Department of Biochemistry, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada.
Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario M5S 3M2, Canada.
ACS Chem Biol. 2024 Sep 20;19(9):2012-2022. doi: 10.1021/acschembio.4c00287. Epub 2024 Aug 12.
Maintenance of the mitochondrial thiol redox state is essential for cell survival. However, we lack a comprehensive understanding of the redox response to mitochondrial glutathione depletion. We developed a mitochondria-penetrating peptide, mtCDNB, to specifically deplete mitochondrial glutathione. A genome-wide CRISPR/Cas9 screen in tandem with mtCDNB treatment was employed to uncover regulators of the redox response to mitochondrial glutathione depletion. We identified nucleoside diphosphate kinase 3 (NME3) as a regulator of mitochondrial dynamics. We show that NME3 is recruited to the mitochondrial outer membrane when under redox stress. In the absence of NME3, there is impaired mitophagy, which leads to the accumulation of dysfunctional mitochondria. NME3 knockouts depleted of mitochondrial glutathione have increased mitochondrial ROS production, accumulate mtDNA lesions, and present a senescence-associated secretory phenotype. Our findings suggest a novel role for NME3 in selecting mitochondria for degradation through mitophagy under conditions of mitochondrial redox stress.
维持线粒体硫醇氧化还原状态对于细胞存活至关重要。然而，我们对谷胱甘肽耗竭引起的氧化还原反应知之甚少。我们开发了一种线粒体穿透肽 mtCDNB，专门用于耗竭线粒体谷胱甘肽。我们采用了一种与 mtCDNB 处理相结合的全基因组 CRISPR/Cas9 筛选方法，以揭示对线粒体谷胱甘肽耗竭的氧化还原反应的调控因子。我们确定核苷酸二磷酸激酶 3（NME3）是线粒体动力学的调节剂。我们表明，NME3 在氧化还原应激下被招募到线粒体外膜。在没有 NME3 的情况下，会出现受损的线粒体自噬，导致功能失调的线粒体积累。耗尽线粒体谷胱甘肽的 NME3 敲除物会增加线粒体 ROS 的产生，积累 mtDNA 损伤，并表现出与衰老相关的分泌表型。我们的研究结果表明，在氧化还原应激条件下，NME3 通过线粒体自噬在选择用于降解的线粒体方面发挥了新的作用。
