title: TGFβ/Activin signalling is required for ribosome biogenesis and cell growth in Drosophila salivary glands.
abstract: Signalling by TGFβ superfamily factors plays an important role in tissue growth and cell proliferation. In Drosophila, the activity of the TGFβ/Activin signalling branch has been linked to the regulation of cell growth and proliferation, but the cellular and molecular basis for these functions are not fully understood. In this study, we show that both the RII receptor Punt (Put) and the R-Smad Smad2 are strongly required for cell and tissue growth. Knocking down the expression of Put or Smad2 in salivary glands causes alterations in nucleolar structure and functions. Cells with decreased TGFβ/Activin signalling accumulate intermediate pre-rRNA transcripts containing internal transcribed spacer 1 regions accompanied by the nucleolar retention of ribosomal proteins. Thus, our results show that TGFβ/Activin signalling is required for ribosomal biogenesis, a key aspect of cellular growth control. Importantly, overexpression of Put enhanced cell growth induced by Drosophila Myc, a well-characterized inducer of nucleolar hypertrophy and ribosome biogenesis.
authors.affiliation: I3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto 4150-180, Portugal tjn29@cam.ac.uk.|Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto 4150-180, Portugal.|Cell Cycle Development Group, Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK.
authors.forename: Torcato
authors.identifier: 0000-0002-9359-7111
authors.initials: T
authors.lastname: Martins
authors.affiliation: I3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto 4150-180, Portugal.|Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto 4150-180, Portugal.
authors.forename: Nadia
authors.initials: N
authors.lastname: Eusebio
authors.affiliation: I3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto 4150-180, Portugal.|Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto 4150-180, Portugal.
authors.forename: Andreia
authors.initials: A
authors.lastname: Correia
authors.affiliation: I3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto 4150-180, Portugal.|Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto 4150-180, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Marinho
authors.affiliation: Centro Andaluz de Biología del Desarrollo (CABD), CSIC-JA-Universidad Pablo de Olavide. Ctra. de Utrera km1, Seville 41013, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Casares
authors.affiliation: I3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto 4150-180, Portugal paulop@ibmc.up.pt.|Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto 4150-180, Portugal.
authors.forename: Paulo S
authors.identifier: 0000-0001-9812-8034
authors.initials: PS
authors.lastname: Pereira
mesh_terms: D030301:Activin Receptors, Type II / Q000235:genetics / Q000378:metabolism*; D028341:Activins / Q000378:metabolism; D000818:Animals; D002453:Cell Cycle; D002466:Cell Nucleolus / Q000378:metabolism; D049109:Cell Proliferation; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D055785:Gene Knockdown Techniques; D012270:Ribosomes / Q000378:metabolism*; D012469:Salivary Glands / Q000196:embryology* / Q000378:metabolism; D015398:Signal Transduction; D051896:Smad Proteins, Receptor-Regulated; D051899:Smad2 Protein / Q000235:genetics / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; D051896:Smad Proteins, Receptor-Regulated; D051899:Smad2 Protein; C115826:Smox protein, Drosophila; D016212:Transforming Growth Factor beta; D028341:Activins; D030301:Activin Receptors, Type II; C425583:put protein, Drosophila
keywords: Drosophila; Punt (Put); TGFβ/Activin; cell growth; nucleolus; ribosome