Figure 7.

CalX overexpression accelerates and enhances rapid store depletion (in vivo DPP). A, ER-150 fluorescence measured in vivo from the DPP in intact flies in wild-type and in flies overexpressing the Na⁺/Ca²⁺ exchanger (pCalX). Rapid depletion was massively enhanced in pCalx flies. Following the initial rapid depletion, ER stores in pCalx flies showed rapid refilling over 10–20 s during the maintained blue excitation. B, Traces in pCalX on faster time scale (y-axis scale same as A): red, initially dark adapted and then after 30–100 s in the dark. C, D, time course of store refilling in pCalX compared with wild-type: after an initial rapid phase (D; pCalx data replotted on faster time course), the slower phase of ER store refilling had a similar time course in wild-type, calx^A and pCalx flies. However, the fast phase was enhanced in pCalX.