Nuclear pores dilate and constrict in cellulo

In eukaryotic cells, nuclear pore complexes (NPCs) fuse the inner and outer nuclear membranes and mediate nucleocytoplasmic exchange. They are made of 30 different nucleoporins and form a cylindrical architecture around an aqueous central channel. This architecture is highly dynamic in space and time. Variations in NPC diameter have been reported, but the physiological circumstances and the molecular details remain unknown. Here, we combined cryo-electron tomography with integrative structural modeling to capture a molecular movie of the respective large-scale conformational changes in cellulo. Although NPCs of exponentially growing cells adopted a dilated conformation, they reversibly constricted upon cellular energy depletion or conditions of hypertonic osmotic stress. Our data point to a model where the nuclear envelope membrane tension is linked to the conformation of the NPC.

Automated summary

Nuclear pore complexes (NPCs) in eukaryotic cells play a crucial role in mediating nucleocytoplasmic exchange. Recent research using cryo-electron tomography and integrative structural modeling reveals that the conformation of NPCs is highly dynamic and can change in response to cellular energy levels and osmotic stress. The data suggests a model where nuclear envelope membrane tension is linked to NPC conformation.