In our research, we explored how proteins and lipids interact to assemble and sustain the nuclear pore complex (NPC)—the essential gateway for molecular traffic between the cell nucleus and cytoplasm. Despite its central role in cellular organization, the mechanisms by which the NPC is built within the nuclear membrane have long remained unclear. Our work provided new mechanistic insight into this process by reconstituting key NPC structures in vitro and examining how membrane composition influences nuclear envelope function.
One major achievement of our study was the successful reconstitution of the NPC basket, a flexible and previously elusive structure located on the nuclear side of the pore. By reconstructing it in a defined membrane system, we were able to map its points of contact with both the NPC core and the inner nuclear membrane (INM). We identified Nup60 as a critical structural element, acting as a flexible suspension cable that anchored the basket and provided structural stability while allowing for necessary dynamic behavior.
In parallel, we investigated the role of lipids in NPC and nuclear envelope function. We demonstrated that the saturation level of lipid acyl chains directly influenced membrane integrity and NPC assembly. Through 3D electron microscopy and live-cell imaging, we showed that increased lipid saturation compromised nuclear envelope stability and hindered NPC function, while unsaturated lipids helped maintain proper membrane structure and transport efficiency.
We also found that cells responded to metabolic stress by reprogramming lipid metabolism to protect the INM. Specifically, cells redirected lipid droplet biogenesis to other subcellular regions, shielding the nuclear envelope from excess unsaturated lipids and preserving its function under challenging conditions.
This work built on our earlier discovery that the INM is not a passive barrier but a metabolically active compartment. We had shown that lipid synthesis enzymes localize to the INM, enabling the nucleus to manage its own lipid environment and regulate membrane composition from within.
Taken together, our findings revealed a close interplay between membrane lipids and NPC architecture, establishing how their coordination is essential for nuclear compartmentalization. By reconstructing key NPC elements and dissecting lipid-dependent mechanisms, we provided a new conceptual framework for understanding how eukaryotic cells build and maintain the nuclear envelope—a defining feature of cellular life.
