UPSTREAM GENOMIC SEQUENCE OF THE HUMAN CONNEXIN26 GENE

Human connexin 26 (Cx26) has been considered to be a candidate suppres sor gene in mammary epithelial cells. To gain insight into the transcr iptional regulation of this gene, we have cloned and sequenced the 5' portion of the gene, which extends 4.8 kb upstream from the ATG transl ation start site. The 3' end of the non-coding exon 1 (160 bp) is loca ted at 3149 bp upstream from the 5' end of exon 2. Comparison between the human Cx26 gene and the mouse gene reveals a highly conserved prom oter region with 81% homology. In addition to six GC boxes and two GT boxes, a TTAAAA box is located at -24 to -19 bp upstream of the transc ription start point. Analogous to the mouse beta-casein gene, the prom oter region of the human Cx26 gene also contains a YY1-like binding si te and a consensus mammary gland factor binding site. (C) 1997 Elsevie r Science B.V.