title: Neuronal nicotinic acetylcholine receptor beta-subunit is coded for by the cDNA clone alpha 4.
abstract: Acetylcholine receptors (AChRs) with high affinity for nicotine but no affinity for alpha-bungarotoxin, which have been purified from rat and chicken brains by immuno-affinity chromatography, consist of two types of subunits, alpha and beta. The beta-subunits form the ACh binding sites. Putative nicotinic AChR subunit cDNAs alpha 3 and alpha 4 have been identified by screening cDNA libraries prepared from rat PC12 cells and rat brain with cDNA probes encoding the mouse muscle AChR alpha-subunit. Here we determine the amino-terminal amino acid sequence of the rat brain AChR beta-subunit by protein microsequencing to be the same as amino acid residues 27-43 of the protein which could be coded by alpha 4. Further, we present evidence consistent with a subunit stoichiometry of alpha 3 beta 2 for this neuronal nicotinic AChR.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000378:metabolism*; D002038:Bungarotoxins / Q000378:metabolism; D002645:Chickens; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism*; D005796:Genes; D046911:Macromolecular Substances; D009474:Neurons / Q000378:metabolism*; D009538:Nicotine / Q000378:metabolism; D051381:Rats; D011978:Receptors, Nicotinic / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D002038:Bungarotoxins; D046911:Macromolecular Substances; D011978:Receptors, Nicotinic; D009538:Nicotine; D004247:DNA