Fibrillarin Ribonuclease Activity is Dependent on the GAR Domain and Modulated by Phospholipids.
Fiche publication
Date publication
mai 2020
Journal
Cells
Auteurs
Membres identifiés du Cancéropôle Est :
Dr VITALE Nicolas
Tous les auteurs :
Guillen-Chable F, Corona UR, Pereira-Santana A, Bayona A, Rodríguez-Zapata LC, Aquino C, Šebestová L, Vitale N, Hozak P, Castano E
Lien Pubmed
Résumé
Fibrillarin is a highly conserved nucleolar methyltransferase responsible for ribosomal RNA methylation across evolution from Archaea to humans. It has been reported that fibrillarin is involved in the methylation of histone H2A in nucleoli and other processes, including viral progression, cellular stress, nuclear shape, and cell cycle progression. We show that fibrillarin has an additional activity as a ribonuclease. The activity is affected by phosphoinositides and phosphatidic acid and insensitive to ribonuclease inhibitors. Furthermore, the presence of phosphatidic acid releases the fibrillarin-U3 snoRNA complex. We show that the ribonuclease activity localizes to the GAR (glycine/arginine-rich) domain conserved in a small group of RNA interacting proteins. The introduction of the GAR domain occurred in evolution in the transition from archaea to eukaryotic cells. The interaction of this domain with phospholipids may allow a phase separation of this protein in nucleoli.
Mots clés
fibrillarin, nucleolus, phosphoinositides, rRNA, ribonucleolar particle, viral progression
Référence
Cells. 2020 May 6;9(5):