Figure 5.

Characterization of synaptosomes and the demonstration of RanBP9 protein in the mouse and human brain synaptosomes. (a) The purity of the synaptosome preparations was verified by immunoblotting the cytosolic (C), homogenate (H) and synaptosomal (S) fractions for two cytosolic proteins, TGFβ and stathmin, two nuclear proteins PCNA and HDAC2 and two synaptic markers, PSD-95 and synaptophysin. Please note enrichment of synaptic proteins and the absence of nuclear protein PCNA and the cytosolic protein TGFβ in the synaptosome fractions attesting to the purity of synaptosomes. (b) Shows amount of RanBP9 in the mouse brain synaptosomes relative to cytosolic and homogenate fractions. (c) Human brain synaptosomes contain much more RanBP9 protein relative to the cytosolic and homogenate fractions. One-way ANOVA followed by posthoc Student–Newman–Keuls multiple comparison test revealed significant differences. The data presented in b and c are mean±S.E.M., n=3, in each group. ***P<0.001 versus cytosolic fractions