Activation of Epac2 by cAMP Authored: May, B, 2009-05-28 03:42:50 Each molecule of Epac2 binds 2 molecules of cAMP. Epac2 binds cAMP less tightly than PKA binds cAMP so it is believed that Epac2 binds cAMP after PKA is saturated. The binding of cAMP by Epac2 activates the guanyl nucleotide exchange activity of Epac2. Epac2 has also been shown to directly bind the SUR1 subunits of ATP-gated potassium channels (KATP channels) in beta cells so Epac2 may regulate potassium transport.<br>Epac2 interacts with the calcium sensor Piccolo in a complex with Rim2 at the cell membrane. This may influence exocytosis of insulin. Epac2 also interacts with the ryanodine-sensitive calcium channel on the ER membrane and may cause release of calcium from the ER into the cytosol. Edited: May, B, 2009-05-28 03:42:50 Pubmed11071853 Pubmed12401793 Pubmed12496249 Pubmed15569269 Pubmed16613879 Pubmed16973695 Pubmed17306374 Pubmed18202100 Reactome Database ID Release 43381608 Reactome, http://www.reactome.org ReactomeREACT_18272 Reviewed: Gillespie, ME, 2009-06-02 00:59:01 has a Stoichiometric coefficient of 2 Epac2 Epac2:cAMP Complex