Pig Intestinal Membrane-Bound Receptor (Guanylyl Cyclase) for Heat-Stable Enterotoxin: cDNA Cloning, Functional Expression, and Characterization

抄録

A cDNA encoding the receptor protein for a heat-stable enterotoxin (STa) produced by enterotoxigenic Escherichia coli was cloned from intestinal epithelial cells of a 10-week-old pig. The cDNA had an open reading frame of 3, 219 base pairs and coded for a protein with 1, 073 amino acid residues. The mature protein consisted of 1, 050 amino acid residues with a molecular mass of ca. 121kDa and was 87% and 82% identical with the human and rat protein, respectively. The CHO cell line overexpressing the pig recombinant STa receptor specifically bound to a photoaffinity-labeled analog of STa and showed marked elevation of the cellular content of cGMP in response to STa.