Chimeric Approach to Identify Molecular Determinants of Nicotinic Acetylcholine Receptors

Nicotinic acetylcholine receptors (nAChRs) are membrane-bound proteins that mediate fast synaptic transmission throughout the nervous system. A functional nAChR subtype is formed by the combination of multiple subunits arranged as homomeric or heteromeric pentamers, each with a distinct pharmacological profile. Disruption of their neurotransmission contributes to various neuropathologies, emphasizing the need for detailed knowledge of receptor structure, function, subunit composition, dynamics, and potential ligand-binding sites. However, their structural complexity as integral membrane proteins has hindered expression in mammalian cell lines and proven even more challenging to crystallize, limiting insights into ligand interactions. Understanding the molecular determinants governing nAChRs function is essential for the rational design of selective therapeutics targeting neurological disorders. The emergence of a chimeric receptor approach has dramatically improved the ability to study these important proteins and opened new avenues for high-throughput screening in drug discovery efforts. This review explains how the design of chimera constructs using soluble homologs, such as AChBP, provides researchers with an immense opportunity to investigate receptor structure-function relationships and subtype-specific properties, thereby facilitating the development of more effective treatments.