InterPro domain: IPR015007

This entry represents a domain found in Nup2, 50 and 61, which are components of the nuclear pore complex.

Nucleoporin 50kDa (NUP50) acts as a cofactor for the importin-alpha:importin-beta heterodimer, which in turn allows for transportation of many nuclear-targeted proteins through nuclear pore complexes. The C terminus of NUP50 binds importin-beta through RAN-GTP, the N terminus binds the C terminus of importin-alpha, while a central domain binds importin-beta. NUP50:importin-alpha:importin-beta then binds cargo and can stimulate nuclear import. The N-terminal domain of NUP50 is also able to actively displace nuclear localisation signals from importin-alpha [ 1 ].

NUP2 encodes a non-essential nuclear pore protein that has a central domain similar to those of Nsp1 and Nup1[ 2 , 3 ]. Transport of macromolecules between the nucleus and the cytoplasm of eukaryotic cells occurs through the nuclear pore complex (NPC), a large macromolecular complex that spans the nuclear envelope [ 4 , 4 , 5 ]. The structure of the vertebrate NPC has been studied extensively; recent reviews include [ 6 , 7 , 8 , 9 ]. The yeast NPC shares several features with the vertebrate NPC, despite being smaller and less elaborate [ 10 , 11 ]. Many yeast nuclear pore proteins, or nucleoporins, have been identified by a variety of genetic approaches [ 12 , 12 , 13 , 14 ]. nup2 mutants show genetic interactions with nsp1 and nup1 conditional alleles [ 15 , 15 ]. Nup1 interacts with the nuclear import factor Srp1 [ 15 ] and with the small GTPase Ran (encoded by GSP1) [ 16 ].

1. Nup50/Npap60 function in nuclear protein import complex disassembly and importin recycling. EMBO J. 24, 3681-9
2. NUP2, a novel yeast nucleoporin, has functional overlap with other proteins of the nuclear pore complex. Mol. Biol. Cell 4, 209-22
3. Yeast genetics to dissect the nuclear pore complex and nucleocytoplasmic trafficking. Annu. Rev. Genet. 31, 277-313
4. Transport routes through the nuclear pore complex. Curr. Opin. Cell Biol. 10, 392-9
5. Transport of macromolecules between the nucleus and the cytoplasm. RNA 4, 351-64
6. Architecture of the nuclear pore complex and its involvement in nucleocytoplasmic transport. Biochem. Pharmacol. 47, 15-20
7. Molecular dissection of the nuclear pore complex. Crit. Rev. Biochem. Mol. Biol. 31, 153-99
8. The nuclear pore complex. Annu. Rev. Biochem. 64, 865-96
9. Toward the molecular details of the nuclear pore complex. J. Struct. Biol. 113, 179-89
10. Isolation of the yeast nuclear pore complex. J. Cell Biol. 123, 771-83
11. Three-dimensional architecture of the isolated yeast nuclear pore complex: functional and evolutionary implications. Mol. Cell 1, 223-34
12. From nucleoporins to nuclear pore complexes. Curr. Opin. Cell Biol. 9, 401-11
13. Genetic approaches to nuclear pore structure and function. Trends Genet. 11, 235-41
14. The nuclear pore complex and nucleocytoplasmic transport. Curr. Opin. Cell Biol. 5, 395-407
15. Genetic and physical interactions between Srp1p and nuclear pore complex proteins Nup1p and Nup2p. J. Cell Biol. 126, 619-30
16. A family of Ran binding proteins that includes nucleoporins. Proc. Natl. Acad. Sci. U.S.A. 92, 7525-9