Langer T, Neupert W
Institut für Physiologische Chemie, Universität München, Germany.
Experientia. 1996 Dec 15;52(12):1069-76. doi: 10.1007/BF01952104.
Various adenosine triphosphate (ATP)-dependent proteases were identified within mitochondria which mediate selective mitochondrial protein degradation and fulfill crucial functions in mitochondrial biogenesis. The matrix-localized PIM1 protease, a homologue of the Escherichia coli Lon protease, is required for respiration and maintenance of mitochondrial genome integrity. Degradation of non-native polypeptides by PIM1 protease depends on the chaperone activity of the mitochondrial Hsp70 system, posing intriguing questions about the relation between the proteolytic system and the folding machinery in mitochondria. The mitochondrial inner membrane harbors two ATP-dependent metallopeptidases, the m- and the i-AAA protease, which expose their catalytic sites to opposite membrane surfaces and cooperate in the degradation of inner membrane proteins. In addition to its proteolytic activity, the m-AAA protease has chaperone-like activity during the assembly of respiratory and ATP-synthase complexes. It constitutes a quality control system in the inner membrane for membrane-embedded protein complexes.
在线粒体中发现了多种依赖三磷酸腺苷（ATP）的蛋白酶，它们介导线粒体蛋白的选择性降解，并在线粒体生物发生中发挥关键作用。基质定位的PIM1蛋白酶是大肠杆菌Lon蛋白酶的同源物，是呼吸作用和维持线粒体基因组完整性所必需的。PIM1蛋白酶对非天然多肽的降解依赖于线粒体Hsp70系统的伴侣活性，这引发了关于线粒体中蛋白水解系统与折叠机制之间关系的有趣问题。线粒体内膜含有两种依赖ATP的金属肽酶，即m-AAA蛋白酶和i-AAA蛋白酶，它们将催化位点暴露于相对的膜表面，并协同降解内膜蛋白。除了蛋白水解活性外，m-AAA蛋白酶在呼吸和ATP合酶复合物组装过程中还具有伴侣样活性。它在内膜中构成了一个针对膜嵌入蛋白复合物的质量控制系统。
