modified proteins from membranes"Nat Cell Biol. 2. 212-218 (2000)

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。