Skip to main content
. Author manuscript; available in PMC: 2011 Jul 6.
Published in final edited form as: Chem Biol. 2011 Feb 25;18(2):243–251. doi: 10.1016/j.chembiol.2010.12.007

Figure 2. R447 is specifically involved in SU binding to and activation of Epac2.

Figure 2

(A) The GLB (5 μM) and cAMP (50 μM Fsk plus 100 μM IBMX) responses of WT (N = 10), D32A/R53A (N = 7), R447A (N = 12), R466A (N = 8), and R819A (N = 8) Epac2 biosensors in HEK293T cells. Values are depicted as mean ± s.d. ***P <1E-08. (B) Time course depicting the diminished GLB-induced response of the R447A mutant (□) Epac2 biosensor compared to the WT (■) Epac2 biosensor. (C) Emission spectrum of the R447A biosensor excited at 435 nm in the basal state (■), after GLB [1 μM ( Inline graphic); 10 μM ( Inline graphic); 100 μM ( Inline graphic)] addition, and after cAMP (500 μM) addition ( Inline graphic). (D) Molecular docking studies identify a putative SU binding site where ACT hydrogen bonds with R447 of Epac2 and makes Van der Waals contacts with F374.