Fig. 5. (A-E) KPT2-TRPV4 cell lines show enhanced GTTR uptake in the absence of extracellular Ca²⁺. After 30 seconds of GTTR treatment, there was little difference in GTTR uptake between KPT2-TRPV4 and KPT2-pBabe cells in the presence of extracellular Ca²⁺ (A,B), with no significant difference in fluorescence intensity of cytoplasmic GTTR (E). Enhanced GTTR uptake was observed in KPT2-TRPV4 cells in the absence of extracellular Ca²⁺ compared with KPT2-pBabe cells (C,D). Similar results were obtained for all the three KPT2-TRPV4 and three KPT2-pBabe cell lines. Fluorescence intensity of cytoplasmic GTTR in KPT2-TRPV4 cells was significantly higher than in KPT2-pBabe cells under conditions of 0 mM or 0.05 mM extracellular Ca²⁺ (E). Fluorescence intensity data are shown as mean ± s.d. ^**P<0.01. Bar in C also applies for A, B and D (20 µm).