Skip to main content
PMC home page
Proceedings of the National Academy of Sciences of the United States of America logoLink to Proceedings of the National Academy of Sciences of the United States of America
. 1996 Jun 25;93(13):6572–6576. doi: 10.1073/pnas.93.13.6572

The binding site of karyopherin alpha for karyopherin beta overlaps with a nuclear localization sequence.

J Moroianu 1, G Blobel 1, A Radu 1
PMCID: PMC39066  PMID: 8692858

Abstract

By using proteolysis, recombinant mutant proteins, or synthetic peptides and by testing these reagents in liquid phase binding or nuclear import assays, we have mapped binding regions of karyopherin alpha. We found that the C-terminal region of karyopherin alpha recognizes the nuclear localization sequence (NLS), whereas its N-terminal region binds karyopherin beta. Surprisingly, karyopherin alpha also contains an NLS. Thus, karyopherin alpha belongs to a group of proteins that contain both a ligand (NLS) and a cognate receptor (NLS recognition site) in one molecule with a potential for autologous ligand-receptor interactions. The NLS of karyopherin alpha overlaps with the binding site of karyopherin alpha for karyopherin beta. Hence, binding of karyopherin beta to karyopherin alpha covers the NLS of karyopherin alpha. This prevents autologous ligand receptor interactions and explains the observed cooperative binding of karyopherin alpha to a heterologous NLS protein in the presence of karyopherin beta.

Full text

PDF
6572

Images in this article

6573Fig. 2
on p.6573
6574Fig. 3
on p.6574

Selected References

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

  1. Adam E. J., Adam S. A. Identification of cytosolic factors required for nuclear location sequence-mediated binding to the nuclear envelope. J Cell Biol. 1994 May;125(3):547–555. doi: 10.1083/jcb.125.3.547. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Chi N. C., Adam E. J., Adam S. A. Sequence and characterization of cytoplasmic nuclear protein import factor p97. J Cell Biol. 1995 Jul;130(2):265–274. doi: 10.1083/jcb.130.2.265. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Cortes P., Ye Z. S., Baltimore D. RAG-1 interacts with the repeated amino acid motif of the human homologue of the yeast protein SRP1. Proc Natl Acad Sci U S A. 1994 Aug 2;91(16):7633–7637. doi: 10.1073/pnas.91.16.7633. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Coutavas E., Ren M., Oppenheim J. D., D'Eustachio P., Rush M. G. Characterization of proteins that interact with the cell-cycle regulatory protein Ran/TC4. Nature. 1993 Dec 9;366(6455):585–587. doi: 10.1038/366585a0. [DOI] [PubMed] [Google Scholar]
  5. Dingwall C., Laskey R. A. Nuclear targeting sequences--a consensus? Trends Biochem Sci. 1991 Dec;16(12):478–481. doi: 10.1016/0968-0004(91)90184-w. [DOI] [PubMed] [Google Scholar]
  6. Enenkel C., Blobel G., Rexach M. Identification of a yeast karyopherin heterodimer that targets import substrate to mammalian nuclear pore complexes. J Biol Chem. 1995 Jul 14;270(28):16499–16502. doi: 10.1074/jbc.270.28.16499. [DOI] [PubMed] [Google Scholar]
  7. Fernandez J., Andrews L., Mische S. M. An improved procedure for enzymatic digestion of polyvinylidene difluoride-bound proteins for internal sequence analysis. Anal Biochem. 1994 Apr;218(1):112–117. doi: 10.1006/abio.1994.1148. [DOI] [PubMed] [Google Scholar]
  8. Görlich D., Kostka S., Kraft R., Dingwall C., Laskey R. A., Hartmann E., Prehn S. Two different subunits of importin cooperate to recognize nuclear localization signals and bind them to the nuclear envelope. Curr Biol. 1995 Apr 1;5(4):383–392. doi: 10.1016/s0960-9822(95)00079-0. [DOI] [PubMed] [Google Scholar]
  9. Görlich D., Prehn S., Laskey R. A., Hartmann E. Isolation of a protein that is essential for the first step of nuclear protein import. Cell. 1994 Dec 2;79(5):767–778. doi: 10.1016/0092-8674(94)90067-1. [DOI] [PubMed] [Google Scholar]
  10. Görlich D., Vogel F., Mills A. D., Hartmann E., Laskey R. A. Distinct functions for the two importin subunits in nuclear protein import. Nature. 1995 Sep 21;377(6546):246–248. doi: 10.1038/377246a0. [DOI] [PubMed] [Google Scholar]
  11. Imamoto N., Shimamoto T., Takao T., Tachibana T., Kose S., Matsubae M., Sekimoto T., Shimonishi Y., Yoneda Y. In vivo evidence for involvement of a 58 kDa component of nuclear pore-targeting complex in nuclear protein import. EMBO J. 1995 Aug 1;14(15):3617–3626. doi: 10.1002/j.1460-2075.1995.tb00031.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Imamoto N., Tachibana T., Matsubae M., Yoneda Y. A karyophilic protein forms a stable complex with cytoplasmic components prior to nuclear pore binding. J Biol Chem. 1995 Apr 14;270(15):8559–8565. doi: 10.1074/jbc.270.15.8559. [DOI] [PubMed] [Google Scholar]
  13. Iovine M. K., Watkins J. L., Wente S. R. The GLFG repetitive region of the nucleoporin Nup116p interacts with Kap95p, an essential yeast nuclear import factor. J Cell Biol. 1995 Dec;131(6 Pt 2):1699–1713. doi: 10.1083/jcb.131.6.1699. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. 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]
  15. Kraemer D. M., Strambio-de-Castillia C., Blobel G., Rout M. P. The essential yeast nucleoporin NUP159 is located on the cytoplasmic side of the nuclear pore complex and serves in karyopherin-mediated binding of transport substrate. J Biol Chem. 1995 Aug 11;270(32):19017–19021. doi: 10.1074/jbc.270.32.19017. [DOI] [PubMed] [Google Scholar]
  16. Liu X., Brodeur S. R., Gish G., Songyang Z., Cantley L. C., Laudano A. P., Pawson T. Regulation of c-Src tyrosine kinase activity by the Src SH2 domain. Oncogene. 1993 May;8(5):1119–1126. [PubMed] [Google Scholar]
  17. Loeb J. D., Schlenstedt G., Pellman D., Kornitzer D., Silver P. A., Fink G. R. The yeast nuclear import receptor is required for mitosis. Proc Natl Acad Sci U S A. 1995 Aug 15;92(17):7647–7651. doi: 10.1073/pnas.92.17.7647. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Moore M. S., Blobel G. The two steps of nuclear import, targeting to the nuclear envelope and translocation through the nuclear pore, require different cytosolic factors. Cell. 1992 Jun 12;69(6):939–950. doi: 10.1016/0092-8674(92)90613-h. [DOI] [PubMed] [Google Scholar]
  19. Moroianu J., Blobel G., Radu A. Previously identified protein of uncertain function is karyopherin alpha and together with karyopherin beta docks import substrate at nuclear pore complexes. Proc Natl Acad Sci U S A. 1995 Mar 14;92(6):2008–2011. doi: 10.1073/pnas.92.6.2008. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Moroianu J., Hijikata M., Blobel G., Radu A. Mammalian karyopherin alpha 1 beta and alpha 2 beta heterodimers: alpha 1 or alpha 2 subunit binds nuclear localization signal and beta subunit interacts with peptide repeat-containing nucleoporins. Proc Natl Acad Sci U S A. 1995 Jul 3;92(14):6532–6536. doi: 10.1073/pnas.92.14.6532. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Nehrbass U., Blobel G. Role of the nuclear transport factor p10 in nuclear import. Science. 1996 Apr 5;272(5258):120–122. doi: 10.1126/science.272.5258.120. [DOI] [PubMed] [Google Scholar]
  22. O'Neill R. E., Palese P. NPI-1, the human homolog of SRP-1, interacts with influenza virus nucleoprotein. Virology. 1995 Jan 10;206(1):116–125. doi: 10.1016/s0042-6822(95)80026-3. [DOI] [PubMed] [Google Scholar]
  23. Peifer M., Berg S., Reynolds A. B. A repeating amino acid motif shared by proteins with diverse cellular roles. Cell. 1994 Mar 11;76(5):789–791. doi: 10.1016/0092-8674(94)90353-0. [DOI] [PubMed] [Google Scholar]
  24. Radu A., Blobel G., Moore M. S. Identification of a protein complex that is required for nuclear protein import and mediates docking of import substrate to distinct nucleoporins. Proc Natl Acad Sci U S A. 1995 Feb 28;92(5):1769–1773. doi: 10.1073/pnas.92.5.1769. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Radu A., Moore M. S., Blobel G. The peptide repeat domain of nucleoporin Nup98 functions as a docking site in transport across the nuclear pore complex. Cell. 1995 Apr 21;81(2):215–222. doi: 10.1016/0092-8674(95)90331-3. [DOI] [PubMed] [Google Scholar]
  26. Rexach M., Blobel G. Protein import into nuclei: association and dissociation reactions involving transport substrate, transport factors, and nucleoporins. Cell. 1995 Dec 1;83(5):683–692. doi: 10.1016/0092-8674(95)90181-7. [DOI] [PubMed] [Google Scholar]
  27. Weis K., Mattaj I. W., Lamond A. I. Identification of hSRP1 alpha as a functional receptor for nuclear localization sequences. Science. 1995 May 19;268(5213):1049–1053. doi: 10.1126/science.7754385. [DOI] [PubMed] [Google Scholar]

Articles from Proceedings of the National Academy of Sciences of the United States of America are provided here courtesy of National Academy of Sciences

RESOURCES