Factors involved in the stop transfer process in membrane protein biogenesis

膜蛋白生物合成中停止转移过程涉及的因素

• 批准号: 09680691
• 负责人: AKIYAMA Yoshinori
• 金额: $ 2.18万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09680691/
• 关键词: FtsH; stop tranfer; membrane proteins; FtsH; SecY; prlA

(1st year) We constructed a model membrane protein, proOmpAl65-LacY(TM12)-PhoA, and analyzed the roles of SecY in its integration into the membrane. We found that this model protein was less stably integrated into the membrane as a result of inefficient strop transfer reaction in the secY125 mutant strain than in the wild type strain. On the other hand, the stop transfer reaction occurred with the enhanced efficiency in the prIA(secY) 4-1 mutant strain. These results strongly suggest that SecY is directly involved in the stop transfer process in biogenesis of membrane proteins.(2nd year) We suggested previously that FtsH is involved in the stop transfer process. We found that, 1) FtsH has affinity to a denatured alkaline phosphatase, 2) the binding of FtsH to a denatured alkaline phosphatase is independent of ATP, 3) FtsH is unable to degrade bound alkaline phosphatase. This denatured protein binding activity of FtsH may have some role in the biogenesis of membrane proteins, especially the stop transfer process.

（第一年）我们构建了模型膜蛋白 proOmpAl65-LacY(TM12)-PhoA，并分析了 SecY 在其整合到膜中的作用。我们发现，由于 secY125 突变菌株中的带状转移反应效率低于野生型菌株，因此该模型蛋白整合到膜中的稳定性较差。另一方面，在prIA(secY)4-1突变株中，终止转移反应的发生效率提高。这些结果强烈表明 SecY 直接参与膜蛋白生物合成中的停止转移过程。（第二年）我们之前建议 FtsH 参与停止转移过程。我们发现，1) FtsH 对变性碱性磷酸酶具有亲和力，2) FtsH 与变性碱性磷酸酶的结合不依赖于 ATP，3) FtsH 无法降解结合的碱性磷酸酶。 FtsH 的这种变性蛋白结合活性可能在膜蛋白的生物发生中发挥一定作用，尤其是停止转移过程。

项目成果

Yoshinori, Akiyama: "Polypeptide-binding of Escherichia coil FtsH(HflB)" Mol. Microbiol.28. 803-812 (1998)

Yoshinori，Akiyama：“大肠杆菌 FtsH(HflB) 的多肽结合”Mol。

Akio Kihara: "Differential pathways for protein dogradation by the FtsH/HflKC membrone-embeded protease complex : an implication from the imterference bxamutam from of new substate" Journal of Molecular Biology. 279. 175-188 (1998)

Akio Kihara：“FtsH/HflKC 膜嵌入蛋白酶复合物降解蛋白质的不同途径：来自新物质的干扰 bxamutam 的暗示”《分子生物学杂志》。

Yoshinori Akiyama: "FtsH" Handbook of Proteolytic Enzymes. 1502-1504 (1998)

秋山义典：“FtsH”蛋白水解酶手册。

Yoshinori, Akiyama: "FisH" Guidebook to Molecular Chaperones and Protein Folding factors. 451-453 (1997)

Yoshinori，Akiyama：“FisH”分子伴侣和蛋白质折叠因子指南。

Yoshinori, Akiyama: "Roles of the periplasmic domain of Escherichia coli Ftsh (HflB) in Protein interactions and activity modulation" J.Mol.Biol.273. 22326-22333 (1998)

Yoshinori，Akiyama：“大肠杆菌 Ftsh (HflB) 周质结构域在蛋白质相互作用和活性调节中的作用”J.Mol.Biol.273。