Figure 5. Interacting domains.

Domain organization of rabip4’ and β3-adaptin (A). The binding domain of AP-3 on rabip4’ was determined with overlapping truncations of rabip4’ in a GST pull-down assay using detergent extracts from rescued mocha fibroblasts. Bound AP-3 was analyzed by Western blotting with antibodies against δ-adaptin. The AP-3 binding site was contained within the FYVE domain of rabip4’ (B) and is specific for rabip4’ since the FYVE domains of Hrs and EEA1 did not bind AP-3 (C). A pull-down assay with GST-rabip4’ and ³⁵S-labeled Myc-tagged β3A truncations showed that the rabip4’ binding site is in the hinge region of β3A (D).