Fibrillarin and Nop56 interact before being co-assembled in box C/D snoRNPs
- Institut Jacques Monod, UMR 7592 CNRS/Universites Paris 6 et 7, 2 Place Jussieu, 75251 Paris Cedex 05 (France)
Small nucleolar RNAs play crucial roles in ribosome biogenesis. They guide folding, site-specific nucleotide modifications and participate in cleavage of precursor ribosomal RNAs. To better understand how the biogenesis of the box C/D small nucleolar RNPs (snoRNPs) occur in a cellular context, we used a new approach based on the possibility of relocalizing a given nuclear complex by adding an affinity tag for B23 to one component of this complex. We selectively delocalized each core box C/D protein, namely 15.5kD, Nop56, Nop58 and fibrillarin, and analyzed the effect of such changes on other components of the box C/D snoRNPs. We show that modifying the localization and the mobility of core box C/D proteins impairs their association with box C/D snoRNPs. In addition, we demonstrate that fibrillarin and Nop56 directly interact in vivo. This interaction, indispensable for the association of both proteins with the box C/D snoRNPs, does not involve the glycine- and arginine-rich domain or the RNA-binding domain but the alpha-helix domain of fibrillarin. In addition, no RNA seems required to maintain fibrillarin-Nop56 interaction.
- OSTI ID:
- 21176187
- Journal Information:
- Experimental Cell Research, Journal Name: Experimental Cell Research Journal Issue: 6 Vol. 315; ISSN 0014-4827; ISSN ECREAL
- Country of Publication:
- United States
- Language:
- English
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