Figure 3.

Signal transduction mechanisms mediated by proteins with a GBA motif.A, proteins with a GBA motif propagate signaling through G protein activation upon stimulation of receptors from different families. B, recruitment of GBA motifs from the cytosol to the plasma membrane via binding to active receptor complexes is sufficient to trigger G protein signaling. G proteins are constitutively attached to membranes, so they cannot be activated by GBA motifs in the cytosol under resting conditions. Once recruited to the proximity of G proteins on membranes, GBA motifs propagate signaling primarily via free Gβγ-dependent mechanisms. C, DAPLE is constitutively recruited to apical cell junctions in epithelia, where it triggers spatially restricted G protein signaling to remodel the apical actin cytoskeleton. DAPLE, dishevelled-associating protein with a high frequency of leucine residues; GBA, Gα-binding-and-activating; GIV, Gα-interacting vesicle-associated protein.