Journal of Cell Science, Vol 110, Issue 24 3019-3030, Copyright © 1997 by Company of Biologists

JOURNAL ARTICLES

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

F Nicolas, C Zhang, M Hughes, M Goldberg, S Watton and P Clarke
Zeneca Laboratory of Molecular and Cellular Biology, School of Biological Sciences, University of Manchester, Manchester M13 9PT, UK.

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.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				R. V. Silverman-Gavrila and A. Wilde Ran Is Required before Metaphase for Spindle Assembly and Chromosome Alignment and after Metaphase for Chromosome Segregation and Spindle Midbody Organization Mol. Biol. Cell, April 1, 2006; 17(4): 2069 - 2080. [Abstract] [Full Text] [PDF]

				J. R. A. Hutchins, D. Dikovskaya, and P. R. Clarke Regulation of Cdc2/Cyclin B Activation in Xenopus Egg Extracts via Inhibitory Phosphorylation of Cdc25C Phosphatase by Ca2+/Calmodium-dependent Kinase II Mol. Biol. Cell, October 1, 2003; 14(10): 4003 - 4014. [Abstract] [Full Text] [PDF]

				A. De Luca, R. Mangiacasale, A. Severino, L. Malquori, A. Baldi, A. Palena, A. M. Mileo, P. Lavia, and M. G. Paggi E1A Deregulates the Centrosome Cycle in a Ran GTPase-dependent Manner Cancer Res., March 15, 2003; 63(6): 1430 - 1437. [Abstract] [Full Text] [PDF]

				F. J. Nicolas, W. J. Moore, C. Zhang, and P. R. Clarke XMog1, a nuclear Ran-binding protein in Xenopus, is a functional homologue of Schizosaccharomyces pombe Mog1p that co-operates with RanBP1 to control generation of Ran-GTP J. Cell Sci., March 10, 2002; 114(16): 3013 - 3023. [Abstract] [Full Text] [PDF]

				J. D. Lane, M. A.S. Vergnolle, P. G. Woodman, and V. J. Allan Apoptotic Cleavage of Cytoplasmic Dynein Intermediate Chain and P150GluedStops Dynein-Dependent Membrane Motility J. Cell Biol., June 25, 2001; 153(7): 1415 - 1426. [Abstract] [Full Text] [PDF]

				G. Guarguaglini, L. Renzi, F. D’Ottavio, B. Di Fiore, M. Casenghi, E. Cundari, and P. Lavia Regulated Ran-binding Protein 1 Activity Is Required for Organization and Function of the Mitotic Spindle in Mammalian Cells in Vivo Cell Growth Differ., August 1, 2000; 11(8): 455 - 465. [Abstract] [Full Text]

				C. Zhang and P. R. Clarke Chromatin-Independent Nuclear Envelope Assembly Induced by Ran GTPase in Xenopus Egg Extracts Science, May 26, 2000; 288(5470): 1429 - 1432. [Abstract] [Full Text]

				M. B. Fasken, R. Saunders, M. Rosenberg, and D. W. Brighty A Leptomycin B-sensitive Homologue of Human CRM1 Promotes Nuclear Export of Nuclear Export Sequence-containing Proteins in Drosophila Cells J. Biol. Chem., January 21, 2000; 275(3): 1878 - 1886. [Abstract] [Full Text] [PDF]

				I. Novoa, M. G. Rush, and P. D'Eustachio Isolated Mammalian and Schizosaccharomyces pombe Ran-binding Domains Rescue S. pombe sbp1 (RanBP1) Genomic Mutants Mol. Biol. Cell, July 1, 1999; 10(7): 2175 - 2190. [Abstract] [Full Text]

				R. H. Kehlenbach, A. Dickmanns, A. Kehlenbach, T. Guan, and L. Gerace A Role for RanBP1 in the Release of CRM1 from the Nuclear Pore Complex in a Terminal Step of Nuclear Export J. Cell Biol., May 17, 1999; 145(4): 645 - 657. [Abstract] [Full Text] [PDF]

				C Pittoggi, L Renzi, G Zaccagnini, D Cimini, F Degrassi, R Giordano, A. Magnano, R Lorenzini, P Lavia, and C Spadafora A fraction of mouse sperm chromatin is organized in nucleosomal hypersensitive domains enriched in retroposon DNA J. Cell Sci., January 10, 1999; 112(20): 3537 - 3548. [Abstract] [PDF]

				M Hughes, C Zhang, J. Avis, C. Hutchison, and P. Clarke The role of the ran GTPase in nuclear assembly and DNA replication: characterisation of the effects of Ran mutants J. Cell Sci., January 10, 1998; 111(20): 3017 - 3026. [Abstract] [PDF]

				S. G. Addinall, P. S. Mayr, S. Doyle, J. K. Sheehan, P. G. Woodman, and V. J. Allan Phosphorylation by cdc2-CyclinB1 Kinase Releases Cytoplasmic Dynein from Membranes J. Biol. Chem., May 4, 2001; 276(19): 15939 - 15944. [Abstract] [Full Text] [PDF]