Reference - Detail
|Author||Martins T, Eusebio N, Correia A, Marinho J, Casares F, Pereira PS.|
|Title||TGFβ/Activin signalling is required for ribosome biogenesis and cell growth in Drosophila salivary glands.|
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.
|MeSH||Activin Receptors, Type II / genetics Activin Receptors, Type II / metabolism* Activins / metabolism Animals Cell Cycle Cell Nucleolus / metabolism Cell Proliferation Drosophila Proteins / genetics Drosophila Proteins / metabolism* Drosophila melanogaster / genetics Drosophila melanogaster / growth & development* Drosophila melanogaster / metabolism Gene Expression Regulation, Developmental Gene Knockdown Techniques Ribosomes / metabolism* Salivary Glands / embryology* Salivary Glands / metabolism Signal Transduction Smad Proteins, Receptor-Regulated Smad2 Protein / genetics Smad2 Protein / metabolism* Transforming Growth Factor beta / metabolism|