The mitochondrial inner membrane can reshape under different physiological conditions. How, at which frequency this occurs in living cells, and the molecular players involved are unknown. Here, we show using state-of-the-art live-cell stimulated emission depletion (STED) super-resolution nanoscopy that neighbouring crista junctions (CJs) dynamically appose and separate from each other in a reversible and balanced manner in human cells. Staining of cristae membranes (CM), using various protein markers or two lipophilic inner membrane-specific dyes, further revealed that cristae undergo continuous cycles of membrane remodelling. These events are accompanied by fluctuations of the membrane potential within distinct cristae over time. Both CJ and CM dynamics depended on MIC13 and occurred at similar timescales in the range of seconds. Our data further suggest that MIC60 acts as a docking platform promoting CJ and contact site formation. Overall, by employing advanced imaging techniques including fluorescence recovery after photobleaching (FRAP), single-particle tracking (SPT), live-cell STED and high-resolution Airyscan microscopy, we propose a model of CJ dynamics being mechanistically linked to CM remodelling representing cristae membrane fission and fusion events occurring within individual mitochondria.

中文翻译：

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sta以依赖MICOS的方式经历膜重塑的连续循环。

线粒体内膜可以在不同的生理条件下重塑。这在活细胞中如何发生，以何种频率发生，以及涉及的分子参与者尚不清楚。在这里，我们展示了使用最先进的活细胞刺激的发射耗竭（STED）超分辨率纳米技术，可以在人体细胞中以可逆和平衡的方式动态地施加相邻的crista交界处（CJs）并彼此分离。使用各种蛋白质标记物或两种亲脂性内膜特异性染料对cr膜（CM）进行染色，进一步揭示了ista经过膜重塑的连续循环。这些事件伴随着随着时间的推移不同的distinct内的膜电位的波动。CJ和CM动力学都取决于MIC13，并且发生在几秒钟的相似时间范围内。我们的数据进一步表明，MIC60作为促进CJ和接触部位形成的对接平台。总体而言，通过采用先进的成像技术，包括光漂白后的荧光恢复（FRAP），单粒子跟踪（SPT），活细胞STED和高分辨率Airyscan显微镜，我们提出了一种CJ动力学模型，该模型与代表重生的CM重塑机械关联单个线粒体内发生的膜裂变和融合事件。