Figure 1.

dFOXO activates InR mRNA transcription in Drosophila S2 cells upon starvation. (A) The Western blot shows that dFOXO gets dephosphorylated upon starvation. S2 cells were incubated for 6 h in HBSS (H) or in complete medium (M), and dFOXO was detected with specific antibodies. (B) qPCR shows that S2 cells incubated in HBSS specifically up-regulate dInR mRNA levels. (C) dFOXO binds to the dInR promoter in S2 cells upon starvation. ChIP was performed in S2 cells incubated in HBSS (H) or complete medium (M) and measured by qPCR. (D) dFOXO activity up-regulates InR protein levels in S2 cells. Control wild-type S2 cells (lanes 1,3) or S2 dFOXOA3 cells (lanes 2,4) were grown in the absence (lanes 1,2) or presence (lanes 3,4) of 600 μM CuSO₄ for 24 h to induce dFOXOA3 expression. dInR, dFOXO, and tubulin levels were analyzed by Western blot analysis with specific antibodies.