Repression of nicotinic acetylcholine receptor expression by antisense RNAs and an oligonucleotide.

Four antisense RNAs, synthesized from cDNA clones coding for the four subunits of the acetylcholine receptor of Torpedo electroplaques, were used to study their effect on the expression of functional Torpedo acetylcholine receptors in Xenopus oocytes. All antisense RNAs inhibited the appearance of functional receptors in the oocyte's surface membrane for at least 1 week. This inhibition was specific because the antisense RNAs did not block the expression of the Cl- channels, also encoded by Torpedo electroplaque mRNA. Experiments with incomplete antisense RNAs and a synthetic oligonucleotide indicate that covering the ribosome binding site or the initiation codon in the mRNA is not a necessary requirement for efficient blocking. Thus, the use of antisense RNAs combined with the Xenopus oocyte system provides a novel approach to screen cDNA libraries for the genes coding for multisubunit neurotransmitter receptors.