Tobin_1995_Br.J.Pharmacol_116_1723

Reference

Title : Relationship between agonist binding, phosphorylation and immunoprecipitation of the m3-muscarinic receptor, and second messenger responses - Tobin_1995_Br.J.Pharmacol_116_1723
Author(s) : Tobin AB , Willars GB , Burford NT , Nahorski SR
Ref : British Journal of Pharmacology , 116 :1723 , 1995
Abstract :

1. Phosphoinositidase C-linked m3-muscarinic receptors expressed in Chinese hamster ovary cells (CHO-m3 cells) are phosphorylated on serine following agonist stimulation. 2. m3-Muscarinic receptor phosphorylation is concentration-dependent requiring a carbachol concentration of 13.2 microM for half maximal stimulation. 3. The phosphorylation concentration-response curve lies to the left of the curve for carbachol binding to muscarinic receptors (KD = 100 microM) in membranes from CHO-m3 cells. In contrast, receptor phosphorylation closely correlates with receptor-mediated phosphoinositidase C activation (EC50 for inositol 1,4,5 trisphosphate accumulation during the peak and plateau phases were 7.14 microM and 5.92 microM respectively) but not with rapid agonist-mediated calcium elevation (EC50 = 0.32 microM) measured in fura-2-AM loaded cells. 4. These data suggest a dissociation of receptor phosphorylation from agonist occupation. Such an apparent 'receptor reserve' for m3-muscarinic receptor phosphorylation may be indicative of a mechanism that is dependent on a small amplification of the receptor signal, though probably dissociated from the calcium signal.

PubMedSearch : Tobin_1995_Br.J.Pharmacol_116_1723
PubMedID: 8528551

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Citations formats

Tobin AB, Willars GB, Burford NT, Nahorski SR (1995)
Relationship between agonist binding, phosphorylation and immunoprecipitation of the m3-muscarinic receptor, and second messenger responses
British Journal of Pharmacology 116 :1723

Tobin AB, Willars GB, Burford NT, Nahorski SR (1995)
British Journal of Pharmacology 116 :1723