Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.
Proc Natl Acad Sci U S A. 2011 Aug 16;108(33):13546-51. doi: 10.1073/pnas.1107553108. Epub 2011 Jul 28.
The translocase of the mitochondrial outer membrane (TOM) complex is the main import pore for nuclear-encoded proteins into mitochondria, yet little is known about its spatial distribution within the outer membrane. Super-resolution stimulated emission depletion microscopy was used to determine quantitatively the nanoscale distribution of Tom20, a subunit of the TOM complex, in more than 1,000 cells. We demonstrate that Tom20 is located in clusters whose nanoscale distribution is finely adjusted to the cellular growth conditions as well as to the specific position of a cell within a microcolony. The density of the clusters correlates to the mitochondrial membrane potential. The distributions of clusters of Tom20 and of Tom22 follow an inner-cellular gradient from the perinuclear to the peripheral mitochondria. We conclude that the nanoscale distribution of the TOM complex is finely adjusted to the cellular conditions, resulting in distribution gradients both within single cells and between adjacent cells.
线粒体膜外转位酶（TOM）复合物是核编码蛋白进入线粒体的主要输入孔，但对于其在外膜中的空间分布知之甚少。超分辨率受激发射损耗显微镜被用来定量确定 Tom20（TOM 复合物的一个亚基）在 1000 多个细胞中的纳米级分布。我们证明 Tom20 位于簇中，其纳米级分布可根据细胞生长条件以及细胞在微菌落中的特定位置进行精细调整。簇的密度与线粒体膜电位相关。Tom20 和 Tom22 簇的分布遵循从核周到外周线粒体的细胞内梯度。我们的结论是，TOM 复合物的纳米级分布可根据细胞条件进行精细调整，从而导致单个细胞内和相邻细胞之间的分布梯度。
