tailieunhanh - Báo cáo khoa học: Allosteric functioning of dimeric class C G-protein-coupled receptors

Whereas most membrane receptors are oligomeric entities, G-protein-coupled receptors have long been thought to function as monomers. Within the last 15 years, accumulating data have indicated that G-protein-coupled receptors can form dimers or even higher ordered oligomers, but the gen-eral functional significance of this phenomena is not yet clear. | ềFEBS Journal MINIREVIEW Allosteric functioning of dimeric class C G-protein-coupled receptors J-P. Pin1-5 J. Kniazeff1-5 J. Liu1-5 V. Binet1-5 C. Goudet1-5 P. Rondard1-5 and L. Prezeau1-5 1 Institut de Genomique Fonctionnelle Montpellier France 2 CNRS UMR5203 Montpellier France 3 INSERM Montpellier France 4 Universite Montpellier-I France 5 Universite Montpellier-II France Keywords activation mechanism allosteric modulators dimerization GPCR Correspondence J-P. Pin Institut de Genomique Fonctionnelle 141 rue de la Cardonille F-34094 Montpellier cedex 5 France Fax 33 467 54 2432 Tel 33 467 14 2988 E-mail jppin@ Received 16 February 2005 accepted 6 April 2005 doi Whereas most membrane receptors are oligomeric entities G-protein-coupled receptors have long been thought to function as monomers. Within the last 15 years accumulating data have indicated that G-protein-coupled receptors can form dimers or even higher ordered oligomers but the general functional significance of this phenomena is not yet clear. Among the large G-protein-coupled receptor family class C receptors represent a well-recognized example of constitutive dimers both subunits being linked in most cases by a disulfide bridge. In this review article we show that class C G-protein-coupled receptors are multidomain proteins and highlight the importance of their dimerization for activation. We illustrate several consequences of this in terms of specific functional properties and drug development. Most membrane receptors including ligand-gated channels tyrosine kinase receptors cytokine receptors and guanylate cyclase receptors form oligomers. This was rapidly recognized as being crucial for the functioning of these receptors. In the case of ligand-gated channel receptors association of 4-5 subunits is required to form an ion channel. In the case of receptors that have a single transmembrane domain it was difficult to imagine how the signal could be transduced