van Loon A P, Brändli A W, Pesold-Hurt B, Blank D, Schatz G
Biocenter, University of Basel, Switzerland.
EMBO J. 1987 Aug;6(8):2433-9. doi: 10.1002/j.1460-2075.1987.tb02522.x.
We reported earlier that the yeast cytochrome c1 presequence (length: 61 amino acids) directs attached proteins to the mitochondrial intermembrane space and that it appears to contain two functional domains: a 'matrix-targeting' domain, and a 'sorting' domain. We have now used gene manipulation together with two different in vivo import assays to map these two domains within the cytochrome c1 presequence. The 'matrix-targeting' domain is contained within the N-terminal 16 residues (or less); by itself, it directs attached proteins to the matrix. The 'sorting' domain extends into the C-terminal 13 residues of the presequence; while it does not mediate intracellular protein transport by itself, it acts together with the preceding 'matrix-targeting' sequence in sorting attached proteins into the intermembrane space. On replacing the authentic 'matrix-targeting' sequence with artificial sequences of different lengths we found that sorting of proteins between the outer membrane and the intermembrane space is not exclusively determined by the length of the N-terminal 'matrix-targeting' sequence.
我们先前报道过，酵母细胞色素c1前导序列（长度：61个氨基酸）可将附着的蛋白质导向线粒体膜间隙，并且它似乎包含两个功能域：一个“基质靶向”域和一个“分选”域。我们现在利用基因操作以及两种不同的体内导入测定法，来确定细胞色素c1前导序列中的这两个域。“基质靶向”域包含在前16个（或更少）N端残基内；其自身就能将附着的蛋白质导向基质。“分选”域延伸至前导序列的C端13个残基；虽然它自身并不介导细胞内蛋白质转运，但它与前面的“基质靶向”序列共同作用，将附着的蛋白质分选到膜间隙。在用不同长度的人工序列替换真实的“基质靶向”序列时，我们发现外膜和膜间隙之间蛋白质的分选并非完全由N端“基质靶向”序列的长度决定。
