Xenopus Ran-binding protein 1: molecular interactions and effects on nuclear assembly in Xenopus egg extracts.

2.50
Hdl Handle:
http://hdl.handle.net/10541/95485
Title:
Xenopus Ran-binding protein 1: molecular interactions and effects on nuclear assembly in Xenopus egg extracts.
Authors:
Nicolás, F J; Zhang, C; Hughes, M; Goldberg, Martin W; Watton, S J; Clarke, P R
Abstract:
Ran is a nuclear GTPase implicated in nucleocytoplasmic transport, the maintenance of nuclear structure, mRNA processing, and cell cycle regulation. By two-hybrid interaction in yeast, we have identified a Xenopus homologue of Ran-binding protein 1 (RanBP1). Xenopus RanBP1 interacts specifically with the GTP-bound form of Ran and forms complexes in Xenopus egg extracts with Ran, importin-beta/karyopherin-beta and importin-alpha/karyopherin-alpha, but not p10, p120/RanBP7, RanBP2 or other nucleoporins. These complexes may play roles in the recycling of Ran and importins/karyopherins during nucleocytoplasmic transport. Increased concentrations of RanBP1 stabilise an interaction between Ran and RCC1 in egg extracts, inhibiting the exchange activity of RCC1 towards Ran. Under these conditions, the assembly of nuclei from chromatin is dramatically affected: the nuclei do not assemble a lamina and become very small with homogeneously condensed chromatin. They fail to actively import proteins and do not undergo DNA replication. By field emission in-lens scanning electron microscopy, we show that these nuclei have an intact nuclear envelope containing pore complexes, but the envelope is highly convoluted. However, RanBP1 does not directly inhibit nuclear protein import in assembled nuclei. These results suggest that RCC1 and/or Ran have a function early in nuclear assembly that is disrupted by RanBP1.
Affiliation:
Zeneca Laboratory of Molecular and Cellular Biology, School of Biological Sciences, University of Manchester, Manchester M13 9PT, UK.
Citation:
Xenopus Ran-binding protein 1: molecular interactions and effects on nuclear assembly in Xenopus egg extracts. 1997, 110 ( Pt 24):3019-30 J. Cell. Sci.
Journal:
Journal of Cell Science
Issue Date:
Dec-1997
URI:
http://hdl.handle.net/10541/95485
PubMed ID:
9365272
Type:
Article
Language:
en
ISSN:
0021-9533
Appears in Collections:
All Paterson Institute for Cancer Research

Full metadata record

DC FieldValue Language
dc.contributor.authorNicolás, F Jen
dc.contributor.authorZhang, Cen
dc.contributor.authorHughes, Men
dc.contributor.authorGoldberg, Martin Wen
dc.contributor.authorWatton, S Jen
dc.contributor.authorClarke, P Ren
dc.date.accessioned2010-04-01T13:58:40Z-
dc.date.available2010-04-01T13:58:40Z-
dc.date.issued1997-12-
dc.identifier.citationXenopus Ran-binding protein 1: molecular interactions and effects on nuclear assembly in Xenopus egg extracts. 1997, 110 ( Pt 24):3019-30 J. Cell. Sci.en
dc.identifier.issn0021-9533-
dc.identifier.pmid9365272-
dc.identifier.urihttp://hdl.handle.net/10541/95485-
dc.description.abstractRan is a nuclear GTPase implicated in nucleocytoplasmic transport, the maintenance of nuclear structure, mRNA processing, and cell cycle regulation. By two-hybrid interaction in yeast, we have identified a Xenopus homologue of Ran-binding protein 1 (RanBP1). Xenopus RanBP1 interacts specifically with the GTP-bound form of Ran and forms complexes in Xenopus egg extracts with Ran, importin-beta/karyopherin-beta and importin-alpha/karyopherin-alpha, but not p10, p120/RanBP7, RanBP2 or other nucleoporins. These complexes may play roles in the recycling of Ran and importins/karyopherins during nucleocytoplasmic transport. Increased concentrations of RanBP1 stabilise an interaction between Ran and RCC1 in egg extracts, inhibiting the exchange activity of RCC1 towards Ran. Under these conditions, the assembly of nuclei from chromatin is dramatically affected: the nuclei do not assemble a lamina and become very small with homogeneously condensed chromatin. They fail to actively import proteins and do not undergo DNA replication. By field emission in-lens scanning electron microscopy, we show that these nuclei have an intact nuclear envelope containing pore complexes, but the envelope is highly convoluted. However, RanBP1 does not directly inhibit nuclear protein import in assembled nuclei. These results suggest that RCC1 and/or Ran have a function early in nuclear assembly that is disrupted by RanBP1.en
dc.language.isoenen
dc.subject.meshAmino Acid Sequence-
dc.subject.meshAnimals-
dc.subject.meshBase Sequence-
dc.subject.meshBiological Transport-
dc.subject.meshCell Cycle Proteins-
dc.subject.meshCell Nucleus-
dc.subject.meshDNA, Complementary-
dc.subject.meshDNA-Binding Proteins-
dc.subject.meshGTP-Binding Proteins-
dc.subject.meshGuanine Nucleotide Exchange Factors-
dc.subject.meshMicroscopy, Electron, Scanning-
dc.subject.meshMolecular Sequence Data-
dc.subject.meshMutagenesis-
dc.subject.meshNuclear Proteins-
dc.subject.meshOvum-
dc.subject.meshProtein Binding-
dc.subject.meshSaccharomyces cerevisiae-
dc.subject.meshSequence Homology, Amino Acid-
dc.subject.meshXenopus-
dc.subject.meshXenopus Proteins-
dc.subject.meshran GTP-Binding Protein-
dc.titleXenopus Ran-binding protein 1: molecular interactions and effects on nuclear assembly in Xenopus egg extracts.en
dc.typeArticleen
dc.contributor.departmentZeneca Laboratory of Molecular and Cellular Biology, School of Biological Sciences, University of Manchester, Manchester M13 9PT, UK.en
dc.identifier.journalJournal of Cell Scienceen
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