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AbstractG protein-coupled receptors (GPCRs) self-associate as dimers or higher-order oligomers in living cells. The stability of associated GPCRs has not been extensively studied, but it is generally thought that these receptors move between the plasma membrane and intracellular compartments as intact dimers or oligomers. Here we show that b2-adrenergic receptors (b2ARs) that self-associate at the plasma membrane can dissociate during agonist-induced internalization. We use bioluminescence-resonance energy transfer (BRET) to monitor movement of Î²2ARs between subcellular compartments. BRET between b2ARs and plasma membrane markers decreases in response to agonist activation, while at the same time BRET between b2ARs and endosome markers increases. Energy transfer between b2ARs is decreased in a similar manner if either the donor- or acceptor-labeled receptor is mutated to impair agonist binding and internalization. These changes take place over the course of 30 minutes, persist after agonist is removed, and are sensitive to several inhibitors of arrestin- and clathrin-mediated endocytosis. The magnitude of the decrease in BRET between donor- and acceptor-labeled b2ARs suggests that at least half of the receptors that contribute to the BRET signal are physically segregated by internalization. These results are consistent with the possibility that b2ARs associate transiently with each other in the plasma membrane, or that b2AR dimers or oligomers are actively disrupted during internalization.
CitationPLoS One. 2011 Feb 22; 6(2):e17361
- Detection of beta 2-adrenergic receptor dimerization in living cells using bioluminescence resonance energy transfer (BRET).
- Authors: Angers S, Salahpour A, Joly E, Hilairet S, Chelsky D, Dennis M, Bouvier M
- Issue date: 2000 Mar 28
- Differences in endosomal targeting of human (beta)1- and (beta)2-adrenergic receptors following clathrin-mediated endocytosis.
- Authors: Liang W, Curran PK, Hoang Q, Moreland RT, Fishman PH
- Issue date: 2004 Feb 15
- Constitutive internalization of G protein-coupled receptors and G proteins via clathrin-independent endocytosis.
- Authors: Scarselli M, Donaldson JG
- Issue date: 2009 Feb 6
- BRET evidence that β2 adrenergic receptors do not oligomerize in cells.
- Authors: Lan TH, Liu Q, Li C, Wu G, Steyaert J, Lambert NA
- Issue date: 2015 May 8
- Demonstration of a direct interaction between β2-adrenergic receptor and insulin receptor by BRET and bioinformatics.
- Authors: Mandić M, Drinovec L, Glisic S, Veljkovic N, Nøhr J, Vrecl M
- Issue date: 2014
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