NEW INSIGHTS ON THE FUNCTIONS OF THE GUANYLYL CYCLASE RECEPTORS

The discovery of at least 29 genes encoding putative guanylyl cyclases in Caenorhabditis elegans has raised the question as to whether there are numerous receptors yet to be discovered in the mammal, The nemato de, however, not only seems ideal to study guanylyl cyclase receptor l ocalization and function, given the large variety of isoforms, but als o leads to possible identification of ligands for orphan guanylyl cycl ases by the use of genetic and behavioral assays, A recent powerful ap proach to describe the function of different guanylyl cyclase isoforms in mammals has been the disruption of the corresponding genes in the mouse, A salt resistant elevation of blood pressure, which corresponds to the phenotype of 50% of all human patients with essential hyperten sion, is observed in mice lacking the GC-A-receptor. Mice missing the GC-C receptor have been shown to be resistant to STa, an E. coli heat- stable enterotoxin, which is largely responsible for travellers diarrh ea in adults and mortality due to diarrhea in infants, (C) 1997 Federa tion of European Biochemical Societies.