M2 Muscarinic Acetylcholine Receptor Phosphorylation Assays
Functionally, M2 muscarinic receptors are able to couple to the pertusiss toxin-sensitive Gi/o-proteins. M2 receptors are expressed in the heart where they have a profound role in the control of cardiac myocyte contraction. In fact, acetylcholine released from vagal parasympathetic neurones reduces heart beating frequency almost exclusively by acting at M2 muscarinic receptors. M2 receptor activity is regulated by phosphorylation of serine271, serine282/serine283, serine286/threonine287/serine288, threonine307/serine309, threonine310/serine311, serine315/serine320 in the 3rd intracellular loop. This nomenclature refers to the human M1 but is highly conserved in mice and rats. For more information on M2 receptor pharmacology please refer to the IUPHAR database. For further reading refer to:
Caulfield MP, Birdsall NJ. International Union of Pharmacology. XVII. Classification of muscarinic acetylcholine receptors. Pharmacol Rev. 1998 Jun;50(2):279-90. PMID: 9647869.
Wess J, Eglen RM, Gautam D. Muscarinic acetylcholine receptors: mutant mice provide new insights for drug development. Nat Rev Drug Discov. 2007 Sep;6(9):721-33. doi: 10.1038/nrd2379. PMID: 17762886.
Birdsall NJM, Bradley S, Brown DA, Buckley NJ, Challiss RJ, Christopoulos A, Eglen RM, Ehlert F, Felder CC, Hammer R, Kilbinger HJ, Lambrecht G, Langmead C, Mitchelson F, Mutschler E, Nathanson NM, Schwarz RD, Thal D, Tobin AB, Valant C, Wess J. Acetylcholine receptors (muscarinic) in GtoPdb v.2021.3. IUPHAR/BPS Guide to Pharmacology CITE. 2021; 2021(3).