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Microinjected U snRNAs are imported to oocyte nuclei via the nuclear pore complex by three distinguishable targeting pathways.
Michaud N, Goldfarb D.
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The inhibitory effects of wheat germ agglutinin and mAb 414 on the nuclear import of all types of U snRNAs indicate that they cross the nuclear envelope through the nuclear pore complex. However, the import of different U snRNAs occurs by kinetically distinct targeting pathways that can be distinguished from one another by the competitive effects of free trimethylguanosine cap dinucleotide (m3GpppG) and P(Lys)-BSA, an efficient synthetic karyophile based on the nuclear localization signal of SV40 large T antigen. The import of U snRNAs that contain 5' m3GpppN caps and are complexed by Sm proteins (U1, U2, U4, and U5) is competed by coinjection with free m3GpppG, indicating a shared transport factor, but not by P(Lys)-BSA. The import of U6 snRNA, which lacks a m3GpppN cap and is not complexed by the Sm proteins, is competed by P(Lys)-BSA but not by free m3GpppG. Thus, by the criterion of kinetic competition, U6 snRNA import is identical to that of the karyophilic proteins P(Lys)-BSA and nucleoplasmin. Uniquely, the import of U3 snRNA, which contains a m3GpppN cap but does not bind Sm proteins is not competed by either free m3GpppG or P(Lys)-BSA. Thus, U3 snRNA appears to be imported by a novel third kinetic pathway.
Adam,
Cytosolic proteins that specifically bind nuclear location signals are receptors for nuclear import.
1991, Pubmed
Adam,
Cytosolic proteins that specifically bind nuclear location signals are receptors for nuclear import.
1991,
Pubmed Adam,
Nuclear protein import in permeabilized mammalian cells requires soluble cytoplasmic factors.
1990,
Pubmed
,
Xenbase Akey,
Protein import through the nuclear pore complex is a multistep process.
1989,
Pubmed
,
Xenbase Akey,
Visualization of transport-related configurations of the nuclear pore transporter.
1990,
Pubmed Baserga,
An intact Box C sequence in the U3 snRNA is required for binding of fibrillarin, the protein common to the major family of nucleolar snRNPs.
1991,
Pubmed Bataillé,
Cytoplasmic transport of ribosomal subunits microinjected into the Xenopus laevis oocyte nucleus: a generalized, facilitated process.
1990,
Pubmed
,
Xenbase Billings,
A murine monoclonal antibody recognizes the 13,000 molecular weight polypeptide of the Sm small nuclear ribonucleoprotein complex.
1985,
Pubmed Breeuwer,
Facilitated nuclear transport of histone H1 and other small nucleophilic proteins.
1990,
Pubmed Bringmann,
Evidence for the existence of snRNAs U4 and U6 in a single ribonucleoprotein complex and for their association by intermolecular base pairing.
1984,
Pubmed Carberry,
A spectroscopic study of the binding of N-7-substituted cap analogues to human protein synthesis initiation factor 4E.
1990,
Pubmed Dabauvalle,
Inhibition of nuclear accumulation of karyophilic proteins in living cells by microinjection of the lectin wheat germ agglutinin.
1988,
Pubmed
,
Xenbase Dabauvalle,
Monoclonal antibodies to a Mr 68,000 pore complex glycoprotein interfere with nuclear protein uptake in Xenopus oocytes.
1988,
Pubmed
,
Xenbase Darzynkiewicz,
Beta-globin mRNAs capped with m7G, m2.7(2)G or m2.2.7(3)G differ in intrinsic translation efficiency.
1988,
Pubmed Davis,
Identification and characterization of a nuclear pore complex protein.
1986,
Pubmed De Robertis,
Intracellular transport of microinjected 5S and small nuclear RNAs.
1982,
Pubmed
,
Xenbase Dworetzky,
The effects of variations in the number and sequence of targeting signals on nuclear uptake.
1988,
Pubmed
,
Xenbase Featherstone,
A monoclonal antibody against the nuclear pore complex inhibits nucleocytoplasmic transport of protein and RNA in vivo.
1988,
Pubmed
,
Xenbase Feldherr,
Movement of a karyophilic protein through the nuclear pores of oocytes.
1984,
Pubmed
,
Xenbase Finlay,
Inhibition of in vitro nuclear transport by a lectin that binds to nuclear pores.
1987,
Pubmed
,
Xenbase Fischer,
An essential signaling role for the m3G cap in the transport of U1 snRNP to the nucleus.
1990,
Pubmed
,
Xenbase Fischer,
Diversity in the signals required for nuclear accumulation of U snRNPs and variety in the pathways of nuclear transport.
1991,
Pubmed
,
Xenbase Garcia-Bustos,
Nuclear protein localization.
1991,
Pubmed Goldfarb,
Synthetic peptides as nuclear localization signals.
,
Pubmed
,
Xenbase Goldfarb,
Nuclear transport.
1989,
Pubmed Gröning,
A new U6 small nuclear ribonucleoprotein-specific protein conserved between cis- and trans-splicing systems.
1991,
Pubmed Hamm,
An abundant U6 snRNP found in germ cells and embryos of Xenopus laevis.
1989,
Pubmed
,
Xenbase Hamm,
In vitro assembly of U1 snRNPs.
1987,
Pubmed
,
Xenbase Hamm,
Monomethylated cap structures facilitate RNA export from the nucleus.
1990,
Pubmed
,
Xenbase Hamm,
The trimethylguanosine cap structure of U1 snRNA is a component of a bipartite nuclear targeting signal.
1990,
Pubmed
,
Xenbase Hashimoto,
U4 and U6 RNAs coexist in a single small nuclear ribonucleoprotein particle.
1984,
Pubmed Holt,
Nuclear pore complex glycoproteins contain cytoplasmically disposed O-linked N-acetylglucosamine.
1987,
Pubmed Kalderon,
Sequence requirements for nuclear location of simian virus 40 large-T antigen.
,
Pubmed Kiss,
Alteration of the RNA polymerase specificity of U3 snRNA genes during evolution and in vitro.
1991,
Pubmed Kleinschmidt,
RNA processing and ribonucleoprotein assembly studied in vivo by RNA transfection.
1990,
Pubmed Krainer,
Pre-mRNA splicing by complementation with purified human U1, U2, U4/U6 and U5 snRNPs.
1988,
Pubmed Lanford,
Comparison of diverse transport signals in synthetic peptide-induced nuclear transport.
1990,
Pubmed
,
Xenbase Lanford,
Effect of basic and nonbasic amino acid substitutions on transport induced by simian virus 40 T-antigen synthetic peptide nuclear transport signals.
1988,
Pubmed Mattaj,
Cap trimethylation of U snRNA is cytoplasmic and dependent on U snRNP protein binding.
1986,
Pubmed
,
Xenbase Mattaj,
Nuclear segregation of U2 snRNA requires binding of specific snRNP proteins.
1985,
Pubmed
,
Xenbase Michaud,
Multiple pathways in nuclear transport: the import of U2 snRNP occurs by a novel kinetic pathway.
1991,
Pubmed
,
Xenbase Neuman de Vegvar,
Nucleocytoplasmic transport and processing of small nuclear RNA precursors.
1990,
Pubmed
,
Xenbase Newmeyer,
Nuclear import can be separated into distinct steps in vitro: nuclear pore binding and translocation.
1988,
Pubmed
,
Xenbase Newmeyer,
An N-ethylmaleimide-sensitive cytosolic factor necessary for nuclear protein import: requirement in signal-mediated binding to the nuclear pore.
1990,
Pubmed
,
Xenbase Ohno,
A nuclear cap binding protein from HeLa cells.
1990,
Pubmed Pan,
Assembly of functional U1 and U2 human-amphibian hybrid snRNPs in Xenopus laevis oocytes.
1988,
Pubmed
,
Xenbase Reuter,
5'-Terminal caps of snRNAs are reactive with antibodies specific for 2,2,7-trimethylguanosine in whole cells and nuclear matrices. Double-label immunofluorescent studies with anti-m3G antibodies and with anti-RNP and anti-Sm autoantibodies.
1984,
Pubmed Rhoads,
Cap recognition and the entry of mRNA into the protein synthesis initiation cycle.
1988,
Pubmed Richardson,
Nuclear protein migration involves two steps: rapid binding at the nuclear envelope followed by slower translocation through nuclear pores.
1988,
Pubmed
,
Xenbase Roberts,
The effect of protein context on nuclear location signal function.
1987,
Pubmed Shumyatsky,
B2 RNA and 7SK RNA, RNA polymerase III transcripts, have a cap-like structure at their 5' end.
1990,
Pubmed Silver,
How proteins enter the nucleus.
1991,
Pubmed Singh,
Gamma-monomethyl phosphate: a cap structure in spliceosomal U6 small nuclear RNA.
1989,
Pubmed Snow,
Monoclonal antibodies identify a group of nuclear pore complex glycoproteins.
1987,
Pubmed
,
Xenbase Stochaj,
A yeast protein that binds nuclear localization signals: purification localization, and antibody inhibition of binding activity.
1991,
Pubmed Tyc,
U3, U8 and U13 comprise a new class of mammalian snRNPs localized in the cell nucleolus.
1989,
Pubmed Vankan,
Domains of U4 and U6 snRNAs required for snRNP assembly and splicing complementation in Xenopus oocytes.
1990,
Pubmed
,
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