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. Alpha-3 subunit can be combined to beta-2 or beta-4 to give rise to functional receptors. Interacts with RIC3; which is required for proper folding and assembly (PubMed:16120769). Interacts with LYPD6 (PubMed:27344019). The heteropentamer alpha-3-beta-2 interacts with alpha-conotoxins ImI and ImII (PubMed:15609996). The heteropentamer alpha-3-beta-2 interacts with alpha-conotoxins ImI, ImII, PnIA, GID and MII (By similarity). The heteropentamer alpha-3-beta-4 interacts with the alpha-conotoxin ImI (PubMed:15609996). Genetic variations in CHRNA3 have been associated with susceptibility to smoking-related behavioral traits and lung cancer, contributing to the smoking quantitative trait locus 3 (SQTL3) [MIM:612052]. The disease is caused by variants affecting the gene represented in this entry. Belongs to the ligand-gated ion channel (TC 1.A.9) family. Acetylcholine receptor (TC 1.A.9.1) subfamily. Alpha-3/CHRNA3 sub-subfamily.