The putative Gαq-inhibiting pepducin P4Pal10 distinctly modulates function of the Gαi-coupled receptors FPR2 and FFA2R in neutrophils

Abstract

AbstractA novel mechanism of action was described, when a protease-activated receptor 4 (P4Pal10) derived lipopeptide (pepducin) was shown to inhibit signaling downstream of several unrelated Gαq-coupled receptors. We show that this putative Gαq-inhibiting pepducin lacks inhibitory effects on signaling downstream of the Gαq-coupled receptors for ATP (P2Y2R) and PAF (PAFR) expressed in human neutrophils. P4Pal10 inhibited however, signaling in neutrophils activated with agonists for the Gαi-coupled formyl peptide receptor 2 (FPR2) but not the closely related FPR1. In addition, the P4Pal10 pepducin was turned into an activating agonist in the presence of an allosteric modulator selective for free fatty acid receptor 2 (FFA2R). The results presented thus reveal Gαq-independent effects of P4Pal10 in modulating FPR2- and FFA2R-mediated neutrophil activation.