Nuclear pore complexes are extremely elaborate structures that mediate the regulated movement of macromolecules between the nucleus and cytoplasm. These complexes are composed of at least 100 different polypeptide subunits, many of which belong to the nucleoporin family. Nucleoporins are pore complex-specific glycoproteins characterized by cytoplasmically oriented O-linked N-acetylglucosamine residues and numerous repeats of the pentapeptide sequence XFXFG. This protein has three distinct domains: a N-terminal region within which a pore targeting domain has been identified, a central region containing multiple zinc finger motifs, and a C-terminal region containing multiple XFXFG repeats.