The muscarinic acetylcholine receptor mediates various cellular responses, including inhibition of adenylate cyclase, breakdown of phosphoinositides and modulation of potassium channels through the action of G proteins. Primary transducing effect is Pi turnover. May have a role in the processing of olfactory and mechanosensory signals; regulation of neurosecretion. Intense staining in the glomeruli of the antennal lobes, the region of the nervous system containing terminals of antennal olfactory sensory neurons and mechanosensory neurons. Also a discrete group of neurosecretory cells in the pars intercerebralis of the brain. Belongs to the G-protein coupled receptor 1 family. Muscarinic acetylcholine receptor subfamily. Contaminating sequence. E.coli genomic contaminant.