The nuclear pore complex core scaffold and permeability barrier: variations of a common theme

- The nuclear pore complex (NPC) is a large, conserved eukaryotic assembly.
- New views of the structure of the NPC's core scaffold are emerging.
- The NPC permeability barrier function is being characterized at the atomic scale.
- The NPC scaffold and the barrier seem to share common structural themes.
- A hypothesis for the evolutionary origin of the permeability barrier is proposed.

The study of the nuclear pore complex (NPC) is a fascinating endeavor, as it not only implies uncovering the 'engineering marvel' of its architecture and function, but also provides a key window into a significant evolutionary event: the origin of the eukaryotic cell. The combined efforts of many groups in the field, with the help of novel methodologies and new model organisms, are facilitating a much deeper understanding of this complex assembly. Here we cover recent advances on the characterization of the structure of the NPC scaffold and of the biophysical mechanisms that define the permeability barrier. We identify common architectural and functional principles between those two NPC compartments, expanding the previous protocoatomer hypothesis to suggest possible evolutionary origins for the FG nucleoporins and the NPC permeability barrier.