Fibrillarin Ribonuclease Activity is Dependent on the GAR Domain and Modulated by Phospholipids
Francisco Guillen-Chable,
Ulises Rodríguez Corona,
Alejandro Pereira-Santana,
Andrea Bayona,
Luis Carlos Rodríguez-Zapata,
Cecilia Aquino,
Lenka Šebestová,
Nicolas Vitale,
Pavel Hozak,
Enrique Castano
Affiliations
Francisco Guillen-Chable
Biochemistry and Molecular Plant Biology Department, Centro de Investigación Científica de Yucatán, A.C. Calle 43 No. 130, Colonia Chuburná de Hidalgo, Mérida C.P. 97200, Yucatán, Mexico
Ulises Rodríguez Corona
Biochemistry and Molecular Plant Biology Department, Centro de Investigación Científica de Yucatán, A.C. Calle 43 No. 130, Colonia Chuburná de Hidalgo, Mérida C.P. 97200, Yucatán, Mexico
Alejandro Pereira-Santana
Industrial Biotechnology Department, Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, A.C., Camino Arenero 1227, el Bajio, Zapopan C.P. 45019, Jalisco, Mexico
Andrea Bayona
Biochemistry and Molecular Plant Biology Department, Centro de Investigación Científica de Yucatán, A.C. Calle 43 No. 130, Colonia Chuburná de Hidalgo, Mérida C.P. 97200, Yucatán, Mexico
Luis Carlos Rodríguez-Zapata
Biotechnology Department, Centro de Investigación Científica de Yucatán, A.C. Calle 43 No. 130, Colonia Chuburná de Hidalgo, Mérida C.P. 97200, Yucatan, Mexico
Cecilia Aquino
Biochemistry and Molecular Plant Biology Department, Centro de Investigación Científica de Yucatán, A.C. Calle 43 No. 130, Colonia Chuburná de Hidalgo, Mérida C.P. 97200, Yucatán, Mexico
Lenka Šebestová
Department of Biology of the Cell Nucleus, Institute of Molecular Genetics of the CAS, v.v.i., Videnska 1083, 142 20 Prague, Czech Republic
Nicolas Vitale
Institute of Celullar and Integrative Neuroscience (INCI), UPR-3212 The French National Centre for Scientific Research & University of Strasbourg, 67000 Strasbourg, France
Pavel Hozak
Department of Biology of the Cell Nucleus, Institute of Molecular Genetics of the CAS, v.v.i., Videnska 1083, 142 20 Prague, Czech Republic
Enrique Castano
Biochemistry and Molecular Plant Biology Department, Centro de Investigación Científica de Yucatán, A.C. Calle 43 No. 130, Colonia Chuburná de Hidalgo, Mérida C.P. 97200, Yucatán, Mexico
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.
