Calcium/calmodulin-dependent cyclic nucleotide phosphodiesterase with a dual specificity for the second messengers cGMP and cAMP, which are key regulators of many important physiological processes. Has a higher efficiency with cGMP compared to cAMP. a nucleoside 3',5'-cyclic phosphate + H2O = a nucleoside 5'-phosphate + H(+) a nucleoside 3',5'-cyclic phosphate + H2O = a nucleoside 5'-phosphate + H(+) 3',5'-cyclic GMP + H2O = GMP + H(+) 3',5'-cyclic AMP + H2O = AMP + H(+) 3',5'-cyclic GMP + H2O = GMP + H(+) 3',5'-cyclic AMP + H2O = AMP + H(+) Binds 2 divalent metal cations per subunit. Site 1 may preferentially bind zinc ions. Binds 2 divalent metal cations per subunit. Site 2 has a preference for magnesium ions. Type I PDE are activated by the binding of calmodulin in the presence of Ca(2+). Activated by the binding of calmodulin in the presence of Ca(2+). Homodimer (By similarity). Interacts with YWHAZ (By similarity). Concentrates in the tail of mature sperm. Expressed in brain, kidney and testis. Belongs to the cyclic nucleotide phosphodiesterase family. PDE1 subfamily. Probable cloning artifact.