Figure 2.

The Cytoplasmic Ca²⁺ Binding Protein Calbindin D_28K Prevents Nuclear Migration of NFAT4, but Not NFAT1

(A) Images compare NFAT1- or NFAT4-cherry movement in cells expressing calbindin D_28K-GFP and were taken at different times after stimulation, as indicated. NFAT constructs used are shown on the right of each row of images, where N1 and N4 denote NFAT1 and NFAT4. Stimuli are also shown on the right.

(B) Aggregate data from experiments as in (A) are summarized. Each point is the mean of between 8 and 13 individual cells. The N1-Thap curve has been offset upward by 0.03, to increase clarity.

(C) In cells expressing PV-NES (untagged) or calbindin D_28K-GFP (indicated on the right of each image), stimulation with LTC₄ after thapsigargin (1 μM) failed to show any NFAT4 movement. LTC₄ was applied 20 min after pre-treatment with thapsigargin. Upper images show rest and then 20 and 40 min after thapsigargin stimulation (control recording from the same cell preparation). In the control and PV-NES experiments, NFAT4-GFP was expressed. In coexpression with calbindin D_28K-GFP, NFAT4-cherry was used instead.

(D) Aggregate data are compared for the conditions shown. Each point is the mean of between 9 and 15 cells. For the graphs, data are represented as mean ± SEM.