[Isoform 1]: Upon acetylcholine binding, 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. . [Isoform 2]: Non functional acetylcholine receptor alpha subunit which is not integrated into functional acetylcholine-gated cation-selective channels. . This is the function of Ensembl gene identifier ENSG00000138435 (CHRNA1, cholinergic receptor nicotinic alpha 1 subunit).