QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Sleeman, J. E. Articles by Lamond, A. I. Search for Related Content PubMed PubMed Citation Articles by Sleeman, J. E. Articles by Lamond, A. I. Social Bookmarking                         What's this?

snRNP protein expression enhances the formation of Cajal bodies containing p80-coilin and SMN

School of Life Sciences, University of Dundee, MSI/WTB Complex, Dow Street, Dundee, DD1 5EH, UK

Author for correspondence (e-mail: a.i.lamond{at}dundee.ac.uk)

Accepted September 6, 2001

Splicing snRNPs (small nuclear ribonucleoproteins) are essential sub-units of the spliceosome. Here we report the establishment of stable cell lines expressing fluorescently tagged SmB, a core snRNP protein. Analysis of these stable cell lines has allowed us to characterize the nuclear pathway that leads to snRNP accumulation in nuclear speckles and has identified a limiting nucleolar step in the pathway that can be saturated by overexpression of Sm proteins. After nuclear import, newly assembled snRNPs accumulate first in a subset of Cajal bodies that contain both p80-coilin and the survival of motor neurons protein (SMN) and not in bodies that contain p80-coilin but lack SMN. Treatment of cells with leptomycin B (LMB) inhibits both the accumulation of snRNPs in nuclear bodies and their subsequent accumulation in speckles. The formation of Cajal bodies is enhanced by Sm protein expression and the assembly of new snRNPs. Formation of heterokaryons between HeLa cell lines expressing Sm proteins and primary cells that usually lack Cajal bodies results in the detection of Cajal bodies in primary cell nuclei. Transient over-expression of exogenous SmB alone is sufficient to induce correspondingly transient Cajal body formation in primary cells. These data indicate that the level of snRNP protein expression and snRNP assembly, rather than the expression levels of p80-coilin or SMN, may be a key trigger for Cajal body formation.

Key words: snRNPs, Cajal bodies, SMN, p80-coilin, leptomycin B

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

This article has been cited by other articles:

				D. Stanek, S. D. Rader, M. Klingauf, and K. M. Neugebauer Targeting of U4/U6 small nuclear RNP assembly factor SART3/p110 to Cajal bodies J. Cell Biol., February 6, 2003; (2003) 200210087. [Abstract] [Full Text] [PDF]

				F.-M. Boisvert, J. Cote, M.-C. Boulanger, P. Cleroux, F. Bachand, C. Autexier, and S. Richard Symmetrical dimethylarginine methylation is required for the localization of SMN in Cajal bodies and pre-mRNA splicing J. Cell Biol., December 10, 2002; (2002) 200207028. [Abstract] [Full Text] [PDF]

				U. Narayanan, J. K. Ospina, M. R. Frey, M. D. Hebert, and A. G. Matera SMN, the spinal muscular atrophy protein, forms a pre-import snRNP complex with snurportin1 and importin {beta} Hum. Mol. Genet., July 15, 2002; 11(15): 1785 - 1795. [Abstract] [Full Text] [PDF]