FIGURE 3.
Large and small heat shock proteins are direct transcriptional targets of dFOXO in Drosophila. A, schematic of Hsp promoters. The putative FREs are denoted by asterisks, and the HSEs are mapped. The arrow denotes the transcription start site. B, dual luciferase reporter assays where dFOXOCA was co-transfected into Drosophila S2 cells along with Hsp-firefly luciferase reporters. Data are plotted as firefly luciferase over renilla luciferase transfection control, normalized to vector-only control (error bars represent S.E.). C, primer extension analysis of in vitro transcription reactions containing recombinant dFOXO and Drosophila embryo nuclear extracts is shown. The promoter driving the transcription of the same reporter is indicated at the top of each reaction. The 4xFRE reporter serves as a positive control, and the histone H.4 promoter serves as a negative control. RNA produced by the reactions was measured by primer extension. Raw phosphorimaging units were used in the quantitation of -fold induction. All reactions were in the linear range of the phosphorimager.