Systems biology of AGC kinases in fungi.

Sch9 appears to be the Saccharomyces cerevisiae homolog of protein kinase B and is involved in the control of numerous nutrient-sensitive processes, including regulation of cell size, cell cycle progression, and stress resistance. Sch9 has also been implicated in the regulation of replicative and chronological life span. Systematic comparison of the phenotypes of sch9 and other AGC kinase mutants in fungal species with their counterparts in model eukaryotic organisms provides insight into the functions of AGC kinases. The availability of data from global studies of protein-protein interactions now makes it possible to predict and validate functional connections between Sch9, its putative substrates, and other proteins. This review highlights several emerging paradigms of AGC kinase signaling that are relevant for growth, development, and aging.