Neuronal acetylcholine receptor subunit beta-3(CHRNB3) is a cell membrane protein and belongs to the ligand-gated ion channel (TC 1.A.9) family. CHRNB3 seems to be composed of two different type of subunits: alpha and beta. The CHRNB3 are (hetero) pentamers composed of homologous subunits. The subunits that make up the muscle and neuronal forms of CHRNB3 are encoded by separate genes and have different primary structure. There are several subtypes of neuronal CHRNB3 that vary based on which homologous subunits are arranged around the central channel. They are classified as alpha-subunits if like muscle alpha-1, they have a pair of adjacent cysteines as part of the presumed acetylcholine binding site. Subunits lacking these cysteine residues are classified as beta-subunits.