1. GPCR and heterotrimeric G-protein signalling.
GPCR and heterotrimeric G-protein signalling. The ligand bound to the GPCR is shown in red. Binding allows the exchange of GDP for GTP by the associated G protein, and dissociation of the protein into Gα and Gβγ subunits. These then have downstream effects on a range of proteins, thereby propagating the signal from the bound ligand. Yellow arrows indicate either activation (up arrow) or inhibition (down arrow) of the targets. Regulators of G-protein signalling (RGS) proteins aid the GTPase activity of the G protein to turn off the signal. Arrestin can bind the receptor following GPCR phosphorylation by G-protein receptor kinase (GRK), desensitizing the receptor to further signalling. Reproduced from Berridge, M.J. (2012) Cell Signalling Biology; doi: /csb , with permission.
Helen Watson Essays Biochem. 2015;59:43-69
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