DISTINCT AND SPECIFIC FUNCTIONS OF CCMP-DEPENDENT PROTEIN-KINASES

cGMP-dependent protein kinases I and II conduct signals from widesprea d signaling systems. Whereas the type I kinase mediates numerous effec ts of natriuretic peptides and nitric oxide in cardiovascular cells, t he type II kinase transduces signals from the Escherichia coli heat-st able enterotoxin, STa, and from the endogenous intestinal peptide, gua nylin, stimulating Cl- conductance of the cystic fibrosis transmembran e conductance regulator (CFTR). Although the two kinases may be interc hangeable for several functions, CFTR regulation specifically requires the type II kinase.