ABSTRACT
The importance of intracellular localization of phosphodiesterases (PDEs) for the proper functioning of 3',5'-cyclic adenosine monophosphate signaling has become apparent in mammalian cells, and signal control by PDE localization may constitute a general paradigm in protozoa as well. The analysis of fungal PDEs has largely developed with the two prototypic yeasts, Saccharomyces cerevisiae and Schizosaccharomyces pombe. SpPDEl was identified by screening for suppressors of the phenotype conferred by the inactivation of the ranl and protein kinase. The CaPDEl gene of the human pathogen Candida albicans was identified by complementation cloning in a PDE-deficient S. cerevisiae strain. DdPDE1 is an extracellular PDE that is present in both a membrane-associated and a soluble form. The N-terminus of the complete polypeptide contains a highly hydrophobic signal sequence of 18 amino acids, indicating that DdPDE1 is anchored in the cell membrane through its hydrophobic N-terminus.
