title: Studies on the role of NonA in mRNA biogenesis.
abstract: The NonA protein of Drosophila melanogaster is an abundant nuclear protein that belongs to the DBHS (Drosophila behavior, human splicing) protein family. The DBHS proteins bind both DNA and RNA in vitro and have been involved in different aspects of gene expression, including pre-mRNA splicing, transcription regulation and nuclear retention of mRNA. We have used double-stranded RNA interference in Drosophila S2 cells to silence the expression of NonA and to investigate its role in mRNA biogenesis. We show that knockdown of NonA does not affect transcription nor splicing. We demonstrate that NonA forms a complex with the essential nuclear export factor NXF1 in an RNA-dependent manner. We have constructed stable S2 cell lines that express full-length and truncated NXF1 fused to GFP in order to perform fluorescence recovery after photobleaching experiments. We show that knockdown of NonA reduces the intranuclear mobility of NXF1-GFP associated with poly(A)(+) RNA in vivo, while the mobility of the truncated NXF1-GFP that does not bind RNA is not affected. Our data suggest that NonA facilitates the intranuclear mobility of mRNP particles.
authors.affiliation: Department of Molecular Biology and Functional Genomics, Stockholm University, SE-10691 Stockholm, Sweden.
authors.forename: Natalia
authors.initials: N
authors.lastname: Kozlova
authors.forename: José
authors.initials: J
authors.lastname: Braga
authors.forename: Josefin
authors.initials: J
authors.lastname: Lundgren
authors.forename: José
authors.initials: J
authors.lastname: Rino
authors.forename: Patrick
authors.initials: P
authors.lastname: Young
authors.forename: Maria
authors.initials: M
authors.lastname: Carmo-Fonseca
authors.forename: Neus
authors.initials: N
authors.lastname: Visa
mesh_terms: D021581:Active Transport, Cell Nucleus; D000818:Animals; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D029721:Drosophila Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000166:cytology; D036681:Fluorescence Recovery After Photobleaching; D009154:Mutation / Q000235:genetics; D009687:Nuclear Proteins / Q000172:deficiency / Q000378:metabolism*; D011485:Protein Binding; D012326:RNA Splicing / Q000235:genetics; D034443:RNA Transport / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis*; D016601:RNA-Binding Proteins / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012261:Ribonucleoproteins / Q000378:metabolism; D012269:Ribosomal Proteins / Q000235:genetics; D014158:Transcription, Genetic
chemical_list: D029721:Drosophila Proteins; C070174:NONA protein, Drosophila; D009687:Nuclear Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins; D012261:Ribonucleoproteins; D012269:Ribosomal Proteins; C107533:RpL32 protein, Drosophila; C026452:messenger ribonucleoprotein