Implication of the box C/D snoRNP assembly factor Rsa1p in U3 snoRNP assembly.
Fiche publication
Date publication
mai 2017
Journal
Nucleic acids research
Auteurs
Membres identifiés du Cancéropôle Est :
Dr BRANLANT Christiane, Pr CHARPENTIER Bruno, Dr MANIVAL Xavier
Tous les auteurs :
Rothé B, Manival X, Rolland N, Charron C, Senty-Ségault V, Branlant C, Charpentier B
Lien Pubmed
Résumé
The U3 box C/D snoRNA is one key element of 90S pre-ribosome. It contains a 5΄ domain pairing with pre-rRNA and the U3B/C and U3C΄/D motifs for U3 packaging into a unique small nucleolar ribonucleoprotein particle (snoRNP). The RNA-binding protein Snu13/SNU13 nucleates on U3B/C the assembly of box C/D proteins Nop1p/FBL and Nop56p/NOP56, and the U3-specific protein Rrp9p/U3-55K. Snu13p/SNU13 has a much lower affinity for U3C΄/D but nevertheless forms on this motif an RNP with box C/D proteins Nop1p/FBL and Nop58p/NOP58. In this study, we characterized the influence of the RNP assembly protein Rsa1 in the early steps of U3 snoRNP biogenesis in yeast and we propose a refined model of U3 snoRNP biogenesis. While recombinant Snu13p enhances the binding of Rrp9p to U3B/C, we observed that Rsa1p has no effect on this activity but forms with Snu13p and Rrp9p a U3B/C pre-RNP. In contrast, we found that Rsa1p enhances Snu13p binding on U3C΄/D. RNA footprinting experiments indicate that this positive effect most likely occurs by direct contacts of Rsa1p with the U3 snoRNA 5΄ domain. In light of the recent U3 snoRNP cryo-EM structures, our data suggest that Rsa1p has a dual role by also preventing formation of a pre-mature functional U3 RNP.
Mots clés
Base Sequence, Binding Sites, Gene Expression Regulation, Fungal, Nuclear Proteins, genetics, Nucleic Acid Conformation, Protein Binding, RNA Precursors, genetics, RNA, Small Nucleolar, genetics, Recombinant Proteins, genetics, Ribonucleoproteins, Small Nuclear, genetics, Ribonucleoproteins, Small Nucleolar, genetics, Ribosomal Proteins, genetics, Ribosomes, genetics, Saccharomyces cerevisiae, genetics, Saccharomyces cerevisiae Proteins, genetics
Référence
Nucleic Acids Res.. 2017 May;: