Figure 5.

Effect of fisetin and Htt on ERK (A) or JNK (B) phosphorylation in Drosophila. Wild-type (-Htt) or Httex1p Q93-challenged (+Htt) flies were fed a normal diet (untreated) or a diet supplemented with fisetin (300 μm) or resveratrol (300 μm) for 19.5 h before harvesting. Three separate collections of heads were isolated, extracts prepared and equal amounts of protein were analyzed by SDS–PAGE and immunoblotting with antibodies to phospho-ERK and total ERK (A) or phospho-JNK and total JNK (B). A representative blot is shown. Since fisetin induces ERK phosphorylation in both the absence and presence of Httex1p Q93 but the effect is stronger in the presence of Httex1p Q93, the exposure of the Httex1p Q93 phospho-ERK blot was for half the time as the exposure of the wild-type phospho-ERK blot. The average phosphoprotein signal from the samples as quantified by densitometry, normalized to total ERK or total JNK and then normalized to the level in the Httex1p Q93 flies fed control diet, was plotted ±SD. *P < 0.05; **P < 0.01; ***P < 0.001 (unpaired t-test).