Fig. 4.

Rotenone specifically activates ERK and AKT. (A) N548 mutant cells were treated with DMSO or rotenone, and AKT and ERK activations were determined by Western blotting by using phospho-specific antibodies against serine 473 AKT, threonine 308 AKT, or threonine 202/tyrosine 204 ERK. Levels of total AKT, ERK, and tubulin served as controls. (B) The specificity of ERK activation was confirmed by testing for activation of distinct kinase pathways. Phospho-ERK served as a positive control. (C) Cells were treated with increasing concentrations of rotenone, and ERK/AKT activation was determined after 8 h. (D) Three independent clonal cell lines expressing the N548 amino acid N-terminal fragment of mutant htt were treated with 10 μM rotenone (Rot), and ERK/AKT activation was determined. (E) ERK/AKT activation was assayed in cells that were treated with DMSO, the Pan-caspase inhibitor Boc-D-fmk (50 μM) (Boc), or rotenone (Rot).