Muscarinic acetylcholine receptor M1 (CHRM1) and muscarinic acetylcholine receptor M3 (CHRM3) (CHRM1, CHRM3)

Muscarinic acetylcholine receptor M1 (CHRM1) and muscarinic acetylcholine receptor M3 (CHRM3) are members of the G protein-coupled receptor (GPCR) family that mediate the effects of acetylcholine in the central and peripheral nervous systems. CHRM1 is primarily expressed in the CNS, where it regulates cognitive functions, memory, and synaptic plasticity, and modulates neurotransmitter release and interplay with glutamatergic systems, impacting conditions such as Alzheimer’s disease and schizophrenia. CHRM3 is broadly expressed in peripheral tissues including smooth muscle and exocrine glands, mediating contraction, secretion, and vascular responses such as nitric oxide-mediated vasodilation. Both CHRM1 and CHRM3 are implicated in diverse diseases; notably, CHRM3 promotes certain cancers and fibrotic responses, while CHRM1 may have protective or opposing roles depending on the context. These receptors are validated therapeutic targets, but successful clinical exploitation requires high subtype selectivity to avoid widespread adverse effects due to their pervasive physiological functions.

Other names

Muscarinic acetylcholine receptor 1M1 receptorM1RAcetylcholine receptor M1Muscarinic acetylcholine receptor 3M3 receptorM3RAcetylcholine receptor M3

Agonists stimulate receptor-mediated Gq/PLC/intracellular calcium signaling Antagonists block receptor-mediated signaling, inhibiting physiological responses such as smooth muscle contraction, secretion, or neurotransmission Allosteric modulators potentiate or inhibit receptor response to acetylcholine