Oligomerization of the alpha 1a- and alpha 1b-adrenergic receptor subtypes. Potential implications in receptor internalization.

Détails

ID Serval
serval:BIB_09C432745ED5
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Oligomerization of the alpha 1a- and alpha 1b-adrenergic receptor subtypes. Potential implications in receptor internalization.
Périodique
Journal of Biological Chemistry
Auteur(s)
Stanasila L., Perez J.B., Vogel H., Cotecchia S.
ISSN
0021-9258 (Print)
ISSN-L
0021-9258
Statut éditorial
Publié
Date de publication
2003
Peer-reviewed
Oui
Volume
278
Numéro
41
Pages
40239-40251
Langue
anglais
Résumé
We combined biophysical, biochemical, and pharmacological approaches to investigate the ability of the alpha 1a- and alpha 1b-adrenergic receptor (AR) subtypes to form homo- and hetero-oligomers. Receptors tagged with different epitopes (hemagglutinin and Myc) or fluorescent proteins (cyan and green fluorescent proteins) were transiently expressed in HEK-293 cells either individually or in different combinations. Fluorescence resonance energy transfer measurements provided evidence that both the alpha 1a- and alpha 1b-AR can form homo-oligomers with similar transfer efficiency of approximately 0.10. Hetero-oligomers could also be observed between the alpha 1b- and the alpha 1a-AR subtypes but not between the alpha 1b-AR and the beta2-AR, the NK1 tachykinin, or the CCR5 chemokine receptors. Oligomerization of the alpha 1b-AR did not require the integrity of its C-tail, of two glycophorin motifs, or of the N-linked glycosylation sites at its N terminus. In contrast, helix I and, to a lesser extent, helix VII were found to play a role in the alpha 1b-AR homo-oligomerization. Receptor oligomerization was not influenced by the agonist epinephrine or by the inverse agonist prazosin. A constitutively active (A293E) as well as a signaling-deficient (R143E) mutant displayed oligomerization features similar to those of the wild type alpha 1b-AR. Confocal imaging revealed that oligomerization of the alpha1-AR subtypes correlated with their ability to co-internalize upon exposure to the agonist. The alpha 1a-selective agonist oxymetazoline induced the co-internalization of the alpha 1a- and alpha 1b-AR, whereas the alpha 1b-AR could not co-internalize with the NK1 tachykinin or CCR5 chemokine receptors. Oligomerization might therefore represent an additional mechanism regulating the physiological responses mediated by the alpha 1a- and alpha 1b-AR subtypes.
Mots-clé
Amino Acid Sequence, Animals, Cell Line, Cricetinae, Fluorescence Resonance Energy Transfer, Fluorescent Dyes, Green Fluorescent Proteins, Humans, Luminescent Proteins/chemistry, Luminescent Proteins/genetics, Microscopy, Confocal, Mutagenesis, Site-Directed, Protein Structure, Quaternary, Receptors, Adrenergic, alpha-1/chemistry, Receptors, Adrenergic, alpha-1/classification, Receptors, G-Protein-Coupled/metabolism, Recombinant Fusion Proteins/chemistry, Recombinant Fusion Proteins/genetics
Pubmed
Web of science
Open Access
Oui
Création de la notice
24/01/2008 11:05
Dernière modification de la notice
20/08/2019 12:31
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