Consiglio Nazionale delle Ricerche Institute of Neuroscience and Department of Biomedical Sciences, University of Padova, 35121 Padua, Italy.
Proc Natl Acad Sci U S A. 2013 Apr 9;110(15):5887-92. doi: 10.1073/pnas.1217823110. Epub 2013 Mar 25.
Here we define the molecular nature of the mitochondrial permeability transition pore (PTP), a key effector of cell death. The PTP is regulated by matrix cyclophilin D (CyPD), which also binds the lateral stalk of the FOF1 ATP synthase. We show that CyPD binds the oligomycin sensitivity-conferring protein subunit of the enzyme at the same site as the ATP synthase inhibitor benzodiazepine 423 (Bz-423), that Bz-423 sensitizes the PTP to Ca(2+) like CyPD itself, and that decreasing oligomycin sensitivity-conferring protein expression by RNAi increases the sensitivity of the PTP to Ca(2+). Purified dimers of the ATP synthase, which did not contain voltage-dependent anion channel or adenine nucleotide translocator, were reconstituted into lipid bilayers. In the presence of Ca(2+), addition of Bz-423 triggered opening of a channel with currents that were typical of the mitochondrial megachannel, which is the PTP electrophysiological equivalent. Channel openings were inhibited by the ATP synthase inhibitor AMP-PNP (γ-imino ATP, a nonhydrolyzable ATP analog) and Mg(2+)/ADP. These results indicate that the PTP forms from dimers of the ATP synthase.
在这里，我们定义了线粒体通透性转换孔（PTP）的分子性质，PTP 是细胞死亡的关键效应因子。PTP 受基质亲环素 D（CyPD）调节，CyPD 也与 FOF1 ATP 合酶的侧臂结合。我们发现 CyPD 在与 ATP 合酶抑制剂苯并二氮杂卓 423（Bz-423）相同的部位结合酶的寡霉素敏感性赋予蛋白亚基，Bz-423 像 CyPD 本身一样使 PTP 对 Ca(2+)敏感，并且通过 RNAi 降低寡霉素敏感性赋予蛋白的表达会增加 PTP 对 Ca(2+)的敏感性。未包含电压依赖性阴离子通道或腺嘌呤核苷酸转位酶的纯化 ATP 合酶二聚体被重建到脂质双层中。在 Ca(2+)存在下，添加 Bz-423 会引发具有典型线粒体大通道电流的通道开放，这是 PTP 的电生理等效物。通道开放被 ATP 合酶抑制剂 AMP-PNP（γ-亚氨基 ATP，一种不可水解的 ATP 类似物）和 Mg(2+)/ADP 抑制。这些结果表明 PTP 由 ATP 合酶的二聚体形成。
