Autoimmunity

Gαq is the α-subunit of Gq protein that is encoded by GNAQ. The heterotrimeric G proteins consist of α-subunit that binds and hydrolyses guanosine-5'-triphosphate as well as a β and a γ-subunit that form an undissociable complex. Based on the types of their α-subunits, G proteins can be grouped into four subfamilies, Gαi, Gαs, Gαq/11 and G12/13 and each

subfamily contents several members of G proteins. Gq protein is a member of the Gαq/11 subfamily. The Gαq containing protein initially attracted attention for its physiological significance is in cardiovascular system. In recent years, its role in immune regulation has been indicated. Studies demonstrated that Gαq plays crucial role in regulating both innate and adaptive immune cells function and it is involved in the development of autoimmune disease. Our group focused on the research of role of Gαq in immune regulation. We found that Gαq was involved in innate immune cells migration. Deficiency of Gαq can lead to abnormal activation, proliferation, differentiation and apoptosis of T-cells and B-cells. We first demonstrated the role of Gαq in autoimmune diseases. We found that Gnaq-/- chimeric mice spontaneously developed autoimmunity with multiorgan involvement and joints swelling. Abnormal expression of Gαq has been found in several autoimmune diseases such as rheumatoid arthritis. Gαq might be used as a novel therapy target autoimmune disease.