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Multiple pathways in nuclear transport: the import of U2 snRNP occurs by a novel kinetic pathway

Protein import to the nucleus is a signal-mediated process that exhibits saturation kinetics. We investigated whether signal bearing proteins compete with U2 and U6 snRNPs during import. When injected into Xenopus oocytes, saturating concentrations of P(Lys)-BSA, a protein bearing multiple nuclear l...

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Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1991
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2288826/
https://www.ncbi.nlm.nih.gov/pubmed/1824847
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description Protein import to the nucleus is a signal-mediated process that exhibits saturation kinetics. We investigated whether signal bearing proteins compete with U2 and U6 snRNPs during import. When injected into Xenopus oocytes, saturating concentrations of P(Lys)-BSA, a protein bearing multiple nuclear localization signals from SV40 large T- antigen, reduce the rate of [125I]P(Lys)-BSA and of [125I]nucleoplasmin import, consistent with their competing for and sharing the same limiting component of the import apparatus. In contrast, saturating concentrations of P(Lys)-BSA do not reduce the rate of HeLa [32P]U2 snRNP assembly or import. The import of U6 snRNP is also competed by P(Lys)-BSA. We conclude that U2 snRNP is imported into oocyte nuclei by a kinetic pathway that is distinct from the one followed by P(Lys)-BSA, nucleoplasmin, and U6 snRNP.
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spelling pubmed-22888262008-05-01 Multiple pathways in nuclear transport: the import of U2 snRNP occurs by a novel kinetic pathway J Cell Biol Articles Protein import to the nucleus is a signal-mediated process that exhibits saturation kinetics. We investigated whether signal bearing proteins compete with U2 and U6 snRNPs during import. When injected into Xenopus oocytes, saturating concentrations of P(Lys)-BSA, a protein bearing multiple nuclear localization signals from SV40 large T- antigen, reduce the rate of [125I]P(Lys)-BSA and of [125I]nucleoplasmin import, consistent with their competing for and sharing the same limiting component of the import apparatus. In contrast, saturating concentrations of P(Lys)-BSA do not reduce the rate of HeLa [32P]U2 snRNP assembly or import. The import of U6 snRNP is also competed by P(Lys)-BSA. We conclude that U2 snRNP is imported into oocyte nuclei by a kinetic pathway that is distinct from the one followed by P(Lys)-BSA, nucleoplasmin, and U6 snRNP. The Rockefeller University Press 1991-01-02 /pmc/articles/PMC2288826/ /pubmed/1824847 Text en This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/).
spellingShingle Articles
Multiple pathways in nuclear transport: the import of U2 snRNP occurs by a novel kinetic pathway
title Multiple pathways in nuclear transport: the import of U2 snRNP occurs by a novel kinetic pathway
title_full Multiple pathways in nuclear transport: the import of U2 snRNP occurs by a novel kinetic pathway
title_fullStr Multiple pathways in nuclear transport: the import of U2 snRNP occurs by a novel kinetic pathway
title_full_unstemmed Multiple pathways in nuclear transport: the import of U2 snRNP occurs by a novel kinetic pathway
title_short Multiple pathways in nuclear transport: the import of U2 snRNP occurs by a novel kinetic pathway
title_sort multiple pathways in nuclear transport: the import of u2 snrnp occurs by a novel kinetic pathway
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2288826/
https://www.ncbi.nlm.nih.gov/pubmed/1824847