Endomembrane-Based Signaling by GPCRs and G-Proteins

G-protein-coupled receptors (GPCRs) and G-proteins have a range of roles in many physiological and pathological processes and are among the most studied signaling proteins. A plethora of extracellular stimuli can activate the GPCR and can elicit distinct intracellular responses through the activation of specific transduction pathways. For many years, biologists thought that GPCR signaling occurred entirely on the plasma membrane. However, in recent decades, many lines of evidence have proved that the GPCRs and G-proteins may reside on endomembranes and can start or propagate signaling pathways through the organelles that form the secretory route. How these alternative intracellular signaling pathways of the GPCR and G-proteins influence the physiological and pathological function of the endomembranes is still under investigation. Here, we review the general role and classification of GPCRs and G-proteins with a focus on their signaling pathways in the membrane transport apparatus.

Automated summary

G-protein-coupled receptors (GPCRs) and G-proteins play important roles in various physiological and pathological processes, and can elicit intracellular responses through different signaling pathways. Recent research suggests that they may not only exist on the plasma membrane, but also on endomembranes, initiating or propagating signaling pathways through these organelles. However, further investigation is needed to understand how these alternative intracellular signaling pathways of GPCRs and G-proteins impact the physiological and pathological function of endomembranes.