Nelson N, Schatz G
Proc Natl Acad Sci U S A. 1979 Sep;76(9):4365-9. doi: 10.1073/pnas.76.9.4365.
Earlier work has shown that mitochondrial proteins synthesized in the cytosol are initially made as larger precursors which are then transferred into the organelles and processed to their mature size in the absence of protein synthesis. It is now demonstrated that depletion of the mitochondrial matrix ATP in intact yeast spheroplasts by various combinations of inhibitors and mutations prevents the processing of precursors to the three largest subunits of the mitochondrial F1-ATPase and two subunits of the cytochrome bc1 complex. These polypeptides are all synthesized outside the mitochondria and transported to the mitochondrial matrix or inserted into the mitochondrial inner membrane. In contrast, depletion of the matrix ATP does not inhibit processing of the precursor to cytochrome c peroxidase; this enzyme is located in the mitochondrial intermembrane space which is freely accessible to ATP made in the cytosol. The processing of extramitochondrially made precursors or the transfer of these precursors across the mitochondrial inner membrane is thus dependent on ATP.
早期研究表明，在细胞质中合成的线粒体蛋白质最初是以较大的前体形式存在，然后被转运到细胞器中，并在没有蛋白质合成的情况下加工成成熟大小。现在已经证明，通过抑制剂和突变的各种组合耗尽完整酵母原生质球中的线粒体基质ATP，会阻止前体加工成线粒体F1-ATP酶的三个最大亚基和细胞色素bc1复合体的两个亚基。这些多肽都是在线粒体外部合成的，并被转运到线粒体基质或插入线粒体内膜。相比之下，基质ATP的耗尽并不抑制细胞色素c过氧化物酶前体的加工；这种酶位于线粒体膜间隙，细胞质中产生的ATP可以自由进入该间隙。因此，线粒体外合成的前体的加工或这些前体穿过线粒体内膜的转运依赖于ATP。
