A designer FG-Nup that reconstitutes the selective transport barrier of the nuclear pore complex

Nuclear Pore Complexes (NPCs) regulate bidirectional transport between the nucleus and the cytoplasm. Intrinsically disordered FG-Nups line the NPC lumen and form a selective barrier, where transport of most proteins is inhibited whereas specific transporter proteins freely pass. The mechanism underlying selective transport through the NPC is still debated. Here, we reconstitute the selective behaviour of the NPC bottom-up by introducing a rationally designed artificial FG-Nup that mimics natural Nups. Using QCM-D, we measure selective binding of the artificial FG-Nup brushes to the transport receptor Kap95 over cytosolic proteins such as BSA. Solid-state nanopores with the artificial FG-Nups lining their inner walls support fast translocation of Kap95 while blocking BSA, thus demonstrating selectivity. Coarse-grained molecular dynamics simulations highlight the formation of a selective meshwork with densities comparable to native NPCs. Our findings show that simple design rules can recapitulate the selective behaviour of native FG-Nups and demonstrate that no specific spacer sequence nor a spatial segregation of different FG-motif types are needed to create selective NPCs. Intrinsically disordered FG-Nups line the Nuclear Pore Complex (NPC) lumen and form a selective barrier where transport of most proteins is inhibited, whereas specific transporter proteins are able to pass. Here, the authors reconstitute the selective behaviour of the NPC by introducing a rationally designed artificial FG-Nup that demonstrates that no specific spacer sequence nor a spatial segregation of different FG-motif types are needed to create selective NPCs.

Automated summary

This study successfully reconstituted the selective behavior of the NPC by introducing an artificial FG-Nup that mimics natural Nups, demonstrating that specific spacer sequences or spatial segregation of different FG-motif types are not needed to create selective NPCs.