Ishigaki Masaya, Iketani Masumi, Sugaya Maki, Takahashi Mayumi, Tanaka Masashi, Hattori Seisuke, Ohsawa Ikuroh
Biological Process of Aging, Tokyo Metropolitan Institute of Gerontology, Itabashi-ku, Tokyo 173-0015, Japan; Division of Biochemistry, School of Pharmaceutical Sciences, Kitasato University, Minato-ku, Tokyo 108-8641, Japan.
Biological Process of Aging, Tokyo Metropolitan Institute of Gerontology, Itabashi-ku, Tokyo 173-0015, Japan.
Mitochondrion. 2016 May;28:79-87. doi: 10.1016/j.mito.2016.03.009. Epub 2016 Apr 25.
We applied stimulated emission depletion (STED) imaging with subdiffraction resolution to submitochondrial structures in mitochondria. Their shapes depend on both a cell's type and its physiological state. Staining with a cationic fluorescent dye, tetramethylrhodamine methyl ester (TMRM), unveiled intriguing details of lamellar structure, consisting of rapidly changeable, curtain-like formations. The TMRM-positive structure colocalized with neither proteins in the matrix nor on the outer membrane, but partially localized with the nucleoid. Suppression of a component in the mitochondrial contact site disrupted the lamellar TMRM-positive structure. Uncoupling of the oxidative phosphorylation system released TMRM from the inner membrane without any alteration in the matrix structure. STED images further showed that complexes of the electron transport chain are located on the surface of TMRM-positive structures. The approach presented here provides novel insights into the in vivo nature of submitochondrial structures, and can be used for further functional investigations of these complex structures.
我们将具有亚衍射分辨率的受激发射损耗（STED）成像技术应用于线粒体中的亚线粒体结构。它们的形状取决于细胞类型及其生理状态。用阳离子荧光染料四甲基罗丹明甲酯（TMRM）染色，揭示了由快速变化的帘状结构组成的层状结构的有趣细节。TMRM阳性结构既不与基质中的蛋白质共定位，也不与外膜上的蛋白质共定位，但部分与类核共定位。线粒体接触位点中一种成分的抑制破坏了层状TMRM阳性结构。氧化磷酸化系统的解偶联使TMRM从内膜释放，而基质结构没有任何改变。STED图像进一步显示，电子传递链复合物位于TMRM阳性结构的表面。本文提出的方法为亚线粒体结构的体内性质提供了新的见解，可用于对这些复杂结构的进一步功能研究。
