Changes in cAMP responses in different subcellular domains following β‐adrenoceptor stimulation. (A–D) Representative time course of changes in the magnitude of the normalized FRET response (ΔR/R0) in cells expressing Epac2‐MyrPalm (MyrPalm), Epac2‐CAAX (CAAX), Epac2‐NLS (NLS) and Epac2‐camps (Epac), under control conditions, and following exposure to 1 nM, 3 nM and 1 μM isoprenaline (Iso). (E) Size of average FRET responses to Iso; 1 nM Iso: MyrPalm, (n = 13); CAAX (n = 9); NLS (n = 7) and Epac2 (n = 7). Iso 3 nM: MyrPalm, (n = 13), CAAX (n = 9); NLS (n = 7) and Epac2 (n = 7). Iso 1 μM: MyrPalm, (n = 18); CAAX (n = 19); NLS (n = 15) and Epac2 (n = 11). There were no significant differences (one‐way ANOVA) in the size of the responses to any given concentration of Iso. All responses were normalized to the maximal responses elicited by 1 μM Iso plus 100 μM IBMX.