The structure of the nuclear pore complex and its degradation in the cellular context
Matteo Allegretti, Christian Zimmerli, Beata Turonova, Wim Hagen, Martin Beck
European Molecular Biology Laboratory, Structural and Computational Biology Unit, 69117 Heidelberg, Germany.
The nuclear pore complex (NPC) is a gigantic membrane protein forming a hole in the nuclear envelope. Due to its dimensions (~100 MDa in human) the elected method to determine the structure of the intact complex scaffold has been cryo electron tomography (cryo-ET). In addition, efforts to investigate the full NPC structure extracting it from its double membrane context have produced two structures in S. cerevisiae.
In our study we perform cryo-FIB-milling coupled to cryo-ET and subtomogram averaging to get the structure of the entire NPC scaffold in exponentially-growing cells.
Our structure shows significant differences in sub-complexes architecture to previous work emphasizing the importance of determining structures of membrane proteins in their native context.
In addition by means of correlative light and electron microscopy we shed the light on a quality control mechanism to degrade NPCs.