Role of phospholipase D2 in the agonist‐induced and constitutive endocytosis of G‐protein coupled receptors

• Published in: Journal of neurochemistry Vol. 97; no. 2; pp. 365 - 372
• Main Authors: Koch, Thomas, Wu, Dai‐Fei, Yang, Li‐Quan, Brandenburg, Lars‐Ove, Höllt, Volker
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.04.2006; Blackwell
• Subjects: Alternative splicing; Analgesics, Opioid - pharmacology; Benzoxazines; Biological and medical sciences; Brefeldin A - pharmacology; Cannabinoid CB1 receptors; cannabinoid receptor 1; Cell Line; Cell receptors; Cell structures and functions; Cloning, Molecular - methods; Data processing; Drug Interactions; Embryos; Endocytosis; Endocytosis - drug effects; Endocytosis - physiology; Enkephalin, Ala-MePhe-Gly- - pharmacology; Enkephalins; Enzyme Activation - drug effects; Enzyme-Linked Immunosorbent Assay - methods; Enzymes; Fundamental and applied biological sciences. Psychology; G protein-coupled receptors; Gene Expression - physiology; Humans; Molecular and cellular biology; Monoamines receptors (catecholamine, serotonine, histamine, acetylcholine); Morphine; Morphine - pharmacology; Morpholines - pharmacology; Naloxone - pharmacology; Naphthalenes - pharmacology; Narcotic Antagonists - pharmacology; Neuropeptide receptors; Neurosciences; Opioid receptors; Opioid receptors (type delta); Opioid receptors (type mu); Overexpression; Phorbol Esters - pharmacology; phosphodiesterase; Phospholipase D - physiology; phospholipase D2; Plasma membranes; Protein Synthesis Inhibitors - pharmacology; Proteins; Pyrazoles - pharmacology; Radioligand Assay - methods; Receptor, Cannabinoid, CB1 - physiology; Receptors, G-Protein-Coupled - agonists; Receptors, G-Protein-Coupled - metabolism; Receptors, Opioid, mu - agonists; Receptors, Opioid, mu - physiology; Temperature; Transfection - methods; Tritium - pharmacokinetics; δ‐opioid receptor; µ‐opioid receptor; Human; p-opioid receptor; phospholipase D2; Peptides; Enzyme; Induction; μ Opioid receptor; Phospholipid; Morphine; Esterases; cannabinoid receptor 1; Kidney; Phospholipase; Endocytosis; Treatment; 8-opioid receptor; Urinary system; Plasma membrane; Hydrolases; G protein; Biological receptor
• ISSN: 0022-3042; 1471-4159
• DOI: 10.1111/j.1471-4159.2006.03736.x

We have recently shown that the μ‐opioid receptor [MOR1, also termed μ‐opioid peptide (MOP) receptor] is associated with the phospholipase D2 (PLD2), a phospholipid‐specific phosphodiesterase located in the plasma membrane. We further demonstrated that, in human embryonic kidney (HEK) 293 cells co‐expressing MOR1 and PLD2, treatment with (D‐Ala2, Me Phe4, Glyol5)enkephalin (DAMGO) led to an increase in PLD2 activity and an induction of receptor endocytosis, whereas morphine, which does not induce opioid receptor endocytosis, failed to activate PLD2. In contrast, a C‐terminal splice variant of the μ‐opioid receptor (MOR1D, also termed MOP1D) exhibited robust endocytosis in response to both DAMGO and morphine treatment. We report here that MOR1D also mediates an agonist‐independent (constitutive) PLD2‐activation facilitating agonist‐induced and constitutive receptor endocytosis. Inhibition of PLD2 activity by over‐expression of a dominant negative PLD2 (nPLD2) blocked the constitutive PLD2 activation and impaired the endocytosis of MOR1D receptors. Moreover, we provide evidence that the endocytotic trafficking of the δ‐opioid receptor [DOR, also termed δ‐opioid peptide (DOP) receptor] and cannabinoid receptor isoform 1 (CB1) is also mediated by a PLD2‐dependent pathway. These data indicate the generally important role for PLD2 in the regulation of agonist‐dependent and agonist‐independent G protein‐coupled receptor (GPCR) endocytosis.