Heterotrimeric G-protein Gi (inactive) Liganded Gi-activating GPCRs bind inactive heterotrimeric G-protein Gi Authored: Jupe, S, 2010-05-18 Edited: Jupe, S, 2010-05-26 Many unrelated GPCRs couple with the Gi G-protein subtype. The G-alpha (i) subunit inhibits the production of cAMP from ATP. In turn, this results in decreased activity of cAMP-dependent protein kinase. There are 8 types of G-alpha (i) known to date:G(i)1, G(i)2, G(i)3, G(i)o, G(i)z, G(i)gust (gustducin) and two G(i)t (retinal transducin) (Downes GB and Gautam N, 1999). Once GDP is exchanged for GTP on the alpha subunit, it dissociates from the G-beta-gamma subunit. Pubmed10644457 Pubmed2834384 Reactome Database ID Release 43749456 Reactome, http://www.reactome.org ReactomeREACT_22289 Reviewed: D'Eustachio, P, 2010-05-21 Ligand:GPCR complexes that activate Gi Ligand:GPCR complexes that activate Gi:Heterotrimeric G-protein Gi (inactive)