Table 1.

The different levels of regulation of the multiple of GPCR-G protein coupling.

Agonist	Receptor	G protein
Nature	Splice variant, RNA editing	Expression level
Potency	Receptor density	Availability
Concentration	Phosphorylation	Compartmentalization
	Palmitoylation Homo- and heteromerization Interaction with accessory proteins Preassembly with G proteins	Regulators of G protein signaling (RGS) Preassembly with the receptor

Adapted from Hermans (2003).