The rat GPRC6A: Cloning and characterization

Wellendorph, Petrine; Burhenne, Nicole; Christiansen, Bo; Walter, Bettina; Schmale, Hartwig; Bräuner‐Osborne, Hans

doi:10.1016/j.gene.2007.03.008

Cited by 49 publications

(49 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This finding is in accordance with previously published data showing that GPRC6A is a promiscuous L-a-amino acid-sensing receptor with a preference for basic amino acids activating an endogenous calcium-sensitive chloride channel in Xenopus laevis oocytes (Kuang et al, 2005;Wellendorph et al, 2005). Previously, a 2Â2-hour washing protocol and a signal-enhancing mutated G q(G66D) protein construct were requisites for achieving responses through the G q pathway in mammalian cell lines Wellendorph et al, 2007), but this is not a necessity in the current setup. To our knowledge, this is the first time that robust G q protein activation has been demonstrated for the GPRC6A receptor without using techniques for improving signaling or assays that do not measure G protein pathways directly.…”

supporting

confidence: 92%

Delineation of the GPRC6A Receptor Signaling Pathways Using a Mammalian Cell Line Stably Expressing the Receptor

Jacobsen

Nørskov-Lauritsen

Thomsen

et al. 2013

J Pharmacol Exp Ther

Self Cite

View full text Add to dashboard Cite

The GPRC6A receptor is a recently "deorphanized" class C G protein-coupled receptor. We and others have shown that this receptor is coactivated by basic L-a-amino acids and divalent cations, whereas other groups have also suggested osteocalcin and testosterone to be agonists. Likewise, the GPRC6A receptor has been suggested to couple to multiple G protein classes albeit via indirect methods. Thus, the exact ligand preferences and signaling pathways are yet to be elucidated. In the present study, we generated a Chinese hamster ovary (CHO) cell line that stably expresses mouse GPRC6A. In an effort to establish fully the signaling properties of the receptor, we tested representatives of four previously reported GPRC6A agonist classes for activity in the G q , G s , G i , and extracellular-signal regulated kinase signaling pathways. Our results confirm that GPRC6A is activated by basic L-a-amino acids and divalent cations, and for the first time, we conclusively show that these responses are mediated through the G q pathway. We were not able to confirm previously published data demonstrating G i -and G s -mediated signaling; neither could we detect agonistic activity of testosterone and osteocalcin. Generation of the stable CHO cell line with robust receptor responsiveness and optimization of the highly sensitive homogeneous time resolved fluorescence technology allow fast assessment of G q activation without previous manipulations like cotransfection of mutated G proteins. This cell-based assay system for GPRC6A is thus useful in highthroughput screening for novel pharmacological tool compounds, which are necessary to unravel the physiologic function of the receptor.

show abstract

supporting

confidence: 92%

Delineation of the GPRC6A Receptor Signaling Pathways Using a Mammalian Cell Line Stably Expressing the Receptor

Jacobsen

Nørskov-Lauritsen

Thomsen

et al. 2013

J Pharmacol Exp Ther

Self Cite

View full text Add to dashboard Cite

show abstract

“…4) (Kuang et al, 2005;Wellendorph et al, 2005Wellendorph et al, , 2007Christiansen et al, 2007). As observed for T1R1/ T1R3, amino acid potency rank orders and efficacies differ among orthologs of mouse, rat, and human receptors .…”

Section: Promiscuous L-amino Acid-sensing Receptorsmentioning

confidence: 88%

“…As observed for T1R1/ T1R3, amino acid potency rank orders and efficacies differ among orthologs of mouse, rat, and human receptors . Using heterologous expression systems, we and others have found that the L-␣-amino acid and Mg 2ϩ in physiologically relevant concentrations (Kuang et al, 2005;Christiansen et al, 2007;Wellendorph et al, 2007) and one report has even demonstrated a direct activation of GPRC6A by Ca 2ϩ (Pi et al, 2005). GPRC6A can thus be speculated to act in concert with CaR, supposedly in a reciprocal fashion, to sense a wide range of both L-amino acids and Ca 2ϩ in plasma or perhaps even in the GI tract.…”

Section: Promiscuous L-amino Acid-sensing Receptorsmentioning

confidence: 90%

“…Given the strikingly broad sensitivity to L-amino acids and the expression of GPRC6A in organs and tissues such as taste tissue, pancreatic islets, liver, skeletal muscle, bone, and fat ( Fig. 3) (Wellendorph and Brä uner-Osborne, 2004;Kuang et al, 2005;Pi et al, 2005;Regard et al, 2007;Wellendorph et al, 2007;), GPRC6A represents a plausible nutrient-sensing receptor (Conigrave and Hampson, 2006). In further support of this, the closely related goldfish odorant receptor 5.24 functions as a nutrient sensor for L-amino acids in sensory tissue of the goldfish (Speca et al, 1999).…”

Section: Promiscuous L-amino Acid-sensing Receptorsmentioning

confidence: 90%

See 1 more Smart Citation

Molecular Pharmacology of Promiscuous Seven Transmembrane Receptors Sensing Organic Nutrients

2009

Self Cite

View full text Add to dashboard Cite

A number of highly promiscuous seven transmembrane (7TM) receptors have been cloned and characterized within the last few years. It is noteworthy that many of these receptors are activated broadly by amino acids, proteolytic degradation products, carbohydrates, or free fatty acids and are expressed in taste tissue, the gastrointestinal tract, endocrine glands, adipose tissue, and/or kidney. These receptors thus hold the potential to act as sensors of food intake, regulating, for example, release of incretin hormones from the gut, insulin/glucagon from the pancreas, and leptin from adipose tissue. The promiscuous tendency in ligand recognition of these receptors is in contrast to the typical specific interaction with one physiological agonist seen for most receptors, which challenges the classic "lock-and-key" concept. We here review the molecular mechanisms of nutrient sensing of the calcium-sensing receptor, the G protein-coupled receptor family C, group 6, subtype A (GPRC6A), and the taste1 receptor T1R1/T1R3, which are sensing L-␣-amino acids, the carbohydrate-sensing T1R2/T1R3 receptor, the proteolytic degradation product sensor GPR93 (also termed GPR92), and the free fatty acid (FFA) sensing receptors FFA1, FFA2, FFA3, GPR84, and GPR120. The involvement of the individual receptors in sensing of food intake has been validated to different degrees because of limited availability of specific pharmacological tools and/or receptor knockout mice. However, as a group, the receptors represent potential drug targets, to treat, for example, type II diabetes by mimicking food intake by potent agonists or positive allosteric modulators. The ligand-receptor interactions of the promiscuous receptors of organic nutrients thus remain an interesting subject of emerging functional importance.In 1894, Emil Fischer published the landmark article in which he for the first time described the "lock-and-key" concept for enzyme-substrate interactions (Fischer, 1894). A few decades later, this concept was transferred to receptors by Paul Ehrlich and John Newport Langley when they studied receptors and their interactions with ligands (for review, see Limbird, 2004;Rang, 2004). A literal interpretetation of the "lock-and-key" concept suggests that each receptor only has one physiological agonist, which is also in line with the naming of the vast majority of liganded receptors by their main endogenous agonist (e.g., acetylcholine receptor, glutamate receptor). During the following decades, receptors were shown to adhere to this scheme, although some exceptions were discovered, such as the adrenergic receptor subtypes responding to both endogenous epinephrine and norepinephrine, albeit with different rank orders (Ahlquist, 1948). However, during the last few years, a number of receptors have been cloned and characterized that are highly promiscuous and thus respond to a range of natural agonists. In addition,

show abstract

“…It has been reported that a chimeric receptor consisting of the goldfish 5.24 (mammalian GPRC6A homolog) outer membrane domain and the mouse GPRC6A trans-and intramembrane domains is activated by GSH but that neither a chimeric receptor consisting of the GPRC6A outer membrane domain and 5.24 trans-and intramembrane domains nor full-length GPRC6A itself is functionally active (28). Wellendorph et al (30) reported that GPRC6A is expressed in rat taste bud-containing epithelia. However, in our experiment, GPRC6A mRNA A, human sensory analyses of the CaSR agonists were performed to determine the kokumi taste with known CaSR agonists.…”

Section: Discussionmentioning

confidence: 99%

Involvement of the Calcium-sensing Receptor in Human Taste Perception

Ohsu

Amino

Nagasaki

et al. 2010

Journal of Biological Chemistry

290

287

View full text Add to dashboard Cite

By human sensory analyses, we found that various extracellular calcium-sensing receptor (CaSR) agonists enhance sweet, salty, and umami tastes, although they have no taste themselves. These characteristics are known as "kokumi taste" and often appear in traditional Japanese cuisine. Although GSH is a typical kokumi taste substance (taste enhancer), its mode of action is poorly understood. Here, we demonstrate how the kokumi taste is enhanced by the CaSR, a close relative of the class C G-protein-coupled receptors T1R1, T1R2, and T1R3 (sweet and umami receptors). We identified a large number of CaSR agonist ␥-glutamyl peptides, including GSH (␥-Glu-Cys-Gly) and ␥-Glu-Val-Gly, and showed that these peptides elicit the kokumi taste. Further analyses revealed that some known CaSR agonists such as Ca 2؉ , protamine, polylysine, L-histidine, and cinacalcet (a calcium-mimetic drug) also elicit the kokumi taste and that the CaSR-specific antagonist, NPS-2143, significantly suppresses the kokumi taste. This is the first report indicating a distinct function of the CaSR in human taste perception.

show abstract

The rat GPRC6A: Cloning and characterization

Cited by 49 publications

References 48 publications

Delineation of the GPRC6A Receptor Signaling Pathways Using a Mammalian Cell Line Stably Expressing the Receptor

Delineation of the GPRC6A Receptor Signaling Pathways Using a Mammalian Cell Line Stably Expressing the Receptor

Molecular Pharmacology of Promiscuous Seven Transmembrane Receptors Sensing Organic Nutrients

Involvement of the Calcium-sensing Receptor in Human Taste Perception

Contact Info

Product

Resources

About