Single-Molecule Transport Across an Individual Biomimetic Nuclear Pore Complex

Abstract

Nuclear pore complexes regulate the selective exchange of RNA and proteins across the nuclear envelope in eukaryotic cells. Biomimetic strategies offer new opportunities to investigate this remarkable transport phenomenon. In this talk, I will show selective transport of proteins across individual biomimetic nuclear pore complexes at the single-molecule level. Each biomimetic complex is constructed by covalently tethering either Nup98 or Nup153 (phenylalanine-glycine (FG) nucleoporins) to a solid-state nanopore. Individual translocation events are monitored using ionic current measurements with sub-millisecond temporal resolution. Transport receptors (ImpB) proceed with a dwell time of ∼2.5 ms for both Nup98- and Nup153-coated pores, whereas the passage of non-specific proteins is strongly inhibited with different degrees of selectivity. For pores up to ∼25 nm in diameter, Nups form a dense and low-conducting barrier, whereas they adopt a more open structure in larger pores. Our biomimetic nuclear pore complex provides a quantitative platform for studying nucleocytoplasmic transport phenomena at the single-molecule level in vitro. ∗ Work carried out by my graduate student Stefan W. Kowalczyk at Delft and in collaboration with Larisa Kapinos and Roderick Y. H. Lim at the University of Basel.