Intramolecular fluorescence resonance energy transfer (FRET) sensors of the orexin OX1 and OX2 receptors identify slow kinetics of agonist activation.

ABSTRACT: Intramolecular fluorescence resonance energy transfer (FRET) sensors able to detect changes in distance or orientation between the 3rd intracellular loop and C-terminal tail of the human orexin OX(1) and OX(2) G protein-coupled receptors following binding of agonist ligands were produced and expressed stably. These were directed to the plasma membrane and, despite the substantial sequence alterations introduced, in each case were able to elevate [Ca(2+)](i), promote phosphorylation of the ERK1/2 MAP kinases and become internalized effectively upon addition of the native orexin peptides. Detailed characterization of the OX(1) sensor demonstrated that it was activated with rank order of potency orexin A > orexin B > orexin A 16-33, that it bound antagonist ligands with affinity similar to th

SUBMITTER: Xu TR 

PROVIDER: S-EPMC3340242 | biostudies-literature | 2012 Apr

REPOSITORIES: biostudies-literature