Regulation of mitochondrial protein transport: Tim23 as a link to the calcium-signalling network in the cell

线粒体蛋白质运输的调节：Tim23 作为细胞钙信号网络的纽带

• 批准号: 176913070
• 负责人: Dr. Fatima Chigri, Ph.D.
• 金额: --
• 依托单位: Abteilung Zellbiologie der Pflanzen
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/176913070?language=en
• 关键词: Regulation; mitochondrial; protein; transport; Tim23

Many metabolic processes essential for plant viability take place in mitochondria. To ensure that function of this organelle is carefully balanced in accordance with requirements of the cell, mitochondria are tightly integrated into diverse regulatory networks. We recently described an influence of calcium/calmodulin on protein import into plant mitochondria at the level of the TIM23 and TIM22 mediated translocation on the inner membrane. Preliminary studies indicate, that Tim23 itself, the central pore of the TIM23 complex, could be a target for the calcium signal. The Arabidopsis genome encodes three paralogues of Tim23, named atTim23-1, atTim23-2 and atTim23-3 and preliminary studies have shown the ability of atTim23-2 to bind calmodulin, thereby suggesting the protein as a potential mediator for calcium/calmodulin regulation of TIM23 translocation. Aim of the project is the functional characterization of all three atTim23’s in order to elucidate their mode of action with a special focus on a link to calcium regulation of mitochondrial protein import. Furthermore, additional components of the calcium regulon of mitochondria will be elucidated, such as the mediator of calcium regulation of TIM22 translocation and the respective sensors of the calcium signals. The overall aim of the proposal is to understand the molecular basis of calcium regulation of mitochondrial protein transport to facilitate future studies on the adaptation of this process to different environmental or developmental cues.

许多对植物生存至关重要的代谢过程发生在线粒体中。为了确保这个细胞器的功能根据细胞的需要得到仔细的平衡，线粒体被紧密地整合到各种调节网络中。我们最近描述了钙/钙调素在TIM23和TIM22介导的细胞膜易位水平上对植物线粒体蛋白质进口的影响。初步研究表明，Tim23复合物的中心孔Tim23本身可能是钙信号的靶点。拟南芥基因组编码Tim23的三个类似物，分别命名为atTim23-1、atTim23-2和atTim23-3，初步研究表明，atTim23-2能够结合钙调蛋白，从而表明该蛋白可能是钙/钙调蛋白调控Tim23易位的潜在介质。该项目的目的是所有三个atTim23的功能表征，以阐明其作用模式，特别关注线粒体蛋白进口钙调节的联系。此外，线粒体钙调控的其他成分将被阐明，如TIM22易位钙调控的介质和钙信号的各自传感器。该提案的总体目标是了解钙调节线粒体蛋白运输的分子基础，以促进未来研究这一过程对不同环境或发育线索的适应性。