Figure 4
From: Increased 90-kDa ribosomal S6 kinase (Rsk) activity is protective against mutant huntingtin toxicity
Increased Rsk activity in STHdhQ111/Q111 cells is mainly regulated by PDK1. (A) Lysates from STHdhQ7/Q7 and STHdhQ111/Q111 cells were subjected to immunoprecipitation with anti-Rsk1 and anti-Rsk2 antibodies and the resulting immunocomplexes were used to determine Rsk activity as indicated in material and methods. Kinase activity was expressed as percentage of Rsk activity in STHdhQ7/Q7 cells and data are the mean ± SEM of three independent experiments. Results were analyzed by Student's t-test. **p < 0.01 as compared with STHdhQ7/Q7 cells. (B) STHdhQ7/Q7 and STHdhQ111/Q111 cells were transfected with the following constructs: HA-RskT574A (to study the role of ERK1/2 on Rsk activity) and HA-RskS380E (to analyze the role of PDK1 on Rsk activity). Twenty-four hours after transfection, both STHdhQ7/Q7 and STHdhQ111/Q111 cells were subjected to Rsk activity assay. Results are the mean ± SEM of three independent experiments and are expressed as percentage of control cells (cells transfected with HA alone). Data were analyzed by two-way ANOVA followed by Bonferroni's post hoc test. **p < 0.01 and ***p < 0.001 as compared with STHdhQ7/Q7 control cells, +p < 0.05 and+++p < 0.001 as compared with STHdhQ111/Q111 control cells and#p < 0.05 as compared with STHdhQ111/Q111 cells transfected with HA-Rsk T574A.