title: The Drosophila Nol12 homologue viriato is a dMyc target that regulates nucleolar architecture and is required for dMyc-stimulated cell growth.
abstract: The nucleolus is a subnuclear factory, the activity of which is required beyond ribosome biogenesis for the regulation of cell growth, death and proliferation. In both Drosophila and mammalian cells, the activity of the nucleolus is regulated by the proto-oncogene Myc. Myc induces the transcription of genes required for ribosome biogenesis and the synthesis of rRNA by RNA polymerase I, a nucleolar event that is rate limiting for cell growth. Here, we show that the fruit fly Nol12 homologue Viriato is a key determinant of nucleolar architecture that is required for tissue growth and cell survival during Drosophila development. We further show that viriato expression is controlled by Drosophila Myc (dMyc), and that the ability of dMyc to stimulate nucleolar and cellular growth depends on viriato expression. Therefore, viriato acts downstream of dMyc to ensure a coordinated nucleolar response to dMyc-induced growth and, thereby, normal organ development.
authors.affiliation: Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto 4150-180, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Marinho
authors.forename: Fernando
authors.initials: F
authors.lastname: Casares
authors.forename: Paulo S
authors.initials: PS
authors.lastname: Pereira
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D002466:Cell Nucleolus / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D049109:Cell Proliferation; D002470:Cell Survival; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism; D017931:DNA Primers / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000166:cytology / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D017344:Genes, Insect; D009687:Nuclear Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D002868:Chromosomal Proteins, Non-Histone; D017931:DNA Primers; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; C102284:Myc protein, Drosophila; D009687:Nuclear Proteins; D014157:Transcription Factors; C047458:fibrillarin