Embryonic chick heart expresses multiple muscarinic acetylcholine receptor subtypes. Isolation and characterization of a gene encoding a novel m2 muscarinic acetylcholine receptor with high affinity for pirenzepine.

摘要: Abstract Muscarinic acetylcholine receptors (mAChR) are G protein-coupled which highly conserved across mammalian species. Chick cardiac mAChR, however, have been shown to be pharmacologically, immunologically, and biochemically distinct from m2 mAChR expressed in heart. We previously reported the isolation characterization of a novel chicken cm4, is chick heart brain. report here an additional gene whose deduced amino acid sequence most homologous receptor. Northern blot analysis demonstrated that this also When stably transfected into Chinese hamster ovary (CHO) cells Y1 adrenal carcinoma cells, expresses receptor protein exhibits high affinity binding for muscarinic antagonist quinuclidinyl benzilate atropine, as well M1-selective pirenzepine M2-selective AF-DX 116. Therefore, when two heterologous cell lines, has pharmacological properties similar m4 those endogenous cells. Consistent with m4, receptors, was able functionally couple both inhibition adenylate cyclase stimulation phosphoinositide metabolism CHO but only conclude study embryonic multiple subtypes their counterparts. Furthermore, degree conservation between suggests differences exist these due relatively small number specific changes rather than larger or structure.