Fig. 5. A model of the regulation of Furin TGN localization by Mint3. Binding of the hydrophobic motif to the adaptor protein AP-1 is required for the budding of Furin from the TGN to endosomes, whereas binding of CK2-phosphorylated Furin acidic cluster to the sorting protein PACS1 transports Furin back from endosomes to the TGN (Thomas, 2002). In the TGN, Mint3 mainly binds to the acidic cluster of Furin and retains most of the Furin molecule in this compartment. However, binding of the YKGL and LI motifs of Furin with Mint3 might compete its binding with AP-1 and hence reduce the budding of Furin from the TGN. CA, catalytic domain; CP, cytoplasmic domain; P, P domain; TM, transmembrane domain.