Isolation and functional characterization of the chick M-5 muscarinic acetylcholine receptor gene

The chick is a widely used system for study of the actions of muscarinic ac etylcholine receptors in the cardiovascular, visual, and nervous systems. W e report the isolation and functional analysis of the gene encoding the chi ck M-5 muscarinic receptor. RT-PCR analysis indicates that the M-5 receptor is expressed at low levels in embryonic chick brain and heart. When expres sed in stably transfected Chinese hamster ovary cells, the M-5 receptor exh ibits high-affinity binding to muscarinic antagonists and mediates robust a ctivation of phospholipase C activity.