Muscarinic acetylcholine receptor M1 (IPR002228)
Short name: Musac_Ach_M1_rcpt
Overlapping homologous superfamilies
Muscarinic acetylcholine receptors are members of rhodopsin-like G-protein coupled receptor family. They play several important roles; they mediate many of the effects of acetylcholine in the central and peripheral nervous system and modulate a variety of physiological functions, such as airway, eye and intestinal smooth muscle contraction, heart rate and glandular secretions. The receptors have a widespread tissue distribution and are a major drug target in human disease. They may be effective therapeutic targets in Alzheimer's disease, schizophrenia, Parkinson's disease and chronic obstructive pulmonary disease [PMID: 15850824, PMID: 17762886].
There are five muscarinic acetylcholine receptor subtypes, designated M1-5 [PMID: 3443095, PMID: 3272174, PMID: 3037705, PMID: 9647869, PMID: 2470172]. The family can be further divided into two broad groups based on their primary coupling to G-proteins. M2 and M4 receptors couple to the pertussis-toxin sensitive Gi proteins, whereas M1, M3 and M5 receptors couple to Gq proteins [PMID: 9647869, PMID: 8853955], which activate phospholipase C. The different subtypes can also couple to a wide range of diverse signalling pathways, some of which are G protein-independent [PMID: 10841527, PMID: 14641022, PMID: 12725869]. All subtypes seem to serve as autoreceptors [PMID: 11714883], and knockout mice reveal the important neuromodulatory role played by this receptor family [PMID: 14744253, PMID: 15474550, PMID: 17762886].
Muscarinic acetylcholine receptor M1 it is common in exocrine glands and the CNS [PMID: 3753655, PMID: 7560279, PMID: 240249], being is particularly abundant in the cerebal cortex and hippocampus [PMID: 15661360, PMID: 7751967]. The receptors have also been also found on esophageal smooth muscle [PMID: 11082420] and bladder tissue [PMID: 16952712]. Their distribution largely overlaps with that of M3 and M4 receptors. M1 receptors are involved in mediating higher cognitive processes, such as learning and memory [PMID: 14744253]. They also play a role in regulation of locomotor activity [PMID: 18431815] and in salivation [PMID: 15266016].
GO:0016907 G protein-coupled acetylcholine receptor activity
GO:0005887 integral component of plasma membrane