Nup116p associates with the Nup82p-Nsp1p-Nup159p nucleoporin complex

Nup116p is a GLFG nucleoporin involved in RNA export processes. We show her e that Nup116p physically interacts with the Nup82p-Nsp1p-Nup159p nuclear p ore subcomplex, which plays a central role in nuclear mRNA export. For this association, a sequence within the C-terminal domain of Nup116p that inclu des the conserved nucleoporin RNA-binding motif was sufficient and necessar y. Consistent with this biochemical interaction, protein A-Nup116p and the protein A-tagged Nup116p C-terminal domain, like the members of the Nup82p complex, localized to the cytoplasmic side of the nuclear pore complex, as revealed by immunogold labeling. Finally, synthetic lethal interactions wer e found between mutant alleles of NUP116 and all members of the Nup82p comp lex. Thus, Nup116p consists of three independent functional domains: 1) the C-terminal part interacts with the Nup82p complex; 2) the Gle2p-binding se quence interacts with Gle2p/Rae1p; and 3) the GLFG domain interacts with sh uttling transport receptors such as karyopherin-beta family members.