4fdd

Structural highlights

Disease

[FUS_HUMAN] Frontotemporal dementia with motor neuron disease;Hereditary essential tremor;Amyotrophic lateral sclerosis;Juvenile amyotrophic lateral sclerosis;Myxofibrosarcoma;Myxoid/round cell liposarcoma. A chromosomal aberration involving FUS is found in a patient with malignant myxoid liposarcoma. Translocation t(12;16)(q13;p11) with DDIT3. A chromosomal aberration involving FUS is a cause of acute myeloid leukemia (AML). Translocation t(16;21)(p11;q22) with ERG. The disease may be caused by mutations affecting the gene represented in this entry. A chromosomal aberration involving FUS is found in a patient with angiomatoid fibrous histiocytoma. Translocation t(12;16)(q13;p11.2) with ATF1 generates a chimeric FUS/ATF1 protein. The disease is caused by mutations affecting the gene represented in this entry. The disease is caused by mutations affecting the gene represented in this entry.

Function

[TNPO1_HUMAN] Functions in nuclear protein import as nuclear transport receptor. Serves as receptor for nuclear localization signals (NLS) in cargo substrates. Is thought to mediate docking of the importin/substrate complex to the nuclear pore complex (NPC) through binding to nucleoporin and the complex is subsequently translocated through the pore by an energy requiring, Ran-dependent mechanism. At the nucleoplasmic side of the NPC, Ran binds to the importin, the importin/substrate complex dissociates and importin is re-exported from the nucleus to the cytoplasm where GTP hydrolysis releases Ran. The directionality of nuclear import is thought to be conferred by an asymmetric distribution of the GTP- and GDP-bound forms of Ran between the cytoplasm and nucleus (By similarity). Involved in nuclear import of M9-containing proteins. In vitro, binds directly to the M9 region of the heterogeneous nuclear ribonucleoproteins (hnRNP), A1 and A2 and mediates their nuclear import. Appears also to be involved in hnRNP A1/A2 nuclear export. Mediates the nuclear import of ribosomal proteins RPL23A, RPS7 and RPL5. Binds to a beta-like import receptor binding (BIB) domain of RPL23A. In vitro, mediates nuclear import of H2A, H2B, H3 and H4 histones, and SRP19. In case of HIV-1 infection, binds and mediates the nuclear import of HIV-1 Rev. Mediates nuclear import of ADAR/ADAR1 (isoform 5) in a RanGTP-dependent manner.^{[1] [2] [3] [4]} [FUS_HUMAN] Binds both single-stranded and double-stranded DNA and promotes ATP-independent annealing of complementary single-stranded DNAs and D-loop formation in superhelical double-stranded DNA. May play a role in maintenance of genomic integrity.

See Also

• Importin

References

1. ↑ Nakielny S, Siomi MC, Siomi H, Michael WM, Pollard V, Dreyfuss G. Transportin: nuclear transport receptor of a novel nuclear protein import pathway. Exp Cell Res. 1996 Dec 15;229(2):261-6. PMID:8986607 doi:10.1006/excr.1996.0369
2. ↑ Jakel S, Gorlich D. Importin beta, transportin, RanBP5 and RanBP7 mediate nuclear import of ribosomal proteins in mammalian cells. EMBO J. 1998 Aug 3;17(15):4491-502. PMID:9687515 doi:10.1093/emboj/17.15.4491
3. ↑ Dean KA, von Ahsen O, Gorlich D, Fried HM. Signal recognition particle protein 19 is imported into the nucleus by importin 8 (RanBP8) and transportin. J Cell Sci. 2001 Oct;114(Pt 19):3479-85. PMID:11682607
4. ↑ Fritz J, Strehblow A, Taschner A, Schopoff S, Pasierbek P, Jantsch MF. RNA-regulated interaction of transportin-1 and exportin-5 with the double-stranded RNA-binding domain regulates nucleocytoplasmic shuttling of ADAR1. Mol Cell Biol. 2009 Mar;29(6):1487-97. doi: 10.1128/MCB.01519-08. Epub 2009 Jan, 5. PMID:19124606 doi:10.1128/MCB.01519-08
5. ↑ Zhang ZC, Chook YM. Structural and energetic basis of ALS-causing mutations in the atypical proline-tyrosine nuclear localization signal of the Fused in Sarcoma protein (FUS). Proc Natl Acad Sci U S A. 2012 Jul 24;109(30):12017-21. doi:, 10.1073/pnas.1207247109. Epub 2012 Jul 9. PMID:22778397 doi:http://dx.doi.org/10.1073/pnas.1207247109