Heterotrimeric G proteins (αβγ) mediate the majority of signaling pathways in mammalian
cells. It is long held that G protein function is localized to the plasma membrane. Here we
examined the spatiotemporal dynamics of G protein localization using fluorescence recovery
after photobleaching, fluorescence loss in photobleaching, and a photoswitchable
fluorescent protein, Dronpa. Unexpectedly, G protein subunits shuttle rapidly (t ½< 1 min)
between the plasma membrane and intracellular membranes. We show that consistent with …