Center of Cellular Nanoanalytics, Integrated Bioimaging Facility, University of Osnabrück, 49076 Osnabrück, Lower Saxony, Germany.
Institute of Molecular Cell Biology, Department of Biology, University of Muenster, 48149 Muenster, Germany.
Biochim Biophys Acta Bioenerg. 2021 Jan 1;1862(1):148322. doi: 10.1016/j.bbabio.2020.148322. Epub 2020 Oct 14.
• Mitochondrial FF ATP synthase is the key enzyme for mitochondrial bioenergetics. Dimeric FF-ATP synthase, is preferentially located at the edges of the cristae and its oligomerization state determines mitochondrial ultrastructure. The ATP synthase inhibitor protein IF1 modulates not only ATP synthase activity but also regulates both the structure and function of mitochondria. In order to understand this in more detail, we have investigated the effect of IF1 on the spatiotemporal organization of the ATP synthase. Stable cell lines were generated that overexpressed IF1 and constitutively active IF1-H49K. The expression of IF1-H49K induced a change in the localization and mobility of the ATP synthase as analyzed by single molecule tracking and localization microscopy (TALM). In addition, the ultrastructure and function of mitochondria in cells with higher levels of active IF1 displayed a gradual alteration. In state III, cristae structures were significantly altered. The inhibition of the hydrolase activity of the FF-ATP synthase by IF1 together with altered inner mitochondrial membrane caused re-localization and altered mobility of the enzyme.
• 线粒体 FF ATP 合酶是线粒体生物能量学的关键酶。二聚体 FF-ATP 合酶优先位于嵴的边缘，其寡聚状态决定了线粒体的超微结构。ATP 合酶抑制剂蛋白 IF1 不仅调节 ATP 合酶的活性，还调节线粒体的结构和功能。为了更详细地了解这一点，我们研究了 IF1 对 ATP 合酶时空组织的影响。生成了稳定的细胞系，过表达 IF1 和组成型激活的 IF1-H49K。通过单分子追踪和定位显微镜（TALM）分析，IF1-H49K 的表达诱导了 ATP 合酶定位和迁移率的变化。此外，具有更高活性 IF1 水平的细胞中线粒体的超微结构和功能显示出逐渐改变。在状态 III 中，嵴结构发生了显著改变。IF1 与改变的线粒体内膜一起抑制 FF-ATP 合酶的水解酶活性，导致酶的重新定位和迁移率改变。
