Activation of G protein-coupled receptors: beyond two-state models and tertiary conformational changes.
Transformation of G protein-coupled receptors (GPCRs) from a quiescent to an active state initiates signal transduction. All GPCRs share a common architecture comprising seven transmembrane-spanning alpha-helices, which accommodates signal propagation from a diverse repertoire of external stimuli across biological membranes to a heterotrimeric G protein. Signal propagation through the transmembrane helices likely involves mechanistic features common to all GPCRs. The structure of the light receptor rhodopsin may serve as a prototype for the transmembrane architecture of GPCRs. Early biochemical, biophysical, and pharmacological studies led to the conceptualization of receptor activation based on the context of two-state equilibrium models and conformational changes in protein structure. More recent studies indicate a need to move beyond these classical paradigms and to consider additional aspects of the molecular character of GPCRs, such as the oligomerization and dynamics of the receptor.
Park
Paul S-H
PS
Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106-4965, USA. paul.park@case.edu
Lodowski
David T
DT
Palczewski
Krzysztof
K
D001665:Binding Sites; D006801:Humans; D008024:Ligands; D008958:Models, Molecular; D015394:Molecular Structure; D017434:Protein Structure, Tertiary; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism*; D012243:Rhodopsin / Q000378:metabolism; D015398:Signal Transduction
D008024:Ligands; D043562:Receptors, G-Protein-Coupled; D012243:Rhodopsin