8-pCPT-2′-O-Me-cAMP-AM activates the cAMP reporter
Epac1-camps. A, expression of a fusion protein of Epac1 and EGFP
in stably transfected INS-1 cells (calibration bar, 0.8 μm).
B, stable expression of Epac1-camps in INS-1 cells (calibration
bar, 3 μm). C, FRET-based live cell imaging of Epac1-camps in
INS-1 cells exposed to 8-pCPT-2′-O-Me-cAMP-AM (20
μm; arrows indicate duration of exposure). D,
single cell population study summarizing the action of
8-pCPT-2′-O-Me-cAMP-AM (ESCA-AM; 20 μm)
to activate Epac1-camps in INS-1 cells. Note that both the non-AM-ester of
8-pCPT-2′-O-Me-cAMP (ESCA, no AM;20 μm)
and acetoxymethyl ester phosphate (Phosphate-AM3; 6.6
μm) were without significant effect. All solutions were
administered in SES containing 0.1% dimethyl sulfoxide. Values above
each histogram bar indicate the numbers of cells (n values) assayed
for each experimental condition. For panels C and D, the
experiment was repeated 3 times with similar results.