Structure of the human M2 muscarinic acetylcholine receptor gene and its promoter

The M-2 muscarinic receptor inhibits the release of acetylcholine from cholinergic fibers in the lungs and elsewhere. In airway parasympathetic neurons, M-2 receptor expression is decreased by viral infections and by interferon-gamma, increasing actylcholine release. Dexamethasone increases IM, receptor expression, decreasing acetylcholine release, We carried out 5 ' rapid amplification of cDNA ends be,ginning with mRNA from human heart and IMR32 human neuroblastoma cells. This demonstrated a 5 ' UTR of 100 BP, corresponding to two sequences on chromosome 7, separated by a 22.6 kB intron. The splice acceptor site is at -45 relative to the initiating atg. The 3000 BP upstream of 5 ' RACE product were subcloned into a pGL3 luciferase reporter vector. Deletional constructs were expressed in IMR32 cells. These demonstrated that 412 BP provided full expression of the reporter gene, and suggested a repressor element between - 1848 and - 1510. (C) 2001 Published by Elsevier Science B.V. All rights reserved.