QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

Vol. 17, Issue 7, 3221-3231, July 2006

This Article Full Text Full Text (PDF) All Versions of this Article: E06-03-0247v1 17/7/3221    most recent Alert me when this article is cited Alert me if a correction is posted Services 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 Lemm, I. Articles by Lührmann, R. Search for Related Content PubMed PubMed Citation Articles by Lemm, I. Articles by Lührmann, R.

Ongoing U snRNP Biogenesis Is Required for the Integrity of Cajal Bodies

Ira Lemm^*, Cyrille Girard, Andreas N. Kuhn^*, Nicholas J. Watkins, Marc Schneider^*, Rémy Bordonné, and Reinhard Lührmann^*

*Department of Cellular Biochemistry, Max-Planck-Institute for Biophysical Chemistry, D-37077 Göttingen, Germany; Institut de Génétique Moléculaire, UMR5535 CNRS, Montpellier, France; and Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, NE2 4HH, United Kingdom

Submitted March 29, 2006; Revised April 13, 2006; Accepted April 27, 2006
Monitoring Editor: Susan Wente

Cajal bodies (CBs) have been implicated in the nuclear phase of the biogenesis of spliceosomal U small nuclear ribonucleoproteins (U snRNPs). Here, we have investigated the distribution of the CB marker protein coilin, U snRNPs, and proteins present in C/D box small nucleolar (sno)RNPs in cells depleted of hTGS1, SMN, or PHAX. Knockdown of any of these three proteins by RNAi interferes with U snRNP maturation before the reentry of U snRNA Sm cores into the nucleus. Strikingly, CBs are lost in the absence of hTGS1, SMN, or PHAX and coilin is dispersed in the nucleoplasm into numerous small foci. This indicates that the integrity of canonical CBs is dependent on ongoing U snRNP biogenesis. Spliceosomal U snRNPs show no detectable concentration in nuclear foci and do not colocalize with coilin in cells lacking hTGS1, SMN, or PHAX. In contrast, C/D box snoRNP components concentrate into nuclear foci that partially colocalize with coilin after inhibition of U snRNP maturation. We demonstrate by siRNA-mediated depletion that coilin is required for the condensation of U snRNPs, but not C/D box snoRNP components, into nucleoplasmic foci, and also for merging these factors into canonical CBs. Altogether, our data suggest that CBs have a modular structure with distinct domains for spliceosomal U snRNPs and snoRNPs.

Address correspondence to: Reinhard Lührmann ( reinhard.luehrmann{at}mpi-bpc.mpg.de)

This article has been cited by other articles:

				D. Stanek, J. Pridalova-Hnilicova, I. Novotny, M. Huranova, M. Blazikova, X. Wen, A. K. Sapra, and K. M. Neugebauer Spliceosomal Small Nuclear Ribonucleoprotein Particles Repeatedly Cycle through Cajal Bodies Mol. Biol. Cell, June 1, 2008; 19(6): 2534 - 2543. [Abstract] [Full Text] [PDF]

				C. Girard, C. Verheggen, H. Neel, A. Cammas, S. Vagner, J. Soret, E. Bertrand, and R. Bordonne Characterization of a Short Isoform of Human Tgs1 Hypermethylase Associating with Small Nucleolar Ribonucleoprotein Core Proteins and Produced by Limited Proteolytic Processing J. Biol. Chem., January 25, 2008; 283(4): 2060 - 2069. [Abstract] [Full Text] [PDF]

				S. Petri, M. Grimmler, S. Over, U. Fischer, and O. J. Gruss Dephosphorylation of survival motor neurons (SMN) by PPM1G/PP2C{gamma} governs Cajal body localization and stability of the SMN complex J. Cell Biol., November 5, 2007; 179(3): 451 - 465. [Abstract] [Full Text] [PDF]

				N. J. Watkins, I. Lemm, and R. Luhrmann Involvement of Nuclear Import and Export Factors in U8 Box C/D snoRNP Biogenesis Mol. Cell. Biol., October 15, 2007; 27(20): 7018 - 7027. [Abstract] [Full Text] [PDF]

				G. B. Gonsalvez, L. Tian, J. K. Ospina, F.-M. Boisvert, A. I. Lamond, and A. G. Matera Two distinct arginine methyltransferases are required for biogenesis of Sm-class ribonucleoproteins J. Cell Biol., August 27, 2007; 178(5): 733 - 740. [Abstract] [Full Text] [PDF]

				Z. Cui and P. J. DiMario RNAi Knockdown of Nopp140 Induces Minute-like Phenotypes in Drosophila Mol. Biol. Cell, June 1, 2007; 18(6): 2179 - 2191. [Abstract] [Full Text] [PDF]

				S. Hausmann, A. Ramirez, S. Schneider, B. Schwer, and S. Shuman Biochemical and genetic analysis of RNA cap guanine-N2 methyltransferases from Giardia lamblia and Schizosaccharomyces pombe Nucleic Acids Res., March 12, 2007; 35(5): 1411 - 1420. [Abstract] [Full Text] [PDF]