The peptide repeat domain of nucleoporin Nup98 functions as a docking site in transport across the nuclear pore complex.
Radu A, Moore MS, Blobel G, Cell, 1995 Apr 21 - link

Identification of a protein complex that is required for nuclear protein import and mediates docking of import substrate to distinct nucleoporins.
Radu A, Blobel G, Moore MS, Proc Natl Acad Sci U S A, 1995 Feb 28 - link