FIGURE 1.

STIM1-YFP translocation and subplasmalemmal puncta formation after Ca²⁺ store depletion in pancreatic islet cells. A, confocal images showing STIM1-YFP translocation and subplasmalemmal puncta formation in response to Ca²⁺ depletion of the ER with 100 μm of the SERCA inhibitor CPA in a superficial islet cell. The trace shows changes in PM-adjacent fluorescence with time, and the numbered arrowheads indicate when respective images were taken. B, TIRF images showing STIM1-YFP translocation and subplasmalemmal puncta formation in response to Ca²⁺ depletion of the ER with 100 μm of the SERCA inhibitor CPA in a superficial islet cell. The trace shows changes in average TIRF intensity with time, and the numbered arrowheads indicate when respective images were taken. C, TIRF intensity recording showing subplasmalemmal accumulation STIM1-YFP in Ca²⁺-deficient medium (0 mm Ca²⁺ and 2 mm EGTA) and during subsequent exposure to 50 μm CPA in a superficial islet cell. D, TIRF intensity recordings showing different patterns of carbachol (Carb)-induced (50 μm) subplasmalemmal accumulation of STIM1-YFP. The glucose concentration was 3 mm in all panels.