GTPγS Assay for Measuring Agonist-Induced Desensitization of Two Human Polymorphic Alpha2B-Adrenoceptor Variants.
Methods Mol Biol
; 2547: 267-273, 2022.
Article
em En
| MEDLINE
| ID: mdl-36068469
ABSTRACT
α2-Adrenergic receptors (ARs) mediate many cellular actions of epinephrine and norepinephrine, including inhibition of their secretion (sympathetic inhibition) from adrenal chromaffin cells. Like many other G protein-coupled receptors (GPCRs), they undergo agonist-dependent phosphorylation and desensitization by GPCR kinases (GRKs), a phenomenon recently shown to play a major role in the sympathetic overdrive that accompanies and aggravates chronic heart failure. A three-glutamic acid deletion polymorphism in the human α2B-AR subtype gene (Glu301-303) causes impaired agonist-promoted receptor phosphorylation and desensitization, resulting in enhanced signaling to inhibition of cholinergic-induced catecholamine secretion in adrenal chromaffin cells. One of the various pharmacological assays that can be used to quantify and quantitatively compare the degrees of agonist-dependent desensitization, i.e., G protein decoupling, of these two polymorphic α2B-AR variants (or of any two GPCRs for that matter) is the guanosine-5'-O-3-thiotriphosphate (GTPγS) assay that can directly quantify heterotrimeric G protein activation.
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Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Norepinefrina
/
Proteínas Heterotriméricas de Ligação ao GTP
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article