Cyclic nucleotide specific phosphodiesterases (PDEs) are important components of all cAMP signalling networks. In humans, 11 different PDE families have been identified to date, all of which belong to the class I PDEs. Pharmaco-logically, theyhavebecome of great interest as targets for the development of drugs for a large variety of clinical condi-tions. PDEs in parasitic protozoa have not yet been exten-sively investigated, despite their potential as antiparasitic drug targets.
