Exportin

Exportins (XPO) or chromosomal maintenance protein mediate the nuclear export of cellular proteins with a leucine-rich export signal (NES) and RNA. XPO is regulated by GTPaseRan. RanGTP bind to XPO forming a ternary complex with the exported protein. The complex diffuses through the nuclear core complex to the cytoplasm and then dissociates.

XPO-1 mediates nuclear transport of cellular proteins bearing a Leu-rich nuclear export signal and of RNA.
XPO-4 mediates nuclear transport of eukaryotic translation initiation factor 5A^[1].
XPO-5 mediates nuclear transport of pre-miroRNAs and short hairpin RNAs^[2].
XPO-t exports tRNA from the nucleus^[3].

Structural highlights

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(PDB code 3icq).^[4]

3D structures of exportin

Exportin 3D structures

Structure of yeast exportin-5 (magenta) complex with GTPaseRan (cyan), Mg+2 (green) and RNA (PDB code 3icq).

Drag the structure with the mouse to rotate

ReferencesReferences

↑ Lipowsky G, Bischoff FR, Schwarzmaier P, Kraft R, Kostka S, Hartmann E, Kutay U, Gorlich D. Exportin 4: a mediator of a novel nuclear export pathway in higher eukaryotes. EMBO J. 2000 Aug 15;19(16):4362-71. PMID:10944119 doi:http://dx.doi.org/10.1093/emboj/19.16.4362
↑ Yi R, Qin Y, Macara IG, Cullen BR. Exportin-5 mediates the nuclear export of pre-microRNAs and short hairpin RNAs. Genes Dev. 2003 Dec 15;17(24):3011-6. Epub 2003 Dec 17. PMID:14681208 doi:http://dx.doi.org/10.1101/gad.1158803
↑ Kohler A, Hurt E. Exporting RNA from the nucleus to the cytoplasm. Nat Rev Mol Cell Biol. 2007 Oct;8(10):761-73. PMID:17786152 doi:http://dx.doi.org/10.1038/nrm2255
↑ Cook AG, Fukuhara N, Jinek M, Conti E. Structures of the tRNA export factor in the nuclear and cytosolic states. Nature. 2009 Sep 3;461(7260):60-5. PMID:19680239 doi:10.1038/nature08394

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

Michal Harel, Alexander Berchansky

[1] Lipowsky G, Bischoff FR, Schwarzmaier P, Kraft R, Kostka S, Hartmann E, Kutay U, Gorlich D. Exportin 4: a mediator of a novel nuclear export pathway in higher eukaryotes. EMBO J. 2000 Aug 15;19(16):4362-71. PMID:10944119 doi:http://dx.doi.org/10.1093/emboj/19.16.4362

[2] Yi R, Qin Y, Macara IG, Cullen BR. Exportin-5 mediates the nuclear export of pre-microRNAs and short hairpin RNAs. Genes Dev. 2003 Dec 15;17(24):3011-6. Epub 2003 Dec 17. PMID:14681208 doi:http://dx.doi.org/10.1101/gad.1158803

[3] Kohler A, Hurt E. Exporting RNA from the nucleus to the cytoplasm. Nat Rev Mol Cell Biol. 2007 Oct;8(10):761-73. PMID:17786152 doi:http://dx.doi.org/10.1038/nrm2255

[4] Cook AG, Fukuhara N, Jinek M, Conti E. Structures of the tRNA export factor in the nuclear and cytosolic states. Nature. 2009 Sep 3;461(7260):60-5. PMID:19680239 doi:10.1038/nature08394

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