Structure and gating of the nuclear pore complex.

Area of Science:

• Cell Biology
• Structural Biology
• Biophysics

Background:

• Nuclear pore complexes (NPCs) regulate macromolecule transport between the nucleus and cytoplasm.
• Understanding NPC structure is crucial for deciphering cellular transport mechanisms.

Purpose of the Study:

• To determine the high-resolution structure of the Xenopus laevis oocyte NPC scaffold and permeability barrier.
• To model the molecular gate at the NPC's central channel.
• To compare native NPC structure with one exhibiting reduced transport activity.

Main Methods:

• Cryo-electron tomography (cryo-ET) of native nuclear envelopes.
• Subtomogram averaging techniques.
• High-resolution structural reconstruction up to 20 Å.

Main Results:

• Resolved individual protein domains within the NPC.
• Proposed a detailed model for the NPC's molecular gate architecture.
• Identified spatial properties of the NPC gate by comparing structures with different transport activities.

Conclusions:

• The study provides unprecedented structural insights into the NPC scaffold and its permeability barrier.
• The proposed molecular gate model advances our understanding of nucleocytoplasmic transport regulation.
• Structural differences correlate with altered NPC transport activity.