Sequences on the N-terminus of ACh receptor subunits regulate their assembly.

Mutant alpha subunits of Torpedo acetylcholine receptors (AChR) were constructed and expressed in Xenopus oocytes together with other normal subunits to investigate regions in the subunit that are required for subunit assembly. I have found that chimeric alpha subunits, consisting of the N-terminal extracellular domain of the AChR alpha subunit, followed either by the hydrophobic transmembrane segments of GABAA receptor or glutamate receptor subunits, were still recognized as the AChR subunit and associated with co-expressed other normal AChR subunits, suggesting that this part of the N-terminal extracellular domain contains 'assembly signals'.