Fig. 5.

Effect of gallein, an inhibitor of Gβγ subunits, on agonist-induced reduction of cAMP levels and ERK activation of HCA₃ and GPR84. CHO-K1 cells were transiently transfected with HCA₃ or GPR84. a The HCA₃-mediated reduction of forskolin (fsk)-induced cAMP levels induced by both, 3HO and 3HDec, was significantly diminished in presence of 50 μM gallein. The GPR84-induced decrease in cAMP levels in presence of gallein was only reduced in case of activation by C10 but not 3HDec. cAMP level of HCA₃- or GPR84-transfected cells in absence of agonist is set 100%, respectively. b Gallein inhibited the 3HDec-induced HCA₃-mediated increase in pERK/total ERK levels completely but the 3HO-induced increase only partially. GPR84-mediated activation of ERK by both, C10 and 3HDec, was equally diminished in presence of gallein. pERK/total ERK of HCA₃- or GPR84-transfected cells in absence of agonist is set 1, respectively. a, b Data is given as mean ± SEM of at least three independent experiments each carried out in triplicates. * P ≤ 0.05; ** P ≤ 0.01; *** P ≤ 0.001