Pfanner N, Craig E A, Hönlinger A
Institut für Biochemie und Molekularbiologie, Universität Freiburg, Germany.
Annu Rev Cell Dev Biol. 1997;13:25-51. doi: 10.1146/annurev.cellbio.13.1.25.
Mitochondria import most of their proteins from the cytosol. Dynamic protein complexes in the mitochondrial outer and inner membranes are responsible for the specific recognition and membrane translocation of preproteins. The preprotein translocase of the outer mitochondrial membrane contains several import receptors and a general import pore. The preprotein translocase of the inner membrane consists of a channel interacting with preproteins in transit and an import motor that includes the matrix heat shock protein Hsp70. Acidic patches of import components are thought to guide the import of positively charged signal sequences (acid chain hypothesis). Energy input is derived from the inner membrane potential and ATP. Proteins in the mitochondrial matrix are required for proteolytic processing and folding of imported proteins. The dynamic nature of the membrane translocase permits sorting of preproteins at distinct stages of the import pathway.
线粒体的大部分蛋白质是从细胞质基质中导入的。线粒体外膜和内膜中的动态蛋白质复合物负责前体蛋白的特异性识别和跨膜转运。线粒体外膜的前体蛋白转位酶包含几种导入受体和一个通用导入孔。内膜的前体蛋白转位酶由一个与转运中的前体蛋白相互作用的通道和一个导入动力装置组成，该动力装置包括基质热休克蛋白Hsp70。导入组件的酸性区域被认为可引导带正电荷的信号序列的导入（酸性链假说）。能量输入来自内膜电位和ATP。线粒体基质中的蛋白质是导入蛋白质进行蛋白水解加工和折叠所必需的。膜转位酶的动态特性允许在前体蛋白导入途径的不同阶段进行分选。
