Cell line-specific transcriptional activation of the promoter of the human guanylyl cyclase C/heat-stable enterotoxin/receptor gene.
The guanylyl cyclase C protein, expressed primarily in the intestine, is the receptor for the heat-stable enterotoxin of Escherichia coli. We have isolated and sequenced the promoter region and the first exon of human guanylyl cyclase C and determined the major site of transcription initiation. Transfection of a -1973/+124 promoter/luciferase gene fusion construct in the Caco-2 intestinal cell line resulted in a high level of expression; results with deletion constructs indicate the presence of multiple positive-acting sequence elements. These promoter elements were not active upon transfection into NIH/3T3 and LLC-PK1 cell lines which do not express GC-C.