Laboratory of Bioenergetics, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614, Poznań, Poland.
J Bioenerg Biomembr. 2009 Aug;41(4):361-7. doi: 10.1007/s10863-009-9231-9. Epub 2009 Aug 19.
Available data indicate that superoxide anion (O(2)(-) ) is released from mitochondria, but apart from VDAC (voltage dependent anion channel), the proteins involved in its transport across the mitochondrial outer membrane still remain elusive. Using mitochondria of the yeast Saccharomyces cerevisiae mutant depleted of VDAC (Deltapor1 mutant) and the isogenic wild type, we studied the role of the TOM complex (translocase of the outer membrane) in the efflux of O(2)(-) from the mitochondria. We found that blocking the TOM complex with the fusion protein pb(2)-DHFR decreased O(2)(-) release, particularly in the case of Deltapor1 mitochondria. We also observed that the effect of the TOM complex blockage on O(2)(-) release from mitochondria coincided with the levels of O(2)(-) release as well as with levels of Tom40 expression in the mitochondria. Thus, we conclude that the TOM complex participates in O(2)(-) release from mitochondria.
现有数据表明，超氧阴离子（O2（-））从线粒体中释放出来，但除了 VDAC（电压依赖性阴离子通道）之外，其跨线粒体外膜运输的相关蛋白仍难以捉摸。使用酵母酿酒酵母突变体（Δpor1 突变体）耗尽 VDAC 和同基因野生型的线粒体，我们研究了 TOM 复合物（外膜易位酶）在 O2（-）从线粒体中流出的作用。我们发现，用融合蛋白 pb（2）-DHFR 阻断 TOM 复合物会减少 O2（-）的释放，特别是在 Δpor1 线粒体的情况下。我们还观察到，TOM 复合物阻断对线粒体中 O2（-）释放的影响与 O2（-）释放水平以及线粒体中 Tom40 表达水平一致。因此，我们得出结论，TOM 复合物参与了线粒体中 O2（-）的释放。
