GENOMIC ORGANIZATION AND PARTIAL DUPLICATION OF THE HUMAN ALPHA-7 NEURONAL NICOTINIC ACETYLCHOLINE-RECEPTOR GENE (CHRNA7)

The human alpha 7 neuronal nicotinic acetylcholine receptor gene (HGMW -approved symbol CHRNA7) has been characterized from genomic clones. T he gene is similar in structure to the chick alpha 7 gene with 10 exon s and conserved splice junction positions. The size of the human gene is estimated to be larger than 75 kb. A putative promoter 5' of the tr anslation start in exon 1 has been cloned and sequenced. The promoter region lacks a TATA box and has a high GC content (77%). Consensus Sp1 , AP-2, Egr-1, and CREB transcription factor binding sites appear to b e conserved between bovine and human genes. The alpha 7 nAChR gene was found to be partially duplicated, with both loci mapping to the chrom osome 15q13 region. A yeast artificial chromosome contig was construct ed over a genetic distance of 5 cM that includes both alpha 7 loci and the region between them. Four novel exons are described, located in g enomic clones containing the partially duplicated gene. The duplicated sequences, including the novel exons, are expressed in human brain. ( C) 1998 Academic Press.