Calcium/calmodulin-dependent 3',5'-cyclic nucleotide phosphodiesterase 1A is a protein in humans that is encoded by PDE1A gene. Cyclic nucleotide phosphodiesterase with a dual-specificity for the second messengers cAMP and cGMP, which are key regulators of many important physiological processes. Has a higher affinity for cGMP than for cAMP.