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Most nuclear proteins are imported by a single pathway.

N Michaud·D S Goldfarb
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Abstract

Using kinetic competition analysis, we show that the import of most Xenopus oocyte nuclear proteins is directed by a single family of nuclear localization signals (NLS). The transport of microinjected [35S]methionine-labeled nuclear proteins into oocyte nuclei was challenged with saturating concentrations of SV40 large T-antigen NLS peptide-BSA (P(Lys)-BSA) and was assessed by SDS-acrylamide gel electrophoresis and fluorography. P(Lys)-BSA was effective at competing the import of virtually all larger polypeptides but had a less marked effect on the mediated import of many smaller polypeptides. Wheat germ agglutinin, an inhibitor of nuclear pore complex function, enhanced the competitive effects of P(Lys)-BSA on the import of both large and small polypeptides. These data indicate that most 35S-labeled Xenopus oocyte nuclear proteins, including nucleoplasmin, contain NLSs that are functionally related to the T-antigen NLS and probably employ the same cytosolic NLS receptor(s).

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Amino Acid SequenceAnimalsBinding, CompetitiveBiological TransportCell CompartmentationCell NucleusEgg ProteinsMolecular Sequence DataMolecular WeightNuclear ProteinsNucleoplasminsPhosphoproteinsPolylysineRNA CapsStructure-Activity RelationshipWheat Germ AgglutininsXenopus laevisJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, P.H.S.

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N Michaud, D S Goldfarb. 1993. Most nuclear proteins are imported by a single pathway.. https://doi.org/10.1006/excr.1993.1230

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