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Abstract 


The Saccharomyces cerevisiae gene, RNA1, encodes a protein with extensive homology to the mammalian Ran/TC4 GTPase activating protein. Using indirect immunofluorescence microscopy, we have demonstrated that rna1-1 mutant cells are defective in nuclear import of several proteins. The same result is obtained when nuclear import is examined in living cells using a nuclear protein fused to the naturally green fluorescent protein. These findings suggest a role for the Rna1p in trafficking of proteins across the nuclear membrane. To investigate this role more directly, an in vitro import assay that monitors the import of a fluorescently labeled substrate into the nuclei of semi-intact yeast cells was used. Import to the nucleus requires the addition of exogenous cytosol. Results indicate that, in contrast to wild-type cytosols, extracts made from rna1-1 mutant cells are unable to support import of the fluorescently labeled substrate into competent nuclei. Immunoblotting demonstrates that these mutant-derived extracts are depleted of Rna1p. However, when purified Rna1p is added back to these extracts the import activity is restored in a dose-dependent manner. These results demonstrate that Rna1p plays a direct role in the import of proteins into the nucleus.

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J Cell Biol. 1995 Sep 1; 130(5): 1017–1026.
PMCID: PMC2120547
PMID: 7657689

Rna1p, a Ran/TC4 GTPase activating protein, is required for nuclear import

Abstract

The Saccharomyces cerevisiae gene, RNA1, encodes a protein with extensive homology to the mammalian Ran/TC4 GTPase activating protein. Using indirect immunofluorescence microscopy, we have demonstrated that rna1-1 mutant cells are defective in nuclear import of several proteins. The same result is obtained when nuclear import is examined in living cells using a nuclear protein fused to the naturally green fluorescent protein. These findings suggest a role for the Rna1p in trafficking of proteins across the nuclear membrane. To investigate this role more directly, an in vitro import assay that monitors the import of a fluorescently labeled substrate into the nuclei of semi- intact yeast cells was used. Import to the nucleus requires the addition of exogenous cytosol. Results indicate that, in contrast to wild-type cytosols, extracts made from rna1-1 mutant cells are unable to support import of the fluorescently labeled substrate into competent nuclei. Immunoblotting demonstrates that these mutant-derived extracts are depleted of Rna1p. However, when purified Rna1p is added back to these extracts the import activity is restored in a dose-dependent manner. These results demonstrate that Rna1p plays a direct role in the import of proteins into the nucleus.

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Selected References

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  • Becker J, Melchior F, Gerke V, Bischoff FR, Ponstingl H, Wittinghofer A. RNA1 encodes a GTPase-activating protein specific for Gsp1p, the Ran/TC4 homologue of Saccharomyces cerevisiae. J Biol Chem. 1995 May 19;270(20):11860–11865. [Abstract] [Google Scholar]
  • Aebi M, Clark MW, Vijayraghavan U, Abelson J. A yeast mutant, PRP20, altered in mRNA metabolism and maintenance of the nuclear structure, is defective in a gene homologous to the human gene RCC1 which is involved in the control of chromosome condensation. Mol Gen Genet. 1990 Oct;224(1):72–80. [Abstract] [Google Scholar]
  • Amberg DC, Goldstein AL, Cole CN. Isolation and characterization of RAT1: an essential gene of Saccharomyces cerevisiae required for the efficient nucleocytoplasmic trafficking of mRNA. Genes Dev. 1992 Jul;6(7):1173–1189. [Abstract] [Google Scholar]
  • Atkinson NS, Dunst RW, Hopper AK. Characterization of an essential Saccharomyces cerevisiae gene related to RNA processing: cloning of RNA1 and generation of a new allele with a novel phenotype. Mol Cell Biol. 1985 May;5(5):907–915. [Europe PMC free article] [Abstract] [Google Scholar]
  • Belhumeur P, Lee A, Tam R, DiPaolo T, Fortin N, Clark MW. GSP1 and GSP2, genetic suppressors of the prp20-1 mutant in Saccharomyces cerevisiae: GTP-binding proteins involved in the maintenance of nuclear organization. Mol Cell Biol. 1993 Apr;13(4):2152–2161. [Europe PMC free article] [Abstract] [Google Scholar]
  • Bischoff FR, Klebe C, Kretschmer J, Wittinghofer A, Ponstingl H. RanGAP1 induces GTPase activity of nuclear Ras-related Ran. Proc Natl Acad Sci U S A. 1994 Mar 29;91(7):2587–2591. [Europe PMC free article] [Abstract] [Google Scholar]
  • Bischoff FR, Krebber H, Kempf T, Hermes I, Ponstingl H. Human RanGTPase-activating protein RanGAP1 is a homologue of yeast Rna1p involved in mRNA processing and transport. Proc Natl Acad Sci U S A. 1995 Feb 28;92(5):1749–1753. [Europe PMC free article] [Abstract] [Google Scholar]
  • Bischoff FR, Krebber H, Smirnova E, Dong W, Ponstingl H. Co-activation of RanGTPase and inhibition of GTP dissociation by Ran-GTP binding protein RanBP1. EMBO J. 1995 Feb 15;14(4):705–715. [Europe PMC free article] [Abstract] [Google Scholar]
  • Bischoff FR, Ponstingl H. Catalysis of guanine nucleotide exchange on Ran by the mitotic regulator RCC1. Nature. 1991 Nov 7;354(6348):80–82. [Abstract] [Google Scholar]
  • Bischoff FR, Ponstingl H. Mitotic regulator protein RCC1 is complexed with a nuclear ras-related polypeptide. Proc Natl Acad Sci U S A. 1991 Dec 1;88(23):10830–10834. [Europe PMC free article] [Abstract] [Google Scholar]
  • Bogerd AM, Hoffman JA, Amberg DC, Fink GR, Davis LI. nup1 mutants exhibit pleiotropic defects in nuclear pore complex function. J Cell Biol. 1994 Oct;127(2):319–332. [Europe PMC free article] [Abstract] [Google Scholar]
  • Bossie MA, DeHoratius C, Barcelo G, Silver P. A mutant nuclear protein with similarity to RNA binding proteins interferes with nuclear import in yeast. Mol Biol Cell. 1992 Aug;3(8):875–893. [Europe PMC free article] [Abstract] [Google Scholar]
  • Chalfie M, Tu Y, Euskirchen G, Ward WW, Prasher DC. Green fluorescent protein as a marker for gene expression. Science. 1994 Feb 11;263(5148):802–805. [Abstract] [Google Scholar]
  • Coutavas E, Ren M, Oppenheim JD, D'Eustachio P, Rush MG. Characterization of proteins that interact with the cell-cycle regulatory protein Ran/TC4. Nature. 1993 Dec 9;366(6455):585–587. [Abstract] [Google Scholar]
  • Dasso M. RCC1 in the cell cycle: the regulator of chromosome condensation takes on new roles. Trends Biochem Sci. 1993 Mar;18(3):96–101. [Abstract] [Google Scholar]
  • Drivas GT, Shih A, Coutavas E, Rush MG, D'Eustachio P. Characterization of four novel ras-like genes expressed in a human teratocarcinoma cell line. Mol Cell Biol. 1990 Apr;10(4):1793–1798. [Europe PMC free article] [Abstract] [Google Scholar]
  • Fabre E, Hurt EC. Nuclear transport. Curr Opin Cell Biol. 1994 Jun;6(3):335–342. [Abstract] [Google Scholar]
  • Flach J, Bossie M, Vogel J, Corbett A, Jinks T, Willins DA, Silver PA. A yeast RNA-binding protein shuttles between the nucleus and the cytoplasm. Mol Cell Biol. 1994 Dec;14(12):8399–8407. [Europe PMC free article] [Abstract] [Google Scholar]
  • Fleischmann M, Clark MW, Forrester W, Wickens M, Nishimoto T, Aebi M. Analysis of yeast prp20 mutations and functional complementation by the human homologue RCC1, a protein involved in the control of chromosome condensation. Mol Gen Genet. 1991 Jul;227(3):417–423. [Abstract] [Google Scholar]
  • Forbes DJ. Structure and function of the nuclear pore complex. Annu Rev Cell Biol. 1992;8:495–527. [Abstract] [Google Scholar]
  • Garcia-Bustos J, Heitman J, Hall MN. Nuclear protein localization. Biochim Biophys Acta. 1991 Mar 7;1071(1):83–101. [Abstract] [Google Scholar]
  • Hartwell LH. Macromolecule synthesis in temperature-sensitive mutants of yeast. J Bacteriol. 1967 May;93(5):1662–1670. [Europe PMC free article] [Abstract] [Google Scholar]
  • Hopper AK, Banks F. A yeast mutant which accumulates precursor tRNAs. Cell. 1978 Jun;14(2):211–219. [Abstract] [Google Scholar]
  • Hopper AK, Traglia HM, Dunst RW. The yeast RNA1 gene product necessary for RNA processing is located in the cytosol and apparently excluded from the nucleus. J Cell Biol. 1990 Aug;111(2):309–321. [Europe PMC free article] [Abstract] [Google Scholar]
  • Hutchison HT, Hartwell LH, McLaughlin CS. Temperature-sensitive yeast mutant defective in ribonucleic acid production. J Bacteriol. 1969 Sep;99(3):807–814. [Europe PMC free article] [Abstract] [Google Scholar]
  • Kadowaki T, Zhao Y, Tartakoff AM. A conditional yeast mutant deficient in mRNA transport from nucleus to cytoplasm. Proc Natl Acad Sci U S A. 1992 Mar 15;89(6):2312–2316. [Europe PMC free article] [Abstract] [Google Scholar]
  • Laemmli UK. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. [Abstract] [Google Scholar]
  • Lee A, Tam R, Belhumeur P, DiPaolo T, Clark MW. Prp20, the Saccharomyces cerevisiae homolog of the regulator of chromosome condensation, RCC1, interacts with double-stranded DNA through a multi-component complex containing GTP-binding proteins. J Cell Sci. 1993 Sep;106(Pt 1):287–298. [Abstract] [Google Scholar]
  • Lounsbury KM, Beddow AL, Macara IG. A family of proteins that stabilize the Ran/TC4 GTPase in its GTP-bound conformation. J Biol Chem. 1994 Apr 15;269(15):11285–11290. [Abstract] [Google Scholar]
  • Matsumoto T, Beach D. The spil GTPase interacts with RCCl in cell cycle dependency. Cold Spring Harb Symp Quant Biol. 1991;56:385–398. [Abstract] [Google Scholar]
  • Melchior F, Paschal B, Evans J, Gerace L. Inhibition of nuclear protein import by nonhydrolyzable analogues of GTP and identification of the small GTPase Ran/TC4 as an essential transport factor. J Cell Biol. 1993 Dec;123(6 Pt 2):1649–1659. [Europe PMC free article] [Abstract] [Google Scholar]
  • Melchior F, Weber K, Gerke V. A functional homologue of the RNA1 gene product in Schizosaccharomyces pombe: purification, biochemical characterization, and identification of a leucine-rich repeat motif. Mol Biol Cell. 1993 Jun;4(6):569–581. [Europe PMC free article] [Abstract] [Google Scholar]
  • Minvielle-Sebastia L, Preker PJ, Keller W. RNA14 and RNA15 proteins as components of a yeast pre-mRNA 3'-end processing factor. Science. 1994 Dec 9;266(5191):1702–1705. [Abstract] [Google Scholar]
  • Moore MS, Blobel G. The GTP-binding protein Ran/TC4 is required for protein import into the nucleus. Nature. 1993 Oct 14;365(6447):661–663. [Abstract] [Google Scholar]
  • Moore MS, Blobel G. A G protein involved in nucleocytoplasmic transport: the role of Ran. Trends Biochem Sci. 1994 May;19(5):211–216. [Abstract] [Google Scholar]
  • Moore MS, Blobel G. Purification of a Ran-interacting protein that is required for protein import into the nucleus. Proc Natl Acad Sci U S A. 1994 Oct 11;91(21):10212–10216. [Europe PMC free article] [Abstract] [Google Scholar]
  • Moreland RB, Langevin GL, Singer RH, Garcea RL, Hereford LM. Amino acid sequences that determine the nuclear localization of yeast histone 2B. Mol Cell Biol. 1987 Nov;7(11):4048–4057. [Europe PMC free article] [Abstract] [Google Scholar]
  • Nelson M, Silver P. Context affects nuclear protein localization in Saccharomyces cerevisiae. Mol Cell Biol. 1989 Feb;9(2):384–389. [Europe PMC free article] [Abstract] [Google Scholar]
  • Nigg EA, Baeuerle PA, Lührmann R. Nuclear import-export: in search of signals and mechanisms. Cell. 1991 Jul 12;66(1):15–22. [Abstract] [Google Scholar]
  • Ohtsubo M, Okazaki H, Nishimoto T. The RCC1 protein, a regulator for the onset of chromosome condensation locates in the nucleus and binds to DNA. J Cell Biol. 1989 Oct;109(4 Pt 1):1389–1397. [Europe PMC free article] [Abstract] [Google Scholar]
  • Osborne MA, Silver PA. Nucleocytoplasmic transport in the yeast Saccharomyces cerevisiae. Annu Rev Biochem. 1993;62:219–254. [Abstract] [Google Scholar]
  • Ouspenski II, Mueller UW, Matynia A, Sazer S, Elledge SJ, Brinkley BR. Ran-binding protein-1 is an essential component of the Ran/RCC1 molecular switch system in budding yeast. J Biol Chem. 1995 Feb 3;270(5):1975–1978. [Abstract] [Google Scholar]
  • Panté N, Aebi U. The nuclear pore complex. J Cell Biol. 1993 Sep;122(5):977–984. [Europe PMC free article] [Abstract] [Google Scholar]
  • Powers MA, Forbes DJ. Cytosolic factors in nuclear transport: what's importin? Cell. 1994 Dec 16;79(6):931–934. [Abstract] [Google Scholar]
  • Rout MP, Wente SR. Pores for thought: nuclear pore complex proteins. Trends Cell Biol. 1994 Oct;4(10):357–365. [Abstract] [Google Scholar]
  • Schlenstedt G, Hurt E, Doye V, Silver PA. Reconstitution of nuclear protein transport with semi-intact yeast cells. J Cell Biol. 1993 Nov;123(4):785–798. [Europe PMC free article] [Abstract] [Google Scholar]
  • Schlenstedt G, Saavedra C, Loeb JD, Cole CN, Silver PA. The GTP-bound form of the yeast Ran/TC4 homologue blocks nuclear protein import and appearance of poly(A)+ RNA in the cytoplasm. Proc Natl Acad Sci U S A. 1995 Jan 3;92(1):225–229. [Europe PMC free article] [Abstract] [Google Scholar]
  • Smith DB, Johnson KS. Single-step purification of polypeptides expressed in Escherichia coli as fusions with glutathione S-transferase. Gene. 1988 Jul 15;67(1):31–40. [Abstract] [Google Scholar]
  • Tachibana T, Imamoto N, Seino H, Nishimoto T, Yoneda Y. Loss of RCC1 leads to suppression of nuclear protein import in living cells. J Biol Chem. 1994 Oct 7;269(40):24542–24545. [Abstract] [Google Scholar]
  • Towbin H, Staehelin T, Gordon J. Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications. Proc Natl Acad Sci U S A. 1979 Sep;76(9):4350–4354. [Europe PMC free article] [Abstract] [Google Scholar]
  • Traglia HM, Atkinson NS, Hopper AK. Structural and functional analyses of Saccharomyces cerevisiae wild-type and mutant RNA1 genes. Mol Cell Biol. 1989 Jul;9(7):2989–2999. [Europe PMC free article] [Abstract] [Google Scholar]
  • Tung KS, Norbeck LL, Nolan SL, Atkinson NS, Hopper AK. SRN1, a yeast gene involved in RNA processing, is identical to HEX2/REG1, a negative regulator in glucose repression. Mol Cell Biol. 1992 Jun;12(6):2673–2680. [Europe PMC free article] [Abstract] [Google Scholar]
  • Wilson SM, Datar KV, Paddy MR, Swedlow JR, Swanson MS. Characterization of nuclear polyadenylated RNA-binding proteins in Saccharomyces cerevisiae. J Cell Biol. 1994 Dec;127(5):1173–1184. [Europe PMC free article] [Abstract] [Google Scholar]

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