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Updated: Jul 18, 2026

Single-Molecule Imaging of Nuclear Transport
Published on: June 9, 2010
Passive and facilitated transport in nuclear pore complexes is largely uncoupled
Bracha Naim1, Vlad Brumfeld, Ruti Kapon
1Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel.
Abstract:
Nuclear pore complexes provide the sole gateway for the exchange of material between nucleus and cytoplasm of interphase eukaryotic cells. They support two modes of transport: passive diffusion of ions, metabolites, and intermediate-sized macromolecules and facilitated, receptor-mediated translocation of proteins, RNA, and ribonucleoprotein complexes. It is generally assumed that both modes of transport occur through a single diffusion channel located within the central pore of the nuclear pore complex. To test this hypothesis, we studied the mutual effects between transporting molecules utilizing either the same or different modes of translocation. We find that the two modes of transport do not interfere with each other, but molecules utilizing a particular mode of transport do hinder motion of others utilizing the same pathway. We therefore conclude that the two modes of transport are largely segregated.
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