Ran-dependent docking of importin-beta to RanBP2/Nup358 filaments is essential for protein import and cell viability.
Ran-dependent docking of importin-beta to RanBP2/Nup358 filaments is essential for protein import and cell viability.
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DOI：
10.1083/jcb.201102018
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发表时间：
2011-08-22
期刊：
影响因子：
--
通讯作者：
van Deursen JM
中科院分区：
文献类型：
--
作者：
Hamada M;Haeger A;Jeganathan KB;van Ree JH;Malureanu L;Wälde S;Joseph J;Kehlenbach RH;van Deursen JM
RanBP2在细胞质纤维处捕获RanGTP-Importin-β复合体，以确保足够的经典NLS介导的蛋白质输入和细胞活力。RanBP2/Nup358是核孔复合体(NPC)胞质细丝的主要成分，是小鼠胚胎发育所必需的，参与大分子转运和有丝分裂，但其具体的分子功能尚不清楚。使用RanBP2条件基因敲除的小鼠胚胎成纤维细胞和一系列突变结构，我们证明了RanBP2的运输功能，而不是有丝分裂功能，是细胞存活所必需的。Cre介导的RanBP2失活导致细胞死亡，M9和经典核定位信号(CNLS)介导的蛋白质输入、核输出信号介导的蛋白质输出和信使核糖核酸输出存在缺陷，但没有明显的有丝分裂失败。含有NPC结合区、三个苯丙氨酸-甘氨酸基序和一个Ran结合域(RBD)的RanBP2片段纠正了所有的转运缺陷，恢复了活性。该片段中rBD的突变导致致死性和与三磷酸鸟苷Importin-β的结合紊乱，Importin-β聚集在核孔，以及CNLS介导的蛋白质输入。这些数据表明，RanBP2的一个关键功能是在细胞质纤维上捕获循环的RanGTP-Importin-β复合体，以允许足够的CNLS介导的货物输入。
RanBP2 captures RanGTP–importin-β complexes at cytoplasmic fibrils to ensure adequate classical NLS–mediated protein import and cell viability. RanBP2/Nup358, the major component of the cytoplasmic filaments of the nuclear pore complex (NPC), is essential for mouse embryogenesis and is implicated in both macromolecular transport and mitosis, but its specific molecular functions are unknown. Using RanBP2 conditional knockout mouse embryonic fibroblasts and a series of mutant constructs, we show that transport, rather than mitotic, functions of RanBP2 are required for cell viability. Cre-mediated RanBP2 inactivation caused cell death with defects in M9- and classical nuclear localization signal (cNLS)–mediated protein import, nuclear export signal–mediated protein export, and messenger ribonucleic acid export but no apparent mitotic failure. A short N-terminal RanBP2 fragment harboring the NPC-binding domain, three phenylalanine-glycine motifs, and one Ran-binding domain (RBD) corrected all transport defects and restored viability. Mutation of the RBD within this fragment caused lethality and perturbed binding to Ran guanosine triphosphate (GTP)–importin-β, accumulation of importin-β at nuclear pores, and cNLS-mediated protein import. These data suggest that a critical function of RanBP2 is to capture recycling RanGTP–importin-β complexes at cytoplasmic fibrils to allow for adequate cNLS-mediated cargo import.
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影响因子：
11.8
作者：
Malureanu, Liviu A.;Jeganathan, Karthik B.;Hamada, Masakazu;Wasilewski, Lisa;Davenport, James;van Deursen, Jan M.
通讯作者：
van Deursen, Jan M.
DOI：
10.1083/jcb.200706015
发表时间：
2007-10-22
期刊：
The Journal of cell biology
影响因子：
--
作者：
Jeganathan K;Malureanu L;Baker DJ;Abraham SC;van Deursen JM
通讯作者：
van Deursen JM
DOI：
10.1016/j.bbamcr.2010.10.014
发表时间：
2011-09
期刊：
Biochimica et biophysica acta
影响因子：
--
作者：
Chook YM;Süel KE
通讯作者：
Süel KE
影响因子：
64.5
作者：
Dobles, M;Liberal, V;Sorger, PK
通讯作者：
Sorger, PK
影响因子：
7.8
作者：
Bastos, R;Lin, A;Burke, B
通讯作者：
Burke, B