Activation of Gi/o Heterotrimeric G Proteins by Alpha Adrenergic Receptors Alpha-2A/2C Authored: May, B, 2009-05-27 03:41:50 Edited: May, B, 2009-05-27 03:41:18 In the pancreatic beta cell, alpha2 adrenergic receptors are coupled to Gi and Go heterotrimeric G-proteins. Binding of adrenaline or noradrenaline by the alpha2 adrenergic receptor acts through protein-protein interaction to stimulate the Gi alpha subunit or Go alpha subunit in heterotrimeric G-protein complexes to exchange GDP for GTP. The particular G alpha subunits have been identified in mice as Gi alpha1, Gi alpha 2, and Go alpha2. Pubmed14514350 Pubmed16352729 Pubmed16371464 Pubmed1645720 Pubmed17900700 Pubmed18162464 Pubmed1849000 Pubmed7641683 Pubmed8099279 Pubmed8662784 Pubmed8997178 Pubmed9760042 Reactome Database ID Release 43400092 Reactome, http://www.reactome.org ReactomeREACT_18311 Reviewed: D'Eustachio, P, 2009-06-02 00:48:17 G-protein i/o alpha:GDP:G-protein beta:G-protein gamma Complex G-protein i/o alpha:GTP:G-protein beta:G-protein gamma Complex