M5 Muscarinic Acetylcholine Receptor Antibodies

The M5 muscarinic acetylcholine receptor, encoded by the CHRM5 gene, is the least abundant muscarinic receptor subtype and is primarily expressed in dopaminergic neurons of the midbrain, cerebral blood vessels, and selected regions of the central nervous system. M5 predominantly couples to Gq/11 proteins, activating phospholipase C signaling and increasing intracellular calcium levels. It is involved in the regulation of dopamine release, cerebral blood flow, and reward-related behaviors. M5 expression is tightly regulated by developmental and tissue-specific transcriptional mechanisms, while receptor activity can be modulated through phosphorylation, desensitization, and internalization. Altered M5 signaling has been implicated in addiction, neurodegenerative disorders, and cerebrovascular dysfunction. Despite its therapeutic potential, no M5-selective drugs have been approved for clinical use to date. Several experimental antagonists and negative allosteric modulators have shown promising results in preclinical studies for reducing drug-seeking behavior and modulating dopaminergic signaling. Continued research aims to develop selective M5-targeted compounds for neurological and psychiatric disorders. For more information on M5 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).