Smeekens S, Bauerle C, Hageman J, Keegstra K, Weisbeek P
Cell. 1986 Aug 1;46(3):365-75. doi: 10.1016/0092-8674(86)90657-4.
The role of the transit peptide in the routing of imported proteins inside the chloroplast was investigated with chimeric proteins in which the transit peptides for the nuclear-encoded ferredoxin and plastocyanin precursors were exchanged. Import and localization experiments with a reconstituted chloroplast system show that the ferredoxin transit peptide directs mature plastocyanin away from its correct location, the thylakoid lumen, to the stroma. With the plastocyanin transit peptide-mature ferredoxin chimera, a processing intermediate is arrested on its way to the lumen. We propose a two domain hypothesis for the plastocyanin transit peptide: the first domain functions in the chloroplast import process, whereas the second is responsible for transport across the thylakoid membrane. Thus, the transit peptide not only targets proteins to the chloroplast, but also is a major determinant in their subsequent localization within the organelle.
利用嵌合蛋白研究了转运肽在叶绿体内部导入蛋白的途径中的作用，在这些嵌合蛋白中，核编码的铁氧化还原蛋白和质体蓝素前体的转运肽发生了交换。用重组叶绿体系统进行的导入和定位实验表明，铁氧化还原蛋白转运肽将成熟的质体蓝素从其正确位置（类囊体腔）导向基质。对于质体蓝素转运肽-成熟铁氧化还原蛋白嵌合体，一个加工中间体在其进入腔的途中被阻滞。我们提出了一个关于质体蓝素转运肽的双结构域假说：第一个结构域在叶绿体导入过程中起作用，而第二个结构域负责跨类囊体膜的转运。因此，转运肽不仅将蛋白质靶向叶绿体，而且是它们随后在细胞器内定位的主要决定因素。
