Fig. 9. Schematic illustration of AQP4 sorting motifs and trafficking in epithelial cells. Upper panel: hydropathy analysis of AQP4 sequence predicted six transmembrane domains connected by five loops. The two C-terminal basolateral targeting motifs (GSYMEV and ETEDLIL) are shown. Stars indicate the three serines phosphorylated by CKII. The adaptor complexes (AP2 and AP3) interacting with the tyrosine-based motif are shown. The residues critical for AQP4–µ subunits interactions (Y277 and V280) are shaded. Lower panel: model of AQP4 trafficking in epithelial cells. Trans-Golgi network (TGN), endosomal (Endo) and lysosomal (Lys) compartments are shown.