BACKGROUND: Exchange protein directly activated by cyclic AMP (cAMP) 1, Epac1, is a newly discovered cAMP target which acts beyond the classical cAMP effector protein kinase A (PKA). The identification of Epac1 overthrows the concept that cAMP activatez single effector. Epac1 is a guanine nucleotide exchange factor (GEF) probably activates small G-protein Rap1. Epac1 ubiquitously expresses in all tissues and therefore should play important roles in cellular signaling. Appreciation of the potential importance of Epac1 has come with the current development of Epac1-selective-cAMP analogs for discriminating the activation from PKA to Epac1. Among those analogs …postprintThe 2011 Winter Meeting of the British Pharmacological Society (BPS), London, U.K., 13-15 December 2011, abstract no. P04