| Structural highlights
Function
RAN_HUMAN GTP-binding protein involved in nucleocytoplasmic transport. Required for the import of protein into the nucleus and also for RNA export. Involved in chromatin condensation and control of cell cycle (By similarity). The complex with BIRC5/ survivin plays a role in mitotic spindle formation by serving as a physical scaffold to help deliver the RAN effector molecule TPX2 to microtubules. Acts as a negative regulator of the kinase activity of VRK1 and VRK2.[1] [2] [3] [4] Enhances AR-mediated transactivation. Transactivation decreases as the poly-Gln length within AR increases.[5] [6] [7] [8]
Publication Abstract from PubMed
Xpo4 is a bidirectional nuclear transport receptor that mediates nuclear export of eIF5A and Smad3 as well as import of Sox2 and SRY. How Xpo4 recognizes such a variety of cargoes is as yet unknown. Here we present the crystal structure of the RanGTP.Xpo4.eIF5A export complex at 3.2 A resolution. Xpo4 has a similar structure as CRM1, but the NES-binding site is occluded, and a new interaction site evolved that recognizes both globular domains of eIF5A. eIF5A contains hypusine, a unique amino acid with two positive charges, which is essential for cell viability and eIF5A function in translation. The hypusine docks into a deep, acidic pocket of Xpo4 and is thus a critical element of eIF5A's complex export signature. This further suggests that Xpo4 recognizes other cargoes differently, and illustrates how Xpo4 suppresses - in a chaperone-like manner - undesired interactions of eIF5A inside nuclei.
Structure of the exportin Xpo4 in complex with RanGTP and the hypusine-containing translation factor eIF5A.,Aksu M, Trakhanov S, Gorlich D Nat Commun. 2016 Jun 16;7:11952. doi: 10.1038/ncomms11952. PMID:27306458[9]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Hsiao PW, Lin DL, Nakao R, Chang C. The linkage of Kennedy's neuron disease to ARA24, the first identified androgen receptor polyglutamine region-associated coactivator. J Biol Chem. 1999 Jul 16;274(29):20229-34. PMID:10400640
- ↑ Moroianu J, Blobel G, Radu A. Nuclear protein import: Ran-GTP dissociates the karyopherin alphabeta heterodimer by displacing alpha from an overlapping binding site on beta. Proc Natl Acad Sci U S A. 1996 Jul 9;93(14):7059-62. PMID:8692944
- ↑ Xia F, Canovas PM, Guadagno TM, Altieri DC. A survivin-ran complex regulates spindle formation in tumor cells. Mol Cell Biol. 2008 Sep;28(17):5299-311. Epub 2008 Jun 30. PMID:18591255 doi:10.1128/MCB.02039-07
- ↑ Sanz-Garcia M, Lopez-Sanchez I, Lazo PA. Proteomics identification of nuclear Ran GTPase as an inhibitor of human VRK1 and VRK2 (vaccinia-related kinase) activities. Mol Cell Proteomics. 2008 Nov;7(11):2199-214. doi: 10.1074/mcp.M700586-MCP200., Epub 2008 Jul 9. PMID:18617507 doi:10.1074/mcp.M700586-MCP200
- ↑ Hsiao PW, Lin DL, Nakao R, Chang C. The linkage of Kennedy's neuron disease to ARA24, the first identified androgen receptor polyglutamine region-associated coactivator. J Biol Chem. 1999 Jul 16;274(29):20229-34. PMID:10400640
- ↑ Moroianu J, Blobel G, Radu A. Nuclear protein import: Ran-GTP dissociates the karyopherin alphabeta heterodimer by displacing alpha from an overlapping binding site on beta. Proc Natl Acad Sci U S A. 1996 Jul 9;93(14):7059-62. PMID:8692944
- ↑ Xia F, Canovas PM, Guadagno TM, Altieri DC. A survivin-ran complex regulates spindle formation in tumor cells. Mol Cell Biol. 2008 Sep;28(17):5299-311. Epub 2008 Jun 30. PMID:18591255 doi:10.1128/MCB.02039-07
- ↑ Sanz-Garcia M, Lopez-Sanchez I, Lazo PA. Proteomics identification of nuclear Ran GTPase as an inhibitor of human VRK1 and VRK2 (vaccinia-related kinase) activities. Mol Cell Proteomics. 2008 Nov;7(11):2199-214. doi: 10.1074/mcp.M700586-MCP200., Epub 2008 Jul 9. PMID:18617507 doi:10.1074/mcp.M700586-MCP200
- ↑ Aksu M, Trakhanov S, Gorlich D. Structure of the exportin Xpo4 in complex with RanGTP and the hypusine-containing translation factor eIF5A. Nat Commun. 2016 Jun 16;7:11952. doi: 10.1038/ncomms11952. PMID:27306458 doi:http://dx.doi.org/10.1038/ncomms11952
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