The adapter importin-alpha provides flexible control of nuclear import at the expense of efficiency.
The adapter importin-alpha provides flexible control of nuclear import at the expense of efficiency.
复制标题
适配器 importin-alpha 提供了核导入的灵活控制，但以效率为代价。
DOI：
10.1038/msb4100160
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发表时间：
2007
影响因子：
9.9
通讯作者：
Macara,IanG
中科院分区：
文献类型：
--
作者：
Riddick,Greg;Macara,IanG
尽管存在一个大的核转运受体家族（核丝蛋白），但大多数已知的进口货物使用一种适配器蛋白，进口蛋白α (Impα)，它将货物与核丝蛋白进口蛋白β (Impβ)连接起来。传输适配器存在的原因尚不清楚。一种假设是，由于Impα再出口与GTP水解耦合，它可以驱动更高浓度的核货物，而不是直接货物与importtin - β结合。然而，计算机模拟预测了相反的结果，并表明直接运输比适配器介导的运输更快。这些预测在实验中得到了验证。这些数据，连同先前对核蛋白输入的分析，表明使用诸如importin‐α之类的适配器为控制核输入率提供了细胞更大的动态范围，但以牺牲效率为代价。
Although there exists a large family of nuclear transport receptors (Karyopherins), the majority of known import cargoes use an adapter protein, Importin‐α (Impα), which links the cargo to a karyopherin, Importin‐β (Impβ). The reason for the existence of transport adapters is unknown. One hypothesis is that, as Impα re‐export is coupled to GTP hydrolysis, it can drive a higher concentration of nuclear cargo than could be achieved by direct cargo binding to Importin‐β. However, computer simulations predicted the opposite outcome, and showed that direct transport is faster than adapter‐mediated transport. These predictions were validated experimentally. The data, together with previous analyses of nuclear protein import, suggest that the use of adapters such as importin‐α provides the cell with increased dynamic range for control of nuclear import rates, but at the expense of efficiency.