Figure 5
From: Increased 90-kDa ribosomal S6 kinase (Rsk) activity is protective against mutant huntingtin toxicity
Striatal cells expressing full-length mhtt show increased levels of Rsk in nuclear and cytosolic compartments. (A) Rsk1, Rsk2, tubulin and NeuN were analyzed by western blot in cytosolic and nuclear fractions of STHdhQ7/Q7 and STHdhQ111/Q111 cells. Four independent experiments were performed in duplicate. Representative immunoblots are shown. We quantified the levels of Rsk1 and Rsk2 in both types of cells and analyzed the ratio between the nuclear and the cytosolic levels for each case. Data were analyzed by two-way ANOVA followed by Bonferroni's post hoc test. *p < 0.05 as compared with STHdhQ7/Q7 cells. (B) Representative photomicrographs showing Rsk1 and Rsk2 immunoreactivity in STHdhQ7/Q7 and STHdhQ111/Q111 cells. The number of cells was quantified according to three different patterns of Rsk1 and Rsk2 localization: homogeneous localization (cytosolic and nuclear), exclusive cytosolic and exclusive nuclear localization. Nuclear localization was determined by co-staining with Hoechst 33258. Results are expressed as percentage of total cell number. Data was analyzed by chi-square (χ2). For Rsk1; χ square df: 102.5, 2 and p < 0.001. For Rsk2: χ square df: 38.11, 2 and p < 0.001.