Cloning and expression of a cDNA encoding bovine muscarinic acetylcholine m3 receptor

Abstract A cDNA clone encoding bovine muscarinic acetylcholine m3 receptor has been isolated from a bovine brain library. Sequencing of this clone has revealed a single open reading frame encoding a protein of 590 amino acids. Comparison with known muscarinic m3 receptor sequences from other species shows a high degree of conservation (92–98% homology) in the protein sequence. COS cells transfected with this cDNA expressed a single high-affinity ( K d = 43.9 pM) binding site for muscarinic receptor ligand N-[ 3 H ] methylscopolamine .