Super-resolved 3D tracking of cargo transport through nuclear pore complexes

Area of Science:

• Cell Biology
• Molecular Biology
• Biophysics

Background:

• Nuclear pore complexes (NPCs) regulate essential nucleocytoplasmic transport.
• Understanding NPC transport dynamics requires high spatial and temporal resolution, which is challenging.
• Existing methods lack the resolution to visualize cargo trajectories relative to NPC structure.

Purpose of the Study:

• To develop and apply a multicolour imaging approach for visualizing NPC cargo transport.
• To achieve high-resolution 3D visualization of cargo trajectories relative to the NPC scaffold.
• To investigate the mechanism and dynamics of nucleocytoplasmic transport.

Main Methods:

• Multicolour imaging technique for 3D visualization.
• Super-resolution microscopy of NPC scaffold structure.
• Experimental and simulation analysis for NPC positional stability.
• Tracking of cargo complexes through NPCs.

Main Results:

• Direct 3D visualization of cargo transport trajectories relative to the NPC scaffold.
• Identification of hourglass-shaped translocation conduits for cargo complexes.
• Evidence for rapid cargo migration through the NPC permeability barrier.
• Mapping of cargo binding sites extending over 100 nm from pore openings.

Conclusions:

• The developed imaging approach enables unprecedented visualization of NPC transport.
• Cargo transport occurs rapidly through defined conduits within or near the NPC scaffold.
• Findings provide insights into the molecular mechanisms of nuclear transport receptor pathways.