Role of phospholipase D2 in the agonist-induced and constitutive endocytosis of G-protein coupled receptors.
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.
Department of Pharmacology and Toxicology, Otto-von-Guericke University, Magdeburg, Germany. Thomas.Koch@Medizin.Uni-Magdeburg.de
Thomas
T
Koch
Dai-Fei
DF
Wu
Li-Quan
LQ
Yang
Lars-Ove
LO
Brandenburg
Volker
V
Höllt
D000701:Analgesics, Opioid / Q000494:pharmacology*; D048588:Benzoxazines; D020126:Brefeldin A / Q000494:pharmacology; D002460:Cell Line; D003001:Cloning, Molecular / Q000379:methods; D004347:Drug Interactions; D004705:Endocytosis / Q000187:drug effects / Q000502:physiology*; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)- / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D015870:Gene Expression / Q000502:physiology; D006801:Humans; D009020:Morphine / Q000494:pharmacology; D009025:Morpholines / Q000494:pharmacology; D009270:Naloxone / Q000494:pharmacology; D009281:Naphthalenes / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D010703:Phorbol Esters / Q000494:pharmacology; D010739:Phospholipase D / Q000502:physiology*; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D011720:Pyrazoles / Q000494:pharmacology; D011869:Radioligand Assay / Q000379:methods; D043884:Receptor, Cannabinoid, CB1 / Q000502:physiology; D043562:Receptors, G-Protein-Coupled / Q000819:agonists / Q000378:metabolism*; D017450:Receptors, Opioid, mu / Q000819:agonists / Q000502:physiology*; D013696:Temperature; D014162:Transfection / Q000379:methods; D014316:Tritium / Q000493:pharmacokinetics
D000701:Analgesics, Opioid; D048588:Benzoxazines; D009025:Morpholines; D009281:Naphthalenes; D009292:Narcotic Antagonists; D010703:Phorbol Esters; D011500:Protein Synthesis Inhibitors; D011720:Pyrazoles; D043884:Receptor, Cannabinoid, CB1; D043562:Receptors, G-Protein-Coupled; D017450:Receptors, Opioid, mu; D014316:Tritium; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D020126:Brefeldin A; D009270:Naloxone; C070417:(3R)-((2,3-dihydro-5-methyl-3-((4-morpholinyl)methyl)pyrrolo-(1,2,3-de)-1,4-benzoxazin-6-yl)(1-naphthalenyl))methanone; D009020:Morphine; C032974:12-O-retinoylphorbol-13-acetate; C105606:phospholipase D2; D010739:Phospholipase D; C109925:AM 281