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 adenylate cyclase inhibition. Signaling promotes phospholipase C activity, leading to the release of inositol trisphosphate (IP3); this then triggers calcium ion release into the cytosol (By similarity). Interacts with ARRB1 and ARRB2. Interacts with RACK1; the interaction regulates CHRM2 internalization (By similarity). Phosphorylation in response to agonist binding promotes receptor internalization. Phosphorylated in response to agonist treatment. Belongs to the G-protein coupled receptor 1 family. Muscarinic acetylcholine receptor subfamily. CHRM2 sub-subfamily.