Skip to main content
PMC home page
The Journal of Cell Biology logoLink to The Journal of Cell Biology
. 1992 Jan 2;116(2):271–280. doi: 10.1083/jcb.116.2.271

O-linked glycoproteins of the nuclear pore complex interact with a cytosolic factor required for nuclear protein import

PMCID: PMC2289292  PMID: 1730755

Abstract

Mediated import of proteins into the nucleus requires cytosolic factors and can be blocked by reagents that bind to O-linked glycoproteins of the nuclear pore complex. To investigate whether a cytosolic transport factor directly interacts with these glycoproteins, O-linked glycoproteins from rat liver nuclear envelopes were immobilized on Sepharose beads via wheat germ agglutinin or specific antibodies. When rabbit reticulocyte lysate (which provides cytosolic factors required for in vitro nuclear import) was incubated with the immobilized glycoproteins, the cytosol was found to be inactivated by up to 80% in its ability to support mediated protein import in permeabilized mammalian cells. Inactivation of the import capacity of cytosol, which was specifically attributable to the glycoproteins, involves stoichiometric interactions and is likely to involve binding and depletion of a required factor from the cytosol. This factor is distinct from an N-ethylmaleimide-sensitive receptor for nuclear localization sequences characterized recently since it is insensitive to N-ethylmaleimide. Cytosol inactivation is suggested to be caused by at least two proteins of the glycoprotein fraction, although substantial capacity for inactivation can be attributed to protein bound by the RL11 antibody, consisting predominantly of a 180-kD glycosylated polypeptide. Considered together, these experiments identify a novel cytosolic factor required for nuclear protein import that directly interacts with O-linked glycoproteins of the pore complex, and provide a specific assay for isolation of this component.

Full Text

The Full Text of this article is available as a PDF (1.4 MB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Adam S. A., Gerace L. Cytosolic proteins that specifically bind nuclear location signals are receptors for nuclear import. Cell. 1991 Sep 6;66(5):837–847. doi: 10.1016/0092-8674(91)90431-w. [DOI] [PubMed] [Google Scholar]
  2. Adam S. A., Lobl T. J., Mitchell M. A., Gerace L. Identification of specific binding proteins for a nuclear location sequence. Nature. 1989 Jan 19;337(6204):276–279. doi: 10.1038/337276a0. [DOI] [PubMed] [Google Scholar]
  3. Adam S. A., Marr R. S., Gerace L. Nuclear protein import in permeabilized mammalian cells requires soluble cytoplasmic factors. J Cell Biol. 1990 Sep;111(3):807–816. doi: 10.1083/jcb.111.3.807. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Akey C. W., Goldfarb D. S. Protein import through the nuclear pore complex is a multistep process. J Cell Biol. 1989 Sep;109(3):971–982. doi: 10.1083/jcb.109.3.971. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Akey C. W. Interactions and structure of the nuclear pore complex revealed by cryo-electron microscopy. J Cell Biol. 1989 Sep;109(3):955–970. doi: 10.1083/jcb.109.3.955. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Bataillé N., Helser T., Fried H. M. Cytoplasmic transport of ribosomal subunits microinjected into the Xenopus laevis oocyte nucleus: a generalized, facilitated process. J Cell Biol. 1990 Oct;111(4):1571–1582. doi: 10.1083/jcb.111.4.1571. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Chelsky D., Ralph R., Jonak G. Sequence requirements for synthetic peptide-mediated translocation to the nucleus. Mol Cell Biol. 1989 Jun;9(6):2487–2492. doi: 10.1128/mcb.9.6.2487. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Davis L. I., Blobel G. Nuclear pore complex contains a family of glycoproteins that includes p62: glycosylation through a previously unidentified cellular pathway. Proc Natl Acad Sci U S A. 1987 Nov;84(21):7552–7556. doi: 10.1073/pnas.84.21.7552. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Davis L. I., Fink G. R. The NUP1 gene encodes an essential component of the yeast nuclear pore complex. Cell. 1990 Jun 15;61(6):965–978. doi: 10.1016/0092-8674(90)90062-j. [DOI] [PubMed] [Google Scholar]
  10. Featherstone C., Darby M. K., Gerace L. A monoclonal antibody against the nuclear pore complex inhibits nucleocytoplasmic transport of protein and RNA in vivo. J Cell Biol. 1988 Oct;107(4):1289–1297. doi: 10.1083/jcb.107.4.1289. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Feldherr C. M., Kallenbach E., Schultz N. Movement of a karyophilic protein through the nuclear pores of oocytes. J Cell Biol. 1984 Dec;99(6):2216–2222. doi: 10.1083/jcb.99.6.2216. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Finlay D. R., Forbes D. J. Reconstitution of biochemically altered nuclear pores: transport can be eliminated and restored. Cell. 1990 Jan 12;60(1):17–29. doi: 10.1016/0092-8674(90)90712-n. [DOI] [PubMed] [Google Scholar]
  13. Finlay D. R., Meier E., Bradley P., Horecka J., Forbes D. J. A complex of nuclear pore proteins required for pore function. J Cell Biol. 1991 Jul;114(1):169–183. doi: 10.1083/jcb.114.1.169. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Finlay D. R., Newmeyer D. D., Price T. M., Forbes D. J. Inhibition of in vitro nuclear transport by a lectin that binds to nuclear pores. J Cell Biol. 1987 Feb;104(2):189–200. doi: 10.1083/jcb.104.2.189. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Franke W. W., Scheer U., Krohne G., Jarasch E. D. The nuclear envelope and the architecture of the nuclear periphery. J Cell Biol. 1981 Dec;91(3 Pt 2):39s–50s. doi: 10.1083/jcb.91.3.39s. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Gerace L., Burke B. Functional organization of the nuclear envelope. Annu Rev Cell Biol. 1988;4:335–374. doi: 10.1146/annurev.cb.04.110188.002003. [DOI] [PubMed] [Google Scholar]
  17. Gerace L., Ottaviano Y., Kondor-Koch C. Identification of a major polypeptide of the nuclear pore complex. J Cell Biol. 1982 Dec;95(3):826–837. doi: 10.1083/jcb.95.3.826. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Goldfarb D. S., Gariépy J., Schoolnik G., Kornberg R. D. Synthetic peptides as nuclear localization signals. Nature. 1986 Aug 14;322(6080):641–644. doi: 10.1038/322641a0. [DOI] [PubMed] [Google Scholar]
  19. Greber U. F., Senior A., Gerace L. A major glycoprotein of the nuclear pore complex is a membrane-spanning polypeptide with a large lumenal domain and a small cytoplasmic tail. EMBO J. 1990 May;9(5):1495–1502. doi: 10.1002/j.1460-2075.1990.tb08267.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Holt G. D., Snow C. M., Senior A., Haltiwanger R. S., Gerace L., Hart G. W. Nuclear pore complex glycoproteins contain cytoplasmically disposed O-linked N-acetylglucosamine. J Cell Biol. 1987 May;104(5):1157–1164. doi: 10.1083/jcb.104.5.1157. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Kalderon D., Roberts B. L., Richardson W. D., Smith A. E. A short amino acid sequence able to specify nuclear location. Cell. 1984 Dec;39(3 Pt 2):499–509. doi: 10.1016/0092-8674(84)90457-4. [DOI] [PubMed] [Google Scholar]
  22. Khanna-Gupta A., Ware V. C. Nucleocytoplasmic transport of ribosomes in a eukaryotic system: is there a facilitated transport process? Proc Natl Acad Sci U S A. 1989 Mar;86(6):1791–1795. doi: 10.1073/pnas.86.6.1791. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Lanford R. E., Kanda P., Kennedy R. C. Induction of nuclear transport with a synthetic peptide homologous to the SV40 T antigen transport signal. Cell. 1986 Aug 15;46(4):575–582. doi: 10.1016/0092-8674(86)90883-4. [DOI] [PubMed] [Google Scholar]
  24. Nehrbass U., Kern H., Mutvei A., Horstmann H., Marshallsay B., Hurt E. C. NSP1: a yeast nuclear envelope protein localized at the nuclear pores exerts its essential function by its carboxy-terminal domain. Cell. 1990 Jun 15;61(6):979–989. doi: 10.1016/0092-8674(90)90063-k. [DOI] [PubMed] [Google Scholar]
  25. Newmeyer D. D., Finlay D. R., Forbes D. J. In vitro transport of a fluorescent nuclear protein and exclusion of non-nuclear proteins. J Cell Biol. 1986 Dec;103(6 Pt 1):2091–2102. doi: 10.1083/jcb.103.6.2091. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Newmeyer D. D., Forbes D. J. An N-ethylmaleimide-sensitive cytosolic factor necessary for nuclear protein import: requirement in signal-mediated binding to the nuclear pore. J Cell Biol. 1990 Mar;110(3):547–557. doi: 10.1083/jcb.110.3.547. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Paine P. L., Moore L. C., Horowitz S. B. Nuclear envelope permeability. Nature. 1975 Mar 13;254(5496):109–114. doi: 10.1038/254109a0. [DOI] [PubMed] [Google Scholar]
  28. Peters R. Fluorescence microphotolysis to measure nucleocytoplasmic transport and intracellular mobility. Biochim Biophys Acta. 1986 Dec 22;864(3-4):305–359. doi: 10.1016/0304-4157(86)90003-1. [DOI] [PubMed] [Google Scholar]
  29. Reichelt R., Holzenburg A., Buhle E. L., Jr, Jarnik M., Engel A., Aebi U. Correlation between structure and mass distribution of the nuclear pore complex and of distinct pore complex components. J Cell Biol. 1990 Apr;110(4):883–894. doi: 10.1083/jcb.110.4.883. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Richardson W. D., Mills A. D., Dilworth S. M., Laskey R. A., Dingwall C. Nuclear protein migration involves two steps: rapid binding at the nuclear envelope followed by slower translocation through nuclear pores. Cell. 1988 Mar 11;52(5):655–664. doi: 10.1016/0092-8674(88)90403-5. [DOI] [PubMed] [Google Scholar]
  31. Robbins J., Dilworth S. M., Laskey R. A., Dingwall C. Two interdependent basic domains in nucleoplasmin nuclear targeting sequence: identification of a class of bipartite nuclear targeting sequence. Cell. 1991 Feb 8;64(3):615–623. doi: 10.1016/0092-8674(91)90245-t. [DOI] [PubMed] [Google Scholar]
  32. Silver P. A. How proteins enter the nucleus. Cell. 1991 Feb 8;64(3):489–497. doi: 10.1016/0092-8674(91)90233-o. [DOI] [PubMed] [Google Scholar]
  33. Snow C. M., Senior A., Gerace L. Monoclonal antibodies identify a group of nuclear pore complex glycoproteins. J Cell Biol. 1987 May;104(5):1143–1156. doi: 10.1083/jcb.104.5.1143. [DOI] [PMC free article] [PubMed] [Google Scholar]
  34. Starr C. M., D'Onofrio M., Park M. K., Hanover J. A. Primary sequence and heterologous expression of nuclear pore glycoprotein p62. J Cell Biol. 1990 Jun;110(6):1861–1871. doi: 10.1083/jcb.110.6.1861. [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Starr C. M., Hanover J. A. A common structural motif in nuclear pore proteins (nucleoporins) Bioessays. 1991 Mar;13(3):145–146. doi: 10.1002/bies.950130309. [DOI] [PubMed] [Google Scholar]
  36. Unwin P. N., Milligan R. A. A large particle associated with the perimeter of the nuclear pore complex. J Cell Biol. 1982 Apr;93(1):63–75. doi: 10.1083/jcb.93.1.63. [DOI] [PMC free article] [PubMed] [Google Scholar]
  37. Wozniak R. W., Bartnik E., Blobel G. Primary structure analysis of an integral membrane glycoprotein of the nuclear pore. J Cell Biol. 1989 Jun;108(6):2083–2092. doi: 10.1083/jcb.108.6.2083. [DOI] [PMC free article] [PubMed] [Google Scholar]
  38. Yamasaki L., Kanda P., Lanford R. E. Identification of four nuclear transport signal-binding proteins that interact with diverse transport signals. Mol Cell Biol. 1989 Jul;9(7):3028–3036. doi: 10.1128/mcb.9.7.3028. [DOI] [PMC free article] [PubMed] [Google Scholar]
  39. Yoneda Y., Imamoto-Sonobe N., Yamaizumi M., Uchida T. Reversible inhibition of protein import into the nucleus by wheat germ agglutinin injected into cultured cells. Exp Cell Res. 1987 Dec;173(2):586–595. doi: 10.1016/0014-4827(87)90297-7. [DOI] [PubMed] [Google Scholar]
  40. Zasloff M. tRNA transport from the nucleus in a eukaryotic cell: carrier-mediated translocation process. Proc Natl Acad Sci U S A. 1983 Nov;80(21):6436–6440. doi: 10.1073/pnas.80.21.6436. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from The Journal of Cell Biology are provided here courtesy of The Rockefeller University Press

RESOURCES