Department of Plant Biology, University of California, Davis, CA, USA.
Plant Signal Behav. 2011 Sep;6(9):1397-401. doi: 10.4161/psb.6.9.16916.
Chloroplast function is largely dependent on its resident proteins, most of which are encoded by the nuclear genome and are synthesized in cytosol. Almost all of these are imported through the translocons located in the outer and inner chloroplast envelope membranes. The motor protein that provides the driving force for protein import has been proposed to be Hsp93, a member of the Hsp100 family of chaperones residing in the stroma. Combining in vivo and in vitro approaches, recent publications have provided multiple lines of evidence demonstrating that a stromal Hsp70 system is also involved in protein import into this organelle. Thus it appears that protein import into chloroplasts is driven by two motor proteins, Hsp93 and Hsp70. A perspective on collaboration between these two chaperones is discussed.
叶绿体的功能在很大程度上依赖于其固有的蛋白质，其中大部分由核基因组编码，并在细胞质中合成。这些蛋白质几乎都是通过位于叶绿体内外膜上的转运体进入叶绿体的。为蛋白质输入提供驱动力的运动蛋白被认为是 Hsp93，它是位于基质中的 Hsp100 家族伴侣蛋白的一员。结合体内和体外方法，最近的出版物提供了多条证据，证明基质中的 Hsp70 系统也参与了该细胞器的蛋白质输入。因此，似乎有两种运动蛋白 Hsp93 和 Hsp70 驱动蛋白质进入叶绿体。本文讨论了这两种伴侣蛋白之间的合作关系。
