It takes two to tango: regulation of G proteins by dimerization

Guanine nucleotide-binding (G) proteins are regulated by GTPase-activating proteins and guanine nucleotide-exchange factors. Another class of G proteins is emerging that are regulated by homodimerization. The authors propose that juxtaposition of the G domains of two monomers across the GTP-binding sites activates the biological function of these proteins and the GTPase reaction.