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. Here, we 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 (Impβ) 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.

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A 1-year-old female Yorkshire terrier was presented to the clinic for a second opinion regarding its poor hair coat condition. According to the owner, the dog has been showing that appearance since the moment it was adopted, at 8 months of age. The owner also mentioned that the dog’s father had a similar fur appearance. External deworming was regularly administered to this dog, and oral fluralaner (Bravecto™) was given at the time of its presentation. No other clinical signs were reported. A complete physical examination was performed, with emphasis on skin and fur assessment. The main findings were the presence of extensive areas of hypotrichosis and alopecia, affecting only dark-haired regions, mainly in the dorsal region, neck and on the outer surface of both pinnae (Figures 1 and 2). The presence of seborrhea and small papules compatible with superficial folliculitis were also identified. No other abnormalities were detected during the remaining examination. The complete blood count and serum biochemistry, including total circulating thyroxine (tT4) were unremarkable. Deep skin scraping and dermatophyte culture were also performed, but both tests were negative for the presence of ectoparasites and fungi, respectively. Finally, the hair follicles from the lesion areas were pulled out and evaluated under a microscope using the trichogram technique. Baths with an anti-seborrheic and anti-microbial shampoo were prescribed, but although seborrhea and folliculitis were quickly controlled with this topical treatment, the alopecic areas remained and no signs of hair regrowth was observed in the following dermatological reassessments.