Functional acetylcholine receptor in PC12 cells reacts with a monoclonal antibody to brain nicotinic receptors.

The use of a variety of probes for neuronal nicotinic acetylcholine receptors has indicated that there are sites on neurons that bind the acetylcholine receptor antagonist alpha-bungarotoxin, but do not regulate cation channels in response to the binding of acetylcholine. Sites with high binding affinity for nicotine and for alpha-bungarotoxin also show different distributions in brain. A monoclonal antibody (mAb35) raised against acetylcholine receptors from Electrophorus electric organ has been used to purify receptors from chick brain. These receptors do not bind alpha-bungarotoxin but have a high affinity for nicotine and antibodies raised against them block the function of acetylcholine receptors in ciliary ganglia. We have raised a monoclonal antibody (mAb270) against acetylcholine receptors from chicken brain (P.J.W., R. Liu, S. Shimasaki, F. Esch, B. Morley & J.M.L., manuscript in preparation), which has been used to purify a similar receptor from rat brain. Here we show that this antibody identifies a functional nicotinic acetylcholine receptor in rat-neuron-like PC12 cells which is probably not encoded by the cDNA clone (lambda PCA48) previously suggested as a candidate for the acetylcholine receptor gene. Additionally, we show that mAb270 binds to the same areas of rat brain as nicotine.