Sorting Nexin 17 Interacts Directly with Kinesin Superfamily KIF1Bbeta Protein

KIF1Bbeta is a member of the Kinesin superfamily proteins (KIFs), which are microtubule-dependent molecular motors that are involved in various intracellular organellar transport processes. KIF1Bbeta is not restricted to neuronal systems, however, is widely expressed in other tissues, even though the function of KIF1Bbeta is still unclear. To elucidate the KIF1Bbeta-binding proteins in non-neuronal cells, we used the yeast two-hybrid system, and found a specific interaction of KIF1Bbeta and the sorting nexin (SNX) 17. The C-terminal region of SNX17 is required for the binding with KIF1Bbeta. SNX17 protein bound to the specific region of KIF1Bbeta (813-916. aa), but not to other kinesin family members. In addition, this specific interaction was also observed in the Glutathione S-transferase pull-down assay. An antibody to SNX17 specifically co-immunoprecipitated KIF1Bbeta associated with SNX17 from mouse brain extracts. These results suggest that SNX17 might be involved in the KIF1Bbeta-mediated transport as a KIF1Bbeta adaptor protein.