Primary structure and functional expression of the human receptor for Escherichia coli heat-stable enterotoxin.

摘要: Heat-stable enterotoxin (STa) produced by Escherichia coli induces intestinal secretion in mammals binding to the brush border membrane of small intestine and activating guanylyl cyclase. We report here cloning expression a cDNA encoding human receptor for STa. The contains both an extracellular ligand site cytoplasmic cyclase catalytic domain, making it member same family as natriuretic peptide receptors. Stable mammalian cell lines over-expressing STa specifically bind 125I-STa (Kd approximately 1.0 nM) respond dramatically increasing (approximately 50-fold) cellular cGMP levels. Sequence comparisons between rat receptors show less conservation domain than similar This divergence may indicate important species differences ligand-receptor interaction.