Importin subunit alpha-3 explained

Importin subunit alpha-3, also known as karyopherin subunit alpha-4, is a protein that in humans is encoded by the KPNA4 gene.^{[1] [2]}

Function

The nuclear import of karyophilic proteins is directed by short amino acid sequences termed nuclear localization signals (NLSs). Karyopherins, or importins, are cytoplasmic proteins that recognize NLSs and dock NLS-containing proteins to the nuclear pore complex. The protein encoded by this gene shares the sequence similarity with Xenopus importin-alpha and Saccharomyces cerevisiae Srp1. This protein is found to interact with the NLSs of DNA helicase Q1 and SV40 T antigen.^[3]

Interactions

KPNA4 has been shown to interact with RECQL and STAT3.^[4]

References

Further reading

• Bukrinsky MI, Haffar OK . HIV-1 nuclear import: in search of a leader . Frontiers in Bioscience . 2 . 4. d578–87 . Dec 1997 . 9366553 . 10.2741/A213. free .
• Bukrinsky MI, Haffar OK . HIV-1 nuclear import: matrix protein is back on center stage, this time together with Vpr . Molecular Medicine . 4 . 3 . 138–43 . Mar 1998 . 9562972 . 2230352 . 10.1007/BF03401911.
• Bukrinsky MI, Sharova N, Dempsey MP, Stanwick TL, Bukrinskaya AG, Haggerty S, Stevenson M . Active nuclear import of human immunodeficiency virus type 1 preintegration complexes . Proceedings of the National Academy of Sciences of the United States of America . 89 . 14 . 6580–4 . Jul 1992 . 1631159 . 49545 . 10.1073/pnas.89.14.6580 . 1992PNAS...89.6580B . free .
• Sharova N, Bukrinskaya A . p17 and p17-containing gag precursors of input human immunodeficiency virus are transported into the nuclei of infected cells . AIDS Research and Human Retroviruses . 7 . 3 . 303–6 . Mar 1991 . 2064827 . 10.1089/aid.1991.7.303 .
• Di Marzio P, Choe S, Ebright M, Knoblauch R, Landau NR . Mutational analysis of cell cycle arrest, nuclear localization and virion packaging of human immunodeficiency virus type 1 Vpr . Journal of Virology . 69 . 12 . 7909–16 . Dec 1995 . 7494303 . 189735 . 10.1128/JVI.69.12.7909-7916.1995.
• Gallay P, Swingler S, Song J, Bushman F, Trono D . HIV nuclear import is governed by the phosphotyrosine-mediated binding of matrix to the core domain of integrase . Cell . 83 . 4 . 569–76 . Nov 1995 . 7585960 . 10.1016/0092-8674(95)90097-7 . 15536328 . free .
• Freed EO, Englund G, Martin MA . Role of the basic domain of human immunodeficiency virus type 1 matrix in macrophage infection . Journal of Virology . 69 . 6 . 3949–54 . Jun 1995 . 7745752 . 189124 . 10.1128/JVI.69.6.3949-3954.1995.
• Gallay P, Swingler S, Aiken C, Trono D . HIV-1 infection of nondividing cells: C-terminal tyrosine phosphorylation of the viral matrix protein is a key regulator . Cell . 80 . 3 . 379–88 . Feb 1995 . 7859280 . 10.1016/0092-8674(95)90488-3 . 15064293 . free .
• von Schwedler U, Kornbluth RS, Trono D . The nuclear localization signal of the matrix protein of human immunodeficiency virus type 1 allows the establishment of infection in macrophages and quiescent T lymphocytes . Proceedings of the National Academy of Sciences of the United States of America . 91 . 15 . 6992–6 . Jul 1994 . 8041734 . 44324 . 10.1073/pnas.91.15.6992 . 1994PNAS...91.6992V . free .
• Howard E. Gendelman . Heinzinger NK, Bukrinsky MI, Haggerty SA, Ragland AM, Kewalramani V, Lee MA, Gendelman HE, Ratner L, Stevenson M, Emerman M . The Vpr protein of human immunodeficiency virus type 1 influences nuclear localization of viral nucleic acids in nondividing host cells . Proceedings of the National Academy of Sciences of the United States of America . 91 . 15 . 7311–5 . Jul 1994 . 8041786 . 44389 . 10.1073/pnas.91.15.7311 . 1994PNAS...91.7311H . free .
• Bukrinsky MI, Haggerty S, Dempsey MP, Sharova N, Adzhubel A, Spitz L, Lewis P, Goldfarb D, Emerman M, Stevenson M . A nuclear localization signal within HIV-1 matrix protein that governs infection of non-dividing cells . Nature . 365 . 6447 . 666–9 . Oct 1993 . 8105392 . 10.1038/365666a0 . 9524217 . 1993Natur.365..666B . 25678 .
• Dubrovsky L, Ulrich P, Nuovo GJ, Manogue KR, Cerami A, Bukrinsky M . Nuclear localization signal of HIV-1 as a novel target for therapeutic intervention . Molecular Medicine . 1 . 2 . 217–30 . Jan 1995 . 8529100 . 2229944 . 10.1007/BF03401569.
• Gallay P, Stitt V, Mundy C, Oettinger M, Trono D . Role of the karyopherin pathway in human immunodeficiency virus type 1 nuclear import . Journal of Virology . 70 . 2 . 1027–32 . Feb 1996 . 8551560 . 189908 . 10.1128/JVI.70.2.1027-1032.1996.
• Bukrinskaya AG, Ghorpade A, Heinzinger NK, Smithgall TE, Lewis RE, Stevenson M . Phosphorylation-dependent human immunodeficiency virus type 1 infection and nuclear targeting of viral DNA . Proceedings of the National Academy of Sciences of the United States of America . 93 . 1 . 367–71 . Jan 1996 . 8552640 . 40239 . 10.1073/pnas.93.1.367 . 1996PNAS...93..367B . free .
• Sato A, Yoshimoto J, Isaka Y, Miki S, Suyama A, Adachi A, Hayami M, Fujiwara T, Yoshie O . Evidence for direct association of Vpr and matrix protein p17 within the HIV-1 virion . Virology . 220 . 1 . 208–12 . Jun 1996 . 8659115 . 10.1006/viro.1996.0302 . free .
• Popov S, Dubrovsky L, Lee MA, Pennathur S, Haffar O, aL-Abed Y, Tonge P, Ulrich P, Rexach M, Blobel G, Cerami A, Bukrinsky M . Critical role of reverse transcriptase in the inhibitory mechanism of CNI-H0294 on HIV-1 nuclear translocation . Proceedings of the National Academy of Sciences of the United States of America . 93 . 21 . 11859–64 . Oct 1996 . 8876228 . 38149 . 10.1073/pnas.93.21.11859 . 1996PNAS...9311859P . free .
• Freed EO, Englund G, Maldarelli F, Martin MA . Phosphorylation of residue 131 of HIV-1 matrix is not required for macrophage infection . Cell . 88 . 2 . 171–3; discussion 173–4 . Jan 1997 . 9008157 . 10.1016/S0092-8674(00)81836-X . 14097368 . free .
• Gallay P, Hope T, Chin D, Trono D . HIV-1 infection of nondividing cells through the recognition of integrase by the importin/karyopherin pathway . Proceedings of the National Academy of Sciences of the United States of America . 94 . 18 . 9825–30 . Sep 1997 . 9275210 . 23276 . 10.1073/pnas.94.18.9825 . 1997PNAS...94.9825G . free .
• Besançon F, Just J, Bourgeade MF, Van Weyenbergh J, Solomon D, Guillozo H, Wietzerbin J, Cayre YE . HIV-1 p17 and IFN-gamma both induce fructose 1,6-bisphosphatase . Journal of Interferon & Cytokine Research . 17 . 8 . 461–7 . Aug 1997 . 9282826 . 10.1089/jir.1997.17.461 .

Notes and References

1. Seki T, Tada S, Katada T, Enomoto T . Cloning of a cDNA encoding a novel importin-alpha homologue, Qip1: discrimination of Qip1 and Rch1 from hSrp1 by their ability to interact with DNA helicase Q1/RecQL . Biochemical and Biophysical Research Communications . 234 . 1 . 48–53 . May 1997 . 9168958 . 10.1006/bbrc.1997.6535 .
2. Köhler M, Ansieau S, Prehn S, Leutz A, Haller H, Hartmann E . Cloning of two novel human importin-alpha subunits and analysis of the expression pattern of the importin-alpha protein family . FEBS Letters . 417 . 1 . 104–8 . Nov 1997 . 9395085 . 10.1016/S0014-5793(97)01265-9 . 84237136 . free .
3. Web site: Entrez Gene: KPNA4 karyopherin alpha 4 (importin alpha 3).
4. Liu L, McBride KM, Reich NC . STAT3 nuclear import is independent of tyrosine phosphorylation and mediated by importin-alpha3 . Proc Natl Acad Sci U S A . 102 . 23 . 8150–5 . Jun 2005 . 15919823 . 1149424 . 10.1073/pnas.0501643102 . 2005PNAS..102.8150L . free .