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. 1993 Feb;12(2):573–583. doi: 10.1002/j.1460-2075.1993.tb05689.x

Nucleo-cytoplasmic transport of U snRNPs: definition of a nuclear location signal in the Sm core domain that binds a transport receptor independently of the m3G cap.

U Fischer 1, V Sumpter 1, M Sekine 1, T Satoh 1, R Lührmann 1
PMCID: PMC413240  PMID: 7679989

Abstract

We have investigated the nuclear transport of U1 and U5 snRNPs by microinjection studies in oocytes from Xenopus laevis using snRNP particles prepared by reconstitution in vitro. Competition studies with snRNPs showed that the Sm core domain of U1 snRNPs contains a nuclear location signal that acts independently of the m3G cap. The transport of U1 snRNP can be blocked by saturation with competitor U1 snRNPs or by U5 snRNPs, which indicates that the signals on the respective Sm core domains interact with the same transport receptors. Further, by using a minimal U1 snRNP particle reconstituted in vitro and containing only the Sm core RNP domain and lacking stem-loops I to III of U1 RNA, we show that this is targeted actively to the nucleus, in spite of the absence of the m3G cap. This indicates that under certain conditions the NLS in the Sm core domain not only is an essential, but may also be a sufficient condition for nuclear targeting. We propose that the RNA structure of a given snRNP particle determines at least in part whether the particle's m3G cap is required for nuclear transport or can be dispensed with.

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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. Branlant C., Krol A., Ebel J. P., Lazar E., Haendler B., Jacob M. U2 RNA shares a structural domain with U1, U4, and U5 RNAs. EMBO J. 1982;1(10):1259–1265. doi: 10.1002/j.1460-2075.1982.tb00022.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Bringmann P., Rinke J., Appel B., Reuter R., Lührmann R. Purification of snRNPs U1, U2, U4, U5 and U6 with 2,2,7-trimethylguanosine-specific antibody and definition of their constituent proteins reacting with anti-Sm and anti-(U1)RNP antisera. EMBO J. 1983;2(7):1129–1135. doi: 10.1002/j.1460-2075.1983.tb01557.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. De Robertis E. M., Lienhard S., Parisot R. F. Intracellular transport of microinjected 5S and small nuclear RNAs. Nature. 1982 Feb 18;295(5850):572–577. doi: 10.1038/295572a0. [DOI] [PubMed] [Google Scholar]
  6. 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]
  7. Dworetzky S. I., Feldherr C. M. Translocation of RNA-coated gold particles through the nuclear pores of oocytes. J Cell Biol. 1988 Mar;106(3):575–584. doi: 10.1083/jcb.106.3.575. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. England T. E., Uhlenbeck O. C. 3'-terminal labelling of RNA with T4 RNA ligase. Nature. 1978 Oct 12;275(5680):560–561. doi: 10.1038/275560a0. [DOI] [PubMed] [Google Scholar]
  9. 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]
  10. Fischer U., Darzynkiewicz E., Tahara S. M., Dathan N. A., Lührmann R., Mattaj I. W. Diversity in the signals required for nuclear accumulation of U snRNPs and variety in the pathways of nuclear transport. J Cell Biol. 1991 May;113(4):705–714. doi: 10.1083/jcb.113.4.705. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Fischer U., Lührmann R. An essential signaling role for the m3G cap in the transport of U1 snRNP to the nucleus. Science. 1990 Aug 17;249(4970):786–790. doi: 10.1126/science.2143847. [DOI] [PubMed] [Google Scholar]
  12. Garcia-Bustos J., Heitman J., Hall M. N. Nuclear protein localization. Biochim Biophys Acta. 1991 Mar 7;1071(1):83–101. doi: 10.1016/0304-4157(91)90013-m. [DOI] [PubMed] [Google Scholar]
  13. 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]
  14. Hamm J., Darzynkiewicz E., Tahara S. M., Mattaj I. W. The trimethylguanosine cap structure of U1 snRNA is a component of a bipartite nuclear targeting signal. Cell. 1990 Aug 10;62(3):569–577. doi: 10.1016/0092-8674(90)90021-6. [DOI] [PubMed] [Google Scholar]
  15. Kalderon D., Richardson W. D., Markham A. F., Smith A. E. Sequence requirements for nuclear location of simian virus 40 large-T antigen. Nature. 1984 Sep 6;311(5981):33–38. doi: 10.1038/311033a0. [DOI] [PubMed] [Google Scholar]
  16. 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]
  17. Kastner B., Bach M., Lührmann R. Electron microscopy of small nuclear ribonucleoprotein (snRNP) particles U2 and U5: evidence for a common structure-determining principle in the major U snRNP family. Proc Natl Acad Sci U S A. 1990 Mar;87(5):1710–1714. doi: 10.1073/pnas.87.5.1710. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Kastner B., Lührmann R. Electron microscopy of U1 small nuclear ribonucleoprotein particles: shape of the particle and position of the 5' RNA terminus. EMBO J. 1989 Jan;8(1):277–286. doi: 10.1002/j.1460-2075.1989.tb03374.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Konings D. A., Mattaj I. W. Mutant U2 snRNAs of Xenopus which can form an altered higher order RNA structure are unable to enter the nucleus. Exp Cell Res. 1987 Oct;172(2):329–339. doi: 10.1016/0014-4827(87)90391-0. [DOI] [PubMed] [Google Scholar]
  20. Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
  21. 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]
  22. Lehmeier T., Foulaki K., Lührmann R. Evidence for three distinct D proteins, which react differentially with anti-Sm autoantibodies, in the cores of the major snRNPs U1, U2, U4/U6 and U5. Nucleic Acids Res. 1990 Nov 25;18(22):6475–6484. doi: 10.1093/nar/18.22.6475. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Lerner E. A., Lerner M. R., Janeway C. A., Jr, Steitz J. A. Monoclonal antibodies to nucleic acid-containing cellular constituents: probes for molecular biology and autoimmune disease. Proc Natl Acad Sci U S A. 1981 May;78(5):2737–2741. doi: 10.1073/pnas.78.5.2737. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Lerner M. R., Steitz J. A. Antibodies to small nuclear RNAs complexed with proteins are produced by patients with systemic lupus erythematosus. Proc Natl Acad Sci U S A. 1979 Nov;76(11):5495–5499. doi: 10.1073/pnas.76.11.5495. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Liautard J. P., Sri-Widada J., Brunel C., Jeanteur P. Structural organization of ribonucleoproteins containing small nuclear RNAs from HeLa cells. Proteins interact closely with a similar structural domain of U1, U2, U4 and U5 small nuclear RNAs. J Mol Biol. 1982 Dec 15;162(3):623–643. doi: 10.1016/0022-2836(82)90392-8. [DOI] [PubMed] [Google Scholar]
  26. Luhrmann R., Appel B., Bringmann P., Rinke J., Reuter R., Rothe S., Bald R. Isolation and characterization of rabbit anti-m3 2,2,7G antibodies. Nucleic Acids Res. 1982 Nov 25;10(22):7103–7113. doi: 10.1093/nar/10.22.7103. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Lührmann R., Kastner B., Bach M. Structure of spliceosomal snRNPs and their role in pre-mRNA splicing. Biochim Biophys Acta. 1990 Nov 30;1087(3):265–292. doi: 10.1016/0167-4781(90)90001-i. [DOI] [PubMed] [Google Scholar]
  28. Mattaj I. W. Cap trimethylation of U snRNA is cytoplasmic and dependent on U snRNP protein binding. Cell. 1986 Sep 12;46(6):905–911. doi: 10.1016/0092-8674(86)90072-3. [DOI] [PubMed] [Google Scholar]
  29. Mattaj I. W., De Robertis E. M. Nuclear segregation of U2 snRNA requires binding of specific snRNP proteins. Cell. 1985 Jan;40(1):111–118. doi: 10.1016/0092-8674(85)90314-9. [DOI] [PubMed] [Google Scholar]
  30. Melton D. A., Krieg P. A., Rebagliati M. R., Maniatis T., Zinn K., Green M. R. Efficient in vitro synthesis of biologically active RNA and RNA hybridization probes from plasmids containing a bacteriophage SP6 promoter. Nucleic Acids Res. 1984 Sep 25;12(18):7035–7056. doi: 10.1093/nar/12.18.7035. [DOI] [PMC free article] [PubMed] [Google Scholar]
  31. Michaud N., Goldfarb D. S. Multiple pathways in nuclear transport: the import of U2 snRNP occurs by a novel kinetic pathway. J Cell Biol. 1991 Jan;112(2):215–223. doi: 10.1083/jcb.112.2.215. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Michaud N., Goldfarb D. Microinjected U snRNAs are imported to oocyte nuclei via the nuclear pore complex by three distinguishable targeting pathways. J Cell Biol. 1992 Feb;116(4):851–861. doi: 10.1083/jcb.116.4.851. [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. Neuman de Vegvar H. E., Dahlberg J. E. Nucleocytoplasmic transport and processing of small nuclear RNA precursors. Mol Cell Biol. 1990 Jul;10(7):3365–3375. doi: 10.1128/mcb.10.7.3365. [DOI] [PMC free article] [PubMed] [Google Scholar]
  34. Newmeyer D. D., Forbes D. J. Nuclear import can be separated into distinct steps in vitro: nuclear pore binding and translocation. Cell. 1988 Mar 11;52(5):641–653. doi: 10.1016/0092-8674(88)90402-3. [DOI] [PubMed] [Google Scholar]
  35. Patton J. R., Patterson R. J., Pederson T. Reconstitution of the U1 small nuclear ribonucleoprotein particle. Mol Cell Biol. 1987 Nov;7(11):4030–4037. doi: 10.1128/mcb.7.11.4030. [DOI] [PMC free article] [PubMed] [Google Scholar]
  36. 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]
  37. 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]
  38. 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]
  39. Singh R., Reddy R. Gamma-monomethyl phosphate: a cap structure in spliceosomal U6 small nuclear RNA. Proc Natl Acad Sci U S A. 1989 Nov;86(21):8280–8283. doi: 10.1073/pnas.86.21.8280. [DOI] [PMC free article] [PubMed] [Google Scholar]
  40. Sumpter V., Kahrs A., Fischer U., Kornstädt U., Lührmann R. In vitro reconstitution of U1 and U2 snRNPs from isolated proteins and snRNA. Mol Biol Rep. 1992 Sep;16(4):229–240. doi: 10.1007/BF00419662. [DOI] [PubMed] [Google Scholar]
  41. Wersig C., Guddat U., Pieler T., Bindereif A. Assembly and nuclear transport of the U4 and U4/U6 snRNPs. Exp Cell Res. 1992 Apr;199(2):373–377. doi: 10.1016/0014-4827(92)90447-g. [DOI] [PubMed] [Google Scholar]

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