Activation of G protein by opioid receptors: role of receptor number and G-protein concentration.
Eur J Pharmacol
; 396(2-3): 67-75, 2000 May 19.
Article
em En
| MEDLINE
| ID: mdl-10822058
ABSTRACT
The collision-coupling model for receptor-G-protein interaction predicts that the rate of G-protein activation is dependent on receptor density, but not G-protein levels. C6 cells expressing mu- or delta-opioid receptors, or SH-SY5Y cells, were treated with beta-funaltrexamine (mu) or naltrindole-5'-isothiocyanate (delta) to decrease receptor number. The time course of full or partial agonist-stimulated ¿35SGTPgammaS binding did not vary in C6 cell membranes containing <1-25 pmol/mg mu-opioid receptor, or 1. 4-4.3 pmol/mg delta-opioid receptor, or in SHSY5Y cells containing 0. 16-0.39 pmol/mg receptor. The association of ¿35SGTPgammaS binding was faster in membranes from C6mu cells than from C6delta cells. A 10-fold reduction in functional G-protein, following pertussis toxin treatment, lowered the maximal level of ¿35SGTPgammaS binding but not the association rate. These data indicate a compartmentalization of opioid receptors and G protein at the cell membrane.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Receptores Opioides delta
/
Receptores Opioides mu
/
Proteínas de Ligação ao GTP
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Eur J Pharmacol
Ano de publicação:
2000
Tipo de documento:
Article
País de afiliação:
Estados Unidos