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Updated: May 30, 2026
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Single-Molecule Imaging of Nuclear Transport
Published on: June 9, 2010
Fluorescence correlation spectroscopy of intact nuclear pore complexes
Francesco Cardarelli1, Luca Lanzano, Enrico Gratton
1Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California, Irvine, California, USA.
Biophysical Journal
|August 17, 2011
Summary
Researchers developed a new method to track single molecules moving through nuclear pore complexes (NPCs) in living cells. This technique reveals regulated transport of karyopherin-β1 (Kapβ1) within the NPC, offering insights into nucleocytoplasmic shuttling.
Area of Science:
- Cell biology
- Biophysics
- Molecular transport
Background:
- Current methods lack the sensitivity to measure single-molecule transport through nuclear pore complexes (NPCs) in intact cells.
- Understanding nucleocytoplasmic transport is crucial for cellular function and disease research.
Purpose of the Study:
- To develop a highly sensitive method for observing single-molecule transport through individual NPCs in live cells.
- To investigate the transport dynamics and regulation of karyopherin-β1 (Kapβ1) at the NPC.
Main Methods:
- Utilized fluorescence correlation spectroscopy (FCS) combined with real-time tracking of single NPC centers of mass.
- Achieved high temporal (millisecond) and spatial resolution in live, unperturbed cells.
Main Results:
- Successfully detected single-molecule transport through a reference pore system.
- Observed a unique distribution of characteristic transport times for Kapβ1 at the NPC.
- Demonstrated that Kapβ1 transport regulation is spatially confined to the pore and dependent on its properties and energy.
Conclusions:
- The developed FCS-based method offers unprecedented nanometer-scale resolution for studying nucleocytoplasmic shuttling under physiological conditions.
- Revealed a novel, spatially restricted regulatory mechanism for Kapβ1 transport at the NPC.
- This technique provides a powerful new tool for investigating molecular transport in the nucleus.
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