Analysis of the mouse and rat CFTR promoter regions

To gain insights into the regulation of the mouse and rat cystic fibrosis transmembrane conductance regulator (CFTR) genes, we cloned and sequenced their respective upstream promoter regions. DNA sequence analysis from either side of exon 1 revealed a complete divergence from the human DNA sequence except for three DNA motifs which consist of a 34 bp stretch and two intron specific elements. Highlights of both the rat and mouse promoter sequences include an extensive purine rich stretch, a Y-box motif and putative Sp1, AP1 sites. Transfection of mouse promoter deletional constructs into expressing and non-expressing CFTR murine cell lines revealed that the Pu.Py stretch and the Y-box act, respectively, as negative and positive elements of basal transcription that confer no apparent tissue specificity.