After binding acetylcholine, the AChR responds by an extensive change in conformation that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane. Neuronal AChR is composed of two different types of subunits: alpha and beta. Beta-4 subunit can be combined to alpha-2, alpha-3 or alpha-4 to give rise to functional receptors. Interacts with RIC3; which is required for proper folding and assembly (By similarity). Interacts with LYPD6 (By similarity). The pentamer alpha3-beta-4 interacts with the conotoxin BuIA (PubMed:16964981). The heteropentamer composed of alpha-3 and beta-4 subunits interacts with the alpha-conotoxin ImI (By similarity). In the brain, it is detected in the medial habenula. In the peripheral nervous system, it is found at least in the adrenal gland. Belongs to the ligand-gated ion channel (TC 1.A.9) family. Acetylcholine receptor (TC 1.A.9.1) subfamily. Beta-4/CHRNB4 sub-subfamily.