Chapter 3 Structure and function of neuronal nicotinic acetylcholine receptors deduced from cDNA clones

Abstract

Publisher Summary This chapter discusses the structure and function of neuronal nicotinic acetylcholine receptors deduced from (complementary DNA) cDNA clones. The neuronal nicotinic acetylcholine receptor is based on the idea that nucleic acids encoding muscle nicotinic acetylcholine receptor subunits would hybridize, at low stringency, to nucleic acids encoding neuronal nicotinic acetylcholine receptor subunits. The chapter discusses the four protein sequences deduced from the nucleotide sequences of cDNA clones. Inspection of these sequences shows remarkable similarity to the subunits of the muscle nicotinic acetylcholine receptor. Each protein has a leader sequence, followed by a stretch of about 210 amino acids unremarkable in their hydropathy. These sequences are followed by three hydrophobic domains. These three domains are thought to form membrane spanning regions, the second of which, in the case of the muscle receptor, is thought to be part of the ion channel. The cytoplasmic domain that follows membrane spanning region III is noticeably not conserved and is variable in length.