Project description:We demonstrate that the cell cycle regulators, E2f /Dp and Rb, control the transcription of ribosomal proteins (RP) in Drosophila embryos. Mutation of E2f1 or Dp and over expression of Rbf1 increase and reduce RP transcription, respectively. Although E2f/Dp/Rb might exert this effect through a repressor complex, the regulatory regions of RP genes do not show an enrichment of canonical E2f binding sites. In addition, E2f1, Dp and Rbf1 also regulate the expression of RACK1, a ribosomal component and a negative regulator of cell cycle progression. These findings strengthen the coupling of cell cycle regulation to protein biosynthesis. Keywords: genotype response