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.

• Klíčová slova
• fibrillarin, nucleolus, phosphoinositides, rRNA, ribonucleolar particle, viral progression,
• MeSH
• chromozomální proteiny, nehistonové chemie   genetika   metabolismus   MeSH
• fosfolipidy metabolismus   MeSH
• HeLa buňky MeSH
• lidé MeSH
• malá jadérková RNA metabolismus   MeSH
• mutace genetika   MeSH
• proteinové domény MeSH
• rekombinantní proteiny metabolismus   MeSH
• ribonukleasy chemie   genetika   metabolismus   MeSH
• ribonukleoproteiny metabolismus   MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• chromozomální proteiny, nehistonové MeSH
• fibrillarin MeSH Prohlížeč
• fosfolipidy MeSH
• malá jadérková RNA MeSH
• rekombinantní proteiny MeSH
• ribonukleasy MeSH
• ribonukleoproteiny MeSH
• RNA, U3 small nucleolar MeSH Prohlížeč