Plays a role in signal transduction by regulating the intracellular concentration of cyclic nucleotides cAMP and cGMP (PubMed:10725373, PubMed:10906126, PubMed:11050148, PubMed:16330539). Catalyzes the hydrolysis of both cAMP and cGMP to 5′-AMP and 5′-GMP, respectively (PubMed:10725373, PubMed:10906126, PubMed:11050148).