Send to

Choose Destination
Trends Pharmacol Sci. 1993 Aug;14(8):303-7.

Constitutive activity of receptors coupled to guanine nucleotide regulatory proteins.

Author information

Howard Hughes Medical Institute, Duke University Medical Center, Durham, NC 27710.


Adrenoceptors are prototypic members of the superfamily of seven transmembrane domain, G protein-coupled receptors. Study of the properties of several mutationally activated adrenoceptors is deepening understanding of the normal functioning of this ubiquitous class of receptors. The new findings suggest an expansion of the classical ternary complex model of receptor action to include an explicit isomerization of the receptors from an inactive to an active state which couples to the G protein ('allosteric ternary complex model'). This isomerization involves conformational changes which may occur spontaneously, or be induced by agonists or appropriate mutations which abrogate the normal 'constraining' function of the receptor, allowing it to 'relax' into the active conformation. Robert Lefkowitz and colleagues discuss the physiological and pathophysiological implications of these new insights into regulation of receptor activity.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center