Fig. 1. Imaging of Ca²⁺-dependent nuclear translocation of GFP–NFAT. (A) Time-lapse images of GFP–NFAT and [Ca²⁺]_i at various time points during and after Ca²⁺ stimulation as indicated in (B). (B) Changes in GFP fluorescence intensity of the cell shown in (A) in the cytoplasmic region (indicated as Cyt) and the nuclear region (Nuc) are plotted with the change in [Ca²⁺]_i. (C and D) Time courses of GFP–NFAT translocation and [Ca²⁺]_i upon Ca²⁺ stimulation for 1.5 min [(C), n = 10] or 20 min [(D), n = 8] (mean ± SEM). The ranges of errors are shown only at selected time points for clarity. (E) Dependence of the peak extent of GFP–NFAT nuclear translocation on the duration of Ca²⁺ stimulation (mean ± SEM; n = 8–21). (F) Efficiency of GFP–NFAT nuclear translocation. Peak nuclear translocation of GFP–NFAT per unit duration of Ca²⁺ stimulation was plotted against the duration of Ca²⁺ stimulation.