Nup2p dynamically associates with the distal regions of the yeast nuclear pore complex
Nup2p dynamically associates with the distal regions of the yeast nuclear pore complex
复制标题
DOI：
10.1083/jcb.153.7.1465
复制
发表时间：
2001-06-25
影响因子：
7.8
通讯作者：
Aitchison, JD
中科院分区：
文献类型：
--
作者：
Dilworth, DJ;Suprapto, A;Aitchison, JD
核质运输是由可溶性运输因子和位于核孔复合体（NPC）内的核孔蛋白之间的相互作用介导的。理解这一过程需要了解可溶性和固定相的成分以及它们之间的界面。在此，我们提供证据表明，Nup2p（先前被认为是一种典型的酵母核孔蛋白，可结合与输入和输出相关的核转运蛋白）以一种受Ran促进的方式与NPC动态结合。当结合到NPC时，Nup2p与对应于核篮和细胞质纤维的区域相关联。在核质面（预计Ran - GTP水平较高），Nup2p与Nup60p结合。NUP60的缺失使Nup2p处于核质中，并损害了Nup2p介导的Kap60p/Srp1p的循环。通过代谢中毒、Ran循环的破坏或体外细胞裂解导致Ran - GTP的耗竭，会使Nup2p从核质转移到NPC的细胞质面。在异核体中也检测到了Nup2p的这种移动性，在异核体中，与核孔蛋白不同，观察到Nup2p从一个细胞核移动到另一个细胞核。总之，我们的数据支持一种模型，即Nup2p的移动促进了核质运输的输入和输出阶段之间的转换。
Nucleocytoplasmic transport is mediated by the interplay between soluble transport factors and nucleoporins resident within the nuclear pore complex (NPC). Understanding this process demands knowledge of components of both the soluble and stationary phases and the interface between them, Here, we provide evidence that Nup2p, previously considered to be a typical yeast nucleoporin that binds import- and export-bound karyopherins, dynamically associates with the NPC in a Ran-facilitated manner. When bound to the NPC, Nup2p associates with regions corresponding to the nuclear basket and cytoplasmic fibrils. On the nucleoplasmic face, where the Ran-GTP levels are predicted to be high, Nup2p binds to Nup60p. Deletion of NUP60 kenders Nup2p nucleoplasmic and compromises Nup2p-mediated recycling of Kap60p/Srplp. Depletion of Ran-GTP by metabolic poisoning, disruption of the Ran cycle, or in vitro by cell lysis, results in a shift of Nup2p from the nucleoplasm to the cytoplasmic face of the NPC. This mobility of Nup2p was also detected using heterokaryons where, unlike nucleoporins, Nup2p was observed to move from one nucleus to the other. Together, our data support a model in which Nup2p movement facilitates the transition between the import and export phases of nucleocytoplasmic transport.