Mutational analysis of the highly conserved arginine within the Glu/Asp-Arg-Tyr motif of the alpha(1b)-adrenergic receptor: effects on receptor isomerization and activation.

Détails

ID Serval
serval:BIB_00EC07485A9B
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Mutational analysis of the highly conserved arginine within the Glu/Asp-Arg-Tyr motif of the alpha(1b)-adrenergic receptor: effects on receptor isomerization and activation.
Périodique
Molecular Pharmacology
Auteur(s)
Scheer A., Costa T., Fanelli F., De Benedetti P.G., Mhaouty-Kodja S., Abuin L., Nenniger-Tosato M., Cotecchia S.
ISSN
0026-895X (Print)
ISSN-L
0026-895X
Statut éditorial
Publié
Date de publication
2000
Volume
57
Numéro
2
Pages
219-231
Langue
anglais
Résumé
We have suggested previously that both the negatively and positively charged residues of the highly conserved Glu/Asp-Arg-Tyr (E/DRY) motif play an important role in the activation process of the alpha(1b)-adreneric receptor (AR). In this study, R143 of the E/DRY sequence in the alpha(1b)-AR was mutated into several amino acids (Lys, His, Glu, Asp, Ala, Asn, and Ile). The charge-conserving mutation of R143 into lysine not only preserved the maximal agonist-induced response of the alpha(1b)-AR, but it also conferred high degree of constitutive activity to the receptor. Both basal and agonist-induced phosphorylation levels were significantly increased for the R143K mutant compared with those of the wild-type receptor. Other substitutions of R143 resulted in receptor mutants with either a small increase in constitutive activity (R143H and R143D), impairment (R143H, R143D), or complete loss of receptor-mediated response (R143E, R143A, R143N, R143I). The R413E mutant displayed a small, but significant increase in basal phosphorylation despite being severely impaired in receptor-mediated response. Interestingly, all the arginine mutants displayed increased affinity for agonist binding compared with the wild-type alpha(1b)-AR. A correlation was found between the extent of the affinity shift and the intrinsic activity of the agonists. The analysis of the receptor mutants using the allosteric ternary complex model in conjunction with the results of molecular dynamics simulations on the receptor models support the hypothesis that mutations of R143 can drive the isomerization of the alpha(1b)-AR into different states, highlighting the crucial role of this residue in the activation process of the receptor.
Mots-clé
Alanine/metabolism, Allosteric Regulation, Amino Acid Motifs, Amino Acid Sequence, Amino Acid Substitution, Animals, Arginine/genetics, Arginine/metabolism, COS Cells, Conserved Sequence, GTP-Binding Proteins/metabolism, Inositol Phosphates/metabolism, Models, Molecular, Mutagenesis, Site-Directed, Phosphorylation, Protein Conformation, Protein Isoforms, Receptors, Adrenergic, alpha-1/chemistry, Receptors, Adrenergic, alpha-1/genetics, Transfection
Pubmed
Web of science
Création de la notice
24/01/2008 11:05
Dernière modification de la notice
20/08/2019 12:23
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