Elucidation of Molecular Mechanisms of Protein Translocation across the Chloroplast Envelope

2022 Fiscal Year Final Research Report

• Project/Area Number: 19H03183
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 43030:Functional biochemistry-related
• Research Institution: Osaka University
• Principal Investigator: Nakai Masato 大阪大学, 蛋白質研究所, 准教授 (90222158)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 葉緑体 / タンパク質輸送 / タンパク質膜透過

Outline of Final Research Achievements

Majority of nuclear-encoded chloroplast proteins are synthesized in the cytosol as a larger preprotein and are then translocated across the outer and inner envelope membranes through TOC and TIC, respectively. Complete translocation of preproteins across the inner envelope membrane to the stroma occurs with the help of a TIC translocon-associated import motor at the stromal side of the inner envelope. Structural details of these mega complexes have still to be investigated. For this sake, we have tried to establish the method to obtain adequate purified complexes for cryoEM structural studies in both quality and quantity.

Free Research Field

植物分子細胞生物学

Academic Significance and Societal Importance of the Research Achievements

葉緑体への蛋白質輸送機構の構造レベルでの理解は、生命が光合成に特化した細胞内小器官としての葉緑体をいかに獲得してき得たのか、その根源の理解に必須の研究課題である。本研究成果を足掛かりとして、この精密な分子装置の構造機能連関の全容の解明に一歩近づいたと言える。