Mitochondrial respiration generates an electrochemical proton gradient across the mitochondrial inner membrane called protonmotive force (PMF) to drive diverse functions and synthesize ATP. Current techniques to manipulate the PMF are limited to its dissipation; yet, there is no precise and reversible method to increase the PMF. To address this issue, we aimed to use an optogenetic approach and engineered a mitochondria-targeted light-activated proton pump that we name mitochondria-ON (mtON) to selectively increase the PMF in Caenorhabditis elegans. Here we show that mtON photoactivation increases the PMF in a dose-dependent manner, supports ATP synthesis, increases resistance to mitochondrial toxins, and modulates energy-sensing behavior. Moreover, transient mtON activation during hypoxic preconditioning prevents the well-characterized adaptive response of hypoxia resistance. Our results show that optogenetic manipulation of the PMF is a powerful tool to modulate metabolism and cell signaling.

中文翻译：

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线粒体质子动力的光遗传学控制影响细胞的应激抵抗力。

线粒体呼吸在线粒体内膜上产生电化学质子梯度，称为质子动力 (PMF)，以驱动多种功能并合成 ATP。目前操纵 PMF 的技术仅限于其耗散；然而，还没有精确且可逆的方法来增加PMF。为了解决这个问题，我们旨在使用光遗传学方法并设计了一种针对线粒体的光激活质子泵，我们将其命名为线粒体-ON (mtON)，以选择性地增加秀丽隐杆线虫的 PMF。在这里，我们表明 mtON 光激活以剂量依赖性方式增加 PMF，支持 ATP 合成，增加对线粒体毒素的抵抗力，并调节能量感应行为。此外，缺氧预处理过程中短暂的 mtON 激活会阻碍缺氧抵抗的适应性反应。我们的结果表明，PMF 的光遗传学操作是调节新陈代谢和细胞信号传导的强大工具。