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

J Neurochem. 2006 Apr;97(2):365-72. doi: 10.1111/j.1471-4159.2006.03736.x. Epub 2006 Mar 15.

Abstract

We have recently shown that the mu-opioid receptor [MOR1, also termed mu-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 mu-opioid receptor (MOR1D, also termed MOP(1D)) 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 delta-opioid receptor [DOR, also termed delta-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.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analgesics, Opioid / pharmacology*
  • Benzoxazines
  • Brefeldin A / pharmacology
  • Cell Line
  • Cloning, Molecular / methods
  • Drug Interactions
  • Endocytosis / drug effects
  • Endocytosis / physiology*
  • Enkephalin, Ala(2)-MePhe(4)-Gly(5)- / pharmacology*
  • Enzyme Activation / drug effects
  • Enzyme-Linked Immunosorbent Assay / methods
  • Gene Expression / physiology
  • Humans
  • Morphine / pharmacology
  • Morpholines / pharmacology
  • Naloxone / pharmacology
  • Naphthalenes / pharmacology
  • Narcotic Antagonists / pharmacology
  • Phorbol Esters / pharmacology
  • Phospholipase D / physiology*
  • Protein Synthesis Inhibitors / pharmacology
  • 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

Substances

  • Analgesics, Opioid
  • Benzoxazines
  • Morpholines
  • Naphthalenes
  • Narcotic Antagonists
  • Phorbol Esters
  • Protein Synthesis Inhibitors
  • Pyrazoles
  • Receptor, Cannabinoid, CB1
  • Receptors, G-Protein-Coupled
  • Receptors, Opioid, mu
  • Tritium
  • Enkephalin, Ala(2)-MePhe(4)-Gly(5)-
  • Brefeldin A
  • Naloxone
  • (3R)-((2,3-dihydro-5-methyl-3-((4-morpholinyl)methyl)pyrrolo-(1,2,3-de)-1,4-benzoxazin-6-yl)(1-naphthalenyl))methanone
  • Morphine
  • 12-O-retinoylphorbol-13-acetate
  • phospholipase D2
  • Phospholipase D
  • AM 281