At Loose Ends: A Guide to the Translocation Channel of the Nuclear Pore Complex for Dummies
David S. Goldfarb
Nuclear transport receptors (NTRs) ferry signal‑bearing cargos to and fro between the nucleus and cytoplasm. Translocation occurs through the central channel of the nuclear pore complex (NPC), which is guarded by scores of FG‑nups. A major unresolved conceptual problem in the nuclear transport field is how the FG‑nups are deployed to establish a sieve‑like barrier that admits large NTR‑cargo complexes but excludes large inert molecules. Several clever and thermodynamically consistent physical models purport to solve the selective permeability barrier problem. However, too little is known at present about the in vivo organization, localization and physical state(s) of the FG‑nups to rule‑out any of the current models. Still, a consensus has emerged that the selective permeability problem can, in theory, be solved using only a few well‑established properties of the FG‑nups.