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Article

  • The EMBO Journal (2001) 20, 1320 - 1330
  • doi:10.1093/emboj/20.6.1320

Kinetic analysis of translocation through nuclear pore complexes

Katharina Ribbeck1 and Dirk Görlich1

  1. ZMBH, INF 282, 69120 Heidelberg, Germany

Correspondence to:

Dirk Görlich, E-mail: dg@zmbh.uni-heidelberg.de

Received 15 December 2000; Accepted 30 January 2001; Revised 29 January 2001

The mechanism of facilitated translocation through nuclear pore complexes (NPCs) is only poorly understood. Here, we present a kinetic analysis of the process using various model substrates. We find that the translocation capacity of NPCs is unexpectedly high, with a single NPC allowing a mass flow of nearly 100 MDa/s and rates in the order of 103 translocation events per second. Our data further indicate that high affinity interactions between the translocation substrate and NPC components are dispensable for translocation. We propose a 'selective phase model' that could explain how NPCs function as a permeability barrier for inert molecules and yet become selectively permeable for nuclear transport receptors and receptor–cargo complexes.

  • Keywords:

    • importin,
    • kinetics,
    • nuclear pore complex,
    • nuclear transport,
    • nuclear transport factor 2