IPO7 explained
Importin-7 is a protein that in humans is encoded by the IPO7 gene.[1] [2]
The importin-alpha/beta complex and the GTPase Ran mediate nuclear import of proteins with a classical nuclear localization signal. The protein encoded by this gene is a member of a class of approximately 20 potential Ran targets that share a sequence motif related to the Ran-binding site of importin-beta. Similar to importin-beta, this protein prevents the activation of Ran's GTPase by RanGAP1 and inhibits nucleotide exchange on RanGTP, and also binds directly to nuclear pore complexes where it competes for binding sites with importin-beta and transportin. This protein has a Ran-dependent transport cycle and it can cross the nuclear envelope rapidly and in both directions. At least four importin beta-like transport receptors, namely importin beta itself, transportin, RanBP5 and RanBP7, directly bind and import ribosomal proteins.
Further reading
- Jäkel S, Görlich D . Importin beta, transportin, RanBP5 and RanBP7 mediate nuclear import of ribosomal proteins in mammalian cells . EMBO J. . 17 . 15 . 4491–4502 . 1998 . 9687515 . 10.1093/emboj/17.15.4491 . 1170780 .
- Paraskeva E . CRM1-mediated recycling of snurportin 1 to the cytoplasm . J. Cell Biol. . 145 . 2 . 255–264 . 1999 . 10209022 . 10.1083/jcb.145.2.255 . 2133107 . Izaurralde E . Bischoff FR . Huber . J . Kutay . U . Hartmann . E . Lührmann . R . Görlich . D .
- Jäkel S . The importin beta/importin 7 heterodimer is a functional nuclear import receptor for histone H1 . EMBO J. . 18 . 9 . 2411–2423 . 1999 . 10228156 . 10.1093/emboj/18.9.2411 . 1171324 . Albig W . Kutay U . Bischoff . F.Ralf . Schwamborn . Klaus . Doenecke . Detlef . Görlich . Dirk .
- Dean KA, von Ahsen O, Görlich D, Fried HM . Signal recognition particle protein 19 is imported into the nucleus by importin 8 (RanBP8) and transportin . J. Cell Sci. . 114 . Pt 19 . 3479–85 . 2001 . 10.1242/jcs.114.19.3479 . 11682607 . 11858/00-001M-0000-0015-3D81-6 . free .
- Bäuerle M, Doenecke D, Albig W . The requirement of H1 histones for a heterodimeric nuclear import receptor . J. Biol. Chem. . 277 . 36 . 32480–32489 . 2002 . 12080050 . 10.1074/jbc.M202765200 . free .
- Strausberg RL . Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences . Proc. Natl. Acad. Sci. U.S.A. . 99 . 26 . 16899–16903 . 2003 . 12477932 . 10.1073/pnas.242603899 . 139241 . Feingold EA . Grouse LH . Derge . JG . Klausner . RD . Collins . FS . Wagner . L . Shenmen . CM . Schuler . GD . 2002PNAS...9916899M . free .
- Gevaert K . Exploring proteomes and analyzing protein processing by mass spectrometric identification of sorted N-terminal peptides . Nat. Biotechnol. . 21 . 5 . 566–569 . 2004 . 12665801 . 10.1038/nbt810 . Goethals M . Martens L . Van Damme . Jozef . Staes . An . Thomas . Grégoire R. . Vandekerckhove . Joël . 23783563 .
- Fassati A . Nuclear import of HIV-1 intracellular reverse transcription complexes is mediated by importin 7 . EMBO J. . 22 . 14 . 3675–3685 . 2003 . 12853482 . 10.1093/emboj/cdg357 . 165627 . Görlich D . Harrison I . Zaytseva . L . Mingot . JM .
- Bouwmeester T . A physical and functional map of the human TNF-alpha/NF-kappa B signal transduction pathway . Nat. Cell Biol. . 6 . 2 . 97–105 . 2004 . 14743216 . 10.1038/ncb1086 . Bauch A . Ruffner H . Angrand . Pierre-Olivier . Bergamini . Giovanna . Croughton . Karen . Cruciat . Cristina . Eberhard . Dirk . Gagneur . Julien . 11683986 .
- King FW, Shtivelman E . Inhibition of nuclear import by the proapoptotic protein CC3 . Mol. Cell. Biol. . 24 . 16 . 7091–7101 . 2004 . 15282309 . 10.1128/MCB.24.16.7091-7101.2004 . 479715 .
- Gerhard DS . The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC) . Genome Res. . 14 . 10B . 2121–2127 . 2004 . 15489334 . 10.1101/gr.2596504 . 528928 . Wagner L . Feingold EA . Shenmen . CM . Grouse . LH . Schuler . G . Klein . SL . Old . S . Rasooly . R .
- Rush J . Immunoaffinity profiling of tyrosine phosphorylation in cancer cells . Nat. Biotechnol. . 23 . 1 . 94–101 . 2005 . 15592455 . 10.1038/nbt1046 . Moritz A . Lee KA . Guo . Ailan . Goss . Valerie L . Spek . Erik J . Zhang . Hui . Zha . Xiang-Ming . Polakiewicz . Roberto D . 7200157 .
- Kahle J, Baake M, Doenecke D, Albig W . Subunits of the heterotrimeric transcription factor NF-Y are imported into the nucleus by distinct pathways involving importin beta and importin 13 . Mol. Cell. Biol. . 25 . 13 . 5339–5354 . 2005 . 15964792 . 10.1128/MCB.25.13.5339-5354.2005 . 1157003 .
- Arnold M, Nath A, Hauber J, Kehlenbach RH . Multiple importins function as nuclear transport receptors for the Rev protein of human immunodeficiency virus type 1 . J. Biol. Chem. . 281 . 30 . 20883–20890 . 2006 . 16704975 . 10.1074/jbc.M602189200 . free .
- Zaitseva L, Myers R, Fassati A . tRNAs promote nuclear import of HIV-1 intracellular reverse transcription complexes . PLOS Biol. . 4 . 10 . e332 . 2007 . 17020411 . 10.1371/journal.pbio.0040332 . 1584419 . free .
- Saijou E . Nucleocytoplasmic shuttling of the zinc finger protein EZI Is mediated by importin-7-dependent nuclear import and CRM1-independent export mechanisms . J. Biol. Chem. . 282 . 44 . 32327–32337 . 2007 . 17848547 . 10.1074/jbc.M706793200 . Itoh T . Kim KW . Iemura . S.-i. . Natsume . T. . Miyajima . A. . free.
Notes and References
- Gorlich D, Dabrowski M, Bischoff FR, Kutay U, Bork P, Hartmann E, Prehn S, Izaurralde E . A novel class of RanGTP binding proteins . J Cell Biol . 138 . 1 . 65–80 . Aug 1997 . 9214382 . 2139951 . 10.1083/jcb.138.1.65 .
- Web site: Entrez Gene: IPO7 importin 7.