Impact of human D398N single nucleotide polymorphism on intracellular calcium response mediated by α3β4α5 nicotinic acetylcholine receptors

► Addition of α5 subunit in the α3β4* receptor does not affect surface expression. ► The maximal agonist-induced calcium response: α3β4α5N < α3β4α5D < α3β4. ► The differences in the agonist response dependent upon [Ca2+]ext, not [Na+]ext. ► Activation of α3β4α5 nAChRs induces greater Ca2+ release from IP3 stores than α3β4. ► Inclusion of the α5 variant did not affect sensitivity of α3β4* nAChRs.