G Protein-coupled Receptors
Published Online: 15 MAR 2009
Copyright © 2001 John Wiley & Sons, Ltd. All rights reserved.
How to Cite
Bockaert, J. 2009. G Protein-coupled Receptors. eLS. .
- Published Online: 15 MAR 2009
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Among membrane-bound receptors that recognize regulatory messages (hormones, neurotransmitters, photon, odours, etc.) the seven transmembrane receptors (7 TM) coupled to G proteins (G protein-coupled receptor, GPCRs) are the most numerous. They represent 3% of the total number of genes in human genome. They have similar three-dimensional (3D) structure but can be grouped into 8 classes that share few sequence similarities. GPCRs are targets for more than 50% of the drugs used in therapy.
Cell–cell communication involved messages (hormone, neurotransmitter growth factors, odorant, etc.) and receptors, the majority of them being GPCRs.
GPCRs are 7 transmembrane receptors. They form homo- or heterodimers.
There are three main classes of GPCRs differing in they primary sequences.
The class 3 is the more original one having it binding site within an extra-cellular structure called ‘Venus fly trap’.
During evolution mutations have tinkered the GPCR structure in order to allow recognition of ligands as diverse as photon, odorant, sugar, proteins, etc.
Virus like human immunodeficiency virus (HIV) virus use GPCRs such as those recognizing chemokines (CCR5, CXCR3) to enter specialized cells such as macrophages or lymphocytes.
GPCRs are allosteric molecules and drugs can be developed enhancing or silencing the effect of the natural ligand without having any effect by themselves.
Mutations of GPCR are responsible of pathologies. These mutations can render the receptor constitutively active or inactive.
- signal transduction;
- G proteins;