Search results for "GPCR"
showing 10 items of 20 documents
Guanosine-Induced Antiproliferative Effects Are Modulated by GPCR Expression in Human Glioma and Melanoma Cell Lines.
2012
Guanosine-Induced Antiproliferative Effects Are Modulated by GPCR Expression in Human Glioma and Melanoma Cell Lines.
Origin of neuronal-like receptors in Metazoa: cloning of a metabotropic glutamate/GABA-like receptor from the marine sponge Geodia cydonium.
1999
To date, no conclusive evidence has been presented for the existence of neuronal-like elements in Porifera (sponges). In the present study, isolated cells from the marine sponge Geodia cydonium are shown to react to the excitatory amino acid glutamate with an increase in the concentration of intracellular calcium [Ca2+]i. This effect can also be observed when the compounds L-quisqualic acid (L-QA) or L-(+)-2-amino-4-phosphonobutyric acid (L-AP-4) are used. The effect of L-QA and L-AP-4, both agonists for metabotropic glutamate receptors (mGluRs), can be abolished by the antagonist of group I mGluRs, (RS)-alpha-methyl-4-carboxyphenylglycine. These data suggest that sponge cells contain an mG…
Understanding and Controlling Food Protein Structure and Function in Foods: Perspectives from Experiments and Computer Simulations
2020
The structure and interactions of proteins play a critical role in determining the quality attributes of many foods, beverages, and pharmaceutical products. Incorporating a multiscale understanding of the structure–function relationships of proteins can provide greater insight into, and control of, the relevant processes at play. Combining data from experimental measurements, human sensory panels, and computer simulations through machine learning allows the construction of statistical models relating nanoscale properties of proteins to the physicochemical properties, physiological outcomes, and tastes of foods. This review highlights several examples of advanced computer simulations at mol…
Recombinant expression, in vitro refolding, and biophysical characterization of the N-terminal domain of T1R3 taste receptor
2012
Facteur d'impact (5 ans) : 1,617Notoriété à 2 ans : Acceptable (biochem.res.methods); The sweet taste receptor is a heterodimeric receptor composed of the T1R2 and T1R3 subunits, while T1R1 and T1R3 assemble to form the umami taste receptor. T1R receptors belong to the family of class C G-protein coupled receptors (GPCRs). In addition to a transmembrane heptahelical domain, class C GPCRs have a large extracellular N-terminal domain (NTD), which is the primary ligand-binding site. The T1R2 and T1R1 subunits have been shown to be responsible for ligand binding, via their NTDs. However, little is known about the contribution of T1R3-NTD to receptor functions. To enable biophysical characteriza…
Interactions between cholinergic and fibroblast growth factor receptors in brain trophism and plasticity
2014
Acetylcholine, acting on both nicotinic receptors (nAChRs) and muscarinic receptors (mAChRs), plays a role in the regulation of synaptic plasticity, being involved in the regulation of cellular processes and cognitive functions, such as learning, memory and attention. Recently, G protein coupled receptors (GPCRs), including mAChRs, have been reported to transactivate tyrosine-kinase receptors (RTK), such as epidermal growth factor receptor (EGFR), and initiate their intracellular signaling. In this minireview we have first analysed the RTK transactivation mechanisms, involving cholinergic receptors, and thereafter the interplay between AChR and neurotrophic factor systems built up by FGF2 a…
An efficient Escherichia coli expression system for the production of a functional N-terminal domain of the T1R3 taste receptor.
2012
http://www.landesbioscience.com/; International audience; Sweet taste is mediated by a dimeric receptor composed of two distinct subunits, T1R2 and T1R3, whereas the T1R1/T1R3 receptor is involved in umami taste perception. The T1R1, T1R2, and T1R3 subunits are members of the small family of class C G protein-coupled receptors (GPCRs). The members of this family are characterized by a large N-terminal domain (NTD), which is structurally similar to bacterial periplasmic-binding proteins and contains the primary ligand-binding site. In a recent study, we described a strategy to produce a functional dimeric human T1R3-NTD. Although the protein was expressed as inclusion bodies (IBs) using the …
Pharmacological Characterization of Loss of Function Mutations of the Human Melanocortin 1 Receptor That Are Associated with Red Hair
2004
Variation in skin color is the major host risk factor for melanoma and other forms of skin cancer. Individuals with red hair show an increased ratio of phaeomelanin to eumelanin in both hair and skin. This ratio is regulated by the melanocortin (MC) 1 receptor. There are several common point mutations in the human MC1 receptor that are overrepresented in North European red-heads, and in individuals with pale skin. In order to determine the functional significance of these mutations, we expressed the Asp84Glu, Val92Met, Arg163Gln, and Asp294His variants of the human MC1 receptors in eukaryotic cells and determined their ability to bind alpha-melanocyte stimulating hormone (MSH) peptides and …
Pharmacological comparison of rat and human melanocortin 3 and 4 receptors in vitro.
2002
Abstract The melanocortin 3 and 4 receptors are G-protein-coupled receptors found in the hypothalamus with important role in regulation of the energy balance. In this study, we performed pharmacological comparison of the rat and human melancortin (MC) 3 and MC4 receptors. We transiently expressed the genes for these receptors individually in a mammalian cell line and determined the binding affinities to several MSH peptides. The results showed no major difference between the rat and human MC3 receptors while the rat MC4 receptor had higher affinity to several peptides compared with the human MC4 receptor. NDP-, α-, β-, γ-MSH, ACTH(1–24), HS014 and MTII had from 5- to 34-fold higher affinity…
Mitochondrial DNA deletion and male infertility
2009
Abstract The term “male infertility” does not constitute a defined clinical syndrome, but rather, a collection of different conditions exhibiting a variety of aetiologies and varying diagnosis. In men, oligozoospermia, asthenozoospermia, teratozoospermia and azoospermia are the main causes of infertility. The present research is aimed to investigate if mtDNA deletions can cause sperm defects in idiopathic astenozoospermic patients with different sperm motility and sperm concentration. The incidence of deletions in mtDNA (mtDNA) was co-related with diagnostic categorization of male infertility when 6.6kb out of the 16.6kb of the mitochondrial genome was amplified from whole sperm samples, f…
Expression and characterization of the human sweet taste receptor expressed in a mammalian inducible cell line
2018
International audience; Sweet taste perception is mediated by a heterodimeric receptor composed of the two distinct protein subunits, TAS1R2 and TAS1R3. TAS1R2 and TAS1R3 subunits are members of the small family of class C GPCRs. Class C GPCRs share a large N-terminal domain (NTD) linked to the heptahelical transmembrane domain by a cysteine-rich region. TAS1R2/TAS1R3 is the primary receptor for a diverse range of sweet compounds including natural sugars, sweet amino acids, artificial sweeteners and plant sweet-tasting proteins. In order to understand the molecular mechanisms that govern receptor – ligand interactions and the relative contribution of the two subunits to the detection of swe…