Two isoforms of the muscle acetylcholine receptor α-subunit are translated in the human cell line TE671

We have previously reported the existence of 2 forms of mRNA for the human muscle acetylcholine receptor (AChR) α-subunit, thought to be generated by alternate splicing of a primary transcript and to encode 2 α-subunit protein isoforms [1]. The 2 predicted α-subunit isoforms, differing by the insertion of 25 amino acids at position 58 59, have been synthesized from cRNA transcripts using rabbit reticulocyte lysates: these protein isoforms could be differentiated by immunoprecipitation using antibodies raised against synthetic peptides. The antibodies were used to demonstrate translation of both AChR α-subunit isoforms in the rhabdomyosarcoma (muscle) cell line TE671, in an approximate 1:1 ratio.