AnkB-188 increases NCX membrane expression and current. (A) Exons encoding the membrane-binding domains of AnkB-188 and AnkB-212. The NCX-binding site maps to ANK2 exons 15–17. (B) 35S-labelled, in vitro translated NCX fragment binds to both AnkB isoforms. Experiments were repeated three times. Coomassie Blue Stain demonstrates equal expression of both isoforms. (C) Detection of the GFP-tag on isoforms by immunoblot and IF in HeLa-T7 cells stably expressing NCX. Scale bar is 5 μm. (D) NCX voltage–current curves of HeLa-T7 cells transiently expressing GFP, AnkB-188, or AnkB-212 (n = 29 for GFP and AnkB-188, n = 27 for AnkB-212, *P < 0.05). (E) NCX expression is increased in the membrane fraction of HeLa-T7 cells expressing AnkB-188. Equal protein loading was demonstrated by immunoblot to pan-actin, while membrane enrichment was demonstrated by immunoblot to caveolin-1. Experiments were reproduced three times.