Neuromedin B receptor, expressed in Xenopus laevis oocytes, selectively couples to Gαq and not Gα11

Shapira, Hagit; Way, James; Lipinsky, Dafna; Oron, Yoram; Battey, James F.

doi:10.1016/0014-5793(94)00570-2

Cited by 46 publications

(30 citation statements)

References 32 publications

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“…Similar pertussis toxin-insensitive activations of phospholipase C leading to intracellular Ca 2ϩ signals have been shown previously for the expression of other G-protein-coupled receptors in Xenopus oocytes, including the M 3 -muscarinic receptor (Stehno-Bittel et al, 1995), the thyrotropin-releasing hormone receptor (Quick et al, 1994;de la Penna et al, 1995), and the neuromedin B receptor (Shapira et al, 1994). This again contrasts with studies on the expression of vertebrate D1-like receptors in rat pituitary GH 4 C 1 cells and SK-N-MC neuroblastoma cells in which no evidence of coupling to G q␣ could be found (Kimura et al, 1995).…”

Section: Discussionsupporting

confidence: 72%

Agonist-Specific Coupling of a ClonedDrosophila melanogasterD1-Like Dopamine Receptor to Multiple Second Messenger Pathways by Synthetic Agonists

et al. 1997

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The mechanism of coupling of a cloned Drosophila D1-like dopamine receptor, DopR99B, to multiple second messenger systems when expressed in Xenopus oocytes is described. The receptor is coupled directly to the generation of a rapid, transient intracellular Ca 2ϩ signal, monitored as changes in inward current mediated by the oocyte endogenous Ca 2ϩ -activated chloride channel, by a pertussis toxin-insensitive G-proteincoupled pathway. The more prolonged receptor-mediated changes in adenylyl cyclase activity are generated by an independent G-protein-coupled pathway that is pertussis toxinsensitive but calcium-independent, and G ␤␥ -subunits appear to be involved in the transduction of this response. This is the first evidence for the direct coupling of a cloned D1-like dopamine receptor both to the activation of adenylyl cyclase and to the initiation of an intracellular Ca 2ϩ signal. The pharmacological profile of both second messenger effects is identical for a range of naturally occurring catecholamine ligands (dopamine Ͼ norepinephrine Ͼ epinephrine) and for the blockade of dopamine responses by a range of synthetic antagonists. However, the pharmacological profiles of the two second messenger responses differ for a range of synthetic agonists. Thus, the receptor exhibits agonist-specific coupling to second messenger systems for synthetic agonists. This feature could provide a useful tool in the genetic analysis of the roles of the multiple second messenger pathways activated by this receptor, given the likely involvement of dopamine in the processes of learning and memory in the insect nervous system.

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Section: Discussionsupporting

confidence: 72%

Agonist-Specific Coupling of a ClonedDrosophila melanogasterD1-Like Dopamine Receptor to Multiple Second Messenger Pathways by Synthetic Agonists

et al. 1997

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“…In an Xenopus oocyte assay with the injection of antisense oligonucleotides, G ␣q was identified as a mediator of the BB 1 receptor response (Shapira et al, 1994). With an in situ reconstitution assay with purified G protein ␣ subunits, it was found that cells expressing the BB 1 receptor activated G ␣q , but not G ␣t or G ␣i/o .…”

Section: G Bb 1 Receptor Signaling Activation and Modulatorymentioning

confidence: 99%

International Union of Pharmacology. LXVIII. Mammalian Bombesin Receptors: Nomenclature, Distribution, Pharmacology, Signaling, and Functions in Normal and Disease States

Jensen

Battey

Spindel³

et al. 2007

Pharmacol Rev

469

720

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“…The initial inward deflection prior to IP 3 or Ca 2ϩ injection is a mechanical artifact due to insertion of the injection pipette. for other pertussis toxin-insensitive G proteins, including G␣ q and G␣ 11 , have been cloned from Xenopus (37,40). Using antibodies against the C-terminal sequence of mouse G q it has been shown that oocytes express several forms of the G q family of ␣ subunits (22).…”

Section: G␣ 16 Inhibition Of Ligand-induced CLmentioning

confidence: 99%

Desensitization of Inositol 1,4,5-Trisphosphate/Ca2+-induced Cl− Currents by Prolonged Activation of G Proteins in Xenopus Oocytes

Quick

Lester

Davidson

et al. 1996

Journal of Biological Chemistry

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Expression of G protein ␣ subunits of the G q family with various G protein-coupled receptors induces activation of an inositol 1,4,5-trisphosphate (IP 3 )/Ca 2؉ -mediated Cl ؊ conductance in Xenopus oocytes. Our present data show that two members of this family, the human G␣ 16 subunit and the murine homologue G␣ 15 , can induce both activation and inhibition of these agonistinduced currents. Although extremely low amounts (10 -50 pg) of injected G␣ 16 subunit cRNA cause modest (ϳ2-fold) enhancement of ligand-induced Cl ؊ currents in oocytes co-injected with thyrotropin-releasing hormone (TRH) receptor cRNA 48 h postinjection, larger G␣ 16 and G␣ 15 cRNA injections cause >10-fold inhibition of TRH or 5HT2c receptor responses. The inhibition is analyzed in this study. The inhibited currents are recovered if various G␤␥ subunit combinations are also expressed with the G␣ subunits. The constitutively active mutant, G␣ 16 Q212L, also causes a strong attenuation of the ligand-induced Cl ؊ currents, but this inhibition is not recovered by co-expression of G␤␥ subunits. These results indicate that the free G␣ subunit is responsible for the inhibitory signal. Although expression of TRH receptor alone produces maximum responses approximately 48 h after injection, co-expression of TRH receptor with G␣ 16 results in enhanced responses 6 -12 h postinjection, followed by complete attenuation at 36 h. Furthermore, injection of G␣ 16 cRNA alone at comparable levels gives rise to spontaneous Cl ؊ currents within 6 -12 h postinjection, suggesting that the early spontaneous activation underlies the later suppression. Expression of other G protein ␣ subunits of the G q family, at cRNA levels considerably higher than effective for G␣ 16 , produces both analogous spontaneous Cl ؊ currents and, later, inhibition of ligand-induced Cl ؊ currents. Experiments with direct injection of IP 3 and of Ca 2؉ suggest that this inhibition is consistent with the down-regulation of IP 3 receptors. These data indicate that both enhancement and inhibition of signaling through G protein-coupled receptors can be mediated by the expression level and/or activity of an individual G protein.Many hormones, neurotransmitters, and growth factors act via G protein-coupled receptors (GPCRs) 1 in a wide range of transduction processes. The phosphoinositide cascade, which controls calcium-stimulated processes such as secretion, chemotaxis, and fertilization, is regulated by G proteins. Phosphoinositide phospholipase C (PLC) catalyzes the hydrolysis of phosphatidyl 4,5-bisphosphate to generate two second messengers, inositol 1,4,5-trisphosphate (IP 3 ) and diacylglycerol. Diacylglycerol in turn activates protein kinase C; IP 3 binds to an intracellular IP 3 receptor/channel to release Ca 2ϩ stores (Ref.

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Neuromedin B receptor, expressed in Xenopus laevis oocytes, selectively couples to G_αq and not G_α11

Cited by 46 publications

References 32 publications

Agonist-Specific Coupling of a ClonedDrosophila melanogasterD1-Like Dopamine Receptor to Multiple Second Messenger Pathways by Synthetic Agonists

Agonist-Specific Coupling of a ClonedDrosophila melanogasterD1-Like Dopamine Receptor to Multiple Second Messenger Pathways by Synthetic Agonists

International Union of Pharmacology. LXVIII. Mammalian Bombesin Receptors: Nomenclature, Distribution, Pharmacology, Signaling, and Functions in Normal and Disease States

Desensitization of Inositol 1,4,5-Trisphosphate/Ca2+-induced Cl− Currents by Prolonged Activation of G Proteins in Xenopus Oocytes

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