Membrane Trafficking Pathways Mediate the Intracellular Distribution of Coenzyme Q

膜运输途径介导辅酶 Q 的细胞内分布

• 批准号: 2343997
• 负责人: Catherine Clarke
• 金额: $ 109.94万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-04-01 至 2027-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2343997&HistoricalAwards=false
• 关键词: Membrane; Trafficking; Pathways; Mediate; Intracellular

Coenzyme Q (CoQ) is essential for energy metabolism and also serves as an antioxidant that protects cell membranes from damage that accrues from life in the presence of oxygen. CoQ is insoluble in water, and its functions rely on its presence in the membrane. CoQ must be transported from the mitochondria where it is made, to other membranes throughout the cell. Cells are also able to take up CoQ from outside the cell and transport it to membranes within the cell. Such movement of CoQ restores energy production and antioxidant protection to cells. However, the mechanisms responsible for such CoQ movement remain mysterious. In this project investigators have identified three proteins that play crucial roles in CoQ movement to where it is needed. One of these proteins binds tightly to CoQ to help it move, and this project will identify how this CoQ “chaperone” protein works with other proteins in the cell components to enable CoQ function. The investigators will also characterize two other proteins they discovered that are essential for correct movement of CoQ. Elucidating the functional roles of these three proteins will advance our understanding of how CoQ is transported throughout the cell. This project will also train graduate and undergraduate students as researchers. Graduate students will teach and mentor undergraduate students, who are active participants in the scientific discoveries. Students will appreciate that there are many unsolved problems in membrane formation and movement within the cell, including routes yet to be discovered. Students will present their research findings at local conferences and at national and international meetings. Coenzyme Q (CoQ) is a hydrophobic lipid molecule essential for mitochondrial respiratory energy metabolism. It also serves as a vital antioxidant that protects cellular membranes from lipid peroxidation. CoQ is synthesized within the inner mitochondrial membrane and must be trafficked to non-mitochondrial membranes. CoQ-deficient cells supplemented with exogenously supplied CoQ are able to take up this insoluble lipid and transport it from the plasma membrane to the mitochondrial inner membrane, where it restores the function of respiratory electron transport. However, the pathways that mediate the intracellular distribution of CoQ remain poorly understood. In order to advance our understanding of CoQ trafficking, this project will characterize three proteins essential for the intracellular distribution of CoQ in the yeast Saccharomyces cerevisiae. The investigators will determine the structure of Coq10, a CoQ-binding protein conserved from yeast to humans. A mixed-vesicle fluorescence-based assay that detects movement of CoQ between vesicles will be used to assess the activity of the Coq10 polypeptide as a CoQ transporter. The project also aims to determine the function of conserved catalytic residues in Coq11. Evidence suggests that Coq11 modulates the mitochondrial CoQ pool and hence, its intracellular distribution. The investigators also discovered that Vps1 is required to mediate CoQ transport. A panel of vps1 mutants with defects in specific functions that affect membrane fusion, fission, and endomembrane trafficking will be used to identify the functional role(s) of Vps1 important for CoQ transport. This project will advance our understanding of how CoQ, and other hydrophobic molecules, are transported throughout cells.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

辅酶Q（COQ）对于能量代谢至关重要，也是一种抗氧化剂，可保护细胞膜免受氧气存在下产生的损害。 COQ不溶于水，其功能依赖于其在膜中的存在。 COQ必须从制造的线粒体中运输到整个细胞中的其他膜。细胞还能够从细胞外接管Coq并将其运输到细胞内的膜。 COQ的这种运动可恢复能源生产和对细胞的抗氧化剂保护。但是，导致这种COQ运动的机制仍然是神秘的。在这个项目中，研究人员已经确定了三种在COQ运动中扮演至关重要的角色的蛋白质。这些蛋白质之一与COQ紧密结合以帮助其移动，该项目将确定该COQ“伴侣”蛋白如何与细胞成分中的其他蛋白质一起使用以启用COQ功能。研究人员还将表征他们发现的另外两种蛋白质，这对于COQ的正确运动至关重要。阐明这三种蛋白质的功能作用将促进我们对COQ在整个细胞中如何运输的理解。该项目还将作为研究人员培训毕业生和本科生。研究生将教和指导本科生，他们是科学发现的积极参与者。学生会喜欢的是，细胞内膜形成和运动中存在许多未解决的问题，包括尚未发现的路线。学生将在当地会议以及国家和国际会议上介绍他们的研究结果。辅酶Q（COQ）是一种疏水性脂质分子，对于线粒体呼吸能代谢必不可少。它也是保护细胞膜免受脂质过氧化的重要抗氧化剂。 COQ是在内部线粒体膜内合成的，必须将其运送到非环膜中。补充外源COQ的COQ含量细胞能够吸收这种不溶性脂质，并将其从质膜传输到线粒体内膜，从而恢复呼吸电子转运的功能。然而，介导COQ细胞内分布的途径仍然很少理解。为了促进我们对COQ贩运的理解，该项目将表征三种对于酿酒酵母中COQ细胞内分布至关重要的蛋白质。研究人员将确定COQ10的结构，COQ10是一种从酵母到人类保守的COQ结合蛋白。基于荧光荧光的评估，检测蔬菜之间COQ运动的运动将用于评估COQ10多肽作为COQ转运蛋白的活性。该项目还旨在确定COQ11中组成催化残差的功能。有证据表明，COQ11调节线粒体COQ池，因此，其细胞内分布。研究人员还发现，VPS1需要进行介导COQ运输。在影响膜融合，裂变和内膜运输的特定功能中具有缺陷的VPS1突变体将用于识别VPS1的功能作用对COQ运输很重要。该项目将促进我们对Coq和其他疏水分子如何运输的理解。该奖项反映了NSF的法定任务，并使用基金会的知识分子优点和更广泛的影响来审查标准，被认为是珍贵的支持。