Figure 4.

 Non-functional PS increases active GSK3β and motor binding to membranes. (A) Subcellular fractionation of adult fly brain membranes on sucrose step gradients from flies expressing PS+14 show that the levels of active GSK3β, KHC and DIC bound to membranes are comparable to WT. (B) Quantification analysis indicated that there were no significant changes in the levels of active GSK3β, KHC and DIC in the 35/8 fraction compared with the WT (using Student’s t-test). Y axis depicts the intensity in AU. N = 3 independent experiments. Data are presented as mean ± SEM. (C) Subcellular fractionation of adult brain membranes from flies expressing non-functional PS, PSD447A, show that the levels of active GSK3β, KHC and DIC bound to membrane was increased compared with WT. (D) For quantification, the ratio of the intensity of KHC/DIC/active GSK3β for the PNS or the 35/8 fraction was determined against the intensity of Rab5 and normalized to WT from three independent experiments. Statistical analysis using Student’s t-test (**), Tukey’s HSD test (&&) and Bonferroni’s test (##) indicated that the changes were significant. For active GSK3β, **P < 0.005 (P = 0.00248) using Student’s t-test, Tukey’s HSD test (indicated by &&) and Bonferroni’s test (indicated by ##), for KHC *P < 0.05 (P = 0.0189) using t-test, Tukey’s HSD test (indicated by &) and Bonferroni’s test (indicated by #) and for DIC **P < 0.05 (P = 0.00069) using Student’s t-test, Tukey’s HSD test (indicated by &&) and Bonferroni’s test (indicated by ##). Y axis depicts intensity in AU. N = 3 independent experiments. Data are presented as mean ± SEM.