The nuclear pore complex is a massive structure that extends across the nuclear envelope, forming a gateway that regulates the flow of macromolecules between the nucleus and the cytoplasm. Nucleoporins are the main components of the nuclear pore complex in eukaryotic cells. NUP50 is a member of the FG-repeat containing nucleoporins that functions as a soluble cofactor in importin-alpha:beta-mediated nuclear protein import. NUP50 may serve as a binding site on the nuclear side of the pore complex for export receptor-cargo complexes. It interacts with multiple transport receptor proteins including p27Kip1. This interaction is required for correct intracellular transport and degradation of p27Kip1.