Subunit folding and alpha delta heterodimer formation in the assembly of the nicotinic acetylcholine receptor. Comparison of the mouse and human alpha subunits.

We have used the mouse α (α M ) and human α (α H ) subunits to investigate the molecular mechanisms of assembly of the mammalian acetylcholine receptor (AChR) transiently expressed in COS cells. COS cells expressing hybrid receptors incorporating α H along with other mouse subunits exhibited a 2-fold higher level of surface α-bungarotoxin (BuTx) binding than cells expressing the wild-type mouse AChR. When expressed either alone or with the 8 subunit in COS cells, α H acquired the BuTx binding conformation (α Tx ) more efficiently than did α M