Gβγ inhibits Epac-induced cell migration. a) SK-Mel-2 cells were infected with adenovirus harboring LacZ or Epac1 followed by the migration assay in the presence of mSIRK or Gp(CH2)pp (10 μM). mSIRK inhibited Epac1-induced melanoma cell migration. *, p < 0.05 vs. LacZ control, #, p < 0.05 vs. Epac1 control. n = 4 except 5 and 10 μM of mSIRK (n = 2). b) Migration assay was performed in SK-Mel-2 cells in the presence or absence of 8-pMeOPT (200 μM), L9A (20 μM) or mSIRK (20 μM). mSIRK, but not L9A, inhibited 8-pMeOPT-induced cell migration. n = 4. c and d) Following the termination of adenovirus harboring LacZ or Epac1, SK-Mel-2 cells were subjected to co-overexpression of Gβ1 and Gγ2 subunits or βARK-CT. Western blot analyses showed increased expression of the target proteins. e) Migration assay was performed in SK-Mel-2 cells. Co-overexpression of Gβ1 and Gγ2 inhibited Epac1-induced cell migration. Overexpression of βARK-CT restored Epac1-induced cell migration even in the presence of mSIRK (20 μM). f) Ablation of Epac1 inhibits GPCR-induced cell migration in melanoma. SK-Mel-2 cells were infected with lentivirus harboring Epac1- or control-shRNA as we previously described . Migration assay was performed in the presence or absence of isoproterenol (ISO) (100 μM), a β-adrenergic receptor agonist. Ablation of Epac1 inhibits both basal and ISO-induced cell migration. n = 4.