Yoneda Y
Department of Cell Biology and Neuroscience, Graduate School of Medicine, Osaka University, Japan.
Genes Cells. 2000 Oct;5(10):777-87. doi: 10.1046/j.1365-2443.2000.00366.x.
In eukaryotic cells, cell functions are maintained in an orderly manner through the continuous traffic of various proteins between the cell nucleus and the cytoplasm. The nuclear import and export of proteins occurs through nuclear pore complexes and typically requires specific signals: the nuclear localization signal and nuclear export signal, respectively. The transport pathways have been found to be highly divergent, but are known to be largely mediated by importin beta-like transport receptor family molecules. These receptor molecules bind to and carry their cargoes directly or via adapter molecules. A small GTPase Ran ensures the directionality of nuclear transport by regulating the interaction between the receptors and their cargoes through its GTP/GDP cycle. Moreover, it has been recently elucidated how the transport system is involved in various functions of cell physiology, such as cell cycle control.
在真核细胞中，细胞核与细胞质之间各种蛋白质的持续运输使细胞功能得以有序维持。蛋白质的核输入和输出通过核输出通过核孔复合体进行，通常分别需要特定信号：核定位信号和核输出信号。已发现运输途径高度多样化，但已知主要由类输入蛋白β运输受体家族分子介导。这些受体分子直接或通过衔接分子结合并运载其货物。一种小GTP酶Ran通过其GTP/GDP循环调节受体与其货物之间的相互作用，确保核运输的方向性。此外，最近已经阐明了运输系统如何参与细胞生理学的各种功能，如细胞周期调控。
