The guanine nucleotide-binding protein (G-protein) cell signaling pathway functions in metabolic regulation, neurotransmission, and embryonic development. The G-protein signaling pathway may be activated by a ligand binding to the G-protein coupled receptor (GPCR). The pathway may be inhibited by phosphorylation of the GPCR by protein kinases and the subsequent binding of arrestin proteins. [1]

Figure 1. Binding of a growth factor (e.g., EGF, HGF) to the G-protein coupled receptor (GPCR) causes a conformational change in the GPCR. The conformational change in the GPCR activates a trimeric GTP binding protein (e.g., GNA11 and GNAQ), resulting in GDP dissociation, GTP association, and resultant activation. The active G-protein regulates activity of target proteins in the cell membrane. Activated target proteins relay signals to other proteins to initiate gene transcription, metabolic regulation, cell growth, and survival. G-protein inactivation occurs when GTP is exchanged for GDP. Specific nodes in the pathway that are therapeutically actionable are noted.


1. All assertions and clinical trial landscape data are curated from primary sources. You can read more about the curation process here.