Diameter Dependence of Transport through Nuclear Pore Complex Mimics Studied Using Optical Nanopores

Diameter Dependence of Transport through Nuclear Pore Complex Mimics Studied Using Optical Nanopores

Klughammer, N. (TU Delft BN/Cees Dekker Lab)
Barth, A. (TU Delft BN/Cees Dekker Lab)
Dekker, Maurice (University Medical Center Groningen)
Fragasso, A. (TU Delft BN/Cees Dekker Lab; TU Delft BN/Bionanoscience)
Onck, Patrick R. (University Medical Center Groningen)

BN/Bionanoscience

2023

The nuclear pore complex (NPC) regulates the selective transport of large biomolecules through the nuclear envelope. As a model system for nuclear transport, we construct NPC mimics by functionalizing the pore walls of freestanding palladium zero-mode waveguides with the FG-nucleoporin Nsp1. This approach enables the measurement of single-molecule translocations through individual pores using optical detection. We probe the selectivity of Nsp1-coated pores by quantitatively comparing the translocation rates of the nuclear transport receptor Kap95 to the inert probe BSA over a wide range of pore sizes from 35 nm to 160 nm. Pores below 55 ± 5 nm show significant selectivity that gradually decreases for larger pores. This finding is corroborated by coarse-grained molecular-dynamics simulations of the Nsp1 mesh within the pore, which suggest that leakage of BSA occurs by diffusion through transient openings within the dynamic mesh. Furthermore, we experimentally observe a modulation of the BSA permeation when varying the concentration of Kap95. The results demonstrate the potential of single-molecule fluorescence measurements on biomimetic NPCs to elucidate the principles of nuclear transport.

http://resolver.tudelft.nl/uuid:3670ec8a-5a12-4e4e-80ed-df5d52f0bb3d

https://doi.org/10.7554/eLife.87174.1

2050-084X

eLife, 12

Institutional Repository

journal article

© 2023 N. Klughammer, A. Barth, Maurice Dekker, A. Fragasso, Patrick R. Onck