Fig. 1. Distribution of Cav1-eGFP in FRT cells in the basal and stimulated states. (A) Confocal image of an FRT cell expressing Cav1-eGFP, showing typical punctuate structures. (B) Confocal image of FRT cells expressing a membrane marker, MEM-eYFP, showing uniform distribution. (C) z stack of confocal images (from bottom to top) illustrate the cellular distribution of Cav1-eGFP in different planes of FRT cells. Cav1-eGFP forms large punctuate structures (indicated by white arrows) on the membrane. The thickness of each slice is 1 µm. Scale bar: 5 µm. (D) A time series of fluorescence images showing that stimulation of FRT cells expressing Cav1-eGFP does not cause internalization of Cav1-eGFP when muscarinic receptors are stimulated using 5 µM carbachol. Scale bar: 2 µm. Total duration of time series is 330 seconds.