Precursors to two nuclear-encoded chloroplast proteins bind to the outer envelope membrane before being imported into chloroplasts.
Precursors to two nuclear-encoded chloroplast proteins bind to the outer envelope membrane before being imported into chloroplasts.
复制标题
两种核编码叶绿体蛋白的前体在被输入叶绿体之前与外膜结合。
DOI：
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发表时间：
1985
影响因子：
4.8
通讯作者：
K. Keegstra
中科院分区：
文献类型：
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作者：
K. Cline;M. Werner;T. Lubben;K. Keegstra
在无细胞翻译系统中合成的叶绿体蛋白的前体形式可以在翻译后输入到分离的、完整的叶绿体中。通过体外翻译杂交选择的mRNA，制备了核酮糖-1，5-二磷酸羧基酶小亚基和捕光叶绿素a/b蛋白的放射化学纯前体，并用于研究这一进口过程。如果用解偶联剂黑色素预处理叶绿体，则不会发生输入，但前体结合到叶绿体表面。在ATP存在下，前体-叶绿体复合体的重新孵化导致结合前体的进口。这种结合似乎是由外叶绿体被膜的蛋白质介导的，因为用蛋白酶预处理叶绿体抑制了它们结合和输入前体的能力。这些结果表明，至少有一部分观察到的结合是与参与进口过程的功能性受体蛋白结合的。
Precursor forms of chloroplast proteins synthesized in cell-free translation systems can be imported posttranslationally into isolated, intact chloroplasts. Radiochemically pure precursors to the small subunit of ribulose-1,5-bisphosphate carboxylase and to the light-harvesting chlorophyll a/b protein have been prepared by in vitro translation of hybrid-selected mRNA and used to study this import process. If chloroplasts are pretreated with the uncoupler nigericin, import does not occur, but the precursors bind to the chloroplast surface. Reincubation of the precursor-chloroplast complex in the presence of ATP results in import of bound precursors. The binding appears to be mediated by proteins of the outer chloroplast envelope membrane because pretreatment of chloroplasts with protease inhibits their ability to bind as well as to import precursors. These results indicate that at least a portion of the observed binding is to functional receptor proteins involved in the import process.