title: Plasma membrane localization of the μ-opioid receptor controls spatiotemporal signaling.
abstract: Differential regulation of the μ-opioid receptor (MOR), a G protein (heterotrimeric guanine nucleotide-binding protein)-coupled receptor, contributes to the clinically limiting effects of opioid analgesics, such as morphine. We used biophysical approaches to quantify spatiotemporal MOR signaling in response to different ligands. In human embryonic kidney (HEK) 293 cells overexpressing MOR, morphine caused a Gβγ-dependent increase in plasma membrane-localized protein kinase C (PKC) activity, which resulted in a restricted distribution of MOR within the plasma membrane and induced sustained cytosolic extracellular signal-regulated kinase (ERK) signaling. In contrast, the synthetic opioid peptide DAMGO ([d-Ala(2),N-Me-Phe(4),Gly(5)-ol]-enkephalin) enabled receptor redistribution within the plasma membrane, resulting in transient increases in cytosolic and nuclear ERK activity, and, subsequently, receptor internalization. When Gβγ subunits or PKCα activity was inhibited or when the carboxyl-terminal phosphorylation sites of MOR were mutated, morphine-activated MOR was released from its restricted plasma membrane localization and stimulated a transient increase in cytosolic and nuclear ERK activity in the absence of receptor internalization. Thus, these data suggest that the ligand-induced redistribution of MOR within the plasma membrane, and not its internalization, controls its spatiotemporal signaling.
authors: Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia. michelle.halls@monash.edu meri.canals@monash.edu.
authors: Michelle L
authors: ML
authors: Halls
authors: Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia.
authors: Holly R
authors: HR
authors: Yeatman
authors: Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia.
authors: Cameron J
authors: CJ
authors: Nowell
authors: Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia.
authors: Georgina L
authors: GL
authors: Thompson
authors: Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia.
authors: Arisbel Batista
authors: AB
authors: Gondin
authors: Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia.
authors: Srgjan
authors: S
authors: Civciristov
authors: Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia. ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia. Department of Anesthesia and Perioperative Medicine, Monash University, Melbourne, Victoria 3004, Australia. Department of Pharmacology, The University of Melbourne, Parkville, Victoria 3052, Australia.
authors: Nigel W
authors: NW
authors: Bunnett
authors: Department of Toxicology and Pharmacology, Georgia Regents University, Augusta, GA 30912, USA.
authors: Nevin A
authors: NA
authors: Lambert
authors: Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia. Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, Victoria 3052, Australia.
authors: Daniel P
authors: DP
authors: Poole
authors: Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia. ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia. michelle.halls@monash.edu meri.canals@monash.edu.
authors: Meritxell
authors: M
authors: Canals
mesh_terms: D000701:Analgesics, Opioid / Q000494:pharmacology*; D002462:Cell Membrane / Q000235:genetics / Q000378:metabolism*; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)- / Q000494:pharmacology*; D057809:HEK293 Cells; D006801:Humans; D009020:Morphine / Q000494:pharmacology*; D017450:Receptors, Opioid, mu / Q000819:agonists / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*
chemical_list: D000701:Analgesics, Opioid; D017450:Receptors, Opioid, mu; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D009020:Morphine