G<sub>Z</sub> coupling to the rat κ‐opioid receptor

Lai, Helen W.L.; Minami, Masabumi; Satoh, Masamichi; Wong, Yung Hou

doi:10.1016/0014-5793(95)00088-q

Cited by 52 publications

(49 citation statements)

References 20 publications

(27 reference statements)

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“…Because the receptors of the opioid family are very similar in their pharmacology and specificity for coupling to G proteins, we investigated whether the DOR and the KOR would likewise be able to induce IP formation through Ga16. As we have previously established the amount of opioid receptor eDNA needed for analyzing receptormediated signal transductions in transient transfection systems (Lai et al, 1995;Tsu et al, 1995a), we examined the effect of transfecting COS-7 cells with DOR eDNA at 0.25 ,ug/ml in the absence or presence of varying amounts of Ga16 eDNA (Fig. 1).…”

Section: Resultsmentioning

confidence: 99%

“…Because the MOR has been shown to interact with Ga16 (Offermanns and Simon, 1995), the present study examines the possible coupling of Ga16 to other subtypes (DOR and KOR) within the opioid receptor family. We have previously demonstrated that the ability of opioid receptors to interact with different G proteins can be conveniently assessed by transient transfection assays (Chan et a!., 1995;Lai et al, 1995;Tsu et al, 1995a). Thus, we monitored 16 coupling by cotransfecting COS-7 cells with cDNAs encoding Ga16 and an opioid receptor, followed by the determination of agonist-induced formation of inositol phosphates (IPs) in the transfected cells.…”

mentioning

confidence: 99%

“…Although the physiological functions regulated by the three opioid receptors are somewhat different, their capacity to interact with various G proteins appears almost identical. For example, all three opioid receptors can inhibit adenylyl cyclase via the PTXinsensitive G~protein (Chan et al, 1995;Lai et al, 1995;Tsu et al, 1995a). Because the MOR has been shown to interact with Ga16 (Offermanns and Simon, 1995), the present study examines the possible coupling of Ga16 to other subtypes (DOR and KOR) within the opioid receptor family.…”

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confidence: 99%

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Differential Coupling of μ‐, δ‐, and κ‐Opioid Receptors to Gα₁₆‐Mediated Stimulation of Phospholipase C

Lee

Joshi

Chan

et al. 1998

Journal of Neurochemistry

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105

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The~i-opioidreceptor has recently been shown to stimulate phosphoinositide-specific phospholipase C via the pertussis toxin-sensitive G15 protein. Given the promiscuous nature of G16 and the high degree of resemblance of signaling properties of the three opioid receptors, both 6-and K-opioid receptors are likely to activate G16. Interactions of 6-and K-opioid receptors with G15 were examined by coexpressing the oploid receptors and Ga15 in COS-7 cells. The 6-selective agonist [D-Pen 2,DPen5] enkephalin potently stimulated the formation of mositol phosphates in cells coexpressing the 6-opioid receptorand Ga 16. The 6-opioid receptor-mediated stimulation of phospholipase C was absolutely dependent on the coexpression of Ga16 and exhibited appropriate ligand selectivity and dose dependency. Similar transfection studies revealed only weak stimulation by the pi-opioid receptor, whereas the K-opioid receptor produced moderate phospholipase C activity. Ga16 thus appeared to interact differentially with the three opioid receptors. Radioligand binding assays indicate that the 1i-opioid receptor was expressed at a lower level than those of the 6-and K-Opioid receptors. To examine if differential coupling to Ga16 is prevalent, a panel of G5-or G1-coupled receptors was coexpressed with Ga16 in COS-7 cells and assayed for agonist-induced stimulation of phospholipase C. Activation of a2-and /12-adrenergic, dopamine D1 and D2, adenosine A1, somatostatin-l and -2, C5a, formyl peptide, and luteinizing hormone receptors all resulted in stimulation of phospholipase C, with maximal stimulations ranging from 1 .5-to almost 17-fold. These findings suggest that the promiscuous Ga16 can in fact discriminate among different receptors and that such preferential interaction might in part be due to the abundance of receptors.

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Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

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confidence: 99%

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Differential Coupling of μ‐, δ‐, and κ‐Opioid Receptors to Gα₁₆‐Mediated Stimulation of Phospholipase C

Lee

Joshi

Chan

et al. 1998

Journal of Neurochemistry

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105

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“…Thus, introduction of GTP-␥-S into cells would activate the entire complement of HEK293 cell G-proteins (Zhou et al, 1995;Zong et al, 1995). Furthermore, we also used somatostatin receptors (Law et al, 1993;Shapiro and Hille, 1993;Reisine and Bell, 1995) and opioid receptors (Shen and Crain, 1994;Avidor-Reiss et al, 1995;Ikeda et al, 1995;Lai et al, 1995;Tallent et al, 1995), both of which can activate a wide variety of G-proteins. Interestingly, all of these manipulations produced robust inhibition of ␣ 1B channels, which had the same ancillary subunit composition as the ␣ 1E channels.…”

Section: Discussionmentioning

confidence: 99%

Selective G-Protein Regulation of Neuronal Calcium Channels

Tóth¹,

Shekter²,

Hui³

et al. 1996

J. Neurosci.

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We examined the properties and regulation of Ca channels resulting from the expression of human ␣ 1B and ␣ 1E subunits stably expressed in HEK293 cells. The ancillary subunits ␤ 1B and ␣ 2 /␦ were also stably expressed in these cell lines. Ca currents in ␣ 1B -expressing cells had the properties of N-type currents. Ca currents in cells expressing ␣ 1E exhibited a novel profile that was similar to the properties of the "R type" Ca current. Introduction of GTP-␥-S into ␣ 1B cells greatly enhanced the extent of prepulse facilitation of the Ca current, whereas it had only a very small effect in ␣ 1E -expressing cells. Activation of somatostatin receptors endogenous to HEK293 cells or opioid receptors, expressed in the cells after transfection, inhibited Ca currents in ␣ 1B -expressing cells. This inhibition was blocked by pertussis toxin and was partially relieved by a depolarizing prepulse. In contrast, no inhibitory effects were noted in cells expressing ␣ 1E channels under the same circumstances. HEK293 cells normally contained G-proteins from all of the four major families. Inhibition of Ca currents by agonists in ␣ 1B -expressing cells was enhanced slightly by the cotransfection of several G-protein ␣ subunits. agonists, however, had no effect in ␣ 1E -containing cells, even after overexpression of different G-protein ␣-subunits. In summary, these results demonstrate that there is a large difference in the susceptibility of ␣ 1B -and ␣ 1E -based Ca channels to regulation by G-proteins. This is so despite the fact that the two types of Ca channels show substantial similarities in their primary sequences.

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“…dopamine-D2, adenosine-A1, formyl peptide, complement C5a, and all three types of opioid receptors [8][9][10][11][12]. Although there is no indication of melatonin-mediated stimulation of adenylyl cyclase nor of possible coupling to PTX-insensitive G proteins, it is conceivable that the melatonin receptor may behave like the other G~-coupled receptors.…”

Section: Introductionmentioning

confidence: 99%

Stimulation of cAMP accumulation by the cloned Xenopus melatonin receptor through G_i and G_z proteins

1995

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The Xenopus melatonin receptor was expressed in human embryonic kidney 293 cells and assayed for cAMP accumulation. In transfected 293 cells expressing the melatonin receptor, melatonin dose-dependently inhibited the endogenous adenylyi cyclases. In contrast, melatonin stimulated the accumulation of cAMP in cells co-expressing the type II adenylyl cyclase. Both the inhibitory and stimulatory responses to melatonin were mediated via Gi-like proteins as they were blocked by pertussis toxin. Upon co-transfection with the oz subunit of G~, the ability of melatonin to regulate both type H and the endogenous adenylyl cyclases became refractory to pertussis toxin, indicating that the melatonin receptor can also couple to Gz. However, other pertussis toxin-insensitive G proteins such as Gq, G~2 and G13 were unable to interact with the melatonin receptor.

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G_Z coupling to the rat κ‐opioid receptor

Cited by 52 publications

References 20 publications

Differential Coupling of μ‐, δ‐, and κ‐Opioid Receptors to Gα₁₆‐Mediated Stimulation of Phospholipase C

Differential Coupling of μ‐, δ‐, and κ‐Opioid Receptors to Gα₁₆‐Mediated Stimulation of Phospholipase C

Selective G-Protein Regulation of Neuronal Calcium Channels

Stimulation of cAMP accumulation by the cloned Xenopus melatonin receptor through G_i and G_z proteins

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GZ coupling to the rat κ‐opioid receptor

Cited by 52 publications

References 20 publications

Differential Coupling of μ‐, δ‐, and κ‐Opioid Receptors to Gα16‐Mediated Stimulation of Phospholipase C

Differential Coupling of μ‐, δ‐, and κ‐Opioid Receptors to Gα16‐Mediated Stimulation of Phospholipase C

Selective G-Protein Regulation of Neuronal Calcium Channels

Stimulation of cAMP accumulation by the cloned Xenopus melatonin receptor through Gi and Gz proteins

Contact Info

Product

Resources

About

G_Z coupling to the rat κ‐opioid receptor

Differential Coupling of μ‐, δ‐, and κ‐Opioid Receptors to Gα₁₆‐Mediated Stimulation of Phospholipase C

Differential Coupling of μ‐, δ‐, and κ‐Opioid Receptors to Gα₁₆‐Mediated Stimulation of Phospholipase C

Stimulation of cAMP accumulation by the cloned Xenopus melatonin receptor through G_i and G_z proteins