Electron tomographic analysis reveals ultrastructural features of mitochondrial cristae architecture which reflect energetic state and aging.
Electron tomographic analysis reveals ultrastructural features of mitochondrial cristae architecture which reflect energetic state and aging.
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DOI：
10.1038/srep45474
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发表时间：
2017-03-30
影响因子：
4.6
通讯作者：
Fu CY
中科院分区：
文献类型：
--
作者：
Jiang YF;Lin SS;Chen JM;Tsai HZ;Hsieh TS;Fu CY
在线粒体内，产生能量的能力依赖于双膜和嵴内陷的结构特征。在这里，我们描述了线粒体嵴结构的新特征，这与细胞器的能量状态相对应。与高能量需求一致，果蝇间接飞行肌的线粒体在密集排列的板层嵴之间表现出广泛的线粒体膜内开关，导致螺旋状嵴网络，并允许双向基质融合。这种高度互联的结构有望实现跨集成区域的膜电位和生物分子的快速平衡。此外，具有mtDNA复制缺陷和加速老化表型的突变果蝇在正常嵴旁积累了含有旋转膜亚段的线粒体。从蛋白质组成和功能的角度来衡量，旋转膜的能量生产能力受损。此外，线粒体融合和裂变动力学在过早衰老的果蝇中受到影响。有趣的是，线粒体中的正常嵴保持着可接受的功能，使其不受质量控制消除的影响。总体而言，通过序列断层电子断层分析，我们在三维空间上描述了线粒体嵴的结构特征，这些特征反映了线粒体dna介导的衰老和能量状态。
Within mitochondria, the ability to produce energy relies upon the architectural hallmarks of double membranes and cristae invaginations. Herein, we describe novel features of mitochondrial cristae structure, which correspond to the energetic state of the organelle. In concordance with high-energy demand, mitochondria of Drosophila indirect flight muscle exhibited extensive intra-mitochondrial membrane switches between densely packed lamellar cristae that resulted in a spiral-like cristae network and allowed for bidirectional matrix confluency. This highly interconnected architecture is expected to allow rapid equilibration of membrane potential and biomolecules across integrated regions. In addition, mutant flies with mtDNA replication defect and an accelerated aging phenotype accumulated mitochondria that contained subsections of swirling membrane alongside normal cristae. The swirling membrane had impaired energy production capacity as measured by protein composition and function. Furthermore, mitochondrial fusion and fission dynamics were affected in the prematurely aged flies. Interestingly, the normal cristae that remained in the mitochondria with swirling membranes maintained acceptable function that camouflaged them from quality control elimination. Overall, structural features of mitochondrial cristae were described in three-dimension from serial section electron tomographic analysis which reflect energetic state and mtDNA-mediated aging.