Evidence for the stabilisation of the high-affinity state of beta-adrenoceptors by an endogenous factor in rat brain

Pharmacological Research : the Official Journal of the Italian Pharmacological Society
V GarnierJ P Tillement

Abstract

Inhibition of binding of the labelled antagonist (-)[3H]CGP 12177 by the full agonist (-)isoproterenol results in shallow competition curves, characteristic of the presence of both high- and low-affinity states of beta-adrenoceptors (betaAR). When in excess, the GTP analog 5'-guanylylimidodiphosphate (GppNHp) is expected to convert all receptors in the high-affinity state to the low-affinity state. However, in the rat cortex and cerebellum synaptosomes, a proportion of the betaAR in the high-affinity state was GppNHp-insensitive. This apparent GppNHp-insensitivity decreased with decreasing temperature of incubation. Moreover, it was totally abolished by the gentle treatment of membranes with 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS). We propose that a protein factor interacts with the betaAR/Gs protein complex and that it induces the GppNHp-insensitivity. This factor would be released by CHAPS in a functional form because it may regenerate the GppNHp-insensitivity after concentration and reconstitution with CHAPS-treated membranes. It is likely that the factor acts as a stabiliser of betaAR in the high-affinity state.

Citations

Jun 25, 2005·Obesity Research·Marci B StrouchGale B Carey
Jul 23, 2011·Journal of Neurochemistry·Jonathan D VerrierEdwin K Jackson
Jun 4, 2002·The Journal of Physiology·Francesca Di SoleCorinna Helmle-Kolb
Jan 27, 2016·Journal of Neurochemistry·Edwin K JacksonPatrick M Kochanek
Dec 25, 2007·British Journal of Pharmacology·T ChiavegattiR O Godinho

❮ Previous
Next ❯

Related Concepts

Related Feeds

Adrenergic Receptors: Trafficking

Adrenergic receptor trafficking is an active physiological process where adrenergic receptors are relocated from one region of the cell to another or from one type of cell to another. Discover the latest research on adrenergic receptor trafficking here.