description
Receptor activated heterotrimeric G proteins consist of the Galpha and the tightly associated Gbeta-gamma subunits. When a ligand binds to a G protein-coupled receptor, it stabilises a conformation with an high affinity for the G-protein bound to GDP. GDP is then exchanged for GTP on the Galpha subunit. This exchange triggers the dissociation of the Galpha subunit from the Gbeta-gamma dimer and the receptor. Galpha-GTP and Gbeta-gamma, can then modulate different signalling cascades and effector proteins, while the receptor is able to activate another G protein, resulting in an amplification cascade. The Galpha subunit will eventually hydrolyze the attached GTP to GDP by its inherent enzymatic activity, allowing it to reassociate with Gbeta-gamma and start a new cycle

external resources
NCBI:1269585
REACTOME:R-HSA-202040
PUBMED:12184727
PUBMED:15294442
PUBMED:9218123

genes
GNAI1 , GNAI2 , GNAI3 , GNAO1 , GNAT1 , GNAT2 , GNAZ , GNB1 , GNB2 , GNB3 , GNG3 , GNG4 , GNG5 , GNG7 , GNG10 , GNG11 , GNGT1 , GNGT2 , OPRM1 , PDYN , POMC , GNB5 , GNG13 , GNG2 , GNG12 , GNB4 , GNG8 , GNAT3 , MIR197 ,