Has a role regulating cGMP transport in Malpighian tubule principal cells. 3',5'-cyclic GMP + H2O = GMP + H(+) Binds 2 divalent metal cations per subunit. Site 1 may preferentially bind zinc ions, while site 2 has a preference for magnesium and/or manganese ions. Interacts with PrBP. Belongs to the cyclic nucleotide phosphodiesterase family.