Constitutively active mutants of the alpha 1B-adrenergic receptor: role of highly conserved polar amino acids in receptor activation.

Details

Serval ID
serval:BIB_6CD62177C2E6
Type
Article: article from journal or magazin.
Collection
Publications
Title
Constitutively active mutants of the alpha 1B-adrenergic receptor: role of highly conserved polar amino acids in receptor activation.
Journal
EMBO Journal
Author(s)
Scheer A., Fanelli F., Costa T., De Benedetti P.G., Cotecchia S.
ISSN
0261-4189 (Print)
ISSN-L
0261-4189
Publication state
Published
Issued date
07/1996
Volume
15
Number
14
Pages
3566-3578
Language
english
Abstract
Site-directed mutagenesis and molecular dynamics simulations of the alpha 1B-adrenergic receptor (AR) were combined to explore the potential molecular changes correlated with the transition from R (inactive state) to R (active state). Using molecular dynamics analysis we compared the structural/dynamic features of constitutively active mutants with those of the wild type and of an inactive alpha 1B-AR to build a theoretical model which defines the essential features of R and R. The results of site-directed mutagenesis were in striking agreement with the predictions of the model supporting the following hypothesis. (i) The equilibrium between R and R depends on the equilibrium between the deprotonated and protonated forms, respectively, of D142 of the DRY motif. In fact, replacement of D142 with alanine confers high constitutive activity to the alpha 1B-AR. (ii) The shift of R143 of the DRY sequence out of a conserved 'polar pocket' formed by N63, D91, N344 and Y348 is a feature common to all the active structures, suggesting that the role of R143 is fundamental for mediating receptor activation. Disruption of these intramolecular interactions by replacing N63 with alanine constitutively activates the alpha 1B-AR. Our findings might provide interesting generalities about the activation process of G protein-coupled receptors.
Keywords
Adrenergic beta-Agonists/metabolism, Amino Acid Sequence, Animals, Cell Line, Transformed, Cercopithecus aethiops, Computer Simulation, Conserved Sequence, Cricetinae, GTP-Binding Proteins/metabolism, Inositol Phosphates/metabolism, Models, Molecular, Molecular Sequence Data, Mutagenesis, Site-Directed, Protein Conformation, Protons, Receptors, Adrenergic, alpha-1/chemistry, Receptors, Adrenergic, alpha-1/genetics
Pubmed
Web of science
Create date
24/01/2008 12:05
Last modification date
20/08/2019 15:26
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