Histidine Phosphotransfer Proteins in Fungal Two-Component Signal Transduction Pathways

The histidine phosphotransfer (HPt) protein Ypd1 is an important participant in theSaccharomyces cerevisiae multistep two-component signal transduction pathway and, unlike the expanded histidine kinase gene family, is encoded by a single gene in nearly all model and pathogenic fungi. Ypd1 is essential for viability in bothS. cerevisiae and inCryptococcus neoformans . These and other aspects of Ypd1 biology, combined with the availability of structural and mutational data inS. cerevisiae , suggest that the essential interactions between Ypd1 and response regulator domains would be a good target for antifungal drug development. The goal of this minireview is to summarize the wealth of data onS. cerevisiae Ypd1 and to consider the potential benefits of conducting related studies in pathogenic fungi.