Dictyostelium discoideum is an excellent eukaryotic model organism for signal transduction research purposes. It is a free-living amoeba, which under nutritional stress utilizes two complex signaling pathways for multicellular development. The primary signaling pathways mechanism that Dictyostelium utilizes are dependent on the secondary messenger's cAMP and cGMP for amplifying the signal and activating important downstream signaling proteins such as PKA. Phosphodiesterase's are one mechanism that Dictyostelium utilizes for the regulating cAMP and cGMP levels that drive signaling. Dictyostelium uses a total of 7 different cAMP and cGMP phosphodiesterases for signaling. RegA is a phosphodiesterase that Dictyostelium utilizes for managing intracellular cAMP levels in the Erk2 signaling pathway. RegA plays a critical role in the Erk2 signaling pathway, however; the role of RegA in pathogenesis and Ras signaling is not currently well understood. Multiple sequence alignment was used to provide significant insight into sequence conservation of RegA and its role in pathogenesis. Sequence conservation was observed in several of RegA's phosphorylation sites in many different eukaryotic pathogens. This suggests that eukaryotic pathogens may utilize many of the same mechanisms for controlling intracellular cAMP levels. To evaluate the role of RegA in Ras signaling, a RegA- mutant cells were labeled with a GFP Ras-binding domain (RBD) reporter gene, stimulated with folate, and observed to determine differences in the response to chemotaxic stimulation. We didn't observe any significant difference suggesting that RegA is not essential in Ras signaling.