Fig. 5.

a Detection of KIF1Bβ in purified mouse synaptoneurosomes. KIF1Bβ is detected in total lysates from the cortex (T; 5 μg total protein) and is enriched in a sample of synaptoneurosomes purified from the cortex (S; 5 μg). The level of detection of synaptophysin, a presynaptic marker, and PSD-95, a postsynaptic marker, are evidence of the enrichment of the synaptoneurosomal preparation, which was essentially devoid of non-neuronal proteins, such as myelin basic protein (MBP) and glial fibrillary acidic protein (GFAP). b Detection of KIF1Bβ in further fractionated synaptoneurosomes. The synaptoneurosomal preparation from mouse cortex was further fractionated into its soluble, pre- and postsynaptic components and probed for KIF1Bβ in parallel with compartment-specific protein markers PSD-95 and synaptophysin. KIF1Bβ was detected in both the pre- and postsynaptic, but not in the soluble fraction. An amount of 15 μg of protein was loaded from each fraction