Muscarinic acetylcholine receptor M1

The muscarinic acetylcholine receptor M1, also known as the cholinergic receptor, muscarinic 1, is a muscarinic receptor.

This receptor is found mediating slow EPSP at the ganglion in the postganglionic nerve, is common in exocrine glands and in the CNS.

It is predominantly found bound to G proteins of class Gq which use upregulation of phospholipase C and therefore inositol trisphosphate and intracellular calcium as a signalling pathway. A receptor so bound would not be susceptible to CTX or PTX. However, Gi (causing a downstream decrease in cAMP) and Gs (causing an increase in cAMP) have also been shown to be involved in interactions in certain tissues, and so would be susceptible to PTX and CTX respectively.

Effects

 * EPSP in autonomic ganglia
 * secretion from salivary glands
 * gastric acid secretion from stomach
 * In CNS (memory?)
 * vagally-induced bronchoconstriction

Mechanism
It couples to Gq, and, to a small extent, Gi andGs. This results in slow EPSP and decreasedK+ conductance

Agonists

 * acetylcholine
 * oxotremorine
 * carbachol
 * McNA343

Antagonists

 * atropine
 * dicycloverine
 * tolterodine
 * oxybutynin
 * ipratropium
 * mamba toxin MT7
 * pirenzepine
 * telenzepine

Gene
The receptor is encoded by human gene CHRM1. It is localized to 11q13.