Fig. 6. Mobilisation of intracellular calcium stores by thapsigargin causes redistribution of PDE4A1 from the Golgi in a PLD-dependent manner. (A) Cos1 cells were transfected with either (1-25)-4A1-GFP (top row), D5A(1-25)-4A1-GFP (middle row) or full-length PDE4A1 (bottom row). Cells were then treated with 2 µM thapsigargin for 30 minutes at 37°C. Where indicated cells were pre-incubated for 10 minutes before thapsigargin treatment with 0.3% (40 mM) butan-1-ol, 0.3% (40 mM) butan-2-ol or calphostin-c (1 µM) and then visualised. Bars, 10 µm. (B) Various organelles were visualised following the treatment of (1-25)-4A1-GFP-transfected Cos1 cells with thapsigargin (2 µM) for 30 minutes at 37°C. The Golgi apparatus was visualised using BODIPY ceramide, the ER using ERtracker, lysosomes using ERtracker and mitochondria using Mitotracker.