FIG. 6.

Activation of endogenous Sgg/Gsk-3 in Drosophila somatic tissues decreased proteasome functionality and reduced longevity; these effects were largely rescued by 6BIO. Relative expression of rpn11, rpn6, α7, β2, β5, trxr1, gstd1, pdpk1, sgg/gsk-3, and cncC/nrf-2 genes (A₁), and representative blots showing 20S-α proteasome subunit expression and total protein ubiquitination (A₂) in young fly tissues after inducible RNAi-mediated Pdpk1 knockdown for 6 days. (B) Relative proteasome activities in young fly tissues following Pdpk1 RNAi for 1, 3, 6, and 10 (1D–10D) days. (C) Longevity curves after induced (or not) Pdpk1 RNAi. (D₁, D₂) Relative expression of the rpn11, rpn6, α7, β1, β2, β5, cncC/nrf-2, and trxr1 genes (D₁) and relative (%) proteasome activities (D₂) after Pdpk1 RNAi in flies treated (or not) for 6 days with the shown 6BIO doses. (D₃) Mean climbing activity (%) of Pdpk1 RNAied middle-aged flies cultured (or not) in the presence of 400 μM 6BIO. (D₄) Longevity curves after inducible Pdpk1 RNAi in flies treated (or not) with 400 μM 6BIO; statistical analyses of life span experiments (C, D₄) are reported in Supplementary Table S1. GAPDH (A₂) and rp49 gene expression (A₁, D₁) were used as reference. Control samples in (B, D₂, D₃) were set to 100%. Bars indicate ± SD (n ≥ 2); *p < 0.05; **p < 0.01. See Western blot in Supplementary Figure S14. Pdpk1, 3-phosphoinositide-dependent protein kinase-1.