These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: The direction of transport through the nuclear pore can be inverted.
    Author: Nachury MV, Weis K.
    Journal: Proc Natl Acad Sci U S A; 1999 Aug 17; 96(17):9622-7. PubMed ID: 10449743.
    Abstract:
    Transport of macromolecules across the nuclear envelope is an active process that depends on soluble factors including the GTPase Ran. Ran-GTP is predominantly located in the nucleus and has been shown to regulate cargo binding and release of import and export receptors in their respective target compartments. Recently, it was shown that transport of receptor-cargo complexes across the nuclear pore complex (NPC) does not depend on GTP-hydrolysis by Ran; however, the mechanism of translocation is still poorly understood. Here, we show that the direction of transport through the NPC can be inverted in the presence of high concentrations of cytoplasmic Ran-GTP. Under these conditions, two different classes of export cargoes are transported into the nucleus in the absence of GTP hydrolysis. The inverted transport is very rapid and can be blocked by known inhibitors of nuclear protein export. These results suggest that the NPC functions as a facilitated transport channel, allowing the selective translocation of receptor-cargo complexes. We conclude that the directionality of nucleocytoplasmic transport is determined mainly by the compartmentalized distribution of Ran-GTP.
    [Abstract] [Full Text] [Related] [New Search]