Modulation of μ-opioid receptor signaling by RGS19 in SH-SY5Y cells.

Abstract

Regulator of G-protein signaling protein 19 (RGS19), also known as Gα-interacting protein (GAIP), acts as a GTPase accelerating protein for Gαz as well as Gαi/o subunits. Interactions with GAIP-interacting protein N-terminus and GAIP-interacting protein C-terminus (GIPC) link RGS19 to a variety of intracellular proteins. Here we show that RGS19 is abundantly expressed in human neuroblastoma SH-SY5Y cells that also express µ- and δ- opioid receptors (MORs and DORs, respectively) and nociceptin receptors (NOPRs). Lentiviral delivery of short hairpin RNA specifically targeted to RGS19 reduced RGS19 protein levels by 69%, with a similar reduction in GIPC. In RGS19-depleted cells, there was an increase in the ability of MOR (morphine) but not of DOR [(4-[(R)-[(2S,5R)-4-allyl-2,5-dimethylpiperazin-1-yl](3-methoxyphenyl)methyl]-N,N-diethylbenzamide (SNC80)] or NOPR (nociceptin) agonists to inhibit forskolin-stimulated adenylyl cyclase and increase mitogen-activated protein kinase (MAPK) activity. Overnight treatment with either MOR [D-Ala, N-Me-Phe, Gly-ol(5)-enkephalin (DAMGO) or morphine] or DOR (D-Pen(5)-enkephalin or SNC80) agonists increased RGS19 and GIPC protein levels in a time- and concentration-dependent manner. The MOR-induced increase in RGS19 protein was prevented by pretreatment with pertussis toxin or the opioid antagonist naloxone. Protein kinase C (PKC) activation alone increased the level of RGS19 and inhibitors of PKC 5,6,7,13-tetrahydro-13-methyl-5-oxo-12H-indolo[2,3-a]pyrrolo[3,4-c]carbazole-12-propanenitrile and mitogen-activated protein kinase kinase 1 2-(2-amino-3-methoxyphenyl)-4H-chromen-4-one, but not protein kinase A (H89), completely blocked DAMGO-induced RGS19 protein accumulation. The findings show that RGS19 and GIPC are jointly regulated, that RGS19 is a GTPase accelerating protein for MOR with selectivity over DOR and NOPR, and that chronic MOR or DOR agonist treatment increases RGS19 levels by a PKC and the MAPK pathway-dependent mechanism.

• Authors: Qin Wang, John R Traynor
• Journal: Molecular pharmacology (Mol Pharmacol) Vol. 83 Issue 2 Pg. 512-20 (Feb 2013) ISSN: 1521-0111 [Electronic] United States
• PMID: 23197645 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)

Chemical References

• Adaptor Proteins, Signal Transducing
• Benzamides
• GIPC1 protein, human
• Opioid Peptides
• Piperazines
• RGS Proteins
• Receptors, Opioid
• Receptors, Opioid, delta
• Receptors, Opioid, mu
• regulator of G-protein signalling 19
• Enkephalin, Ala(2)-MePhe(4)-Gly(5)-
• 4-(alpha-(4-allyl-2,5-dimethyl-1-piperazinyl)-3-methoxybenzyl)-N,N-diethylbenzamide
• Colforsin
• Morphine
• nociceptin
• Protein Kinase C
• Mitogen-Activated Protein Kinases
• Adenylyl Cyclases
• Nociceptin Receptor

Topics

• Adaptor Proteins, Signal Transducing (genetics, metabolism)
• Adenylyl Cyclases (genetics, metabolism)
• Animals
• Benzamides (pharmacology)
• Colforsin (pharmacology)
• Enkephalin, Ala(2)-MePhe(4)-Gly(5)- (pharmacology)
• HEK293 Cells
• Humans
• Mitogen-Activated Protein Kinases (genetics, metabolism)
• Morphine (pharmacology)
• Opioid Peptides (pharmacology)
• PC12 Cells
• Piperazines (pharmacology)
• Protein Kinase C (genetics, metabolism)
• RGS Proteins (genetics, metabolism)
• Rats
• Receptors, Opioid (genetics, metabolism)
• Receptors, Opioid, delta (agonists, genetics, metabolism)
• Receptors, Opioid, mu (agonists, genetics, metabolism)
• Signal Transduction (drug effects)
• Nociceptin Receptor