Fig. 4. Overexpressed cyclophilin B suppresses Ca²⁺ release from the ER in response to ER stress. Relative changes in cytosolic Ca²⁺ level in the indicated transfectants (n=20) are shown in the left panels and are plotted in the right panels. (A) Green color represents intracellular Ca²⁺. Red arrow (left panel) and dotted line (right panel). (B) Each transfectant was treated with 4 mM EGTA to reduce extracellular background Ca²⁺ prior to treatment with 1 µM Tg. In A and B the red arrowheads (left panel) and dotted line (right panel) indicate the Tg treatment point. In B the blue arrow (left panel) and dotted line (right panel) indicate the EGTA treatment point.