Fig. 5.

GPN inhibits TPC2-dependent Ca²⁺ signals. (A-C) Effects of acute challenge with DMSO (A), 200 µM GPN (B) or 1 µM thapsigargin (C) on Ca²⁺ signals evoked by TPC2-A1-N (30 µM). Experiments were performed using HeLa cells expressing TPC2-GCaMP6s in the absence of external Ca²⁺. Ionomycin (2 µM) was added at the end of the experiments. An increase in GCaMP6s fluorescence corresponds to an increase in cytosolic Ca²⁺. (D) Summary data quantifying the effect of GPN and thapsigargin on the magnitude of the TPC2-A1-N-evoked responses (n=5-10). *P<0.05, **P<0.01 (Mann–Whitney U-tests).