Promoter elements conferring neuron-specific expression of the β2-subunit of the neuronal nicotinic acetylcholine receptor studiedin vitro and in transgenic mice

Abstract Several genes encoding subunits of the neuronal nicotinic acetylcholine receptors have been cloned and regulatory elements involved in the transcription of the α2 and α7-subunit genes have been described. Yet, the detailed mechanisms governing the neuron-specific transcription and the spatio-temporal expression pattern of these genes remain largely uninvestigated. The β2-subunit is the most widely expressed neuronal nicotinic receptor subunit in the nervous system. We have studied the structural and regulatory properties of the 5′ sequence of this gene. A fragment of 11633 bp of upstream sequence is sufficient to drive the cell-specific transcription of a reporter gene in both transient transfectin assays and in transgenic mice. Deletion analysis and site-directed mutagenesis of this promoter reveal two negative elements and one positive element. The positively-acting sequence includes one functional E-☐. One of the repressor elements is located in the transcribed region and is the NRSE/RE1 sequence already described in promoters of neuronal genes. In this paper, we describe the neuron-specific promoter of the gene encoding the neuronal nicotinic acetylcholine receptor β2-subunit.