RanBP1 is crucial for the release of RanGTP from importin β‐related nuclear transport factors

FEBS Letters

Bischoff, F.Ralf²  Görlich, Dirk¹ 

[1]Zentrum für Molekulare Biologie der Universität Heidelberg, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany

[2]Abteilung Molekulare Biologie der Mitose, Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany

关键词: Nuclear transport;    Importin;    Transportin;    CAS;    RanBP1;    RanGTP;    GTP-bound form of Ran;    RanGDP;    GDP-bound form of Ran;    GAP;    GTPase activating protein;    NPC;    nuclear pore complex;   

DOI  :  10.1016/S0014-5793(97)01467-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Nucleocytoplasmic transport appears mediated by shuttling transport receptors that bind RanGTP as a means to regulate interactions with their cargoes. The receptor·RanGTP complexes are kinetically very stable with nucleotide exchange and GTP hydrolysis being blocked, predicting that a specific disassembly mechanism exists. Here we show in three cases receptor·RanGTP·RanBP1 complexes to be the key disassembly intermediates, where RanBP1 stimulates the off-rate at the receptor/RanGTP interface by more than two orders of magnitude. The transiently released RanGTP·RanBP1 complex is then induced by RanGAP to hydrolyse GTP, preventing the receptor to rebind RanGTP. The efficient release of importin β from RanGTP requires importin α, in addition to RanBP1.

【 授权许可】

Unknown