Structure, Function, Pharmacology, and Therapeutic Potential of the G Protein, Gα _/q,11

G protein coupled receptors (GPCRs) are one of the major classes of cell surface receptors and are associated with a group of G proteins consisting of three subunits termed alpha, beta, and gamma. G proteins are classified into four families according to their α subunit; Gα _i, Gα _s, Gα _12/13, and Gα _q. There are several downstream pathways of Gα _q of which the best known is upon activation via guanosine triphosphate (GTP), Gα _q activates phospholipase Cβ, hydrolyzing phosphatidylinositol 4,5-biphosphate into diacylglycerol and inositol triphosphate and activating protein kinase C and increasing calcium efflux from the endoplasmic reticulum. Although G proteins, in particular, the Gα _q/11 are central elements in GPCR signaling, their actual roles have not yet been thoroughly investigated. The lack of research of the role on Gα _q/11 in cell biology is partially due to the obscure nature of the available pharmacological agents. YM-254890 is the most useful Gα _q-selective inhibitor with antiplatelet, antithrombotic, and thrombolytic effects. YM-254890 inhibits Gα _q signaling pathways by preventing the exchange of guanosine diphosphate for GTP. UBO-QIC is a structurally similar compound to YM-254890, which can inhibit platelet aggregation and cause vasorelaxation in rats. Many agents are available for the study of signaling downstream of Gα _q/11. The role of G proteins could potentially represent a novel therapeutic target. This review will explore the range of pharmacological and molecular tools available for the study of the role of Gα _q/11 in GPCR signaling.