Genomic structure and promoter analysis of the rat Kir7.1 potassium channel gene (Kcnj13)

In the brain inwardly rectifying potassium channel Kir7.1 subunits are pred ominantly expressed in the choroid plexus and meninges. To investigate this tissue-specific expression pattern, we characterized the genomic organizat ion and the 5' proximal promoter of the rat Kir7.1 gene (Kcnj 13), Starting from the major transcriptional initiation site, three exons in Kcnj13 give rise to the dominant similar to1.45 kb transcript in brain. Adjacent to th e transcriptional start the minimal promoter which, uncommon for ion channe ls, contains a TATA- and CAAT-box is controlled by AP-1 factors and account s for high gene expression levels. Luciferase reporter gene responses drive n by the first 2.1 kb of the 5' flanking region were similarly high in epit helial FRTL-5 and neuronal N2A cells, suggesting that neuron-specific repre ssor elements are located remote from the non-selective minimal promoter. ( C) 2000 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.