Fig. 5. The PDZ motif and tyrosine-based motif are not important for PMCA2xb targeting in HCs. (A-D) Surface scans (plane 2 in E) and orthogonal views (plane 1 in E) of stacks of confocal images of HCs transfected with mutated PMCA2xb in separate and merged channels. Small panels on the right show cross-sectional high-resolution scan (plane 3 in E) of the basolateral PM taken around the midpoint of the transfected HC in merged channel. Aa sequences of the b-tail; mutations are in red. The Tyr-based Tyr-Glu-Gly-Leu motif at position 1121-1124 (YEGL), is not a basolateral targeting motif for PMCA2 (B,C). The C-terminal PDZ-domain-interacting Glu-Thr-Ser-Leu motif at position 1209-1212 (ETSL), does not seem to influence the basolateral targeting of the pump (A,C). However, the deletion of residues 1153-1166 in the double mutated Tyr1121Ala isoform and the deletion of the ETSL motif alters the vectorial basolateral targeting of the protein and causes it to localize to the apical pole as well (D). (F) Summary of our data. b, b-tail; AP, apical PM localization; BL, basolateral PM localization. Bars, 5 µm.