Different internalization properties of the alpha1a- and alpha1b-adrenergic receptor subtypes: the potential role of receptor interaction with beta-arrestins and AP50.

Détails

ID Serval
serval:BIB_6460AFA5F5AC
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Different internalization properties of the alpha1a- and alpha1b-adrenergic receptor subtypes: the potential role of receptor interaction with beta-arrestins and AP50.
Périodique
Molecular Pharmacology
Auteur(s)
Stanasila L., Abuin L., Dey J., Cotecchia S.
ISSN
1521-0111 (Electronic)
ISSN-L
0026-895X
Statut éditorial
Publié
Date de publication
2008
Volume
74
Numéro
3
Pages
562-573
Langue
anglais
Résumé
The internalization properties of the alpha1a- and alpha1b-adrenergic receptors (ARs) subtypes transiently expressed in human embryonic kidney (HEK) 293 cells were compared using biotinylation experiments and confocal microscopy. Whereas the alpha1b-AR displayed robust agonist-induced endocytosis, the alpha1a-AR did not. Constitutive internalization of the alpha1a-AR was negligible, whereas the alpha1b-AR displayed significant constitutive internalization and recycling. We investigated the interaction of the alpha1-AR subtypes with beta-arrestins 1 and 2 as well as with the AP50 subunit of the clathrin adaptor complex AP2. The results from both coimmunoprecipitation experiments and beta-arrestin translocation assays indicated that the agonistinduced interaction of the alpha1a-AR with beta-arrestins was much weaker than that of the alpha1b-AR. In addition, the alpha1a-AR did not bind AP50. The alpha1b-AR mutant M8, lacking the main phosphorylation sites in the receptor C tail, was unable to undergo endocytosis and was profoundly impaired in binding beta-arrestins despite its binding to AP50. In contrast, the alpha1b-AR mutant DeltaR8, lacking AP50 binding, bound beta-arrestins efficiently, and displayed delayed endocytosis. RNA interference showed that beta-arrestin 2 plays a prominent role in alpha1b-AR endocytosis. The findings of this study demonstrate differences in internalization between the alpha1a- and alpha1b-AR and provide evidence that the lack of significant endocytosis of the alpha1a-AR is linked to its poor interaction with beta-arrestins as well as with AP50. We also provide evidence that the integrity of the phosphorylation sites in the C tail of the alpha1b-AR is important for receptor/beta-arrestin interaction and that this interaction is the main event triggering receptor internalization.
Mots-clé
Adaptor Protein Complex 2/metabolism, Adaptor Protein Complex mu Subunits/metabolism, Animals, Arrestins/metabolism, Biotinylation, Cell Line, Cricetinae, Endocytosis, Gene Silencing, Humans, Immunoprecipitation, Mutant Proteins/metabolism, Protein Binding, Protein Transport, Rats, Receptors, Adrenergic, alpha-1/chemistry, Receptors, Adrenergic, alpha-1/metabolism, Recombinant Fusion Proteins/metabolism, Structure-Activity Relationship
Pubmed
Web of science
Création de la notice
30/10/2009 13:18
Dernière modification de la notice
03/03/2018 17:49
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