11 Integration of nutrient signalling pathways in the yeast Saccharomyces cerevisiae

Abstract

The ability to sense and to respond to changes in the nutrient availability is an essential feature for the survival of every organism. Saccharomyces cerevisiae has several signal transduction cascades to optimally adapt its metabolism to the availability of nutrients in the environment. In this chapter, we focus on the convergence of signal transduction pathways for nutrient sensing in budding yeast. In the first part, we will give an overview of the glucose-induced signal transduction pathways, focusing in particular on the Ras/cAMP pathway and its pleiotropic characteristics. Secondly, the current knowledge of the protein kinases Sch9 and Pho85 in nutrient-induced signal transduction is reviewed. Finally, the interconnectivity between these multiple pathways in glycogen biosynthesis, control of Msn2 activity and pseudohyphal growth will be discussed. We conclude that complex networks are involved in the integration of nutrient signals, regulating the complete transcriptome and metabolome in an intriguingly dynamical manner.